There are so many more things to talk about in BIOL 1404 then we possibly have time to discuss. Thus, every semester I have to decide what to mention and what to leave out of lectures. This year I decided not to discuss a couple of terms during lecture and after talking to a couple of students I see that it might have been helpful to talk about these terms.
When we talked about natural selection we concluded that natural selection should produce selfish traits (those that maximize the survival and reproduction of individuals). Thus, natural selection should maximize an organism's "individual fitness" (the number of genes that an individual passes on by reproducing itself).
Kin selection suggests that sometimes we can pass on genes by helping our close relative to reproduce more than they would have without out help. Genes that are passed on by helping your close relatives to reproduce are known as "inclusive fitness".
Thus, "total fitness" (the total number of genes passed on by an individual) is he sum of "individual fitness" and "inclusive fitness".
Total fitness = individual fitness + inclusive fitness.
When we reexamine the process of natural selection we see that natural selection maximizes total fitness. Thus, sometimes an organism can pass on more genes by increasing its inclusive fitness at the expense of its individual fitness.
Expected Learning Outcomes
By the end of this course a fully engaged student should be able to
- define and distinguish between individual fitness, inclusive fitness, and total fitness
- discuss the role of inclusive fitness in the selection of altruistic acts via kin selection.
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