In the later half of this summer I attended two conferences.
Held in August, ESEB 2025 was the biennial conference of the European Society of Evolutionary Biology. This year it was hosted in Barcelona, Spain, and had nearly 2000 delegates and, as always, a wide array of sessions with themes covering all manner of themes in evolutionary biology. Ranging from methods of phylogenomic analysis at deep time-scales, to the evolution of sex-chromsomes, and the management of the evolution of resistance to bio-control agents.
I was selected to give a talk in a session on “Socially Transferred Materials”. To me this sounded like a very broad topic and I was curious to know how much in common we would all have. To my surprise, there are many parallels, or at least potential parallels, across things like manipulative seminal fluids, vertically transmitted symbiotic fungi or bacteria, and the other things speakers presented on. Jen Perry gave a lovely talk trying to synthesise some of these commonalities through the lense of theory “signals and receivers”. On the most basic level, for example, the transmitters and the receivers are likely to co-evolve, either in order to improve the efficiency of the signal, or in order to avoid or pay less attention to costly signals. And the signals (or socially transferred components) are likely to become adapted or transmitted in a way that is adapted to the local environment. In sum, I thought the session was very interesting, and I look forward to keeping an eye on what the other speakers end up working on in the future.
At the same time as ESEB 2025, the annual Festa Major de Gracia was being held. The festival takes place in Gracia, an old part of Barcelona, where the residents of each quarter or street picks a theme, and decorates their street with all manner of homemade decorations fitting that theme. Apparently preparations start as early as May. One street, Carrer Perill, had chosen “Biodiversity and Evolution” as their theme, the coincidence with ESEB 2025 was too good to ignore, and local evolutionary biologists together with a [local outreach consulting outfit](https://lacienciaalteumon.cat/about-us-2/) organised for an all day outreach event at the festival. One of the events of the outreach day was a series of mini-talks, one of which I was asked to give. I jumped at the opportunity as I thought it sounded so much fun. Although in many ways it feels like the stakes are higher when speaking to the public or non-specialists, than to my peers. For one, one needs to make the topics accessible, not assuming too much knowledge, for another, one needs to make it engaging. In that respect, I am lucky with my work focussing on sex and reproduction, the topics are naturally quite interesting to many people. However, because we are humans, I often find that we have many biases in that area. My goal with my talk was to present several exceptions to the common rules that we take for granted. In particular, I wanted to talk about how:
i) sexual reproduction is not the only way to reproduce
ii) that even with sexual reproduction it is not necessary for there to be two sexes (i.e. differently sized [sex cells or gametes](https://en.wikipedia.org/wiki/Gamete))
iii) even with two sexes, there do not have to be separately sexed individuals (i.e. hermaphroditism is actually quite common)
and finally,
iv) that even with sexual reproduction, two sexes, and separately sexed individuals, reproduction is not necessarily cooperative and harmonious, with males and females often having different conflicting “preferences”.
I had a great time giving my talk and I thought there was a great turn out.
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| My giving a short public talk at Festa Major de Gracia. Photo credit to Jeremias Brand |
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| Some other impressions from the festival. top) a street decorating entirely as a beehive, creating a great effect with sun filtering through the honeycombs. bottom) an enormous papier maché model of a Drosophila melanogaster fly! |
Later in September, I attended “Biology of Sperm” (BoS), also held every two years, which is a conference dedicated to the study of sperm, eggs, genitalia, reproductive fluids, and typically in an explicitly evolutionary context. In other words, these are my peopl. I had a great time giving a talk and wonderful and productive discussions about it throughout the whole week. We had a lovely trip to the local gelateria where I tried a lemon and basil gelato, divine!