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I'm a life-long New Englander, father of 4 challenging kids (I know: I'm supposed to say "wonderful", but while that'd be true, technically speaking, it'd also be misleading), and fortunate husband to my favorite wife of more than 20 years. I've got over 20 years experience breaking things as a test engineer, quality engineer, reliability engineer, and most recently (and most enjoyably) a Product Safety / EMC Compliance Engineer. In the photo, I'm on the left.

Wednesday, April 4, 2012

Big Brain Theory - A Conversation with Andrew about Evolution

Earlier this week I was referred to a fellow blogger who had just posted about the evolution of a larger brain size as (largely) a result of eating meat. It's a good story at Live Like Dirt. I think that I like this site, as it talks a lot about some subjects that I find fascinating, and the author, one Andrew Holmes, seems quite knowledgeable in his field.

I shared with Andrew my meager thoughts on humans eating meat and how that might or might not impact brain size. You may read, recall, or re-read them here, and here.

Andrew did me the kindness of reading these, and then promptly posted a tutorial on how the human brain evolved, and the importance...the necessity...of eating meat to make that happen. That post is back on the Live Like Dirt blog.

Now that we're all caught up, I do have some responses and thoughts to further the discussion.

In opening, Andrew took issue with my suggestion that humans were not  designed to eat meat. His assertion is that humans weren't designed at all, and that evolution is a completely random and stochastic process.

Without burning too much of anyone's time, I'm hoping that he and I can agree to disagree about this point. When I look at many aspects of the human body, I can't deny that it was clearly designed. If I were to accept this development as a random stochastic process (and this may seem counter intuitive), then I would have expected to see more than one species in the history of the world having evolved a larger brain.

Much like there have been multiple large-tooth cat species (as in saber tooth) in the archaeological record, and there have been a few different forms of elephant-like creatures (mastodons, mammoths, elephants...), I would expect to see that there would have been more than one creature that developed large brains (our sized brains).

In a random process, it is my experience that when you see one instance of an output, you will see it again. If you consider big brains to be a 1-in-a-billion statistical deviation (wild ass guess, right there), I think (with no data, mind you) that we should have seen this evolutionary big brain development at least a few times in the half billion years that the countless life forms have been blundering about.

Could this mean that big brain evolution isn't a result of a random, stochastic process? Could be. I don't know for a fact; all I'm doing is thinking and theorizing...asking questions in the dark. So, Andrew feels that it's not a design, perse, and I think it is. Who's right? I don't know. But his answer leaves me with questions, and mine doesn't. Am I right? I don't know.

I think that one reason why I do spend so much time on this point is that we both feel that it's important. Also, the way I read Andrew's response, this particular point reads as though it's absolute, incontrovertible fact. That may not be the intent, or the real case, but it sure reads that way to me. It reads to me like he dismisses the design theory as an impossibility, and that brings a quote to my mind:

If an elderly but distinguished scientist says that something is possible he is almost certainly right, but if he says that it is impossible he is very probably wrong.
~Arthur C. Clarke

Andrew then walks through what I will admit is a very likely scenario about things that contributed to growing our brains, but even while the assertion reads to me like "this is the way it happened", it's peppered with probabilistic language such as "could provide", and "more likely", and other similar language. The use of this language makes it impossible for me to disagree with the message (which is to say I agree: the large brain could provide an advantage, and would be more likely to pass on their traits...excellent writing, in my opinion).

David says, "The reason our ancestors didn't evolve larger brains prior to six million years ago is because meat eating was probably a much less frequent activity at that time."

This is a confusing sentence to my simple mind: it starts out by telling me that it's going to explain why we didn't evolve a large brain earlier, but then say "probably". It suggests that meat is the reason...probably.

Is it? I don't know.

David then says, "I think that's a pretty good explanation for how humans evolved to have such large brains." I think so too. Is it THE explanation? I don't know.

If you like news about the history of the world, though, it looks like Live Like Dirt is a good place to find snippets of it.

9 comments:

  1. I am a believer in evolution rather than design. That said there have been so many things and will be so many more that I change my mind about I am not prepared to be dogmatic about my beliefs. And as a vegetarian I do hope he is wrong about the link with brain size and meat eating.

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    1. Actually, I don't think that evolution and design theory are incompatible or mutually exclusive. I believe in both, really.

      However, I don't think that we came from single-celled organisms to where we are today strictly by a process of random chance. And where did those single-celled organisms come from, anyway? Why are there still single-celled organisms - why did not all of them change and morph, even a little, over the ages?

      I'm glad that people can change their minds too. That's what keeps me asking questions!

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  2. Whether large brains evolved from eating meat or by design I really don't know...but there is one thing I "probably" do know and that is; there are some pretty large sized brains out there with not much in them worth knowing and a bunch more that are applied to even more stuff not worth knowing and most of them reside in Canadian politicians. And you can take that to the bank "maybe" "likely" "in all probability".

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    1. LOL! And they're all sharks and snakes too! :)

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  3. The only thing I'm certain about is that nothing is certain. It's fun to take your wits for a walk, at least until someone brings along a firearm.

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    1. Damn! I always go for these walks with one or the other...NEVER both, and the "woods" are often filled with other folks who are armed.

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  4. Holy moly, look what I started. LOLOL! I just had a good read of both your posts. Fascinating debate. BTW: you suddenly changed Andrew's name to 'David' half way down. ;) Humans can't always be 100% certain, no, but I think the fact that something is 'highly probable' from the evidence and knowledge we have to date, (probably) doesn't discredit its truth. The fact is we are getting closer and closer to the answers all the time.

    Are you saying that only humans are "designed"? Because of our further developed brains? Or are you saying every single thing is designed?

    I recently watched a documentary on 'chaos theory' and the butterfly effect which showed how random patterns emerge. There are infinite reactions and possibilities, all going on over billions of year -- I don't think it's that easy to replicate any given outcome as there are no set formulas. Hence, we as humans are unique (and so is everything else). For now...

    What I've been contemplating lately, is this: through evolution, could humans have evolved souls? Could spirituality itself have evolved into being?

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    1. I wonder why I suddenly changed Andrew's name...frickin' weird! You're not the first to point it out, but it's still weird.

      This whole field of human development seems to be a popular subject; I hope you don't mind if I speak to your questions in a post instead of a reply here...there's too much to talk about.

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  5. I don't buy the "random" thing at all... I think we evolve to what we need to be, not to something random.

    Perhaps eating meat facilitated the growth, but maybe the growth was just because we were thinking more than doing. I'm sure there HAD to be a lot more thinking on our parts, since we were never all that formidable an opponent, relatively speaking. And our young take, what, 15 years before coming physically into their own? Defending the family and hunting would have had to take a lot of strategy. I think THAT is WHY the brain grew. The how may have involved the eating of a wide variety of nutrients.

    But looking at evolution, I think there's likely nothing random about it.

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