One of the (many) things that drive me bats

| 67 Comments

From Nova’s Becoming Human, Part 1 at -9:00 (Nova uses a countdown timer). Discussing the hypothesis that short-term (hundreds to thousands of years) extreme climate variability drove human evolution, and particularly increases in brain size, in the ramp-up from 400 cc or so to Homo habilis’s 600 or 700 cc, and maybe on to larger brained successors, the film says:


Narrator: “This observation led [Rick Potts] to an amazing new idea: Rapid [climate] change as a catalyst for our evolution.”
Rick Potts: “And I began to think that well maybe it’s not the particular environment of a savanna that was important, but the tendency of the environment to change.”

[Here it is]

Narrator: “Could it be that the need to survive violent swings of climate made our ancestors more adaptable?”

Right. And it was the need of giraffes to reach higher branches with yummier leaves that made them grow longer f***ing necks. Gaaaaah!!! Lamarck is dead! And so is Bergson.

That locution, that phraseology, that notion that a “need” somehow drives evolution, drives me bats. “Needs” don’t make populations evolve anything. Now, properties of an environment may select for traits in a population if appropriate variants occur, and as a result of that selective process the population may be more adapted to that selective environment. And it’s not necessarily implausible that an environment that varies irregularly on an appropriate time grain (bunches of generations) could select for some sort of generalized adaptability on the part of a population provided there’s some genetic basis for that adaptability that gives individuals a reproductive advantage, but a “need” doesn’t “make” the trait evolve. If that were the case we’d have wings and gills.

67 Comments

(Beaver, thinking hard) “Chainsaw! Chainsaw! CHAINSAW!”

AT least they didn’t say that humans evolved bigger brains “in order to ensure the survival of the species”.

I can see why it drives you bats, but I can also see why the comment has to be as brief as possible. What would you think of “Perhaps extremely variable climates select for greater adaptability”?

Lamarck is dead!!! Long live epigenetics!!!

My two main sources for developmental biology are Rudyard Kipling and Frank Capra. This sounds like a perfectly valid just-so-story on how Clarence got his wings.

So you’re arguing that humans didn’t need to survive - that they could have gone on living and evolving without surviving? Interesting hypothesis. I await your evidence.

Or are you saying that the word “need” has only one interpretation?

Or are you arguing, as Dave Luckett points out, that evolutionists should ramble on in dense detail and leave it up to the sound-bite engineers to condense what they said into something truly dumb instead of using shorthand to get their point across?

I suppose they could speculate that “climatic variation may have rewarded those with larger brains.” But I also agree that going into pedantic detail about how the need for larger brains doesn’t cause larger brains starts getting too involved. Maybe some speculative background about how species may have gone extinct because traits needed to survive didn’t happen to appear at the right time? And that most species today are descendents of “lucky” lineages, whose ancestors blundered into something appropriate for the times - and which was quickly adopted for that reason.

Dave Luckett said:

I can see why it drives you bats, but I can also see why the comment has to be as brief as possible. What would you think of “Perhaps extremely variable climates select for greater adaptability”?

“Could it be that the ability to survive violent swings of climate made our ancestors more successful?” is just as brief.

What I would object most to is the narrator calling it a new idea. I took physical anthro over 30 years ago and the climate change associated with brain size increase wasn’t news then. It was common knowledge that the savannas were increasing in size and there was a lot of volcanic activity from time to time. The Laetoli footprints are in volcanic ash. It wasn’t always a nice place to live. What place is?

Why wasn’t the climate changing for chimps? It will likely be a complex mix of factors where we aren’t going to pin it on one main culprit. Founder effects in genetics, upright stance, tool use, other environmental factors. I can posit some mutation or combination of mutations that would result in some synergy of upright stance and tool use that led our ancestor down (or up) a selective path to larger brain size. Our ancestors were bipedal for millions of years before the brain size started increasing dramatically.

We probably have to look into the motor differences between chimps and humans. You might call chimps clumsy when it comes to manipulating tools. When did this change in our ancestors? Chimps have great hand eye coordination when it comes to brachiating through trees, but the fine manipulation of their fingers and forearms isn’t there. Once that changed I could see a rapid increase in the need for more brain power. With bipedal gait the hands are free and such mutations are more likely to be selected for. It looks like it took a while for the development of such fine motor skills.

Ian wrote:

“So you’re arguing that humans didn’t need to survive…”

Exactly. You got it. There was no preordained plan. There was no guiding force. There was no one else to even care if humans survived or not. They just happened to adapt quickly enough, that’s all. It could have been otherwise. Humans could have gone the way of the dinosaurs. It is only in reptospect that humans had to survive.

One of my favorite cartoons is a picture of a dinosaur reading a book about trilobites. The point is that the fossil record shows that over 90% of al species that have ever lived have gone extinct and that the average lifespan of individual species is only about a million years. It also shows that those who do not learn from the lessons of history are idiots.

DS said: They [Humans] just happened to adapt quickly enough, that’s all. It could have been otherwise.

I’m sure it was ‘otherwise’ for a lot of them. Some hominids happened to adapt quickly enough…the rest died.

Though slightly OT I’m not entirely convinced by the environment argument itself. Wouldn’t it require that the environmental variation occurred within human lifepan timescales but continued to vary for hundreds or thousands of years? Extreme variation on both time scales simultaneously seems a bit of a stretch.

DS said: They [Humans] just happened to adapt quickly enough, that’s all. It could have been otherwise.

It was otherwise for the half-dozen or so humanlike species that didn’t make it.

Variation on both time scales is known to have happened.

There is evidence that about 50 individual Ice Ages occurred over the last 2.5 million years, taking up to about 100k years to build, and less than 10k years to melt.

In addition, some catastrophic events also are known to have occurred, the worst of which is the eruption of the volcano Toba in Indonesia about 70k years ago. That eruption is one of the most violent eruptions ever known, with at least one estimate of 2800 km3 of ash. It has been suggested as the origin of the human genetic bottleneck of around that time, and certainly would have had profound global climatic effects. Those effects would have been experienced globally within months, and might have lasted for a few decades.

eric said:

DS said: They [Humans] just happened to adapt quickly enough, that’s all. It could have been otherwise.

I’m sure it was ‘otherwise’ for a lot of them. Some hominids happened to adapt quickly enough…the rest died.

Though slightly OT I’m not entirely convinced by the environment argument itself. Wouldn’t it require that the environmental variation occurred within human lifepan timescales but continued to vary for hundreds or thousands of years? Extreme variation on both time scales simultaneously seems a bit of a stretch.

Ron Okimoto said:

What I would object most to is the narrator calling it a new idea. I took physical anthro over 30 years ago and the climate change associated with brain size increase wasn’t news then.

Yeah, William Calvin, for one, has argued that for decades.

IanW wrote

So you’re arguing that humans didn’t need to survive - that they could have gone on living and evolving without surviving? Interesting hypothesis. I await your evidence.

I’m having a tough time figuring out how that came out of what I wrote. Dave Luckett has the right idea:

“Perhaps extremely variable climates select for greater adaptability”?

Yeah, that wouldn’t have screeched like fingernails on a blackboard.

I’m with you on this Richard; it’s one of my pet peeves too. The way the narrator’s question is phrased begs the question in my mind, “Umm…didn’t all species, those that lived and those that died off during that time span, have a [i]need[/i] to survive violent swings of climate? If so, why isn’t such being used as a explanation for ALL traits across all organisms?” Just seems like the writer didn’t quite understand what he or she was implying with the question.

I recognize the danger of talking teleologically, but isn’t it just a shorthand way of expressing something? The discussion reminds me of the time a pedantic philosopher caught me saying that a pendulum obeys a certain equation. Well, of course it does no such thing; that is a shorthand way of saying that the equation accurately describes the motion of the pendulum. Using teleological language in biology is a more serious error, but it is not all that serious.

Matt Young said:

I recognize the danger of talking teleologically, but isn’t it just a shorthand way of expressing something? The discussion reminds me of the time a pedantic philosopher caught me saying that a pendulum obeys a certain equation. Well, of course it does no such thing; that is a shorthand way of saying that the equation accurately describes the motion of the pendulum. Using teleological language in biology is a more serious error, but it is not all that serious.

Matt, I do think it’s a serious error in a show aimed at the general public to segue from a paleontologist offering a tentative adaptationist hypothesis (which isn’t all that new, as noted above) to a teleological statement like that in the quotation. It reinforces a widespread misconception about evolution when with a little investment of thought (see Dave Luckett’s suggestion) it could have been avoided.

Some good points are being raised here; you should share them with the NOVA producers. They are squarely on the side of science.

“That locution, that phraseology, that notion that a “need” somehow drives evolution, drives me bats. “Needs” don’t make populations evolve anything. “

It’s interesting that it makes knowledgeable evolutionists like you peeved, and it makes creationists snicker. Perhaps realizing that the creationists get this one thing right over some of our fellow evolutionists, and they relish in rubbing our noses in it, is a key factor that drives you bats.

Meanwhile, I need some more money, so I’m going to evolve a stuffed wallet.

RBH said:

Matt Young said:

I recognize the danger of talking teleologically, but isn’t it just a shorthand way of expressing something? The discussion reminds me of the time a pedantic philosopher caught me saying that a pendulum obeys a certain equation. Well, of course it does no such thing; that is a shorthand way of saying that the equation accurately describes the motion of the pendulum. Using teleological language in biology is a more serious error, but it is not all that serious.

Matt, I do think it’s a serious error in a show aimed at the general public to segue from a paleontologist offering a tentative adaptationist hypothesis (which isn’t all that new, as noted above) to a teleological statement like that in the quotation. It reinforces a widespread misconception about evolution when with a little investment of thought (see Dave Luckett’s suggestion) it could have been avoided.

I agree that teleological language is common in the shop talk among researchers; sometimes it is even done with subtle geek humor.

But many of us have also struggled with the misconceptions it causes among those whom we purport to teach. One just has to look at the horrible mangling of the concepts of entropy and the second law of thermodynamics, even among physicists and engineers. This has been an issue that has gone on for decades, and it has only recently come to the attention of the physics community and being addressed.

Part of the reason that physicists and engineers can get away with those misconceptions is because they “plug-and-chug” in their use of the concepts. If asked to explain what they are doing, many can only revert to the “math” but not explain in a coherent manner what they are doing. Hence, they have a false confidence in their understanding. If they move into new territory with these misconceptions, they fail.

We really do have to pay attention to our words. It not only clarifies our own thinking, it helps us communicate better with the public and gives pseudo-scientists less fodder to work with in their deceptions.

Much of the work going on within the Physics Education Research community over the last four decades deals with exactly these issues. What used to consist of anecdotal reports of student misconceptions has become a well-studied catalog of misconceptions that lead eventually to confusion and misapplication. While I may not agree with many of the “remedies” for such misconceptions, the mere cataloguing of them, and the thought process behind them, shows where these misconceptions can lead.

Whatever you think of the show, part 2 is on tomorrow. (It’s a 3-part series.)

Just wanted to add my comments from a Christian point of view: It is critically important to get the language correct on this subject. Sorry, but there is a difference between this show and a show about pendulums obeying an equation. I was yelling at the TV as these sentences where being broadcast. Is it more expensive to get the verbiage right, or could it be that the writers don’t actually grasp evolution?

As a real world example of how this plays out: If the show would have done a better job on this point, I would have used it next summer at a camp for Christian kids to learn about evolution. As it is, I’ll keep looking.

Richard Hudson said:

Is it more expensive to get the verbiage right, or could it be that the writers don’t actually grasp evolution?

It is not necessarily more expensive or requires more verbiage. But it does require more thought and careful selections of context and preparation to introduce scientific concepts.

Usually the concept is presented first, and then the words used to define the concept works best. And that means putting in the time and effort to grasp the idea before attempting to explain it.

I would also point out that even experts get careless with their use of shorthand language. Normally when speaking to colleagues, all the background knowledge is in place and such brevity doesn’t get in the way of communication.

But people without the background, especially those who understand words in an entirely different context, will often get confused. They will frequently extrapolate the meanings of the words from the contexts with which they are familiar into the new context where the concept to which the word applies is entirely different.

That is often why scientists invent new words for scientific concepts (e.g., entropy). But, unfortunately, over the course of time, the analogies used to explain the concepts contribute to confusion (e.g., entropy = disorder).

Then there is the problem of the proliferation of new disciplines in which the same word can mean something different.

That’s life; we have to live with it. But we all, scientists and laypersons alike, have to put forth the effort to get the concepts right. Concepts are the key; the words follow, and the context tells us what the words mean.

ormally when speaking to colleagues, all the background knowledge is in place and such brevity doesn’t get in the way of communication.

Yeah, it’s easy for people familiar with the concepts to forget that sometimes part of their audience doesn’t have that familiarity.

Henry

At least they didn’t blame it on an asteroid. I know these things probably happened but me thinks the tool box may be getting short of anything but hammers.

Robert Gotschall said:

At least they didn’t blame it on an asteroid. I know these things probably happened but me thinks the tool box may be getting short of anything but hammers.

Would that make them hammeroids?

Wheels said:

Would that make them hammeroids?

Thor had hammeroids? Now Atlas I could understand.

Mike Elzinga said:

Wheels said:

Would that make them hammeroids?

Thor had hammeroids? Now Atlas I could understand.

Of course. There’s piles of evidence.

Dave Luckett said:

Mike Elzinga said:

Wheels said:

Would that make them hammeroids?

Thor had hammeroids? Now Atlas I could understand.

Of course. There’s piles of evidence.

Hah - now the punsters are driving this discussion.

Frank said:

“That locution, that phraseology, that notion that a “need” somehow drives evolution, drives me bats. “Needs” don’t make populations evolve anything. “

It’s interesting that it makes knowledgeable evolutionists like you peeved, and it makes creationists snicker. Perhaps realizing that the creationists get this one thing right over some of our fellow evolutionists, and they relish in rubbing our noses in it, is a key factor that drives you bats.

Do you really think that creationists get this subtlety?

Words like “need” in this context, or Matt Young’s pendulum “obeying” laws of physics are just a shorthand. In a presentation of this sort (especially from NOVA), accuracy is a must, even though we are going to slip up in our casual conversations. If we are too vigilant, our point gets lost in tortured sentences.

Steve P. said:

But if texbook writers insist on inserting a particular philosophical spin into textbooks, and teachers agree to promote that spin in the science classroom, then Christianity wants to be represented in equal part. Not a difficult issue, really.

If you are honestly not seeking to promote your atheistic worldview in the science classroom, you will not have a problem with ‘equal time or no time’.

Just what does science have to do with atheism?

Do you understand that scientists come from all sorts of ethnic, national, religious, and political backgrounds? What relevance should any of that have in teaching science?

And just why do you think textbook writers are putting some “philosophical spin” on science? I happen to know a number of excellent textbook writers; I have written a considerable amount of instructional materials myself. We don’t put “philosophical spin” on it; we try to get it right and make it understandable to students and laypersons.

I don’t know where you get your “philosophy of science” or your “philosophy of anything else”, but you clearly don’t understand science.

Neither I nor any of my colleagues purport to tell others how to deal with the notions of deities in their lives.

But we sure as hell object to those sectarians who go out of their way to inject misinformation and misconceptions into science courses by pretending it is “freedom of speech”, “academic freedom”, “religious tolerance”, or any other bogus notion that they claim gives they the right to splatter their misconceptions everywhere without having to go through the vetting process that science does.

The same goes for those pseudo-philosophers and quantum religion gurus who spin peoples heads with affectations of erudition and higher thinking that fakes the appearance of science and deep philosophical analysis. They are just as fake.

Whether you want believe it or not, whether or not you are capable of understanding it, there is such a thing as objective reality; and there are many of us who have been in contact with it our entire lives and know how it works. And we can also recognize when crap is totally wrong.

Steve P., the only takeaway I can find in your post in that you’ve never read a science textbook.

Ever.

No science text promotes any particular philosophy or religion (methodological naturalism, I must note is not a religion - it’s merely a pragmatic requirement that science provides testable explanations of things that can be tested).

So don’t worry - nobody is teaching your kids atheism. Fortunately, they’re not teaching them Christianity, either.

The irony of this is that the implication of “need” is representative of something that must occur, or is required for one reason or another. How do you reconcile this with a process that has no cause or motive?

Supposed evolution from a single celled organism into a multi-trillion celled human being would have had to overcome insurmountable odds just to make a single increase in overall genetic information.

It’s not just the fact that it is highly improbable though; without a “need” for evolution to occur, overcoming the odds necessary to blindly stumble from 0 to 3 billion base pairs of genetic information in the genome is subsequent to half the world’s population spontaneously winning the lottery, without ever having played.

Your faith in the ability of a magical process to achieve unparalleled success in bio-engineering feats, without even requiring a “need” or cause to sustain or propel it, is evidence only of your desire to remain willingly ignorant.

anonymouse said:

The irony of this is that the implication of “need” is representative of something that must occur, or is required for one reason or another. How do you reconcile this with a process that has no cause or motive?

Dear me, you are confused. The whole point is that the Theory of Evolution doesn’t posit a need. No “need”, hence no motivation. But that doesn’t mean that evolution hasn’t got a cause. It is caused by random mutation plus natural selection.

Supposed evolution from a single celled organism into a multi-trillion celled human being would have had to overcome insurmountable odds just to make a single increase in overall genetic information.

Would you care to have a go at defining what you mean by “overall genetic information”? I could use a laugh.

It’s not just the fact that it is highly improbable though;

You have no idea what you’re talking about. Evolutionary change is not only probable, it’s inevitable. Better yet, it has been repeatedly observed, even to the level of speciation directly in the field and in the laboratory, and in the fossil record to beyond that level.

without a “need” for evolution to occur, overcoming the odds necessary to blindly stumble from 0 to 3 billion base pairs of genetic information in the genome is subsequent to half the world’s population spontaneously winning the lottery, without ever having played.

If the lottery has three billion tickets, and you have one, the chances are three billion to one against you winning. But that someone will win is certain, if the lottery is honest. And only one winner is necessary. That one can pass the ‘winnings’ on. That’s all that’s required.

This has been explained so many times here and elsewhere that to trot this particular misunderstanding out again only means that you have done no investigation at all, and are only parroting blind prejudice.

Your faith in the ability of a magical process to achieve unparalleled success in bio-engineering feats, without even requiring a “need” or cause to sustain or propel it, is evidence only of your desire to remain willingly ignorant.

Faith, yet. Magic, yet. Can you say the word “projection”?

But all right, I’ll play your silly game. Let’s throw evolution completely out of the window. It never happened. Now, all around us we have different species of living things. How did they get to be all different, yet hierarchically perfectly nested? Let’s have your opinion about how it happened. Oh, and some evidence from nature to back it up. Please show your working.

The irony of this is that the implication of “need” is representative of something that must occur, or is required for one reason or another.

In that context, a “need” is something without which the species would decline in numbers and maybe die out completely. If that “need” is satisfied by the genome of some small subset of the species, the traits that do that would tend to spread through the species. If there’s not a subset of the species with such a trait, the species is in trouble.

Supposed evolution from a single celled organism into a multi-trillion celled human being would have had to overcome insurmountable odds just to make a single increase in overall genetic information.

It’s not a one step process, it’s an accumulation of small steps. Sure, the odds of any particular combination of genes is low, but we’re looking at the result in hindsight, not looking at the starting point betting on what the later results will look like.

Henry

Henry J said:

If that “need” is satisfied by the genome of some small subset of the species, the traits that do that would tend to spread through the species. If there’s not a subset of the species with such a trait, the species is in trouble.

viz. >90% of all species that have ever existed. Evolution is actually extremely inefficient and wasteful. Hardly what one would expect from design by an intelligence.

Steve P. said:

Mike, I am curious as to how one could possibly objectify a natural experience? We are on the inside looking in. We would have to disassociate ourselves from what it is we are investigating.

This is obviously not possible from a material perspective. How do we objectively study nature using natural means? How do we ‘know’ what we see with the eyes in our head is what is? If we are simply a wheel in nature’s ever-emergent biological gadgetry, we have no hope of objectifying any experience.

Silly Steve P…we have no need to ‘know’ what we see with our eyes is what is - we only need react to what we perceive is. For example, who cares if all this is an illusion? As a non-Christian, if I can’t perceive a difference between the reality being and illusion and reality being real, then they are logically the same thing from a perception standpoint. The entire experience is objective by definition since there is NO alternative perception.

Now, as a conservative, fundamentalist Christian this presents some philosophical issues however. Indeed if everything is an illusion, then Christianity is false. But for me, it makes no difference because all I go on is what my senses reveal to me. If my senses are lying, no biggie - the experience either kills whatever “me” their is experiencing the illusion or the experience doesn’t kill me, but continues to act in a repeatable manner such that I have no way to detect any reason to think it isn’t reality. Thus, I continue to rely on my senses with 100% assurance that they are providing reliable information.

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This page contains a single entry by Richard B. Hoppe published on November 9, 2009 12:47 AM.

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