Thursday, May 5, 2011

Between Two Hominins

It's well underway already, but I wanted to post the link to the live feed of Sanjay Gupta's interview of Don Johanson and Richard Leakey at the AMNH tonight.

http://www.amnh.org/live/

It's fascinating. They are tried and true explainers. Leakey's devlish grins are priceless. Johanson is a master at this.

If I wasn't traveling tomorrow, I'd post all about what bugged me. Instead, I'll just jot some concerns down now.

Particularly, and this is big, neither one of them corrected Sanjay Gupta when he asked if humans could experience "devolution" or "de-evolution." Johanson just spoke about differential reproduction, etc.. Getting, as expected, a lot of audience laughter. You can't ask him to be responsible for all evolution education, and especially not during one interview. However, you'd think that mistaken term ("devolution") would ring a loud nauseating bell in either of their minds.

Devolution or de-evolution is JUST evolution. To say it's something separate is to define evolution as progress or the attainment of (or striving for) perfection. When, instead, evolution is only change through time. And only what's necessary (or what's not so bad) is what normally works for an organism and allows it to keep evolving (rather than go extinct).

All this talk (by Johanson mostly) about Africa being perfectly poised (I believe that's a quote) for the origins of Homo sapiens... Well, of course! That's where we think it happened and it happened there. In Africa. Why's it got to be perfect and seemingly destined?

Look, as long as Africa was all right and not awful, then that's all that was required for Homo sapiens to first emerge there (as if "emergence" is something that even actually happens over deep time).

It's not like our species is baby Jesus and we need to create this perfect birth story where the manger was just so and the swaddling was all clean and Mary was just glowing and hardly perspiring and the on-looking animals were all well-behaved and Joseph loved Mary so much.

Evolution usually isn't about perfection. It's just about what works and what doesn't. And that's not just true for slime mold evolution but for human evolution as well.

18 comments:

Anne Buchanan said...

Right on, Holly!

Holly Dunsworth said...

I don't watch these things all poised to pounce. I genuinely enjoyed it and appreciate, respect, and admire both these paleoanthropologists a great deal. I just wanted to clear up some trouble spots. (And I miss Alan... wouldn't he have been a hoot up there?)

Holly Dunsworth said...

To ask anyone to learn evolution in one semester of intro to biology or intro to bioanth is ridiculous. We need better K-12 standards for Sanjay Gupta's sake. Common misconceptions like the existence of "devolution" and the assumption that evolution is only about progress aren't simply bad because they're wrong, they are dangerous concepts that can support racism and anti-environmentalism and worse.

Holly Dunsworth said...

An older post of mine relates nicely to this problem with devolution and progress: http://ecodevoevo.blogspot.com/2011/03/halfway-man.html

Anonymous said...

I think you may have pounced a little early and not given the context of the question. Gupta was asking about physiological advantages that may be lost. You are getting too caught up on the term. If we develop a decrease in pulmonary efficiency or cognitive capabilities, as Gupta reasonably explained, then it is a very fair question and nurtured the discussion. Unfortunately for you Holly, you still rely on your K-12 education, when the discussion has advanced and even develops at forums like this one. Boo on you Holly.

Ken Weiss said...

It has been argued that loss of function can occur more simply and be fixed more rapidly than gain of new function. The arguments for the loss-is-easy view are easy, but less so for the gain of function, and beyond this comment.

People speaking to the public media who are scientists should know better than to use catch phrases and the like, as it sounds as if was done here (and as is all too common, perhaps especially in human evolution and genetics).

Holly is right to say that a melodramatic or new-sounding term, as if a new discovery, like 'devolution' is not needed. So your 'boo' is not warranted, and your reference to K-12 is very unclear even in that context.

The idea that something is an 'advantage' and might be lost is, as Holly said, rather anti-evolutionary. If it wasn't advantageous, and suffered mutations and went away, then it is not, from an evolutionary point of view, a disadvantage (relative to what else was going at the time, at least).

That humans have lost functions of our ancestors is undeniable (claws, fangs, the efficacy of quadrupedal locomotion, and so on).

We might do well with wings these days, and even in the past, but there was no evolutionary 'call' for such a thing in our lineage.

So what humans might do without in the future, not at all a new subject but one discussed in anthropology for decades, is similar in nature.

Holly Dunsworth said...

Obviously we need to write a lengthy explanation for what's at issue here.

Frances Forrest said...

I am so glad you brought this up! It is a HUGE pet peeve of mine. De-evolution suggests that there is some definite direction to evolution and that we are going the wrong way. In reality, there is no right or wrong direction in evolution and there is no end goal. Natural selection may cause certain genes to become more common in a population if they are advantageous in that environment but of course no genes or traits are advantageous in every situation. Sorry for the long ramble....I know I am preaching to the quire but I couldn't help myself!

Holly Dunsworth said...

Thank you Frances. This is so helpful! You never have to excuse your contribution to the MT especially when you offer new ways to think through concepts (or to explain concepts) that we're discussing. And the support is much appreciated too :).

Holly Dunsworth said...

Dan Lieberman's got our back (down with devolution and this notion of progress): http://www.nytimes.com/roomfordebate/2011/05/12/do-we-want-to-be-supersize-humans/we-still-have-the-bodies-of-hunter-gatherers

TODD TRIMMER said...

I'd still argue evolution can be bidirectional. Let's say a particular environment is static. Large swaths of a species in that environment are hit with an external force diminishing their DNA - pollution, chemical mutagens, pathogens, etc. Over each successive generation, more and more individuals start to exhibit traits LESS suitable to that static environment. They become more susceptible to the heat, cannot run as fast from predators, etc. Enough of them still survive to perpetuate the next generation, but deterioration of their DNA continues. New traits that do arise confer no reproductive or survival advantage in that environment over individuals not possessing the trait. When the species does become extinct (at least in that particular environment), how will you explain their demise? They clearly transitioned from a state of more probable survival to a state of less probable survival despite everything else staying the same. Evolution might not have an ultimate end goal, but it does place higher value on some states over others, relative to one another. If evolution never had direction under any circumstances, then how would we even detect its presence?

Holly Dunsworth said...

"Evolution might not have an ultimate end goal, but it does place higher value on some states over others, relative to one another."

Not so. Evolution cannot value or place value. Only humans can do that.

Ken Weiss said...

I agree with holly, but maybe the issues are more subtle than in disagreement. Some traits or genomic variants reproduce more than others, by chance or because of whatever each instance experienced in its circumstances.

After the fact, one can say that 'evolution' (an anthropomorphism of a mechanical process) 'placed higher value' only if one is using a value-neutral sense of the word 'value'.

In practice, we may see what proliferated most (because it's here and we have ways to reconstruct what came before), but I think as you said, Holly, we then look at the result and our explanations are inextricably affected by what we think happened in terms of what we perceive and can think was 'better'. The differential proliferation could have been for other reasons, that we don't think of, and the idea of 'better' is our value-term.

Holly Dunsworth said...

I don't like my post's tone and wouldn't post it if the interview was occurring today, at least not like I wrote it. However, it does follow a major theme of many of my writings here on the MT ...one of my passionate dislike of our (i.e. teachers, writers, thinkers, scientists, all...) personification of evolution. And not so much because it's incorrect in a natural world but far moreso because of the connection that it has to using evolution to support racism, sexism, human exceptionalism, etc... basically to Evolution's P.R. problem.

Ken Weiss said...

Everything any of us do is subject to revision or reassessment, but anyone who knows you knows you're not a nasty person, and you have every right to your passions. In this case the justification repeatedly made in the name of Darwin or genetics, for doing horrible things to people, is worth objecting passionately to.

Holly Dunsworth said...

Yes. And less passionately, I completely disagree with your suggestion of the potential to use "value" if it was "value-neutral."

Holly Dunsworth said...

Wait a second... maybe that's not a suggestion! I think I misread the rhetoric.

Ken Weiss said...

Yes! I was being ironic. One never or rarely uses 'value' without implicitly or explicitly implying the common-use sense of the term, which you objected to, and I agree!