Jordan S. Martin

Enjoyed collaborating with @lbliard.bsky.social et al on new paper using Wytham long term great tit data, particularly deploying @jsmartin.bsky.social's powerful Covariance Reaction Norm approach to investigate how stable trade-offs are across environmental gradients
academic.oup.com/jeb/advance-...

Figure showing how the correlation between mass and recruitment in Wytham Great Tits depends on environmental conditions - in particular note switch from almost none to very strong with increasing population density

New research just out in J Evol Biol: led by @lbliard.bsky.social with @jsmartin.bsky.social @dzchilds.bsky.social @paniw.bsky.social & Arpat Ozgul using the very cool Covariance Reaction Norm approach to test environmental dependence of trade-offs in great tits
academic.oup.com/jeb/advance-...

Ecological harshness has a weak influence on reproductive trade-offs in a great tit population Abstract. Lack’s seminal work on bird clutch sizes has spurred expansive research on reproductive trade-offs, especially focusing on offspring quantity–qua

New paper out in @jevbio.bsky.social
Using 58 years of data, we look at the effect of environmental variation on reproductive trade-offs in great tits.

With @jsmartin.bsky.social, @dzchilds.bsky.social, Ella Cole, @sheldonbirds.bsky.social, @paniw.bsky.social & Arpat Ozgul

doi.org/10.1093/jeb/...

The “I” in egalitarianism: Hadza hunter-gatherers averse to inequality primarily when personally unfavorable Abstract. Many economists contend that humans have strong, universal, other-regarding equality preferences with deep evolutionary roots. Indeed, many hunte

📢 New Paper 🚨

Hadza food-sharing is egalitarian, yet offers in giving games have never matched the equitable redistribution seen in real life.

In this study, we allowed people to give *or* take. Lifelike equitable distributions only appeared when people took from peers in surplus.

bit.ly/4kvLOwA

I hope to see some of you in Bielefeld for this upcoming workshop on measuring and modeling plasticity. ECRs in and around Germany with a penchant for statistics should consider applying while spots remain available!

Thanks for your kind words and endorsement, Tanay! 😃

A pdf of the advert can also be found on my website: socioecoevo.weebly.com/opportunitie...

I am looking for a PhD student to join my new Socio-Eco-Evo group, hosted in Katie Peichel's Evolutionary Ecology Division @ University of Bern. We're offering a fully funded 4-year position, studying social plasticity and behavioral adaptation among stickleback in Greenland. Please share around!

Social plasticity and individuality shape variation in contest behaviour Abstract. Physical contests are critical in most animals in determining access to limited resources such as territories, food and sexual partners. Individu

New paper out in @royalsocietypublishing.org Biology Letters. We show that variability in contest behaviour can emerge from plastic responses to modest size differences between focal males and their rivals.

#Drosophila
#Diptera

royalsocietypublishing.org/rsbl/article...

Estimating (Non)Linear Selection on Reaction Norms: A General Framework for Labile Traits It remains difficult to empirically estimate nonlinear selection on individual reaction norms, inhibiting robust tests of adaptive theory and accurate predictions of phenotypic evolution for labile t...

New paper out now in Ecology & Evolution:

"Estimating (non)linear selection on reaction norms:
A general framework for labile traits"

Work done in collaboration with Yimen Araya-Ajoy, Niels Dingemanse, @ali--wilson.bsky.social, and David Westneat.

onlinelibrary.wiley.com/doi/10.1002/...

Quantitative Genetics in Natural Populations Phenotypes evolve under natural selection if, and only if, they are genetically variable. While evolutionary ecologists have long studied natural sele…

Myself and Alastair Wilson wrote an updated version of our 2016 primer to quantitative genetics in the wild: www.sciencedirect.com/science/arti.... Happy to share a copy if interested. It is also on research gate

Unfortunately this paper isn't open access, but there is a copy available on my RG: www.researchgate.net/profile/Jord...

Measuring selection on reaction norms: Lack’s principle and plasticity in clutch size We applied a novel multivariate analysis to measure linear and nonlinear selection on components of a complex reaction norm that was expected to be shaped

New paper out now in Evolution, co-led with Dave Westneat!

Using long-term data on house sparrows, we find that quantity-quality tradeoffs near a local fitness ridge favor more or less canalized clutch size distributions in response to environmental variability.

academic.oup.com/evolut/advan...

With #eseb2025 coming to a close, it is time to start making plans for 2026. Interested in the interface of evolution 🧬 and ecology 🌳? Come to our #ExE conference hosted by @uniexecec.bsky.social in beautiful #Cornwall. Leave your email address at tinyurl.com/EvolxEcol to join our mailing list!

Cross-species implementation of an innate courtship behavior by manipulation of the sex-determinant gene In accepting a courting male, Drosophila subobscura females require nuptial gift giving in which a male gives regurgitated crop contents to her mouth to mouth. No similar behavior is found in D. melan...

A landmark paper for the evolutionary biology of behavior. Fascinating work on how manipulating cell type-specific gene expression can rewire the brain to produce a key mating behavior observed in a sister species that diverged ~35 mya.

www.science.org/doi/10.1126/...

Detecting context dependence in the expression of life history trade‐offs This proof-of-concept paper highlights that the context dependence of trade-offs can be successfully detected, hence potentially improving our understanding of life-history theory. Photo credit: Arpa...

For those interested in learning more about phenotypic versions of the CRN, especially for life history traits, check out some awesome recent work and applications in collaboration with @lbliard.bsky.social

besjournals.onlinelibrary.wiley.com/doi/full/10....

ecoevorxiv.org/repository/v...

Ultimately, I hope the method will aid in better understanding how quantitative G x E is shaping multivariate trait evolution in response to dynamic social and ecological change (socio-eco-evo) on contemporary timescales.

I also demonstrate the utility of the CRN using an exceptional long-term dataset on meerkat behavior from work by @tomhouslay.bsky.social et al. (big thanks to Tom!) The CRN shows how specialization among cooperative tasks changes plastically in response to sex, age, dominance, and group size.

I use simulations to show that the CRN is not only a valid model for inferring complex environmental effects, but also that it can outperform standard methods at modest sample size in more idealized scenarios with a single environmental effect (climate warming).

There are great methods for estimating environmental effects on trait (co)variances, but their utility is limited for investigations of complex environmental effects in the field, esp. when repeated measurements and/or experimental breeding designs are unfeasible. The CRN answers this challenge.

While G and P can be highly stable under certain conditions, there are many cases where trait (co)variances are expected to rapidly respond to continuous environmental change across space and time. Explaining the dynamics of trait development and evolution requires understanding these relationships.

Covariance reaction norms: A flexible method for estimating complex environmental effects on trait (co)variances Estimating quantitative genetic and phenotypic (co)variances is crucial for investigating evolutionary ecological phenomena such as developmental integration, life history trade-offs and niche spe...

My first solo author paper is now available in early view at Methods in Ecology and Evolution! I develop a covariance reaction norm (CRN) model for estimating continuous, multivariate, and nonlinear environmental effects on G and P matrices.

besjournals.onlinelibrary.wiley.com/doi/10.1111/...

Frequency dependence favours social plasticity and facilitates socio‐eco‐evolutionary feedback in fluctuating environments Read the free Plain Language Summary for this article on the Journal blog.

Hot on the tail of our Tsimane IGE study comes the theory paper that motivated it! What are the ecological causes and evolutionary consequences of social plasticity in dynamic environments? See our new Functional Ecology paper to find out more

besjournals.onlinelibrary.wiley.com/doi/10.1111/...

Big thanks to my excellent collaborators and coauthors on the project @ali--wilson.bsky.social, @dingemanselab.bsky.social, David Westneat, and Yimen Araya-Ajoy

Frequency dependence favours social plasticity and facilitates socio‐eco‐evolutionary feedback in fluctuating environments Read the free Plain Language Summary for this article on the Journal blog.

Hot on the tail of our Tsimane IGE study comes the theory paper that motivated it! What are the ecological causes and evolutionary consequences of social plasticity in dynamic environments? See our new Functional Ecology paper to find out more

besjournals.onlinelibrary.wiley.com/doi/10.1111/...

Indirect genetic effects among neighbors promote cooperation and accelerate adaptation in a small-scale human society Social effects on fertility promote population growth and the evolution of flexible cooperation in a small-scale human society.

I'm very excited to share the central paper from my PhD out now in Science Advances. We investigated how social effects among neighbors shape the evolution of reproductive cooperation and the pace of adaptive population growth among the Indigenous Tsimane of Bolivia.
www.science.org/doi/10.1126/...

Thanks, Tanay! 😃

Deep thanks and appreciation are owed to my coauthors, particularly those on Bsky @babeheim.bsky.social and @mgurven.bsky.social, as well as my PhD advisor @jaeggiadrian.bsky.social for their excellent collaboration and support.

These findings provide critical support for the social drive hypothesis, suggesting that IGEs can precipitate socio-eco-evolutionary feedback that drives rapid population growth and social evolution in human societies. Please see the paper for further details and discussion!

We also show that the local consequences of IGEs fluctuate across neighborhoods and communities in response to socioecological factors. This suggests that plasticity in reproductive cooperation is also being maintained by spatiotemporal variation in neighbors' effects on one another's fertility.