Units and Levels of Selection

This week we will discuss Units and Levels of Selection.

Our reading for this week is: Sapienza, Burian (2010) Does Selection Operate Primarily on Genes.

You'll find a copy in this dropbox folder.

Summary:
Carmen Sapienza and Richard Burian explore whether natural selection operates primarily on genes. Sapienza defends genic selectionism, arguing that natural selection typically targets genes, using examples such as antibiotic resistance in bacteria and meiotic drive in mammals, where individual genes or genetic structures directly influence reproductive outcomes. He contends that even complex traits often derive from variation at a small number of loci, and that natural selection is unlikely to act effectively on traits involving more than 10–12 unlinked genes. Burian, in contrast, cautions against overgeneralizing the gene’s primacy. He emphasizes the complexity of genotype-phenotype relationships and argues that many traits result from interactions among multiple genes and environmental factors. Burian asserts that selection often acts at multiple biological levels—genes, individuals, populations—simultaneously. Both authors acknowledge that while genes play a crucial role, the unit of selection debate cannot be resolved without integrating molecular, developmental, and ecological perspectives.

For background you may prefer to just read some of the Stanford Encyclopedia article on the topic here: https://plato.stanford.edu/entries/selection-units/

If it's your first time, don't feel obligated to read anything in advance, but bring your iPad or tablet, if you have one. All are welcome, if philosophically inclined. Try to arrive early. We start the discussion at 12:15pm, exactly. Here's a little something about skepticism and something more on other philosophical topics. We are closer to Hawthorne than to Kuhn.

If the meeting is full, join the waitlist and check again on Sunday morning. You may find a spot has opened up. Also, see what meetings are coming up in the weeks ahead.