Expelled! Exposed!! : Greg Laden's Blog

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Expelled! Exposed!!

Posted on: April 9, 2008 2:35 PM, by Greg Laden

Please Visit Expelled Exposed ... the National Center for Science Education's official response to the Ben Stein movie Expelled .. you will find this collection of resources helpful!!!!!!

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funny, one of the bottom links on that page is to the washington post article about susan crocker. a curious article, but one sentence jumped out at me as being particularly annoying.

The grace of the cheetah, the beauty of a butterfly's wings and the complexity of the human brain were all achieved by the same general process that allows bacteria to evolve into a resistant strain -- they required the death of those less quick, less strong and less smart.

that last part...

as I understand evolution, evolution does not require the death of anything, simply the failure to breed... no?

Posted by: peter | April 9, 2008 3:22 PM

Evolution absolutely requires death. Resources are limited, and over time, mutations accumulate and genetic combos go out of date. Age demands death, and death demands sex. It is a never ending cycle.

Posted by: Greg Laden | April 9, 2008 3:24 PM

true, but all things die, so it's not like that is a preventative. even the successful varieties of a species eventually die, but the successful ones are simply the ones that breed before they do.

Posted by: peter | April 9, 2008 4:52 PM

But there is a difference between something that dies because it gets run over by a truck and something getting old (and then it dies). Not all creatures age. Aging can be selected for by natural selection.

Posted by: Greg Laden | April 9, 2008 5:53 PM

I see what Peter is saying, but I'm just a lay person and may be full of beans. :)

Consider the following:

These puppies are all born in the same litter:

A has a mutation that increases his speed making him a better hunter.
B has a mutation that increases his speed making him a better hunter.
C is an "average" wolf.
D has a mutation that decreases his ability to process odors.

C might survive just fine as an average wolf, as wolves have for generations and may or may not pass on his genes.

D lives to a ripe old, but because of his poor hunting skills his chance of breeding is eliminated.

B survives just fine but is an average wolf in the pack. He never rises to alpha wolf and never take a mate yet leads a long and healthy life.

A, by pure chance, is able to become an alpha wolf in the pack and pass on his genes.

What I understand Peter to be saying is that B can lead a perfectly healthy and perfectly long life. And yet because of circumstances beyond his control, never has the opportunity to pass on his genes. Similarly, D does not have to die young because of his poor luck in the mutation pool. His genetic mutation only has to be bad enough that it is not passed on over time.

Evolution isn't about who lives or dies when, but who gets to breed the most and leave the most offspring.

Posted by: Bob | April 9, 2008 6:16 PM

both right, It occurred to me that the concentration on which one dies being the primary thought in the referred to comment is the kind of thing that seems to make people think of things like social darwinism and eugenics as part of the whole argument.

being run over by a truck will have an effect on whether or not your genes get passed on, but given that it is a relatively rare occurrence, (I hope,) then the primary thing that determines whether or not you pass your genes, (or variations thereof) is whether or not you get to have (successful) sex with an appropriate mate. as Bob points out, you don't have to die to fail to pass on your genes, you just have to be unattractive. (and I don't just mean in the aesthetic sense)

I suppose that part of my difficulty with the phrase in the article is that it implies that it requires the death of an organism to promote evolution, rather than the survival. (dare I say it is poorly framed? hmmm probably not given recent arguments.)

I write all this, and realize that Bob has really phrased this better than I have.

Posted by: peter | April 9, 2008 7:19 PM

That may be true for that particular litter of wolves but the essence of natural selection is environment and chance. The best wolf ever born may have been grabbed by an eagle as a pup and therefore missed it's chance of passing on it's superior genes. What is important is, over time, and millions of wolves, the slightly superior ones statistically had the advantage over their lesser siblings and gradually made the species what it is today. Breeding is important, but luck is a factor. If that one special wolf hadn't died as a pup, we might be living in caves and wolves might be blogging on the internet!!

Posted by: Wordave | April 9, 2008 7:32 PM

luck yes, but not necessarily death. if that pup had survived but simply been sterilized, (one claw in the wrong place can ruin your day...) or simply damaged, or even just displaced, it would have been just as unlikely to propagate. (though perhaps in that way a wolf is a bad example.) but it still would have been a genealogical superior wolf. no?

the point being that the comment in the article is basically inaccurate by its use of the phrase "...required the death..." in that context. you have expanded the definition (properly I think) to be simply environment and chance. in the article in question, those that were "...less quick, less strong and less smart." would probably have been less likely to propagate anyway. I'm probably being over-persnickety about the phrasing in the article, but it bothered me, and I see this was a pretty good place to take my quibble.

thanks all...

Posted by: peter | April 9, 2008 8:11 PM