Tuesday, July 17, 2012

Did you know that the hyrax is closely related to the elephant?



Working at the zoo, there are a lot of conversations where I have to sort of skip over complicated points about biology, and condense things into soundbytes.  My ultimate goal is to keep simplifying something from being dumbing it down.  It's the hardest part about working at the zoo vs. the Discovery Center.  I try to keep information concrete, which is pretty easy given that we have all sorts of animal skulls and stuff to teach with.

The place where this comes up most is in conversations about classification and "relationships" between animals.  I think people in general think of these things as more concrete than they actually are.  I know I always did.  Linneas had no idea what DNA was, so a lot of the relationships that were determined to exist historically were based on things like outside appearance.  After you spend some time learning about single-celled organisms, you start to realize that the traditional means of defining a species are really not so relevant.  Asexually-reproducing organisms are pretty much classified by how much of their genetic code they share.  After a certain degree of difference in highly-conserved regions of their genetic material, they're considered different species.

This was especially interesting to think about when I worked in medical microbiology.  These microorganisms are critters that you can't see without a microscope, and are really only interesting to us insofar as as they affect our health.  I got to a point where it began to sound like semantics to me.  I mean, once penicillin kills an infectious agent, who cares what species or subspecies it is?  In my own medical care, I certainly don't much care (not enough to pay for the tests).  When it comes to epidemiology, however, the story is different.  Genetic signatures can help trace the sources of outbreaks.

This is exactly what people are talking about when they say "race is a construct."  Race, and species classification, are just systems we use to understand and categorize the world around us.  The natural world doesn't need us to tell it what we think of it.

I do this science education stuff in an area where people are often a little hostile to the idea of evolution.  I think a better understanding of this kind of thing would be really helpful, because popular conceptions of evolution are convoluted by the hierarchical pictures like the above.  I wonder how much resistance to evolution would go away once people had a better understanding of it.

(I don't mean to give the impression that I always felt like I understood this.  Most of the insight I'm trying to get across here were realizations I had in lecture halls in college, feeling like I should have always understood this stuff.  In case you're curious, the classes that were most instrumental to these realizations were anthropology 101, history of biology, biology for majors, and genetics.)

A rock hyrax
An African elephant