The Evolutionary Ecology of Thermal Fertility Limit

Gen­er­ously fun­ded by the European Soci­ety for Evol­u­tion­ary Bio­logy (ESEB) Spe­cial Top­ics Net­work (STN) program.

Cli­mate change poses a major threat to biod­iversity and pre­dic­tions about future devel­op­ments are dom­in­at­ing the news. We want to con­trib­ute by focus­ing on the ques­tion of how altered tem­per­at­ure regimes affect repro­duc­tion. Cur­rent pre­dic­tions on changes in spe­cies abund­ance and dis­tri­bu­tion in response to heat stress often use spe­cies crit­ic­al thermal lim­its (CTL) and rarely con­sider fer­til­ity. This is a poten­tially ser­i­ous flaw, because there is sub­stan­tial evid­ence that fer­til­ity can be extremely vul­ner­able to high tem­per­at­ures, such as the evol­u­tion of extern­al testes in mam­mals and insects los­ing fer­til­ity at sub­leth­al tem­per­at­ures doc­u­ment. With­in this net­work, we want to bring togeth­er sci­ent­ists inter­ested in the­or­et­ic­al and empir­ic­al research on spe­cies thermal fer­til­ity lim­its and how this may affect spe­cies’ responses to cli­mate change. The over­arch­ing aim is to unite the dif­fer­ent research areas inter­ested in this field ran­ging from field eco­lo­gists, labor­at­ory exper­i­ment­al­ists, repro­duct­ive bio­lo­gists, tax­onom­ists, micro­cli­mat­ists and the­or­eti­cians to assemble and provide a data­base with rel­ev­ant thermal lim­it data cov­er­ing a broad tax­on base and repeated sampling effort for a selec­ted core set of spe­cies across Europe.

Our ini­tial focus is on inver­teb­rates; giv­en how easy many are to work with. Ulti­mately, though we are inter­ested in the impact of tem­per­at­ure on fer­til­ity across the bio­lo­gic­al world. Hence, we encour­age sci­ent­ists work­ing on repro­duc­tion in plants and ver­teb­rates to con­sider join­ing. Our over­all goal is to cre­ate a more focused and cohes­ive research field address­ing research on thermal fer­til­ity lim­its and advance the field to identi­fy and provide the data needed.

With­in the STN we want to bring togeth­er research­ers to

  • out­line and agree on pro­to­cols to col­lect data on fer­til­ity lim­its across a broad taxo­nom­ic base
  • address the rel­at­ive role of adapt­ive and plastic responses to thermal heterogeneity
  • mod­el how this know­ledge changes pre­dic­tions on spe­cies’ responses to cli­mate change

To achieve this we invite inter­ested European groups to jointly col­lect data across diverse taxa, to devel­op a broad and cohes­ive data­base. To facil­it­ate this we will organ­ise work­shops, sum­mer schools and ESEB con­fer­ence satel­lite meet­ings that are aimed to:

  1. provide a for­um for research­ers (from PhDs to pro­fess­ors) work­ing in areas of thermal evol­u­tion and eco­logy, loc­al adapt­a­tion, and evol­u­tion­ary mod­el­ling, to meet and interact
  2. determ­ine a shared best-prac­tice meth­od­o­logy to test both thermal fer­til­ity lim­its and crit­ic­al thermal lim­its, res­ult­ing in a set of stand­ard­ized pro­to­cols that can be widely employed both in the wild and the labor­at­ory to col­lect com­par­able data across diverse spe­cies and populations
  3. identi­fy a core set of widely dis­trib­uted spe­cies across Europe, and determ­ine stand­ard­ized sampling pro­ced­ures across dif­fer­ent regions, to test for loc­al adapt­a­tion and clin­al dif­fer­ences in response to thermal heterogeneity
  4. motiv­ate devel­op­ment of the­ory link­ing spa­tial and tem­por­al thermal het­ero­gen­eity with the evol­u­tion­ary and eco­lo­gic­al con­sequences of thermal fer­til­ity limits
  5. explore how micro­cli­mat­ic thermal envir­on­ments might mit­ig­ate the poten­tial to pre­dict spe­cies’ responses to cli­mate change
  6. identi­fy and address the­or­et­ic­al gaps
  7. design work­shop-linked sum­mer schools to train young research­ers in the rel­ev­ant empir­ic­al meth­od­o­lo­gies as well as to teach the­or­et­ic­al and spe­cies dis­tri­bu­tion mod­el­ling in sub­sequent meetings.
  8. cre­ate a shared data­base of thermal fer­til­ity limits

How to join?

If you are inter­ested in join­ing, please con­tact Claudia Fricke (, Aman­da Bret­man (, Tom Price ( or Rhonda Snook (

Act­ive con­sor­ti­um mem­ber­ship requires a com­mit­ment and con­tri­bu­tion to at least one of the following:

(1) lend your expert­ise to con­trib­ute towards for­mu­lat­ing the best prac­tise stand­ard pro­tocol or modelling

(2) use the stand­ard­ized pro­to­cols to col­lect and con­trib­ute data to the thermal fer­til­ity lim­it data base

(3) organ­ise a meeting/ workshop

Picture of Amanda Bretman
Aman­da Bretman
Picture of Claudia Fricke
Claudia Fricke
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Tom Price
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Rhonda Snook