Godfrey Hewitt Mobility Award

In this pro­ject, our goal was to explore the chro­mo­some evol­u­tion of the Petunia-Cal­i­b­rachoa-Fabi­ana clade, a fas­cin­at­ing group of plants serving as a mod­el sys­tem to under­stand plant evol­u­tion in south­ern South Amer­ica. We aimed to shed light on the evol­u­tion­ary his­tory of the group, con­nect­ing it to the spe­ci­ation pro­cess, cur­rent hybrid­iz­a­tion cap­ab­il­it­ies, and the devel­op­ment of ancient repro­duct­ive bar­ri­ers that may have pre­ven­ted hybrid­iz­a­tion.
To address these ques­tions, we ger­min­ated seeds from rep­res­ent­at­ives of each genus in the clade: P. inflata, C. par­vi­flora, and F. densa. Using the H8Q pro­tocol, we fixed samples and examined mul­tiple meta­phases of each spe­cies to count and meas­ure chro­mo­some pairs. To deduce poten­tial chro­mo­some rearrange­ments influ­en­cing changes in chro­mo­some num­bers dur­ing evol­u­tion, we ana­lyzed meta­phase slides using CMA/DAPI band­ing and Fluor­es­cent in Situ Hybrid­iz­a­tion (FISH) to identi­fy the loc­a­tion and num­ber of rDNA and telomeres.
The fund­ing from the God­frey Hewitt Mobil­ity Award enabled me to expand my know­ledge in cyto­gen­et­ics. Over one month, I immersed myself in the field, exper­i­en­cing every step from seed ger­min­a­tion to slide pre­par­a­tion and con­duct­ing FISH pro­to­cols. I had the priv­ilege of learn­ing from experts in the field, includ­ing Dr. Rocio Deanna, Dr. Juan
Urdampil­leta, Dr. Amália Ibiapino, and PhD stu­dent Dav­id Hoy­os.
At present, we have pre­lim­in­ary res­ults con­firm­ing the chro­mo­somal num­bers of each genus. We will now delve into explor­ing chro­mo­some meas­ure­ments and band­ing pat­terns to com­pre­hend the evol­u­tion of chro­mo­somes. These find­ings will soon be com­piled into a sci­entif­ic art­icle for publication.

My PhD pro­ject focuses on the causes and the mech­an­isms of repro­duct­ive sen­es­cence (the decline in repro­duct­ive per­form­ance with age) in males. Age-spe­cif­ic repro­duct­ive suc­cess of males is dir­ectly determ­ined by the suc­cess of males in com­pet­ing for mat­ing and fer­til­iz­a­tion oppor­tun­it­ies. There­fore, a detailed under­stand­ing of the mech­an­isms involved in the pro­cess of repro­duct­ive sen­es­cence requires a wide diversity of data (e.g. life his­tory traits, physiolo­gic­al data) with­in an anim­al pop­u­la­tion where the age of indi­vidu­als is known with certainty.

Thanks to the God­frey Hewitt Mobil­ity Award, I was able to travel to the Uni­ver­sity of Otago, where I could explore how olfact­ory per­cep­tion of social con­di­tions influ­ences repro­duct­ive age­ing in male mice (Mus mus­cu­lus). This oppor­tun­ity allowed me to learn new labor­at­ory tech­niques, such as assess­ing Sperm DNA Frag­ment­a­tion, along­side very tal­en­ted people that are famil­i­ar to this sub­ject. The data col­lec­ted dur­ing this jour­ney are going to be used to expand our know­ledge of the mech­an­isms under­ly­ing post-cop­u­lat­ory traits sen­es­cence. These skills will be use­ful for a future pro­ject in my home-labor­at­ory, aim­ing to study post-cop­u­lat­ory traits’ sen­es­cence this time in a wild pop­u­la­tion of ungu­late. I am truly grate­ful to the ESEB for giv­ing me the chance to devel­op this part of my PhD, and for allow­ing me to work with anoth­er research team, which was incred­ibly bene­fi­cial for me.

My PhD com­bines both the­or­et­ic­al and exper­i­ment­al approaches to invest­ig­ate eco-evol­u­tion­ary dynam­ics in nat­ur­al fresh­wa­ter phyto­plank­ton com­munit­ies. After con­duct­ing the exper­i­ment­al part at the Uni­ver­sity of Kon­stanz in Ger­many, the God­frey Hewitt Award gave me the oppor­tun­ity to vis­it the lab of Prof. Elena Litch­man at Carne­gie Insti­tu­tion in Stan­ford (CA) to com­bine the­or­et­ic­al eco­logy and evol­u­tion to under­stand the com­plex dynam­ics of plank­ton communities.

Under­stand­ing the struc­ture of nat­ur­al plank­ton com­munit­ies and how the envir­on­ment shapes it is an ongo­ing chal­lenge. Spe­cies Abund­ance Dis­tri­bu­tion (SAD) have been used to under­stand the mech­an­isms under­ly­ing com­munity assembly as they describe the abund­ance dis­tri­bu­tion of each spe­cies in a com­munity, and reflects at the same time com­munity rich­ness, even­ness and dis­sim­il­ar­ity. We use rank abund­ance dis­tri­bu­tions (RADs) to invest­ig­ate how com­munity struc­ture evolves in respond to envir­on­ment­al abi­ot­ic and biot­ic gradi­ents over time. It is now well-estab­lished, but still under­stud­ied, that strong eco­lo­gic­al inter­ac­tions often lead to intense selec­tion and rap­id evol­u­tion­ary response in com­munit­ies and these rap­id evol­u­tion­ary changes influ­ence back eco­sys­tem struc­ture and func­tion. To address eco-evol­u­tion­ary dynam­ics, we adopt a trait-based approach, i.e. trait-abund­ance dis­tri­bu­tions (TADs). Traits pre­dict that iden­tity and abund­ance of dom­in­ant spe­cies is determ­ined by their traits and envir­on­ment­al con­di­tions, there­fore TADs are a use­ful tool to under­stand the com­munity trait selec­tion under envir­on­ment­al gradi­ents and to explain fur­ther the mech­an­isms shap­ing com­munity structure.

The research stay did not only allow me to learn new meth­ods and approaches to ana­lyse long-term plank­ton data­sets, but it also gave me the chance to gain an inter­na­tion­al exper­i­ence and extend my pro­fes­sion­al network.

My PhD at the Insti­tute of Evol­u­tion Sci­ences of Mont­pel­li­er aims to study eco­typ­ic differ­en­ti­ation in differ­ent spe­cies of fish. Using a com­par­at­ive gen­om­ics frame­work, I study the gen­om­ic archi­tec­ture under­ly­ing diver­gence and the evol­u­tion­ary tra­ject­or­ies of eco­types. One of my study spe­cies is the long-snouted seahorse (Hip­po­cam­pus gut­tu­lat­us) that is sub­divided into differ­ent lin­eages and shows lagoon and mar­ine eco­types in the Medi­ter­ranean Sea. To fur­ther invest­ig­ate this struc­ture, we sequenced ~110 whole gen­omes, includ­ing museum and his­tor­ic­al samples of up to 150 years of age. My God­frey Hewitt Mobil­ity Award allowed me to spend two months work­ing on this data in col­lab­or­a­tion with Andrew Foote at the NTNU Nat­ur­al His­tory Museum in Trond­heim (Nor­way). Andrew is an ancient/degraded DNA spe­cial­ist and could provide cru­cial guid­ance with regards to the bioin­form­at­ic pro­cessing and filter­ing steps of my data. His pre­vi­ous work has also focused on cases of spe­ci­ation in mar­ine sys­tems, feed­ing our dis­cus­sions about the ana­lys­is and inter­pret­a­tion of my res­ults. This mobil­ity peri­od allowed me to advance in my study and has res­ul­ted in con­crete out­comes (oral present­a­tion at ESEB2022 and a manu­script soon to be submitted).

My research pro­ject focuses on under­stand­ing the evol­u­tion­ary his­tory of the Phil­is­ca spiders by com­bin­ing the ana­lys­is of their genet­ic diversity and geo­graph­ic­al dis­tri­bu­tion. The spe­cies belong­ing to this genus evolved, in the last 10 mil­lion years, in the Val­divi­an Forest across Argen­tina and Chile, where they had been exposed to sev­er­al cli­mat­ic and geo­lo­gic­al events. Com­bin­ing the inform­a­tion derived from the genet­ic ana­lys­is as well as from the dis­tri­bu­tion mod­el­ing allows us to bet­ter under­stand the role gla­ci­ations and oro­gen­ic pro­cesses had on the evol­u­tion of this amaz­ing group.
The fund­ing obtained through the God­frey Hewitt Award allowed me to travel to Chile in order to sample in areas that had not been explored in the past for Phil­is­ca spiders. Dur­ing this field­work trip I stopped in dif­fer­ent Nation­al Parks look­ing for new col­lec­tion sites to enlarge my data set. I traveled across 5000 km col­lect­ing through moun­tains, tem­per­ate forests, vol­canos, coastal areas and dry forests. I was able to drive across the low­est areas of the Andes and see by myself the changes in biod­iversity all the way between Chile and Argen­tina. These new data points are being used for devel­op­ing poten­tial dis­tri­bu­tion mod­els and I’m also cur­rently work­ing on extract­ing DNA from the col­lec­ted samples in order to per­form pop­u­la­tion genet­ic ana­lys­is.
I am really thank­ful to the European Soci­ety for Evol­u­tion­ary Bio­logy for grant­ing me this award that allowed me to broaden the study area of my research. Without this help, it would­n’t be pos­sible to do it.

My PhD invest­ig­ates intra and inter-spe­cies inter­ac­tions in spider’s to fur­ther the under­stand­ing of adapt­ive responses to the envir­on­ment.  A part of my thes­is focuses on the poten­tial role of host-sym­bionts inter­ac­tions in shap­ing host’s adapt­at­ive responses to urb­an­isa­tion. I have col­lec­ted Garden cross spiders (Aran­eus dia­dematus) in urb­an and rur­al areas in Den­mark. I have used 16S sequen­cing to determ­ine the micro­bi­o­me com­pos­i­tion of urb­an and rur­al spiders. The God­frey Hewitt Mobil­ity Award allowed me to vis­it Dr Bonte’s group in Ghent for two months to learn and apply Bayesian Joint Spe­cies Dis­tri­bu­tion Mod­el­ling to ana­lyze micro­bi­o­me com­pos­i­tion in a spa­tial con­text. This mobil­ity allows me to broaden my prac­tic­al skills and con­cep­tu­al know­ledge and devel­op my aca­dem­ic network.

Pro­ject can­celled due to the pandemic.

Nat­ur­al cli­mate change and human activ­it­ies have affected eco­sys­tems world­wide, in part through hab­it­at loss and frag­ment­a­tion (HL&F). While some spe­cies got extinct, oth­ers have sur­vived, likely keep­ing genet­ic inform­a­tion about these past envir­on­ment­al changes. Sev­er­al stat­ist­ic­al approaches exist for recon­struct­ing past demo­graph­ic event, includ­ing HL&F. How­ever, most of these meth­ods assume that pop­u­la­tions are either not struc­tured or sub­divided in small units among which gene-flow occurs with equal prob­ab­il­ity (e.g., island mod­els). Although use­ful, these approaches ignore the import­ance of geo­graph­ic­ally-lim­ited dis­pers­al. In fact, spa­tial pro­cesses have been recog­nized to have an import­ant role in shap­ing genet­ic vari­ation with­in spe­cies. As part of my PhD research, I was inter­ested in explor­ing and devel­op­ing mod­els that could infer time since HL&F using genet­ic data from geo­graph­ic­ally-struc­tured pop­u­la­tions. The fund­ing from the God­frey Hewitt Mobil­ity Award (GHMA) allowed me to carry-out this research with Prof. Gra­ham Coop, at the Uni­ver­sity of Cali­for­nia (Dav­is). This research led to the devel­op­ment of a new spa­tial frame­work that mod­el homo­zy­gos­ity and the dis­tri­bu­tion of Iden­tity-By-Des­cent seg­ments in a bounded two-dimen­sion­al pop­u­la­tion sub­jec­ted to HL&F. I explored dif­fer­ent mod­el’ imple­ment­a­tions for identi­fy­ing the one show­ing highest accur­acy and cal­cu­la­tion speed. Besides, the fund­ing of GHMA also allows me to inter­act with vari­ous world- lead­ing sci­ent­ists in the field of pop­u­la­tion and evol­u­tion­ary bio­logy in UC Dav­is and in the San Fran­cisco Bay area. This oppor­tun­ity has def­in­itely con­trib­uted to my sci­entif­ic and per­son­al development.

My PhD research has focused on study­ing the host-para­site inter­ac­tion between the threespine stickle­back (Gas­ter­o­steus aculeatus) fish and the cest­ode Schis­to­ceph­alus solidus. In Alaska, where I con­duc­ted my research, ocean­ic stickle­back col­on­ized fresh­wa­ter hab­it­ats repeatedly and inde­pend­ently since the last gla­cial max­im­um. In these fresh­wa­ter hab­it­ats, ocean­ic stickle­back first encounter S. solidus, a troph­ic­ally trans­mit­ted para­site that is not viable in the ocean. In 2021, I was awar­ded the God­frey Hewitt Mobil­ity Award, which enabled me to col­lect tis­sue samples from four Alaskan stickle­back pop­u­la­tions that vary in their sus­cept­ib­il­ity to the para­site. The goal of this pro­ject was to char­ac­ter­ize baseline immune pro­files of wild-caught stickle­back from high-infec­tion and low-infec­tion pop­u­la­tions. Addi­tion­ally, I wanted to determ­ine the up- and down-reg­u­la­tion of genes upon infec­tion and invest­ig­ate wheth­er these genes differed between the pop­u­la­tions. I am cur­rently work­ing on a manu­script to pub­lish the res­ults of this study.
When I applied for the God­frey Hewitt Mobil­ity Award my primary PhD advisor had retired due to health reas­ons, and there was insuf­fi­cient fund­ing for me to com­plete my research. How­ever, thanks to the award, I was able to col­lab­or­ate with oth­er stickle­back research­ers from dif­fer­ent Uni­ver­sit­ies and not only col­lect the neces­sary samples but also estab­lished valu­able con­nec­tions with pro­fes­sion­als in my field.

Over 240 mil­lion people are infec­ted chron­ic­ally with Hep­at­it­is B Vir­us (HBV), with a mil­lion dying as a res­ult of related dis­eases each year. Long-lived cova­lently closed cir­cu­lar DNA (cccDNA) is formed as part of the HBV vir­al life cycle, but stand­ard-of-care treat­ments do not tar­get the cccDNA reser­voir and hence rarely cure the infec­tion. Because tak­ing liv­er biopsies is risky, the mech­an­isms main­tain­ing the HBV reser­voir are largely unknown and there is there­fore great interest in nov­el ways to under­stand the dynam­ics of cccDNA in human untreated and treated infec­tion. Here we shall use math­em­at­ic­al mod­els to tackle this chal­lenge and explore new path­ways involved in the per­sist­ence of HBV infections.

Explor­ing long-non­cod­ing regions of wasp gen­omes in Prof Mar Albà’s lab in Barcelona

As the Renfe/SNCF train is rolling out of Bar­celona on this morn­ing of 31st March 2022, I reflect on the month I have just spent col­lab­or­at­ing with Prof M. Mar Albà Soler at the GRIB (Research Pro­gramme on Bio­med­ic­al Inform­at­ics in Bar­celona Bio­med­ic­al Research Park) thanks to the ESEB God­frey Hewitt Mobil­ity Award.

I am a postdoc at Uni­ver­sity Col­lege Lon­don in the lab of Prof Seiri­an Sum­ner, with whom I have worked the last two years on under­stand­ing the evol­u­tion of social organ­isa­tion in wasps and bees. We use gen­om­ics and tran­scrip­tom­ics data­sets to invest­ig­ate the molecu­lar
mech­an­isms that are asso­ci­ated with the mul­tiple ori­gins of social com­plex­ity. Right at the start of my postdoc, I chose to apply for the ESEB Mobil­ity Grant to expand our ques­tions to lar­ger data­sets, namely the non-cod­ing regions of the gen­omes. I had read sev­er­al papers from Prof Mar Albà, whom is the Head of Evol­u­tion­ary Gen­om­ics Group, and was inspired by her latest find­ings on the ori­gins of de novo genes using mam­mal and yeast mod­els. I decided to reach out to her by email, detail­ing the plan of research: could we test the
pipelines on our wasp data­sets? After few writ­ten exchanges, we sub­mit­ted the Mobil­ity Grant applic­a­tion and were suc­cess­ful in obtain­ing the grant at the turn of the new year 2020. Need­less to say, the next two years proved more chaot­ic than anti­cip­ated. We are
thank­ful for ESEB to allow sev­er­al time extensions.

The Mobil­ity grant gave me the funds to travel to Prof Mar Albà’s lab and stay in Bar­celona. The warm wel­come that I received from Mar and her research team was fant­ast­ic: I had access to a desk in the shared office with Master’s and PhD stu­dents, I atten­ded weekly lab meet­ings and sem­inars, I could ask dir­ect tech­nic­al and bio­lo­gic­al ques­tions on my pro­ject. This ideal situ­ation would not have been pos­sible if I had stayed in Lon­don. At the end of the month, I leave with more tech­nic­al expert­ise and deep­er bio­lo­gic­al under­stand­ing of those long-non­cod­ing regions of the gen­omes. I also leave with a strong con­nec­tion with Prof Mar Alba, her research team and the GRIB, which will no doubt have a large, pos­it­ive impact in my career.

I am grate­ful to have had access to this Mobil­ity Grant and would recom­mend to all Early Career Research­ers to apply. As I am writ­ing this report in an inter­na­tion­al train, wear­ing a FFP2 mask, with fel­low trav­el­lers that I recog­nise as Ukrain­i­an refugees, I am equally thank­ful that I was able to travel for research, in the cur­rent situ­ation where health, cli­mate and polit­ic­al crises hinder sci­entif­ic progress.

Next stop, Par­is Gare de Lyon, then a Eurostar to London.

Dr Emeline Favr­eau
ESEB God­frey Hewitt Mobil­ity Award Budget: 1,600 Euros and 26,1 Kg CO2

Com­pared to anim­als, flower­ing plants exhib­it a stag­ger­ing level of repro­duct­ive diversity, includ­ing a mul­ti­tude of trans­itions from herm­aph­rod­it­ism (com­bined sexes) to dioecy (phys­ic­ally sep­ar­ate males and females) via the evol­u­tion of new genet­ic sex-determ­in­a­tion sys­tems. Sev­er­al major out­stand­ing ques­tions about why and how these trans­itions occur can only be addressed by study­ing the repeated evol­u­tion of new genet­ic sex-determ­in­a­tion sys­tems with­in closely related spe­cies in a single lin­eage. The Hawaii­an Wikstroemia offer a truly unique oppor­tun­ity to study exactly these con­di­tions: they rep­res­ent an endem­ic radi­ation in the Hawaii­an Islands from a single herm­aph­rod­ite ancest­or that exhib­its at least two and pos­sibly three inde­pend­ent trans­itions from herm­aph­rod­it­ism to dioecy. As an early-career postdoc, I had ini­ti­ated a col­lab­or­a­tion with col­leagues in Hawaii to study the gen­om­ics of sex-determ­in­a­tion in this fas­cin­at­ing group. In 2020, I received an ESEB God­frey Hewitt Mobil­ity Award to help devel­op this col­lab­or­a­tion by vis­it­ing my col­leagues and con­duct­ing field work on the islands of O’ahu, Hawai’i, and Kaua’i. Like many, how­ever, the COVID-19 pan­dem­ic threw a wrench in my travel plans, and after a year of delay, I came up with a crazy idea to keep the pro­ject alive: I sent my moth­er. Though it sounds strange at first, she is very qual­i­fied: a retired bio­lo­gist with over two dec­ades of exper­i­ence doing remote field work and genet­ics, plus she was fully vac­cin­ated and able to travel domest­ic­ally with­in the U.S. while travel from Europe was still highly uncer­tain. The plan worked per­fectly. In June 2021 she was able to suc­cess­fully sample pop­u­la­tions on all three islands rep­res­ent­ing 5 spe­cies and all three forms of dioecy. The leaf tis­sue she col­lec­ted for DNA extrac­tions has since been used to assemble a draft gen­ome for one form of dioecy and identi­fy can­did­ate sex-linked gen­ome regions, and the seeds she col­lec­ted are now healthy green­house pop­u­la­tions at Lund Uni­ver­sity in Sweden that are now flower­ing and being used for
ongo­ing cross­ing exper­i­ments. Moreover, her stay with my col­leagues strengthened our col­lab­or­a­tion in unex­pec­ted ways by mak­ing it more per­son­al some­how. Sci­ence has long been a mul­ti­gen­er­a­tion­al enter­prise in our fam­ily, but it is a truly unique feel­ing to see my daugh­ter help tend green­house plants grown from seeds col­lec­ted by her grand­moth­er on the oth­er side of the world in the Hawaii­an islands!

My PhD pro­ject focused on the evol­u­tion of sexu­al sys­tems in plants. Although I mostly stud­ied the evol­u­tion of sex chro­mo­somes, I was also inter­ested in gene expres­sion dif­fer­ences between males and females (i.e. the sex-biased gene expres­sion – SBGE). Ini­tially, the pro­ject foun­ded by the God­frey Hewitt Mobil­ity Award was to stay four months at the ETH Zurich, to study SBGE in a spe­cies for which the dioecy (i.e. plants with sep­ar­ate sexes) is recent, Silene acaul­is ssp exscapa. How­ever, because of the pan­dem­ic, we were not able to col­lect the data needed for this ana­lys­is, and a stay of sev­er­al months in anoth­er coun­try was not pos­sible.
Thus, the pro­ject changed and I have moved for 6 weeks in the Evol­u­tion-Eco­logy-Pale­on­to­logy labor­at­ory (EEP), in Lille (France). This labor­at­ory was an inter­est­ing altern­at­ive as a col­lab­or­a­tion on oth­er Silene spe­cies was already ongo­ing with the pro­fess­or Pas­cal Touz­et. Dur­ing my vis­it, I stud­ied the genes dif­fer­en­tially expressed in nine Silene dioecious spe­cies, for which data were already acquired. This data­set is unique since it spans dioecious spe­cies deriv­ing from sev­er­al inde­pend­ent events of trans­ition to dioecy. Moreover, bey­ond this col­lab­or­a­tion, my stay in Lille was also a great oppor­tun­ity to inter­act with spe­cial­ist of the evol­u­tion of sexu­al sys­tems in plants, since the labor­at­ory EEP is a ref­er­ence in this field.

Pro­ject can­celled due to the pandemic.

Pro­ject can­celled due to the pandemic.

Pro­ject can­celled due to the pandemic.

In 2018, I have received the grant with­in 4th call for the Pro­gram for Research and Mobil­ity Sup­port of Start­ing Research­ers by CAS. The aim of sup­por­ted pro­ject was to invest­ig­ate wheth­er geo­graph­ic­ally and genet­ic­ally dis­tinct sub­spe­cies of Mus mus­cu­lus carry dis­tinct lymph­o­cyt­ic chori­omen­ingit­is vir­us (LCMV) strains and wheth­er ongo­ing hybrid­iz­a­tion could poten­tially allow LCMV to switch host, by sampling in detail across their con­tact zone. Part of the pro­ject was planned as the for­eign stay at the Uni­ver­sity of Edin­burgh (13. 7. 2019 – 26. 1. 2020). The aim of this stay was to learn how to ana­lyse gen­om­ic data and then ana­lyse my own LCMV gen­om­ic data. How­ever, with two small kids (4 and 2 years), the relo­ca­tion of whole fam­ily showed up as fin­an­cially demand­ing pro­ject. Thanks to God­frey Hewitt Mobil­ity Award we were able to com­bine the care of our chil­dren (our kids fre­quen­ted great Out­door Nurs­ery Edin­burgh) and work. Dur­ing my stay I had oppor­tun­ity to learn how to pro­cess, ana­lyse (e.g. qual­ity con­trol, de-novo assembly) and inter­pret gen­om­ic data. I also atten­ded here one week-long gen­om­ic course lead by bioin­form­aticians from Edin­burgh Gen­om­ics. After this course I was able to work with my own LCMV data and start to ana­lyse them. Dur­ing my stay at the Uni­ver­sity of Edin­burgh I have also oppor­tun­ity to learn how to isol­ate long DNA frag­ments by Phen­ol Chlo­ro­form extrac­tion and pro­cess sequen­cing by Min­ION, the port­able, real-time device for DNA and RNA sequen­cing. GHM award def­in­itely helped us to bal­ance our fam­ily budget and allowed me to take part in this fel­low­ship, which was cer­tainly bene­fi­cial for my sci­entif­ic career.

The God­frey Hewitt Mobil­ity Award allowed me to work for three The God­frey Hewitt Mobil­ity Award allowed me to work for three months in Mérida, Mex­ico, where I was hos­ted by Dr Javi­er Quéz­ada Euán at the Depart­ment of Api­cul­ture at the Autonom­ous Uni­ver­sity of Yucatan. My aim was to meas­ure the costs and bene­fits of social­ity in the socially plastic orch­id bee Euglossa viridissima by meas­ur­ing the fit­ness of social females (in terms of off­spring num­ber) using a remov­al exper­i­ment. Manip­u­la­tion of social nests proved to be too big of a dis­turb­ance for the bees, as all of the manip­u­lated nests were sub­sequently aban­doned. I there­fore adap­ted the pro­ject to col­lect data on the related­ness and kin struc­ture between adult females and between adults and off­spring in social nests through microsatel­lite gen­o­typ­ing. I did this by col­lect­ing adult females (dom­in­ant and sub­or­din­ate) and their off­spring after the main repro­duct­ive peri­od of the adults had ceased. The res­ults indic­ate that E. viridissima has a plastic social struc­ture that is not lim­ited to mat­ri­fili­al asso­ci­ations; nests also con­sist of sor­or­al or unre­lated groups, though nev­er­the­less adhere to a dom­in­ance struc­ture. Moreover, I found that com­plete monoply of  repro­duc­tion by the dom­in­ant female was rather uncom­mon; sub­or­din­ate females and non-nest­mates repro­duced with­in the same nest. Even though the ini­tially planned exper­i­ment was not suc­cess­ful, I could col­lect data to provide inter­est­ing insights into the beha­vi­our­al flex­ib­il­ity of E. viridissima, which will be pub­lished and incor­por­ated into my PhD thesis.

Under­stand­ing how organ­isms adapt to chem­ic­al pres­sures (e.g., plant alle­l­o­chem­ic­als and insect­icides) is a cent­ral theme in evol­u­tion­ary eco­logy. In my postdoc­tor­al research at UC Berke­ley, I exploited the power of Dro­so­phila genet­ics to identi­fy how the mon­arch but­ter­fly (Danaus plexip­pus) evolved res­ist­ance to the car­di­ac glyc­os­ide tox­ins
pro­duced by the plants that it col­on­izes (Kar­ageorgi et al., 2019). I found that three amino sub­sti­tu­tions in the α‑subunit (ATPα) of its sodi­um pump, the tar­get of car­di­ac glyc­os­ides, are suf­fi­cient to con­fer full res­ist­ance to car­di­ac glyc­os­ides. Inter­est­ingly, pop­u­la­tions of Dro­so­phila sub­obscura in Europe were described to carry the same three res­ist­ance muta­tions in their ATPα as the mon­arch but­ter­fly (Peguer­oles et al., 2016). D. sub­obscura there­fore provided for me a very attract­ive sys­tem to explore the func­tion­al evol­u­tion and pop­u­la­tion genet­ics of res­ist­ance to car­di­ac glyc­os­ides, which had only been stud­ied before in the mac­ro­e­volu­tion­ary context.

Thanks to the sup­port of the God­frey Hewitt Mobil­ity award, in sum­mer 2019 I launched col­lab­or­a­tions with Dr. John Vontas in Greece and Dr. Fran­cisco Rodrig­uez-Trelles in Spain and per­formed field­work in which I col­lec­ted and gen­o­typed D. sub­obscura lines car­ry­ing the res­ist­ance muta­tions in their ATPα. In my postdoc­tor­al lab with Dr.
White­man at UC Berke­ley, I then found that the homo­zyg­ous D. sub­obscura lines were res­ist­ant to car­di­ac glyc­os­ides. In 2020, I star­ted a new postdoc pos­i­tion in the lab of Dr. Dmitri Pet­rov at Stan­ford and received a K99/R00 Path­way to Inde­pend­ence Award to study the genet­ics of adapt­a­tion to tox­ic envir­on­ments. The focus of this five-year pro­ject is to study how and why res­ist­ance to car­di­ac glyc­os­ides evolved in wild pop­u­la­tions of Dro­so­phila sub­obscura. There­fore, the God­frey Hewitt Mobil­ity award played a sig­ni­fic­ant role in the dir­ec­tion to devel­op my inde­pend­ent research pro­gram and enhanced my career in evol­u­tion­ary biology.

Thanks to the God­frey Hewitt Mobil­ity award, I was able to vis­it the Uni­ver­sity of Zurich for two months in 2019 to col­lab­or­ate on an exper­i­ment with Prof. Dr. Stefan Lüpold. While we had issues with the Wolba­chia infec­ted Dro­so­phila melano­gaster lines that were ini­tially going to be used for this pro­ject, I was able to com­plete a nov­el exper­i­ment that examined gen­o­type x diet inter­ac­tions on male repro­duct­ive per­form­ance. For this, we used isolines of flies that were genet­ic­ally mod­i­fied to ubi­quit­ously express green fluor­es­cent pro­tein in the sperm heads and somat­ic cells. Each isoline was reared on either a high, inter­me­di­ate, or low nutri­ent diet to allow a G x E exper­i­ment­al design. Males from each of the diet and isoline com­bin­a­tion were allowed to con­sec­ut­ively mate with up to five dif­fer­ent females, and the repro­duct­ive beha­viour with each female was recoded. After each mat­ing had ceased, the repro­duct­ive tracts of the females were dis­sec­ted, and the num­ber of sperm trans­ferred at each mat­ing was coun­ted under a micro­scope fit­ted with a fluor­es­cent fil­ter. Through this, we detec­ted inter­est­ing pat­terns in male abil­ity to invest in repro­duc­tion, includ­ing rap­id sperm deple­tion and increas­ing reluct­ance to mate with each suc­cess­ive female. We also show effects of diet and isoline on male repro­duct­ive per­form­ance. This pro­ject led to fur­ther fol­low up exper­i­ments that are in the pro­cess of being com­bined and pre­pared for pub­lic­a­tion. This was a highly valu­able exper­i­ence for me as it allowed me to devel­op many new skills and form new con­nec­tions. This pro­ject ulti­mately led to being awar­ded a Swiss Gov­ern­ment Excel­lence Post-Doc­tor­al Schol­ar­ship to con­tin­ue research in this area (unfor­tu­nately declined due to the inter­na­tion­al COVID situation).

The God­frey Hewitt Mobil­ity Award allowed me to work for four months at the Uni­ver­sity of Mont­pel­li­er (March-June, 2019), work­ing under the super­vi­sion of Oliv­er Kaltz. The aim of this pro­ject was to explore wheth­er exper­i­ment­al selec­tion on dis­pers­al alters host and patho­gen life-his­tory traits and how such responses to selec­tion may influ­ence range expan­sions and the spread of epi­dem­ic waves. Exist­ing long-term selec­tion lines for high and low dis­pers­al in a host-patho­gen sys­tem, allowed me to test the evol­u­tion­ary responses of the patho­gen Holospora undu­lata, in response to dis­pers­al selec­tion imposed on its host Para­me­cia caudatum. Shortly, in the para­site assay, we found that para­sites at the inva­sion front main­tain high­er dis­pers­al than para­sites at the estab­lished core, and this increase in dis­pers­al was asso­ci­ated with reduced vir­ulence and a shift in trans­mis­sion strategy towards more ver­tic­al trans­mis­sion. These res­ults sug­gest that dif­fer­ent seg­ments of an epi­dem­ic wave may be under diver­gent selec­tion pres­sures, shap­ing the evol­u­tion of para­site life his­tory. This work was recently accep­ted in Eco­logy Let­ters and is cur­rently in press. My stay at Mont­pel­li­er has been fruit­ful in a num­ber of ways; the pro­ject has giv­en me the oppor­tun­ity to gain exper­i­ence with a new host-para­site mod­el sys­tem and have broadened my inter­na­tion­al net­work, bridging the way for future col­lab­or­at­ive pro­jects. A num­ber of addi­tion­al co-authored papers like­wise came out of my time in Mont­pel­li­er, and this stay has there­fore been par­tic­u­larly good for my early aca­dem­ic career.

The God­frey Hewitt Mobil­ity Award allowed me to stay one month at the UCL Genet­ics Insti­tute in July 2019 work­ing under the super­vi­sion of Aida Andrés. The main aim of this pro­ject was to ana­lyse how bal­an­cing selec­tion shapes gen­om­ic pat­terns at func­tion­al loci in pop­u­la­tions sub­jec­ted to dif­fer­ent levels of genet­ic drift. Pre­cisely we worked on the ques­tion: to what extent can bal­an­cing selec­tion main­tains diversity des­pite the effect of genet­ic drift? To do so, we are using one pre-bot­tle­neck (ancient) and two dif­fer­ent post-bot­tle­neck (con­tem­por­ary) pop­u­la­tions of the highly endangered Iberi­an lynx (Lynx pardinus). Dur­ing this month I was work­ing on devel­op­ing and run­ning a script to ana­lyse whole-gen­ome data. This script com­prises sev­er­al steps. First, we run NCD2 stat­ist­ics on allele fre­quency data. This stat­ist­ic –developed in Aida’s lab- detects sig­na­tures of long-term bal­an­cing selec­tion on dif­fer­ent gen­om­ic regions by meas­ur­ing the dif­fer­ence between a tar­get fre­quency (assumed to be the equi­lib­ri­um fre­quency under bal­an­cing selec­tion, e.g. 0.5) and the allele fre­quency of a par­tic­u­lar region (con­sid­er­ing SNPs and fixed dif­fer­ences as inform­at­ive sites). Once we have detec­ted regions under bal­an­cing selec­tion in the three pop­u­la­tions, we char­ac­ter­ized these regions and com­pared them among the dif­fer­ent pop­u­la­tions. For instance, we tested wheth­er win­dows under bal­an­cing selec­tion are enriched for func­tion­al SNPs, or if among the genes under bal­an­cing selec­tion we found any GO-term being enriched. Pre­lim­in­ary res­ults sug­gest that the com­par­is­on of the pre-bot­tle­neck and post-bot­tle­neck pop­u­la­tions will give us valu­able insights on the action of bal­an­cing selec­tion and drift on spe­cies facing sim­il­ar con­ser­va­tion con­cerns. Besides pro­gress­ing on my research, being at the UCL allowed me to inter­act with dif­fer­ent research­ers that could poten­tially lead to future col­lab­or­a­tions. Alto­geth­er, the exper­i­ence has been invalu­able to me, and it would surely boost my future research stages.

Dur­ing my PhD thes­is, I was inter­ested in study­ing how changes in gene expres­sion under­lie phen­o­typ­ic plas­ti­city and vari­ation with­in spe­cies, allow­ing organ­isms to respond to envir­on­ment­al cues and max­im­ise their fit­ness accord­ingly. To tackle this prob­lem, I focused my research on the pea­cock blenny Salaria pavo, which exhib­its both intra- and inter-spe­cif­ic vari­ation in repro­duct­ive beha­viour. In the present pro­ject, my aim was to invest­ig­ate wheth­er gene expres­sion was the main driver in sex role shift in court­ship beha­viour between two pop­u­la­tions of the pea­cock blenny, or genet­ic dif­fer­en­ti­ation was also a play­er in the observed plas­ti­city. The God­frey Hewitt Mobil­ity Award allowed me to spend three weeks at Dr Alis­on E. Wright’s lab, a NERC Inde­pend­ent Research Fel­low at the Uni­ver­sity of Shef­field with extens­ive know­ledge in gen­om­ic and evol­u­tion­ary pro­cesses under­ly­ing sex dif­fer­ences. Our strategy of ana­lys­is was to test for dif­fer­ences in mat­ing com­pet­i­tion among pop­u­la­tions, where we com­pared rates of evol­u­tion and pop­u­la­tion-level poly­morph­isms across sex-biased and unbiased genes for brain and gon­ads and link these pat­terns of expres­sion and selec­tion to the cor­res­pond­ing roles in court­ship beha­viour. Dur­ing my stay, I had the oppor­tun­ity to devel­op my bioin­form­at­ic skills and learn cut­ting-edge tech­niques for ana­lys­ing next-gen­er­a­tion sequen­cing data, as well as to improve my know­ledge in evol­u­tion­ary ana­lyses and test dif­fer­ent hypo­thes­is for my work in particular.

The aim of my PhD dis­ser­ta­tion research is to under­stand the causes under­ly­ing decel­er­a­tion of mor­pho­lo­gic­al diver­gence. Sev­er­al reas­ons have been spec­u­lated, includ­ing on-going gene flow (admix­ture), reduc­tion of stand­ing genet­ic vari­ation, genet­ic and devel­op­ment­al con­straints. Funds from the God­frey Hewitt Mobil­ity Award allowed me to travel to the Uni­ver­sity of Urb­ana Cham­paign in Illinois (UIUC) to work with Prof. Juli­an Catchen who is a renown bioin­form­atician. Dur­ing this research exchange, I received ori­ent­a­tion and train­ing on RAD­seq data ana­lyses, focus­ing on mit­ig­at­ing biases of PCR-duplic­a­tion in the gen­er­ated data­set. We have dis­covered that mor­pho­lo­gic­ally-identic­al worms are genet­ic­ally dis­tinct, yet some degree of admix­ture has occurred in the past (i.e. gene-flow in ancient lineages).

Identi­fy­ing the con­sequences and drivers of con­text-depend­ent dis­pers­al is import­ant for both eco­lo­gic­al and evol­u­tion­ary research. The role of dis­pers­al for com­munity struc­ture may strongly depend on the dis­pers­al strategy (e.g. informed versus unin­formed) used, and this may con­sequently influ­ence diversity pat­terns found in the meta­com­munity. The God­frey-Hewitt mobil­ity award allowed me to vis­it the lab of CRNS research­er Dr. Emanuel Fron­hofer to set up an indi­vidu­al-based mod­el to invest­ig­ate the con­sequences of the evol­u­tion­ary stable strategy for con­text-depend­ent versus unin­formed dis­pers­al. Because few stud­ies looked at the effects of con­text-depend­ent dis­pers­al to diversity pat­terns in a meta­com­munity con­text, I decided to first focus on the con­sequences of con­text-depend­ent dis­pers­al in hori­zont­al com­munit­ies. Using two dif­fer­ent sets of net­work struc­tures (Nearest-Neigh­bour 8 versus optim­al chan­nel net­work) that dif­fer in con­nectiv­ity and topo­logy, we explored the eco-evol­u­tion­ary con­sequences of con­textde­pend­ent versus ran­dom dis­pers­al and its con­sequences for biod­iversity. I found that con­textde­pend­ent dis­pers­al res­ults in high­er loc­al diversity. How­ever, the under­ly­ing mech­an­isms explain­ing this pat­tern depended on the land­scape con­text. For the optim­al chan­nel net­work, increased diversity was medi­ated through high­er evol­u­tion­ary stable con­text-depend­ent dis­pers­al rates. Where­as for the nearest neigh­bour land­scape this was due to fit­ness equal­iz­ing mech­an­isms. Dur­ing this pro­ject, I received extens­ive train­ing in eco­lo­gic­al and evol­u­tion­ary mod­el­ling on dis­pers­al dynam­ics in meta­com­munit­ies. This pro­ject formed the basis for future pro­jects with the lab of Dr. Fron­hofer, in which we will con­tin­ue to invest­ig­ate the eco­lo­gic­al and evol­u­tion­ary con­sequences of con­text-depend­ent dis­pers­al in more com­plex settings.

Patho­gens are per­vas­ive effect­ing nearly every liv­ing organ­ism often with strong fit­ness effects. Coe­volu­tion between hosts and their patho­gens is there­fore com­mon and is a pro­cess that has the poten­tial to shape biod­iversity. The endan­ger­ment and extinc­tion of a num­ber of spe­cies is indeed known to be affected by their patho­gens in the form of infec­tious dis­ease. Our goal, there­fore, was to under­stand how coe­volu­tion between hosts and infec­tious patho­gens effects the genet­ic diversity of small pop­u­la­tions. Com­bin­ing math­em­at­ic­al tech­niques from epi­demi­ology and pop­u­la­tion genet­ics we found that coe­volu­tion­ary mech­an­isms act to reduce the genet­ic vari­ab­il­ity of small pop­u­la­tions and increase the vari­ab­il­ity of large ones. We identi­fy sev­er­al pre­dict­ors for the sens­it­iv­ity of a pop­u­la­tion to loss of genet­ic vari­ation through para­sit­ism and explore their implic­a­tions for future con­ser­va­tion efforts.

Mito­chon­dria are organ­elles present in almost all anim­al cells that not only set the effi­ciency at which organ­isms con­vert food into cel­lu­lar energy (ATP) dur­ing oxid­at­ive phos­phoryla­tion (OXHPOS res­pir­a­tion) but also act as import­ant sig­nal­ing cen­ter and are involved in the redox homeo­stas­is. There­fore, changes in mito­chon­dri­al func­tion can impact a wide range of phen­o­typ­ic traits as a con­sequence of alter­a­tions in ATP pro­duc­tion or redox homeo­stas­is. Remark­ably, mito­chon­dria have recept­ors for ster­oid hor­mones, and expos­ure to these hor­mones have demon­strated to mod­u­late the organ­elle func­tions through a wide range of path­ways, from changes in gene expres­sion and mito­chon­dri­al pro­tein syn­thes­is to (un)activation of mito­chon­dri­al com­plexes involved in ATP and redox homeo­stas­is. Hence, mater­nally-derived andro­gens may affect mito­chon­dri­al func­tion dur­ing devel­op­ment and ulti­mately account for pleio­trop­ic effects on off­spring phen­o­type. The God­frey Hewitt Mobil­ity Award allowed me to join Dr. Pierre Bize’s group (Uni­ver­sity of Aber­deen) to work in the alpine swift colony breed­ing at Bienne and Solo­thurn (Switzer­land), and receive train­ing to meas­ure mito­chon­dri­al func­tion using high res­ol­u­tion respir­o­metry. Dur­ing the research stay, we run a pilot study ana­lyz­ing mito­chon­dri­al func­tion from par­ents and off­spring through the repro­duct­ive event and developed a col­lab­or­at­ive pro­ject to keep on explor­ing the inter­play between mater­nally derived hor­mones and mito­chon­dri­al function.

The God­frey Hewitt Mobil­ity Award allowed to spend three months work­ing with Dr. Gil­berto Ocampo at the Autonom­ous Uni­ver­sity of Aguas­cali­entes, Mex­ico. Dur­ing that peri­od, I worked on evol­u­tion­ary aspects of para­sit­ic plant mor­pho­logy, espe­cially ana­lyz­ing and com­par­ing the struc­ture of the haus­tori­um, an organ that medi­ates the com­mu­nic­a­tion between para­sit­ic plants and their hosts, among dif­fer­ent plant clades. Under the super­vi­sion of Dr. Ocampo, I was able to fur­ther my know­ledge on plant phylo­gen­et­ics, learn­ing how to use dif­fer­ent soft­ware and per­form­ing a broad range of ana­lyses. I was also able to plan and carry out field trips in three dif­fer­ent Mex­ic­an states. Dur­ing these trips, 10 para­sit­ic plant spe­cies were sampled, most of them endem­ic to Mex­ico and Cent­ral Amer­ica, such as Len­noa mad­re­poroides (Len­noacae­ae) and Mitras­te­mon matudae (Mitras­te­mon­aceae), rare and poorly under­stand spe­cies. Finally, I was also able to vis­it two of the largest herb­ar­ia in Mex­ico, the Herb­ar­i­um of the Nation­al Autonom­ous Uni­ver­sity of Mex­ico and the Herb­ar­i­um of the Eco­logy Insti­tute. The work car­ried out dur­ing my time in Mex­ico provided res­ults for three chapters of my PhD thes­is, which was defen­ded and approved earli­er this year. One of these chapters has been recently approved to be pub­lished as part of a book by on plant onto­geny. The second and third ones will soon be sub­mit­ted to publication.

The Cape flor­ist­ic region is fam­ous for its extraordin­ary diversity in flor­al forms and func­tions and pol­lin­a­tion modes, mak­ing it an ideal place to study pol­lin­at­or-driv­en diver­si­fic­a­tion and spe­ci­ation in flower­ing plants. Thanks to the sup­port from the God­frey Hewitt mobil­ity award I was able to join the lab of Prof. Bruce Ander­son at Stel­len­bosch Uni­ver­sity to con­duct a short-term postdoc pro­ject after com­plet­ing my PhD stud­ies. Anderson´s lab has recently developed a nov­el meth­od to label indi­vidu­al pol­len grains, which offers the pos­sib­il­ity to track pol­len move­ment between flowers of dif­fer­ent kind and study pol­lin­at­or medi­ated repro­duct­ive isol­a­tion. Using this meth­od, we could show that two sym­patric col­our morphs of the sun­dew Drosera cis­ti­flora attract dis­tinct pol­lin­at­or assemblages, and that this res­ults in strong assort­at­ive mat­ing. Thus, our exper­i­ment sup­por­ted the hypo­thes­is that flor­al col­our is not only loc­ally adap­ted to dif­fer­ent pol­lin­at­or com­munit­ies among pop­u­la­tions as pre­vi­ously stud­ied by Ander­son, but also that col­our vari­ation leads to repro­duct­ive isol­a­tion in sym­patry. Because spe­ci­ation requires both diver­gence and repro­duct­ive isol­a­tion, the pro­ject added import­antly to our under­stand­ing of the role of flower col­our for diver­gence in D. cis­ti­flora. Per­son­ally, this research vis­it provided me vari­ous new exper­i­ences and skills that will be advant­age­ous for my future career.

One of the single most extraordin­ary examples of host-para­site co-evol­u­tion is shown by cymothoid iso­pods, which are oblig­ate para­sites of fish, includ­ing many com­mer­cially import­ant spe­cies. Cymothoids are highly diverse with ~400 spe­cies across 43 genera,and exhib­it strik­ing para­sit­ic strategies: some spe­cies even sup­plant their host’s tongue! Yet, des­pite such remark­able adapt­a­tions little is known about the evol­u­tion­ary his­tory of the fam­ily, the pro­cesses that cre­ated the remark­able diversity of extant taxa and the con­tem­por­ary pat­tern of host-para­site inter­ac­tions. I using a phylo­ge­n­om­ic approach to research the co-evol­u­tion­ary dynam­ics of cymothoids and their hosts with molecu­lar sequence data obtained from museum spe­ci­mens. The God­frey Hewitt Mobil­ity Award allowed me to extract and ana­lyse DNA from 40 cymothoid spe­cies col­lec­ted from the Nation­al Museum of Nat­ur­al His­tory, Wash­ing­ton D.C., and to receive labor­at­ory and bioin­form­at­ics train­ing spe­cif­ic to the study of ancient DNA from the Paleo­ge­n­om­ics lab at the Uni­ver­sity of Cali­for­nia Santa Cruz.

Innate beha­vi­or is cru­cial in the life his­tory of most anim­al spe­cies. In insects, innate pref­er­ences are respons­ible for a mul­ti­tude of beha­vi­ors includ­ing flower vis­it­a­tion in naïve pol­lin­at­ors and mate find­ing in moths. How­ever, des­pite its import­ance in anim­al beha­vi­or, the evol­u­tion of innate pref­er­ences remains poorly under­stood. The God­frey Hewitt Mobil­ity Award allowed me to spend 4 weeks with Jean- Chris­tophe San­doz at the Centre Nation­al de la Recher­che Sci­en­ti­fique (CNRS) in Gif- sur-Yvette, France, to study neur­al mech­an­isms under­ly­ing the evol­u­tion of innate odor pref­er­ences in orch­id bees. I received detailed train­ing in tech­niques to char­ac­ter­ize the neuroana­tomy of olfact­ory cen­ters of the brain includ­ing tis­sue pre­par­a­tion, con­focal micro­scopy, and 3D recon­struc­tion of neuropils. This allowed me to char­ac­ter­ize the neuroana­tomy of male and female orch­id bees of dif­fer­ent spe­cies cul­min­at­ing in a paper pub­lished in the Journ­al of Com­par­at­ive Neur­o­logy. The paper describes sexu­al dimorph­ism in the orch­id bee brain, includ­ing female- spe­cif­ic and male-spe­cif­ic struc­tures that might be involved in social and sexu­al com­mu­nic­a­tion. Ongo­ing and future pro­jects with the San­doz lab will allow me to study the neur­on­al evol­u­tion of innate odor pref­er­ences in orch­id bee chem­ic­al com­mu­nic­a­tion in more detail.

The God­frey Hewitt Mobil­ity Award allowed me to spend 3 months in 2017 at the Aus­trali­an Nation­al Uni­ver­sity work­ing with Prof. Michael Jen­nions and Dr. Megan Head. With them I explored the con­di­tion depend­ent costs of mat­ing for females in the seed beetle Cal­lo­sobruchus mac­u­lat­us, which led to an art­icle pub­lished in Beha­vi­or­al Eco­logy in 2018. This beetle is a com­monly used mod­el spe­cies to study the evol­u­tion and implic­a­tions of sexu­al con­flict. Dur­ing my pro­ject, I wanted to test wheth­er the rear­ing envir­on­ment of males and females affected the costs that males impose on their mates. This is because both sexu­ally ant­ag­on­ist­ic male traits and the female’s abil­ity to res­ist male-imposed costs might be con­di­tion-depend­ent. By exper­i­ment­ally manip­u­lat­ing female and male body con­di­tion by rear­ing lar­vae on a good or poor qual­ity diet I tested wheth­er the fit­ness cost of mat­ing for a female depended on her and/or her mate’s body con­di­tion. As expec­ted, females in bet­ter con­di­tion had high­er fit­ness, and females differed in their beha­viour in rela­tion to male con­di­tion. Both res­ults are poten­tially indic­at­ive of great­er sexu­al con­flict. Although my ori­gin­al pro­ject aimed to explore the effects of urb­an­iz­a­tion in liz­ards, the dif­fi­culty in cap­tur­ing an adequate sample size of anim­als made me change the exper­i­ment. This exper­i­ence with a new mod­el sys­tem and in a slightly dif­fer­ent top­ic provided me with a new set of skills that will be use­ful in my future research stages.

The aim of my dis­ser­ta­tion research is to under­stand how indi­vidu­als invest in spe­cif­ic life his­tory traits (namely, repro­duc­tion and immunity) when faced with sur­viv­al threats under vari­ous cir­cum­stances (e.g., across age and gen­o­types). Funds from the God­frey Hewitt Mobil­ity Award allowed me to travel to West­ern Sydney Uni­ver­sity (WSU) to work with Dr. John Hunt to explore how nutri­tion-depend­ent con­di­tion influ­ences repro­duc­tion and immunity fol­low­ing an immune-chal­lenge, thus expand­ing the scope of my dis­ser­ta­tion. Hunt is an expert on nutri­tion­al geo­metry, a tech­nique which tests effects of spe­cif­ic com­bin­a­tions of mac­ronu­tri­ents while hold­ing cal­or­ic value con­stant. Dur­ing this trip, I received train­ing on pre­par­ing these diets as well as refin­ing my tech­niques and meth­od­o­logy in nutri­tion­al geo­metry to pre­pare for use at my home insti­tu­tion this sum­mer (2018). Addi­tion­ally, I was able to col­lab­or­ate with Dr. Clarissa House (also of WSU) to devel­op sperm quan­ti­fic­a­tion tech­niques with­in my study sys­tem (the dec­or­ated crick­et, Gryl­lodes sigil­lat­us). We dis­covered that G. sigil­lat­us sperm can read­ily be coun­ted without the use of costly and time-con­sum­ing DNA-stain­ing tech­niques due to their auto­fluor­es­cence under UV light. I also received train­ing on gas-chro­ma­to­graphy mass-spec­tro­metry to ana­lyze amino acid pro­files (which are known to influ­ence qual­ity) of sper­ma­to­phy­laxes (which func­tion as nup­tial gifts in this spe­cies) and cutic­u­lar hydro­car­bons pro­files derived from G. sigil­lat­us. Dur­ing my month-long stay at WSU, I have received train­ing on tech­niques and fostered col­lab­or­a­tions which will be invalu­able to me fol­low­ing gradu­ation at the end of the year and through­out my research career.

I was for­tu­nate enough to use my God­frey Hewitt Mobil­ity Award to spend sev­er­al weeks work­ing in Prof. Hanna Kokko’s lab at the Uni­ver­sity of Zürich. While my DPhil work at the Uni­ver­sity of Oxford was focused on the molecu­lar mech­an­isms of sperm com­pet­i­tion and the evol­u­tion of ejac­u­late com­pos­i­tion, this award provided me with the oppor­tun­ity to ded­ic­ate time to work­ing on a quite dif­fer­ent prob­lem I was inter­ested in: why do pair-bon­ded birds con­tin­ue to dis­play after select­ing a mate? The most com­monly cited explan­a­tion for the elab­or­ate dis­plays seen between partnered bird spe­cies is their use in mate choice. But there are numer­ous examples of dis­plays, such as incub­a­tion stint changeover duets in Pro­cel­lari­forms and nest-site selec­tion dances in boobies, that take place long after part­ner­ships form. Long, even, after the chick has hatched. I was inter­ested in the pos­sib­il­ity that such dis­plays might be used to com­mu­nic­ate inform­a­tion between part­ners, inform­a­tion that can be used to optim­ally coordin­ate par­ent­al care to ensure a partner’s sur­viv­al. Dur­ing my time with Hanna, I worked on a syn­thet­ic review that explored this pos­sib­il­ity, but it raised an addi­tion­al, more fun­da­ment­al, prob­lem: when should an indi­vidu­al care about their partner’s sur­viv­al in the first place? After all, there may be ‘plenty more fish in the sea’, so to speak. With Hanna, I received train­ing in con­struct­ing evol­u­tion­ary mod­els, which I used to build a mod­el of the evol­u­tion of part­ner care to explore con­di­tions under which indi­vidu­als may redir­ect invest­ment from par­ent­al to part­ner care. The exper­i­ence was hugely enrich­ing and provided me with a new net­work of col­lab­or­at­ors, for which I am very grateful.

In my PhD thes­is, I am study­ing the evol­u­tion of sea­son­al coat col­or change in hares (Lepus). I am apply­ing gen­om­ic tools (phylo­ge­n­om­ics, pop­u­la­tion gen­om­ics) to under­stand how many times sea­son­al cam­ou­flage evolved in the genus and to study its genet­ic basis. The God­frey Hewitt Mobil­ity Award allowed me to start a pop­u­la­tion level study using white-tailed jack­rab­bits (Lepus town­sendii) as a new mod­el to study the evol­u­tion and genet­ic basis of winter coat col­or determ­in­a­tion. I organ­ized a field exped­i­tion to Col­or­ado, in Janu­ary 2018, in col­lab­or­a­tion with Prof. Jef­frey Good and Prof. Scott Mills, from the Uni­ver­sity of Montana. The main aim of this field exped­i­tion was to col­lect spe­ci­mens along a trans­ition zone of winter coat col­or in white-tailed jack­rab­bits to per­form a gen­ome scan for winter coat col­or genet­ic determ­in­ants. The labor­at­ory work includ­ing these samples is under­way. With this exped­i­tion, I not only obtained samples, but also gained field work exper­i­ence, and estab­lished con­tacts at the Uni­ver­sity of Montana and in Col­or­ado, that will be use­ful for future research. Finally, this was the first field exped­i­tion to include a new sys­tem, the white-tailed jack­rab­bit, in a broad col­lab­or­at­ive pro­ject that aims at study­ing the evol­u­tion and eco­logy of sea­son­al coat col­or change.

This award allowed me to spend 5 weeks in North Ice­land in June-July 2017 to con­duct a field exper­i­ment. The main aim of this pro­ject was to invest­ig­ate the bal­ance between gene flow and diver­gent selec­tion at a sym­patric pop­u­la­tion of three-spined stickle­backs inhab­it­ing a geo­therm­ally heated pond and an adja­cent cold lake. These warm-water and cold-water stickle­backs are mor­pho­lo­gic­ally and physiolo­gic­ally diver­gent des­pite the absence of a geo­graph­ic­al bar­ri­er between them. Since the two hab­it­ats are con­nec­ted by a nar­row creek, there is poten­tial for gene flow. To test for dis­pers­al between these hab­it­ats, I PIT-tagged 400 stickle­backs and tracked their move­ments over a 1‑month peri­od. Dur­ing this vis­it, I had the oppor­tun­ity to meet and inter­act with research­ers at Hólar Uni­ver­sity Col­lege, which could poten­tially lead to future collaborations.

Hiberna­tion is defined as a suc­ces­sion of tor­por phases, dur­ing which anim­als decrease their meta­bol­ism and their body tem­per­at­ure to a large extent. Most hibernat­ors – i.e. fat-stor­ing hibernat­ors – fat­ten pri­or to hiberna­tion and rely to a large extent on stored fat as an energy source in winter where­as food-stor­ing hibernat­ors hoard very large amounts of food in their bur­row pri­or to winter and rely exclus­ively on these hoards as an energy source through­out winter. Although tor­por is expressed through­out winter, hibernat­ors do not remain con­stantly tor­pid. Bouts of tor­por are indeed inter­rup­ted by peri­od­ic rewarm­ing (arous­als), fol­lowed by eutherm­ic phases. Fat- and food-stor­ing hibernat­ors exhib­it import­ant vari­ations in their hiberna­tion pat­tern. Fat-stor­ing hibernat­ors express long and deep bouts of tor­por com­pared to food-stor­ing hibernat­ors. Con­sequently, food-stor­ing hibernat­ors arouse more fre­quently and spend more time eutherm­ic than fat-stor­ing hibernat­ors. The dur­a­tion of the eutherm­ic phases and the num­ber of arous­als have been cor­rel­ated to cel­lu­lar age­ing in fat-stor­ing hibernat­ors. I thus aim at com­par­ing cel­lu­lar age­ing of fat- and food-stor­ing hibernat­or spe­cies in rela­tion with their pat­tern of hiberna­tion, with the main hypo­thes­is that food-stor­ing hibernat­ors will express great­er rates of age­ing than fat-stor­ing hibernat­ors, asso­ci­ated to reduced somat­ic main­ten­ance dur­ing hiberna­tion. The ESEB fin­an­cial sup­port allowed me to col­lect­ing data on the fat-stor­ing Columbi­an ground squir­rel (Sper­mo­philus columbi­anus) in Canada. My stay at the RB Miller Research Sta­tion (Uni­ver­sity of Cal­gary) field sta­tion has been ded­ic­ated to the devel­op­ment of the buc­cal swabs tech­nique on this spe­cies, data col­lec­tion and the asso­ci­ated DNA extrac­tion for cel­lu­lar age­ing analyses.

The God­frey Hewitt Mobil­ity Award allowed me spend 4 weeks with Dr Patrick Fer­ree at Clare­mont Col­leges, Cali­for­nia as part of my PhD research on epi­gen­et­ic mech­an­isms involved in Paternal Gen­ome Elim­in­a­tion (PGE) in the scale insect, Pla­no­coc­cus citri. The main aim of the vis­it was to get train­ing in the use of cyto­gen­et­ic tech­niques to study the epi­gen­et­ic mech­an­isms involved in PGE. I used equip­ment provided by the Fer­ree labor­at­ory to dis­sect, fix and stain gam­etes and embry­os in order to estab­lish the pres­ence or absence of his­tone modi­fic­a­tions involved in gene silen­cing. This skill is extremely use­ful for my research, as part of my thes­is will focus on the role of his­tone modi­fic­a­tions in PGE spe­cies through­out devel­op­ment. I was also trained to use con­focal micro­scopy. Finally, I was able to exchange ideas with an expert in the field of epi­gen­et­ic modi­fic­a­tions and their role in insect repro­duc­tion and also start col­lab­or­a­tion between our two research groups.

For my PhD thes­is, I am study­ing the evol­u­tion of dis­pers­al, which is the move­ment of organ­isms between hab­it­at patches. Dis­pers­al influ­ences a wide vari­ety of evol­u­tion­ary pro­cesses, includ­ing loc­al adapt­a­tion and spe­ci­ation; how­ever, des­pite its import­ance, we lack a full under­stand­ing of how dis­pers­al depends on char­ac­ter­ist­ics of the envir­on­ment and the indi­vidu­al. This is because dis­pers­al is dif­fi­cult to study in the field or lab. The God­frey Hewitt Mobil­ity Award allowed me to travel to Scot­land to work with Dr. Justin Trav­is, an eco­e­volu­tion­ary mod­el­ler. We built a the­or­et­ic­al mod­el to explore how dis­pers­al is influ­enced by envir­on­ment­al and phen­o­typ­ic factors. In this mod­el, indi­vidu­als dis­perse between hab­it­at patches of dif­fer­ent qual­ity in order to avoid com­pet­ing with oth­er indi­vidu­als, espe­cially their rel­at­ives. How­ever, dis­pers­ing incurs a cost: every time an indi­vidu­al dis­perses, it uses up some of its energy reserves. Using this mod­el, we found that pop­u­la­tions evolve strategies in which indi­vidu­als with large energy reserves dis­perse, but indi­vidu­als with low energy reserves do not. We plan to test this the­or­et­ic­al pre­dic­tion in a real bio­lo­gic­al sys­tem – the com­mon back­swim­mer (Notonecta undu­lata), a semi-aquat­ic insect.

The fit­ness land­scape is a use­ful meta­phor for the study of the rela­tion­ship between gen­o­types or phen­o­types, and fit­ness. Pre­vi­ous stud­ies have shown that increas­ing gene expres­sion can mask the effects of dele­ter­i­ous muta­tions, which sug­gests that the expres­sion-fit­ness land­scape may impact on how organ­isms adapt to new envir­on­ments. This pro­ject provided an ini­tial assess­ment of the fit­ness land­scape of gene expres­sion, using empir­ic­al data of yeast clones with sev­er­al levels of Hsp90 expres­sion grow­ing in dif­fer­ent envir­on­ments, in a total of 50 exper­i­ment­al treat­ments. We observed that the expres­sion-fit­ness land­scape is more extens­ively affected by tem­per­at­ure than by salin­ity gradi­ents. The explor­at­ory data obtained through this pro­ject serve as the basis for a grant pro­pos­al to the Por­tuguese Sci­ence Found­a­tion, and an eval­u­ation of the obtained res­ults by means of a the­or­et­ic­al mod­el will be presen­ted at this year’s ESEB conference.

The ESEB’s God­frey Hewitt Mobil­ity Award allowed me to do two vis­its to the ancient DNA (aDNA) labor­at­ory of the Centre for Geo­Gen­et­ics in Copen­ha­gen. The aim was to invest­ig­ate the gen­om­ic dynam­ics of a lead­ing-edge niche col­on­isa­tion using the bot­tlen­ose dol­phin as a case-study spe­cies. I learned ancient DNA labor­at­ory tech­niques with Dr. Andrew Foote that is DNA extrac­tion from dol­phin sub­fossil samples from 5,600 to 9,000 YBP, lib­rary pre­par­a­tion and lib­rary qual­ity-checks. We build 42 lib­rar­ies on 22 samples using nor­mal extrac­tion and for some of them bleach treat­ment pre­vi­ous extrac­tion. We sequenced the lib­rar­ies on one lane of sequen­cing and then pro­cessed the data and estim­ated endo­gen­ous con­tent. We are now going to per­form whole gen­ome enrich­ment cap­ture on the three best samples. In addi­tion, our col­lab­or­at­ors Petra Korlevic and Dr. Mat­thi­as Mey­er from the Max Planck Insti­tute for Evol­u­tion­ary Anthro­po­logy in Leipzig provided us with a bot­tlen­ose dol­phin sub­fossil DNA lib­rary with 37% endo­gen­ous con­tent. We sequenced the whole gen­ome of this sample at a cov­er­age of 4x. Pre­lim­in­ary res­ults indic­ated that there may have been past admix­ture between dol­phin pop­u­la­tions that were thought to be on totally dis­tinct evol­u­tion­ary tra­ject­or­ies. The ancient samples will there­fore allow revis­it­ing the demo­graph­ic his­tory of the species.

My PhD pro­ject is about ‘the evol­u­tion of flor­al scent’. Flor­al scent is one import­ant plant sig­nal that serves mul­tiple func­tions such as pol­lin­at­or attrac­tion and herb­i­vore deterrence. How­ever, more quant­it­at­ive stud­ies and pre­dic­tion stud­ies are needed to under­stand the mech­an­ism of flor­al scent evol­u­tion. Prof. Derek Roff is well known for his con­tri­bu­tions in quant­it­at­ive genet­ics. We col­lab­or­ated on a short pro­ject to explore more inter­est­ing pat­terns of selec­tion and evol­u­tion based on my unique data­set of bi-dir­ec­tion­al arti­fi­cial selec­tion on flor­al scent (Zu et al. 2016). There were two main object­ives of the pro­ject: 1) to find out wheth­er or not some evol­u­tion­ary pro­cesses were under­go­ing in the low lines in spite of the unchanged pop­u­la­tion mean; 2) to test wheth­er or not a pos­it­ive lin­ear trait cor­rel­a­tion will remain the same through­out the selec­tion pro­ced­ures. We found that 1) though mean trait val­ues some­times did not change after selec­tion, the dis­tri­bu­tions of scent com­pound val­ues have changed after selec­tion, sug­gest­ing there were under­go­ing evol­u­tion­ary responses to selec­tion; 2) two flor­al scent com­pounds phenylacetal­de­hyde and α‑farnesene were pos­it­ive cor­rel­ated, and the cor­rel­a­tion of the two com­pounds remained unchanged after three-gen­er­a­tion selec­tion, albeit the changes of the abso­lute amount of the two com­pounds. Thanks to the oppor­tun­ity and fin­an­cial sup­port provided by ESEB God­frey Hewitt Mobil­ity Award, I have the chance to vis­it Derek Roff’s lab. This exper­i­ence inspired me in many aspects of sci­entif­ic research. The col­lab­or­a­tion res­ul­ted some inter­est­ing find­ings on the quant­it­at­ive genet­ic per­spect­ives of flor­al scent com­pounds and a manu­script is being pre­pared based on the findings.

Sex alloc­a­tion is a field I am very inter­ested in and one the remain­ing mys­tery is how and why trans­itions between gen­o­typ­ic and envir­on­ment­al sex determ­in­a­tion occur. The God­frey Hewitt mobil­ity award allowed me to vis­it Dr. Lisa Schwanz for 10 days at the Uni­ver­sity of New South Wales to col­lab­or­ate on a the­or­et­ic­al mod­el aim­ing to fill this gap. The idea of the mod­el is that if juven­ile sur­viv­al to matur­ity is influ­enced by tem­per­at­ure and if males and females mature at dif­fer­ent ages, then tem­per­at­ure-depend­ent sex determ­in­a­tion (a form of envir­on­ment­al sex determ­in­a­tion) should be selec­ted for. The aim of my vis­it was to build a data­set com­pil­ing data on sex-determ­in­ing mech­an­isms and sex-spe­cif­ic age at matur­ity of liz­ards, snakes, cro­codiles and tuatar­as to add to the turtle data already col­lec­ted by Dr. Schwanz and her col­leagues. We then used phylo­gen­et­ic gen­er­al­ised least square mod­els to test for a rela­tion­ship between sex-determ­in­a­tion mech­an­isms and dif­fer­ence in age at matur­ity in these groups, but unfor­tu­nately the res­ults did not cor­rob­or­ate the pre­dic­tions of the model.

The God­frey Hewitt Mobil­ity Award allowed me to carry out a cross-fos­ter­ing exper­i­ment in a nat­ur­al pop­u­la­tion of collared flycatch­ers on the Island Got­land, Sweden. The aim of this exper­i­ment was to invest­ig­ate effects of genet­ics and envir­on­ment on among-indi­vidu­al vari­ation in red blood cell (RBC) attrib­utes, par­tic­u­larly mito­chon­dri­al dens­ity. In con­trast to mam­mals, birds pos­sess func­tion­al mito­chon­dria in their RBCs, thus offer­ing unique oppor­tun­it­ies to obtain meas­ures of mito­chon­dri­al num­bers and func­tion using low invas­ive pro­ced­ures: blood sampling instead of sur­gery or cull­ing. Inform­a­tion was col­lec­ted on RBC para­met­ers in 263 nest­lings and 145 adults, and the pre­lim­in­ary res­ults indic­ate that (i) indi­vidu­als with lar­ger RBCs have few cir­cu­lat­ing cells; (ii) lar­ger RBCs are enclos­ing lar­ger num­ber of mito­chon­dria and lower levels of ATP; (iii) RBC size is mod­er­ately her­it­able (19%); and lar­ger nest­lings have smal­ler RBCs. This work was done in col­lab­or­a­tion with Dr. Pierre Bize, Uni­ver­sity of Aber­deen, and Dr. Blandine Doli­gez, Uni­ver­sity of Lyon 1.

The God­frey Hewitt Mobil­ity Award allowed me to vis­it Dr. Andy Gard­ner at the Uni­ver­sity of St Andrews to con­struct a math­em­at­ic­al mod­el to invest­ig­ate the func­tion of the “soldier”-caste of cer­tain poly­em­bryon­ic para­sit­oid wasps. Wheth­er the sol­diers are there to pro­tect their broth­ers and sis­ters, or that they actu­ally kill their broth­ers to make room for their sis­ters, has been a source of con­tro­versy for over a cen­tury. We found that the com­pet­ing hypo­theses make dif­fer­ent pre­dic­a­tions about pat­terns of gene expres­sion. These con­trast­ing pre­dic­tions point to a pos­sible res­ol­u­tion of the con­tro­versy of the sol­diers’ func­tion, and could also help research­ers dis­cov­er new genes for sol­dier­ing, by look­ing at the expres­sion pat­terns for can­did­ate genes, and see which ones are deac­tiv­ated accord­ing to their par­ent of ori­gin. The study, “Intra­ge­n­om­ic con­flict over sol­dier alloc­a­tion in poly­em­bryon­ic para­sit­oid wasps”, was accep­ted to be pub­lished in the April 2016 issue of The Amer­ic­an Nat­ur­al­ist.

Thanks to ESEB’s God­frey Hewitt Mobil­ity award, I was able to con­duct a field sur­vey in Spain dur­ing the spring of 2015, and a research vis­it to Prof. John Pannell’s lab at Uni­ver­sity of Lausanne, Switzer­land. I stud­ied the impact of Kal­ca­pi­on semiv­it­attum (Api­onid­ae), a mono­phag­ous foli­vore with stem-bor­ing lar­vae, on life-his­tory traits of Mer­cur­ial­is anuua (Euphor­bi­aceae), an annu­al herb with dif­fer­ent ploidy levels (from dip­loid, to hexaploid) and repro­duct­ive sys­tems (monoecy, andro­di­oecy, dioecy) across its range. In order to explore the poten­tial role of herb­i­vore spe­cial­ists in plant repro­duct­ive sys­tem evol­u­tion, I searched for dif­fer­ences in infest­a­tion intens­ity among the plant genders, in nat­ur­al and exper­i­ment­al con­di­tions. I also looked for evid­ence of insect spe­cial­iz­a­tion to dif­fer­ent ploidy levels, and its poten­tial role in con­tact zone shift and dip­loid range expan­sion. The samples were col­lec­ted across the mone­cious hexaploid / dioecious dip­loid con­tact zone, along the Medi­ter­ranean coast, from Bar­celona to Valen­cia. Plants were meas­ured and dis­sec­ted, and leaf samples were pre­served by fast dry­ing in silica gel. Grubs were coun­ted and pre­served in alco­hol, along with col­lec­ted adults. In Lausanne, loc­al insects were suc­cess­fully reared on both dip­loid and hexaploid plants. A phylo­geo­graph­ic study K. semivit­tatum across the range of M. annua is in preparation.

When assess­ing mate or com­pet­it­or con­di­tion, anim­als often rely on orna­ment­al sig­nals that are costly to pro­duce and/or main­tain, thus nat­ur­al selec­tion is expec­ted to favour the evol­u­tion of sexu­al orna­ments that hon­estly reflect indi­vidu­al qual­ity. Where­as orna­ments are known to reflect physiological/social qual­ity of the bear­er and be implic­ated in both male and female king pen­guin pair­ing decisions, we lack know­ledge on how physiolo­gic­al status dur­ing moult, the time these orna­ments are renewed, may determ­ine their showy nature. The God­frey Hewitt Mobil­ity Award allowed me to work under the super­vi­sion of Dr Pierre Bize from the Uni­ver­sity of Aber­deen. By exper­i­ment­ally increas­ing Cor­ticos­t­er­one bas­al level and stim­u­lat­ing the immune sys­tem dur­ing moult we high­light that some orna­ment­al fea­tures appear more intrins­ic­ally linked to genet­ic indi­vidu­al qual­ity where­as oth­ers are determ­ined by individual’s physiolo­gic­al status at the time of the moult.

Cooper­at­ive beha­viours provide bene­fits to the recip­i­ents but are costly to the act­or. Cooper­at­ive beha­viours can only be selec­ted if costs of cooper­a­tion are com­pensated by fit­ness bene­fits. These bene­fits can be either dir­ect or indir­ect. How­ever, the import­ance of sexu­al bene­fits has been over­looked in non-human spe­cies. In col­lab­or­a­tion with the Soci­able Weaver Research Pro­ject lead by Dr. Rita Cov­as (CIBIO-Por­tugal & FitzPatrick Insti­tute-South Africa) and Dr. Claire Doutre­lant (CNRS-France), I pro­posed to exam­ine the role of sexu­al selec­tion in the evol­u­tion of cooper­a­tion in this cooper­at­ively breed­ing pas­ser­ine. I wanted to invest­ig­ate wheth­er help­ers would increase their nest­lings pro­vi­sion­ing when play­backs of female songs are broad­cas­ted. With the God­frey Hewitt Mobil­ity Award, I bought the mater­i­als needed to con­duct field exper­i­ments in South Africa. Unfor­tu­nately, El Niño phe­nomen­on caused intense drought in Africa that impacted drastic­ally the weavers’ repro­duc­tion and pre­ven­ted me from con­duct­ing my exper­i­ment. Non­ethe­less, I ini­ti­ated a col­lab­or­a­tion with Dr. Fanny Rybak (Uni­ver­sity Paris­Sud, France), a spe­cial­ist in acous­tic com­mu­nic­a­tion, which allowed me to pre­pared play­backs and per­formed pilot exper­i­ments test­ing the feas­ib­il­ity of the exper­i­ment. I also recor­ded males and females songs to increase the num­ber of play­backs I will be able to use dur­ing the exper­i­ment next year. These songs are cur­rently ana­lysed acous­tic­ally and show inter­est­ing sex differences.

Selfish genet­ic ele­ments are diverse and ubi­quit­ous across the tree of life. Intra-gen­om­ic con­flict, driv­en by these ele­ments can cause rap­id, pop­u­la­tion spe­cif­ic co-evol­u­tion and spe­ci­ation genes have been asso­ci­ated with mei­ot­ic drive chro­mo­somes (selfish chro­mo­somes that bias their trans­mis­sion into the next gen­er­a­tion at the cost of their sis­ter chro­mo­some). How­ever, des­pite interest in mei­ot­ic drive caus­ing spe­ci­ation, few tests have examined wheth­er nat­ur­ally occur­ring drivers cre­ate incom­pat­ib­il­it­ies between pop­u­la­tions. Pre­vi­ously, I have found that XCMD from Tunisia is incom­pat­ible when crossed into Spain and UK pop­u­la­tions, cre­at­ing strong incom­pat­ib­il­it­ies res­ult­ing in male infer­til­ity. The God­frey Hewitt mobil­ity award allowed me to field sample Moroc­can pop­u­la­tions to expand my work in this sys­tem. I found the first defin­it­ive evid­ence that there are act­ive XCMD chro­mo­somes in Moroc­can pop­u­la­tions of Dro­so­phila sub­obscura. Res­ults from genet­ic ana­lys­is sug­gest there is a single ori­gin of mei­ot­ic drive in Dro­so­phila sub­obscura, which sub­sequently spread across North Africa, and very recently into south­ern Spain. We find no evid­ence for incom­pat­ib­il­it­ies between a driver from Tunisia and pop­u­la­tions of flies col­lec­ted from Morocco. There is how­ever, some evid­ence for sup­pres­sion of a Tunisi­an driver in Morocco, which will require fur­ther study.

The God­frey Hewitt Mobil­ity Award allowed me to work under the super­vi­sion of Dr. Moya-Laraño, at the Esta­ción Exper­i­ment­al de Zonas Ári­das- CSIC Almer­ía, Spain. Dur­ing the three short stays fun­ded by this award we developed an Indi­vidu­al Based Mod­el con­cern­ing the evol­u­tion of inter­ac­tions of two closely related spider mite spe­cies. Tetra­nychus urticae and T. evansi com­pete in host plants, mainly Solen­aceae, and it has been found that their com­pet­it­ive inter­ac­tions in tomato plants are influ­enced by the fact that the two spe­cies have dis­tinct capa­cit­ies of deal­ing with tomato plant defenses. T. evansi is able to down­reg­u­late these defenses, while T. urticae does not have this abil­ity and trig­gers the plant defenses upreg­u­la­tion. The aim of the mod­el is to study the evol­u­tion of strategies under coex­ist­ence. For the first time we imple­men­ted mul­ti­di­men­sion­al quant­it­at­ive genet­ics in a hap­lodip­loid sys­tem. The mod­el we developed is spa­cially expli­cit and includes 3 traits: dis­pers­al, induction/downregulation of defenses and assim­il­a­tion efficiency.

I was par­ti­cip­at­ing in a trans­plant of Salix herb­acea between alpine micro­hab­it­ats (snowbeds and ridges) in the Swiss Alps. I was able to travel there for the second year thanks to a God­frey Hewitt Mobil­ity Award. This work was done in col­lab­or­a­tion with oth­er PhD stu­dents and research­ers based in Dav­os and Kon­stanz and the exper­i­ment was fin­anced by a Swiss Sin­er­gia grant. Inter­est­ingly, we detec­ted plas­ti­city rather than adapt­ive dif­fer­en­ti­ation and this fits well with the high levels of gene flow through­out the entire pop­u­la­tion that we have pre­vi­ously repor­ted (see “Small-scale pat­terns in snow­melt tim­ing affect gene flow and the dis­tri­bu­tion of genet­ic diversity in the alpine dwarf shrub Salix herb­acea”). As we did not find any adapt­ive dif­fer­en­ti­ation we did not pur­sue fur­ther genet­ic stud­ies of this mater­i­al, rather we con­cen­trated on a more range wide sampling in order to estab­lish gen­o­type-phen­o­type asso­ci­ations and to identi­fy genet­ic regions under selection.

My PhD pro­ject focus on the evol­u­tion of genet­ic vari­ation in the con­text of bio­lo­gic­al inva­sion. To address this ques­tion I am study­ing the recent inva­sion of Europe and the USA by the Asi­an spot­ted­wing Dro­so­phila, Dro­so­phila suzukii. The first chapter of my PhD is focused on the evol­u­tion of the G‑matrix in the invas­ive pop­u­la­tions of D. suzukii com­pared to their nat­ive coun­ter­parts, using quant­it­at­ive genet­ics and con­trolled breed­ing design from live D. suzukii stocks. The second chapter is centered on the infer­ence of the inva­sion routes of D. suzukii using microsatel­lite mark­ers and Bayesian mod­els to test for dif­fer­ent inva­sion scen­ari­os and dis­crim­in­ate the most prob­able routes of intro­duc­tion of the spe­cies. Both these pro­jects need a large amount of samples from nat­ive and invaded areas of D. suzukii. Thanks to the God­frey Hewitt Mobil­ity Award, I was able to travel to Japan, one of D. suzukii’s nat­ive area, to col­lect pre­cious samples for my pro­ject. This mis­sion was also a great oppor­tun­ity to meet and col­lab­or­ate with Japan­ese research­ers who greatly helped my project.

My goal is to under­stand spa­ti­otem­por­al vari­ation in assort­at­ive mat­ing and its asso­ci­ation with spa­ti­otem­por­al vari­ation in dis­rupt­ive selec­tion – both of which will be related to envir­on­ment­al vari­ation and phen­o­typ­ic prop­er­ties of an incip­i­ent spe­cies. To do this, I worked with a group of research­ers who are study­ing spa­ti­otem­por­al vari­ation in selec­tion and beak shape in Darwin’s finches on the Galápa­gos Islands. The God­frey Hewitt Award allowed me to con­duct my field work in the Galápa­gos where I planned to col­lect data between pop­u­la­tions and com­pare it to pre­vi­ously col­lec­ted data to assess spa­ti­otem­por­al vari­ation in assort­at­ive mat­ing. How­ever the breed­ing sea­son star­ted later than expec­ted, so I focused my field work on under­stand­ing how humans are alter­ing selec­tion on beak shape in Darwin’s finches. The role of human influ­ence is anoth­er com­pon­ent of the long term research study­ing Darwin’s finches.

The God­frey Hewitt Mobil­ity Award allowed me to vis­it Dr. Marta Sánchez at the Esta­ción Bio­ló­gica de Doñana (CSIC) in Sevilla, Spain, as part of my PhD research on host-para­site coe­volu­tion in Artemia. Artemia (brine shrimp) are often heav­ily para­sit­ized, and are mainly infec­ted by cest­odes (which use them as an inter­me­di­ate host) and microspor­idia. The main pur­pose of my vis­it was to learn how to identi­fy the elev­en dif­fer­ent cest­ode spe­cies infect­ing Medi­ter­ranean brine shrimp, most of which are not eas­ily detec­ted or dif­fer­en­ti­ated. This skill will be very use­ful as I track the cest­ode pre­val­ence in my sample pop­u­la­tions. I also sampled loc­al Artemia and exper­i­ment­ally invest­ig­ated the impact of pol­lu­tion on infec­tion by microspor­idia. Finally, I was able to exchange ideas and start some col­lab­or­a­tions with the sci­ent­ists at the Esta­ción Bio­ló­gica de Doñana dur­ing my visit.

Dom­in­ance hier­arch­ies are wide­spread in anim­al soci­et­ies. Indi­vidu­als at the top of the hier­archy get pri­or­ity access to resources. From beha­vi­our­al obser­va­tions, it is known that hier­arch­ies are determ­ined by a series of ant­ag­on­ist­ic inter­ac­tions, where the win­ners attain the top of the hier­archy. How­ever, enga­ging in ant­ag­on­ist­ic inter­ac­tions implies some costs because indi­vidu­als can die while fight­ing. How should indi­vidu­als bal­ance their enrol­ment in ant­ag­on­ist­ic inter­ac­tions, giv­en that they face a trade-off between access-to-resources and sur­viv­al? Dur­ing my lab vis­it at Pro­fess­or Theraulaz’s group in Toulouse, I addressed this ques­tion using an evol­u­tion­ary mod­el where nat­ur­al selec­tion drives beha­vi­our­al strategies that determ­ine indi­vidu­als’ enrol­ment in ant­ag­on­ist­ic fights. I find that the trade-off, between sur­viv­al and access-to-resources, causes a branch­ing point. There­fore, two dif­fer­ent strategies evolve. One that engages in many fights and mono­pol­ize resources, but runs the risk of dying. And anoth­er one, that fights less often and enjoys high sur­viv­al, but is less likely mono­pol­ize resources. These two strategies are main­tained in the pop­u­la­tion by fre­quency-depend­ent selection.

My PhD research in ancient pop­u­la­tion genet­ics focuses on spe­cies-envir­on­ment inter­ac­tions and the influ­ence of envir­on­ment­al change on spe­cies extinc­tion. It aims to invest­ig­ate the influ­ence of cli­mate warm­ing on the extinc­tion of the Great Auk, a cold adap­ted sea bird that went extinct in the 19th cen­tury. The pro­ject aims to recon­struct the pop­u­la­tion dynam­ics of the Great Auk through time using com­plete mito­chon­dri­al gen­ome sequence data, and to cor­rel­ate pop­u­la­tion size and range changes with con­tem­por­an­eous envir­on­ment­al factors to identi­fy factors that may have been det­ri­ment­al or bene­fi­cial for Great Auk pop­u­la­tions. The God­frey Hewitt Mobil­ity Award sup­por­ted a two week trip to Uni­ver­sity of Cali­for­nia, Santa Cruz, Paleo­ge­n­om­ics lab, to work with­in Beth Shapiro’s group. The main aim of the trip was to learn state of the art tech­niques for ana­lys­ing pop­u­la­tion genet­ic data using BEAST soft­ware but it also allowed me to meet and work with lead­ers of the field.