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Wednesday, January 04, 2006 

This view of life

Over my "vacation" (which unfortunately ended up being more work than play), I was at a dinner with two of my best friends from the past 15-odd years. For whatever reason, the topic turned to evolution--and we quickly realized that we had, erm, differing opinions on whether evolution actually occurred or not. Now, this was pretty depressing to me, as both of them are very intelligent women, and one happens to work in a scientific field. So, we retreated to a coffee shop for some animated conversation on science, religion, and politics. I don't know if I changed any minds or not, but that wasn't really my goal anyway--rather, just to talk about the evidence that supported evolution, and to discuss their own reservations and objections. Obviously there were only so many things we could cover, but it was an interesting chat (and I hope I wasn't too harsh. It's a topic that makes me a bit...excitable.)

Anyhoo, I wish I'd had this op-ed on me. Written by evolutionary biolgist Olivia Judson, it highlights just a few things that make evolution so amazing:
Organisms like the sea slug Elysia chlorotica. This animal not only looks like a leaf, but it also acts like one, making energy from the sun. Its secret? When it eats algae, it extracts the chloroplasts, the tiny entities that plants and algae use to manufacture energy from sunlight, and shunts them into special cells beneath its skin. The chloroplasts continue to function; the slug thus becomes able to live on a diet composed only of sunbeams.

Still more fabulous is the bacterium Brocadia anammoxidans. It blithely makes a substance that to most organisms is a lethal poison - namely, hydrazine. That's rocket fuel.

And then there's the wasp Cotesia congregata. She injects her eggs into the bodies of caterpillars. As she does so, she also injects a virus that disables the caterpillar's immune system and prevents it from attacking the eggs. When the eggs hatch, the larvae eat the caterpillar alive.

It's hard not to have an insatiable interest in organisms like these, to be enthralled by the strangeness, the complexity, the breathtaking variety of nature.
This is what I find so incredibly cool about biology. It's not quite like any other science--life makes it messier.

In Jurassic Park, Jeff Goldblum's character, skeptical of the measures that have been implemented to control the park's dinosaur inhabitants, notes that "life will find a way." And indeed, it does--in nature as well as in the movies. And for me, it's so interesting to learn about, as Judson describes it, the "breathtaking variety" of those ways. Hairworms making their grasshopper hosts take a dive. Tiny molecular changes that can result in drastic effects on an outcome, or even lead to a cultural phenomenon. Sure, sometimes it's gruesome; the dearly departed WinAce's collection of organisms that look designed has a plethora of fascinating--if somewhat nasty--organisms that are part of this variety. Life ain't always beautiful butterflies and flowers--it's also parasites, and bacteria, and a whole lot of "kill or be killed" situations. And while biology doesn't rely as much on equations and formulas as some of the other natural sciences, Judson notes:
It's that small facts add up to big pictures. For although Mother Nature's infinite variety seems incomprehensible at first, it is not. The forces of nature are not random; often, they are strongly predictable.

For example, if you were to discover a new species and you told me that the male is much bigger than the female, I would tell you what the mating system is likely to be: males fight each other for access to females. Or if you discover that the male's testicles make up a large part of his weight, I can tell you that the females in his species consort with several males at a time.

Suppose you find that a particular bacterium lives exclusively in the gullets of leeches and helps them digest blood. Then I can tell you how that bacterium's genome is likely to differ from those of its free-living cousins; among other changes, the genome will be smaller, and it will have lost sets of genes that are helpful for living free but useless for living inside another being.
And while we find much that is predictable, many interesting areas of research seek to discover why we see something that, on the surface, *doesn't* fit those patterns. Why would some populations, for example, have a higher rate of the gene that causes sickle cell anemia, an often-fatal condition in people who possess 2 mutant copies of the gene? It didn't seem to fit--until it was noted that the heterozygotes had greater resistance to malaria, and thus, there was a reason for this unexpected pattern.

It truly is humbling to think about all that we've discovered about the variety of life on this planet, and even more humbling to consider the vast amount we know little or nothing about. Alas, the experience of Judson is all too common:
When I was in school, I learned none of this. Biology was a subject that seemed as exciting as a clump of cotton wool. It was a dreary exercise in the memorization and regurgitation of apparently unconnected facts. Only later did I learn about evolution and how it transforms biology from that mass of cotton wool into a magnificent tapestry, a tapestry we can contemplate and begin to understand.
I think I've mentioned before that this my high school bio class was like this as well--lots of memorization, a good dose of anatomy, but no emphasis on evolution to tie it all together. In fact, I thought biology was boring before I took an intro course in college. I'm happy to admit I was totally wrong (something I don't do very often!).
Some people want to think of humans as the product of a special creation, separate from other living things. I am not among them; I am glad it is not so. I am proud to be part of the riot of nature, to know that the same forces that produced me also produced bees, giant ferns and microbes that live at the bottom of the sea.

For me, the knowledge that we evolved is a source of solace and hope. I find it a relief that plagues and cancers and wasp larvae that eat caterpillars alive are the result of the impartial - and comprehensible - forces of evolution rather than the caprices of a deity.

More than that, I find that in viewing ourselves as one species out of hundreds of millions, we become more remarkable, not less so. No other animal that I have heard of can live so peaceably in such close quarters with so many individuals that are unrelated. No other animal routinely bothers to help the sick and the dying, or tries to save those hurt in an earthquake or flood.
I very much agree with this. Elsewhere online, I was involved in a discussion about evolution with a number of people with a host of different beliefs, from atheist to a self-described fundamentalist Christian. One Christian (who actually happens to be in seminary) stated his view on the topic:
And for me, there is something deeply spiritual about that idea, of connectedness to all of the planet on some level. I don't find that evolution challenges my spirit; rather, learning more about how nature interconnects allows me to find more footing with my own life and walk with God.
This feeling of interconnection is something any of us can experience, regardless of our religious beliefs (or lack thereof). To steal a quote from Darwin, there is grandeur in this view of life--and I'm happy I evolved.



About me

  • I'm Tara C. Smith
  • From Iowa, United States
  • I'm a mom and a scientist, your basic stressed-out, wanna-have-it-all-and-do-it-all Gen Xer. Recently transplanted from Ohio to Iowa, I've spent most of my life in the midwest (with 4 years of college spent out east in "soda" territory). My main interest, and the subject of my research, is infectious disease: how does the microbe cause illness? What makes one strain nasty, and another "avirulent?" Are the latter really not causing any disease, or could some of those be possible for the development of chronic disease years down the road? Additionally, I've spent a lot of time discussing the value of teaching evolution, and educating others about "intelligent design" and other forms of creationism. My interest in history of science and medicine is also useful as a way to tie all of the above interests together. [Disclaimer: the views here are solely my own, and do not represent my employer, my spouse, that guy who's always sitting by the fountain when I come into work, or anyone else with whom I may be remotely affiliated.]
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