Insights from Three Years of Measuring Anolis sagrei Reproductive Success

Female Festive Anole (photo: Ambika Kamath)

Female Festive Anole (photo: Ambika Kamath)

Sexual dimorphism–differences between the sexes in what they look like–is rampant across animals. But how do these differences arise? Why and how might natural selection or sexual selection act differently on males and females? In a new paper from Duryea et al. (2016) published last month, we begin to see what answers to these questions look like in our very favourite organism, the festive anole, Anolis sagrei.

The data presented in this paper is unprecedented in anoles–by catching every lizard on Kidd Cay for four successive years, the authors assigned parentage to three generations of offspring, and thus assigned reproductive success to three generations of adults. Using these measures of reproductive success for males and females, they ask a straightforward question: is reproductive success correlated with body size, and do these relationships differ between males and females?

The results, however, are not straightforward: patterns of selection differ quite a bit across the three years of sampling, especially in females. But overall, we see directional selection on body size in males (bigger males father more offspring who survive to adulthood than smaller males), possibly explaining why male festive anoles are 30% larger than females.

We don’t yet understand the origins of sexual size dimorphism in anoles–why in particular, does the shape of selection on female body size vary so much? Do large males sire more offspring who survive to adulthood because they mate more often, or because their offspring are somehow better at surviving? Duryea et al. have propelled forward the state of our knowledge with a formidable dataset that raises exciting new questions.

5 thoughts on “Insights from Three Years of Measuring Anolis sagrei Reproductive Success

  1. Just curious! As used in this posting when did the Brown Anole Anolis sagrei’s common name become the Festive Anole?

    1. So “festive anole” was coined by Jonathan Losos in an only semi-serious attempt to make Anolis sagrei’s common name a bit more fun than “brown anole”, as outlined in this post here: http://www.anoleannals.org/2013/11/06/re-branding-the-brown-anole/
      I put it in here mostly for fun, but as I read the comments on the previous post, perhaps there is some room for confusion. But this, precisely, is why we have scientific names, and why there’s an advantage to scientific names remaining stable unless a change is absolutely necessary!

      1. Thank you for the interesting link. I missed that posting. Being well known in The Bahamas as the Brown Anole (Anolis sagrei) that is what I will continue to call it to avoid future confusion!

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