Tree of life

I was just going to give you a music video today because I didn't have any blogworthy material and expect to be a little busy with other things, but this was interesting; when I was looking at the RSS feed from Pharyngula, I found that P.Z. Myers had a piece up on this wonderful little--no, that's the wrong word, it's compact but ginormous--thing:



What you're looking at is a radial tree of life created by some University Of Texas researchers--David M. Hillis, Derrick Zwickl, and Robin Gutell--designed to show the biological relationships between about 3,000 species whose RNA has been sampled. The full size thing, a fifty-three inch by fifty-three inch PDF file, can be downloaded here, and it's worth visiting the page and downloading it to your machine just to get a good gander at it.

You should certainly take a look at this little arc, at the very, very least:



Hello, entire human race! Aren't we just adorable?

I don't know if it needs to be said but we'll mention it anyway: as many or all of you probably already know, the linear "tree of life" images most of us saw in our biology textbooks (and soon to be excised from Texas schoolbooks altogether, one imagines), are awful (Texas, ironically, may be doing students a small favor, on second thought). They create the illusion of progress in evolution, which is more than a little deceptive since evolution is not an inherently progressive process. Creatures whose innate traits give them advantages when passing on their genetic information to future generations pass those traits on, whether those traits involve greater complexity or greater simplicity of form. There are reasons for complexity, mind you, some selective (finding new environmental niches in which there's room for a new competing species frequently involves greater specialization), some accidental (once a physical feature has become fixed in a population, it tends to remain even as new features are added--hence, to provide a standard-issue f'r'instance, humans possess an organ that appears to serve little more purpose than to occasionally become infected and kill its owner unless surgically removed).

The linear tree spiking up from some distant past into an eternal present implies progress that isn't there, while an eternally-expanding ring whose edge holds a flickering array of appearing and vanishing species is, I think, probably as perfect as a visual can be (in two dimensions, at least--a sphere might be even better if you could maybe make it a hologram like the one used to plan the demise of the second Death Star in Return Of The Jedi). Somewhere at the distant center of the supernova is whatever microscopic, watery, self-contained chemistry kit that sat briefly on the threshold between adaptive self-replication and soup. And here on the surface--ourselves, crammed in with every single living creature we can see and the billions of living or lifelike critters we can't.

It is a thing, a hell of a thing, to marvel at, brothers and sisters.

Go in peace.


Comments

Popular Posts