Tuesday, October 24, 2017

My so-called view of life

It's no secret I love evolution.

But I usually feel like such an outsider when it comes both to how it's done professionally and in pop culture. I think it's my tendency to see proximate rather than ultimate causes and it's the ultimate causes that seduce and bedazzle. I've learned that if you question ultimate evolutionary narratives, you're a party pooper. I'm a party pooper.

Here I am
Typing to myself
I've got the outsider's blues

Let's start with some recent fish science. These guppies of the same species, born big and born little, have been very nicely shown to grow at the same pace. The big ones are born later and into a competitive food environment. Researchers offer that it's due to selection for context-dependent control over gestation length/birth timing.  But why? What about a proximate view? Surely the mother's context and its impact on her biology and on her eggs and babies is important. There may be no need to imagine a fancy adaptation that switches birth timing so that babies are badass food competitors ... Like there is no need to imagine a fancy adaptation that switches birth timing so that human babies escape the birth canal in time.

And, also today, there's news of a conference paper on human inbreeding. Most everyone believes inbreeding is bad, especially evolutionary scientists, many of whom rely on it being bad to make sense of animal behavior through their own culturally-tinted, taboo-tainted goggles. It's also foundational to how many evolutionary scientists explain cooperation with non-kin and our taboos against inbreeding. The news report linked above describes an enormous study of parents, all over the world, who are cousins who produce children. There's a list of biological trends for the outcomes of inbreeding that are assumed to be less than ideal (e.g. these kids are 1 cm shorter than average and less than 1 kg lighter at birth) and it's explained by genetics, of combining genomes of close relatives. Included in these traits of interest is age at first sex (delayed in offspring of inbreeding), age at first birth (same), number of opposite-sex partners (fewer in the inbred), number of offspring (fewer begat by the inbred). Sooo, I trend with the inbred. Am I inbred? No. To me, these trends don't scream bad genes from naughty parents. These outcomes look like they'd be influenced pretty heavily by complex cultural conditions and socioeconomic status, which may be intimately linked with conditions that pair-up cousins in the first place. Did these factors enter into the analysis? We'll have to wait and see when the paper's published.

And another news item today has me kicking a can out here. What if, rather than it being due to a fancy adaptation to seasonal fluctuation in resources, shrews' skulls shrink over winter as they experience the pressure and temperature of hard, cold dirt?

For some reason today--and maybe it's because my life writ-large lacks much opportunity to hold these discussions with people in real life, and my life writ-small has me pulled hard away from learning and doing evolution, period--I'm feeling nostalgic. The guppies, the inbreeding, and the shrew skulls awoke some ghosts of my past...

What if perpetual evolution due to mutation* causes speciation, rather than natural selection?

There's no way that everything that differs between males and females is explained by sexual selection. So what if body size and strength differences are a bigger story than that?

In that vein, what if women are smart BECAUSE HUMANS ARE SMART, and not to outfox rapists?

What if man's big penis is due to man's big vagina and not so much due to survival of the biggest?

What if the same mutation in multiple individuals can be induced by a virus? That kind of head start would seem to make it much easier for a mutation to go to fixation whether due to drift or selection.

I'm more similar, genetically, than 50% to my mom, to you, and to every single person on this planet. So what are we actually supposed to learn from all these fancy evolutionary equations that insist I'm only 50% similar to my parents, and less and less similar to everyone else, including you, in the tree?

And, I realize this may sound silly and obvious, but animals don't know where babies come from. Given the words we use, reading about the evolution of animal behavior is so confusing, in this light.

To those who get it
To evolution's outsiders
Do you wanna form a band?

* (and, in the myriad species who have it, the coin-flip of extinction or inheritance for each part of the genome, known as recombination and segregation during the halving of the genome during sperm and egg production)