Is evolution being taught incorrectly?

Factual Questions
1

I saw a program on pax-tv which attempted to poke holes in the theory of evolution the other day.

Interested, I followed up on some of the claims they made in a book called Evolution: Fact or Fiction? by biologists at the U of Cal at Berkley… (I forgot the main author’s name).

They brought up three or so points which I had not ever read about in school while studying evolution.

The Cambrian Explosion, or Biology’s Big Bang.

They said that all of a sudden, in the animal kingdom, all sorts of phyla (pl. of phylum?) just came into being, without any fossil record of their ancestors.

The authors state that the slow progression of evolution is not evident, and that Darwin’s theory doesn’t address this phenomenon that occurred 500+ million yrs. ago.

Therefore, they claim, it isn’t an evolutionary TREE or life, but an evolutionary THICKET which is responsible for the variety of life we see today. (I really didn’t understand this point too well.)

This question kinda delves into GD territory, but it’s relevant here:

There is still no explanation as to how life truly began.

They claim that the odds of life beginning are so slim (1.4 to the 40th power?) that there is no chance that such a random occurance could happen twice, or the three times needed to support the “evolutionary thicket” idea, which they claim is the only “chance” Darwin’s theory has left.

Now I have always been a firm believer in evolutionary theory, however I must say that the issues this book brought up did stir up my beliefs somewhat.

If anyone needs a direct cite on any of the admittedly scattered info I’ve set forth above, let me know.

So what’s the straight dope? Does the fossil record not support evolution?

2

You’d probably do best to search through talkorigins. I’m no expert, but my understanding is that we don’t really understand enough about the beginnings of life to make any meaningful calculations of probability (and besides, their calculations are probably based on overly simple assumptions).

As to the question of whether the fossil record supports evolution…basically, the fossil record doesn’t leave a whole lot of doubt. Evolution is as well-supported a fact as gravity, or entropy; the question is how it occurred rather than whether it did. Again, go through talkorigins. There’s a lot of information there.

3

Just out of curiousity, did they have anything to say on the odds on the spontaneous appearance of a supreme being, of which there exists no concrete evidence? :slight_smile:

4

One of the major misconceptions about the Cambrian Explosion is that this represents a major origin of life. What it actually represents is a signifcant increase in the fossilizable (is that a word?!) body types. As such, we would not expect to see the soft-bodied ancestors of the Cambrian forms in any great abundance (organisms lacking “hard parts” don’t fossilize well, except under extremely rare circumstances). That we don’t see such forms, or, to put it another way, that we see just what we expect we should see, certainly does nothing to invalidate evolution.

As for the “thicket” vs “tree” analogy, I’m not sure what they meant by that either. Perhaps they mean that life supposedly evolved from numerous ancestors, rather than a single common one?

5

I’d just like to pop in here and point out that “virtually no chance” is not the same thing as “no chance”.

Thank you.

No, wait- I’ve got more. How in the heck did they come up with that figure anyway? However they did it, I see it as another way of saying “We’ve calculated that -yes- there is a very small chance that the commonly accepted theory of evolution could have been the mechanism at work which resulted in the Cambrian Explosion.” That sounds like a concession to me.

6

Calculations on the origin of life, which concerns abiogenesis, not evolution, are riddled with logical errors. Trying to calculate the odds that an event which has already occurred will happen exactly as it did will always yield extremely improbable results. For example, take a deck of cards and deal out 4 hands of 13 cards each. Now pick up the hands and look at them. The chances that you would have dealt the precise layout you did are something like 8 x 10^67, or 10 raised to the 67th power. Does this mean you did not get that hand? Of course not. And there is no conceivable reason why abiogenesis would need to happen more than once.

For a more detailed explanation of these issues, see Talk Origin’s The Abiogenesis Interim FAQ and Lies, Damned Lies, Statistics and Probability of Abiogenesis Calculations.

7

Acco40, can you give a cite to the book you mentioned? It may help someone answer your questions, if you don’t consider them answered already.

8

Just to address some of the things that have come up:

No, the authors still believe in evolutionary theory; they just believe that is it taught incorrectly/leaving important parts out… it doesn’t get into God or religion.

The authors said that this theory is invalid because we have been able to get reliable fossil evidence from bacteria that is much older than the pre-cambrian soft-bodies forms that seem to be missing. The animals that led to hard-bodied animals are gone. The book uses the term “spontaniously appeared”.

No. Their main argument was that Darwin’s theory states that evolutionary processes work very slowly, and that one adaptation invites another. The authors cite evidence that different phyla appeared seemingly out of nothing… that these animals had features which were not supported in the fossil record of animals preceeding them.

Yeah, I think that’s what they meant. Especially to explain the differences between eukaryotic and prokaryotic cells.

9

Hardcore:

In the OP I said that the name of the book was Evolution: Fact or Fiction? I also remember that the book was written by a evolutionary scientist at U of Cal at Berkley (I forgot his name though!) and it was published in 2000. That’s all I know for sure.

It is intelligently written, only slightly subjective against current evolutionary edicts, and brings up weak points in Darwin’s theory. They claim that Darwin’s theory is at best faulty, at worst invalid.

They were bringing up points (the ones I’ve listed above) which I really didn’t have an answer for… as I’ve stated before, I have long been an evolutionist, but this book was bringing up evidence to the contrary that I had never heard of before.

Now, I only read the juicy parts of the book because I was in the bookstore. I’ll head back tonite probably and get the author’s name.

That’s the book.

Now the TV show I saw before it on pax-TV was hardcore pro-Christian, good ol’ fashion science-stomper stuff which goes beyond the scope of GQ…

10

Are you sure the name is not actually Icons of Evolution: Science or Myth?, by Jonathan Wells?

The customer reviews on amazon are interesting. The “Customers who bought this books also bought…” is telling, though.

11

bashere, that’s the one I think it is also, but I prefer to wait on confirmation before I rip into it. :wink:

12

Not directly relevant, but I thought I’d put in a quick plug for my molecular evolution faq:
http://psyche11.home.mindspring.com/molevol2.html

I’ll address the OP more directly once we find out what, exactly, the book was.

-Ben

13

A search on Amazon didn’t turn up an “Evolution: Fact or Fiction.”

It does turn up: Icons of Evolution, The Evolution Man or How I Ate My Father, and Conquerors and Explorers.

Lots of people have made claims that Darwin’s Theory of Evolution by Natural Selection is invalid, but I’ve yet to see any proof of these claims.

Similarly, lots of people have claimed that abiogenesis is hopelessly improbable. However, since no one knows the mechanism(s?) by which abiogenesis may have taken place, how one goes about calculating its liklihood is a mystery to me. I look on all such calculations as highly suspect, and hardcore has posted some excellent reasoning in that respect.

Also, I know some of the evolutionary biology professors at Berkeley, and I’m at a loss to say which of them would publish a book with such claims in it. Perhaps you’re thinking of Philip Johnson, who is a professor of law at Berkeley (not a biologist), and who has written books critical of evolutionary theory. He is, not coincidentally, a Christian.

14

Acco40: The problem with this notion of “a sudden increase in Phyla”, is that higher taxonomic categories are not comparable across different groups. They are merely artificial placeholders used for the sake of forming a hiearchical structure that our little brains find useful for categorizing things :slight_smile: . A phylum is the terminal taxonomic designation ( short of “Kingdom” ) - All its application in this case means is that we have a bunch of critters who nobody is sure what they’re related to. So by default the are placed in “new phyla”. But this has no particular significance - You could say new family, new tribe, new order, it wouldn’t really matter. We’re talking about a relative handful of actual species here. Where this book ( and SJG in Wonderful Life, which this book is almost surely appealing too ) makes a mistake is claiming that there is something awe-inspiring about these dozens of diverse new phyla suddenly appearing, when we “only have 20-odd extant phyla around today”.

Nonsense. We could have two extant phyla - The sudden appearance of twenty “new phyla” in the fossil reciord, each with a handful of species, would mean nothing at all. The obscure phylum Sipunculida is not comparable to the huge phylum Mollusca. They are not defined the same way. They do not have equivalent diversity. They do not have equivalent impact on this world’s ecology ( every Sipunculid on this planet could die tomorrow and nobody outside of a handful of experts would ever notice ).

The word phylum is not invested with any significance - like I said, in this case it is just a default. Taxonomic categories above the level of species only have meaning internal to the particular group they are applied too. A few systematists ( Jacques Gauthier for one, who drilled this into my head :smiley: ) have suggested scrapping the Linnaen system entirely, partly to eliminate this confusion ( and partly for a few others ).

  • Tamerlane
15

Well, no one ever said we have no fossils prior to the CE. We have trace fossils, and some few soft-bodies were lucky enough to become fossilized. However, for the most part, it’s a major crap shoot. As for the bacteria, there are a gazillion bacteria around, and even at one-in-a-million odds, you’re still going to come up with a fairly large number of bacteria fossils/trace fossils. So, I’d say their argument is invalid.

Besides, bacteria are not the immmediate pre-cursors to the CE critters. So, I repeat what I stated earllier - the Cambrian Explosion represents an increase in the number of organisms with fossilizable hard parts. We would not expect to find their immediate ancestors, not because they weren’t there, but because their body types were not conducive to fossilization.

16

Jacques Gauthier is my hero (well, one of them, anyway).

17

Although I didn’t check the websites mentioned, I could add that evolution isn’t currently being taught as one long, slow process. They talk about punctuated equilibrium, where things go along changing painfully slow if at all and suddenly there is a big change and new organisms popping up for numerous reasons. Several methods and theories of evolution are currently being taught, and I’ve never heard in school of any one of them being deemed as “the one and only way it happened”. So no, I don’t think evolution is being taught wrong (although the odd prof here and there may emphasize their personal favorite theory).

18

Darwin’s Finch: He’s a sharp one, there’s no denying :slight_smile: . I try to keep his big list/paper of vertebrate synapomorphies lying around for quick reference. Only I can never remember where I left it, on those rare occasions I actually need it :wink: .

  • Tamerlane
19

For an excellent, excellent discussion of both of these issues, check out “At Home in the Universe” by Stuart Kauffman. He discusses both issues, and several others, in a very unique way. Long story made short: far from being wildly improbable, these types of events are almost inevitable, given the right conditions. It should be a must read for anyone interested in evolution, IMHO. No, I’m not him. :smiley:

Oh, and as for the old “Darwin didn’t cover this” argument, I hope everyone is reassured, rather than disturbed, to find out that we’ve made some progress since his time…

20

Actually, Darwin did cover this, and a surprising number of other objections to his theory. Of course, both the objections and Darwin’s responses were often substantially different in form than they are today, because both biology and archeology have advanced immeasurably, but the root issues are not new, and Darwin addressed them as amply as he could at the time in the various editions of The Origin of Species.

For anyone interested in what Darwin did write, and what modern evolutionary biology makes of it today, I highly recomend Steve Jones’ book Almost Like a Whale: The Origin of Species Updated. I got it from my uncle while I was in the UK, and I’m not sure if it’s available in the US, though.