the rules of fitness

I’ve been thinking about natural selection a lot, lately (and not just because I picked up Natalie Angier’s The Canon the other day). Turns out Bruce Cohen explains Darwin’s concept of “fitness” pretty well:

Survival or mortality selection – Organisms that survive at least to the end of their reproductive phase are fitter than those who don’t, because they’re likely to have more offspring.

Mating success or sexual selection – Many species have some form of mate selection process which makes some organisms more likely to mate or likely to mate more often and thus produce more offspring.

Family size or fecundity selection – The more mature offspring (that is, those that live to reproduce themselves) produced by an organism, the fitter it is. This takes into account the two major reproduction strategies:

-produce as many offspring as possible, putting as little resource into each as possible (squids, for instance, do this),

-produce fewer offspring, putting significant resources into each, to increase each one’s chances of making it to reproductive age (humans do this).

I brought these concepts up with my students the other day after watching Radiant City. Among other things, the film argues that the housing developments now sprawling across North America will have an incredibly short life cycle, and that if they don’t prove their own sort of reproductive fitness (ie the ability to sustain a population past a second generation by providing ample resources for growth, like jobs), they will die out and become part of conspicuous consumption’s cookie cutter fossil record. I wish I had had this list handy, at the time.

Also, I highly recommend The Canon: A Whirligig Tour of the Beautiful Basics of Science. I know too little about the sciences in general, and recognizing this I picked up the book with a birthday gift card. I’m very happy I did. I just wish I could go back to my undergraduate biology teacher and apologize to her for not being a better student during that hellish winter when I was more concerned with penetrating Immanuel Kant’s murky depths than peering down a microscope. Truly I am sorry. I like this stuff a lot better now, I promise.

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