December 12, 2004


Everything That Rises Must Converge: The "inevitable and preordained trajectories" of evolution.: a review of Life's Solution: Inevitable Humans in a Lonely Universe by Simon Conway Morris (William Dembski, December 2004, Books & Culture)

Simon Conway Morris is a distinguished scientist with a professorship in evolutionary paleobiology at Cambridge University. In Life's Solution, he enters the debate on the direction of evolution. Is it indeed a random affair that might well have turned out differently, as many orthodox Darwinians argue, or was the emergence of intelligent, self-reflective beings built into the process from the start? Conway Morris' answer is suggested by his subtitle: "Inevitable Humans in a Lonely Universe."

The central theme of Life's Solution is biological convergence. "Convergence" here refers to a counterintuitive result from evolutionary biology. When organisms share some feature, the first impulse of evolutionary biologists is to attribute the similarity to evolution from a common ancestor. Similarity is thus explained as a common inheritance.

Not every feature of biological similarity, however, can be attributed to descent from a common evolutionary ancestor. Indeed, biologists have shown that organisms can share a feature of similarity and yet have no common ancestor that exhibited that feature. This means that in the evolution of organisms sharing such a feature, the feature had to be reinvented separately on a number of occasions. This is biological convergence, and Conway Morris documents many fascinating examples of it (in addition to a general index, Life's Solution includes a five-page, double-columned index devoted strictly to convergences).

Biological convergence becomes downright astonishing when the similarity verges on identity. One of the best-known examples of striking convergence is the evolution of the camera-eye in vertebrates and cephalopods (e.g., human and octopus eyes respectively). These eyes are highly complex and almost point-for-point identical (the only obvious difference is the neural wiring—in vertebrates it is backwards, the nuclear layer being in front of the retina, which results in a blind spot). Yet, according to evolutionary theory, humans and octopuses had separate evolutionary precursors of which neither possessed eyes at all. Thus, in the evolution of humans and octopuses, evolution required the reinvention of virtually identical camera-eyes from scratch twice.

This is remarkable. Nor is convergence an isolated, anomalous fact of biology. Rather, it is the norm. Virtually identical biological structures and functions keep getting reinvented, and in ways that cannot be attributed to a common inheritance from a common evolutionary ancestor. Conway Morris documents this fact at length and with awe. It's no accident that "eerie" is one of the most used words in Life's Solution.

But what does this all mean? Why is biological convergence important in the wider scheme of things? Conway Morris belongs to that growing circle of thinkers—others include Paul Davies, Stuart Kauffman, and Michael Denton—who reject the claim that evolution is haphazard.

Don't know about convergence, but the divergence from even the neoDarwinist synthesis is becoming universal.

Posted by Orrin Judd at December 12, 2004 3:16 PM

William Dembski, the reviewer, is an proponent of ID and savages Morris in this review:

"According to Conway Morris, biological convergence suggests that evolution is a goal-directed process limited to fixed paths. But this suggestion is not a scientific proposal. Biological convergence, as Conway Morris employs it, merely points to a metaphysical possibility, to wit, the possibility that evolution is teleological. The actual scientific evidence that he employs from biological convergence, however, at best shows that evolution is limited to fixed paths, not that it has goals. ... It is the familiar trap of theoretical biology: problems get converted into their own solutions. ... Accordingly, life is an agent that acts purposively to solve the problems that must be solved for evolution to take the form it does, replete with biological convergences. This is fine as far as it goes. But where is the experimental support? Where are the theoretical principles?"

Posted by: jd watson at December 12, 2004 6:23 PM

My library is packed for a move, so I can't give cites, but convergence in evolution, while startling, is not a huge mystery or a sign of design. Evolution happens in part through a process of randomness within constraints, as is demonstrated in simplified form in John Conway's game of Life. Similarly, two different branches of living could evolve similar eyes or whatever, because they share the constraints of Earth's environment.

Posted by: PapayaSF at December 12, 2004 6:53 PM


As a non-scientist, am I wrong in being suspicious when I hear the experts talk about what "could" have happened?

Posted by: Peter B at December 12, 2004 7:44 PM

Peter: well, I think your suspicons are misplaced, yes. Broadly, there are sciences (e.g. chemistry) that can do experiments in a lab to verify theories, and those that can't (e.g. astrophysics). Evolution is more in the latter category, so what they do is try to figure out what fits the evidence, and come up with models and predictions and limited experiments to try. For over a century, tens of thousands of biologists, paleontologists, geologists, etc. have tried to make sense of the fossil record. Pretty much all of them agree that evolution occurred, though there is some disagreement as to details. Contrary to some opinions on this blog, it's not all just a big conspiracy to destroy Christianity.

Posted by: PapayaSF at December 12, 2004 9:27 PM

Just as American hegemony is the end of history, human hegemony is the end of evolution. Our partaking of the Logos equips us to have dominion over every creature. If say, dolphins, or ostritches were ever to start to get uppity, we would deal with them.

We might make choices about our own development, but we are never gong to have to worry about being knocked off by a new species. Cultural, i.e. Spencerian, evolution, completely trumps the Darwinian kind, because it is so much faster. The physically meta-evolving species will be in competition with our cultural adaption to it, and we have ways.

Posted by: Lou Gots at December 13, 2004 4:09 PM

At last a citation of a darwinist who has some respectability, at least with me.

I'll have to put the book on my list.

My first thought, though, is there is may be less here than meets the eye (hah hah).

It happens (or perhaps was designed to be so) that biologically active molecules are strongly affected by radiation in the visible light range (and somewhat red and violet on either side).

It then, in retrospect, seems unsurprising that lots and lots of systems would evolve to use visible light. As Lynn Margulies put it (quoting from memory): Wherever there is a photon, life will find a way to use it.

Thus, 38 (by one count) separate evolutions of visible light-capturing biological organs (and that's just among animals).

Convergence is remarkable, but no more remarkable, it seems to me, than a number of other life functions. If the octopus-mammal systems were identical, I might have some explaining to do.

But they are not identical. In an engineering sense, they are extremely different, as different, say, an spark-induced and diesel internal combustion engines.

This does not, to me, argue for intelligent design. If the designer were intelligent, wouldn't he have chosen the better of the two systems.

Particularly since the better one evolved first. Why did he go back and design a new system that works worse?

Posted by: Harry Eagar at December 13, 2004 10:06 PM


Perhaps you could post a review of the book?

Posted by: Jeff Guinn at December 14, 2004 7:08 AM

Harry, it's too easy to knock down straw men of this issue. Convergent evolution argues against 7-24 hour days, "Bible is literally true" creationism. I remember talking to such a believer once and mentioning a stone trilobite I had found at the Red Hill site. Not to worry, he told me, God planted fossils to test the faith of the weak.

Convergent evolution does not argue against intelligent design, only against the most literal versions of it. Could it not be that it is through adaptation and competition that the intelligent design is actualized?

Posted by: Lou Gots at December 14, 2004 2:56 PM


Yes it could.

Or not.

How to know which?

Posted by: Jeff Guinn at December 15, 2004 7:44 AM

Jeff G: I cannot answer because I do not know what "intelligent " means here. I do not comprehend the Logos, even when I see Him in the Monstrance.

I can grasp, however, that biological convergence neither disproves nor proves intelligent design. Arguing that it disproves inteligence because the Creator would then be gratuitiously redundant is just trivial, sort of like saying God would have done it differently if only He had known all the facts. God knows in advance how the game wiil end, but perhaps He still enjoys a good match.

Posted by: Lou Gots at December 15, 2004 1:18 PM

Jeff, I intend to try.

Lou, I'm not trying to argue that the Creator would be redundant.

But if you're going to talk about 'intelligent,' without further ado, then we have to think of it as meaning what it commonly means -- that we do something in a sensible way, that we do not make boards by cutting up a tree trunk in one-inch lengths and then glue the pieces back together to make 2 by 4s.

One reason the darwinians and the other naturalists rejected ID in the first place was that it was not, on examination, anything like intelligent.

Falling back on saying, well, we don't know the mind of god does not answer. By calling it 'intelligent' we have just said we DO know the mind of god.

I heard that argument a million times as a Catholic. The universal solvent of a Christian who's lost the argument.

Posted by: Harry Eagar at December 16, 2004 1:52 AM


The quarrel is not that Creation is not Intrelligent but that it's not as nice as you'd like it to be. God doesn't meet your own standards so you reject Him.

Posted by: oj at December 16, 2004 7:58 AM


God doesn't meet Christian standards, either.

Harry isn't rejecting God, just the invocation of intelligence.

Posted by: Jeff Guinn at December 16, 2004 12:35 PM


Yes, to be a Jew or a Christian is to accept that God isn't who we'd like Him to be and we aren't who He hoped we'd be.

Posted by: oj at December 16, 2004 12:45 PM

Who said anything about nice? You are saying there is intelligence involved. I'm asking, how?

Here's a conundrum for you that proves that while life can be convergent, it does not have to be:

1. If life develops according to an intelligent plan, and

2. There are green amphibians, fish, reptiles and fish,

3. why are there no green mammals?

On what argument from a plan do you predict that failure to converge?

Posted by: Harry Eagar at December 16, 2004 1:07 PM

God thought lizards should be different than mammals.

Posted by: oj at December 16, 2004 1:25 PM

Yes, to be a Jew or a Christian is to accept that God isn't who we'd like Him to be and we aren't who He hoped we'd be.

No. To be a Christian, less so a Jew, is to worship a God wholly unlike the one that exists.

Posted by: Jeff Guinn at December 17, 2004 12:07 PM

Just so long as you agree He exists.

Posted by: oj at December 17, 2004 12:58 PM


The question of God's existence is unanswerable.

What is answerable though, is that if God does exist, It bears no resemblance to the simulacrum on display in organized religion.

Posted by: Jeff Guinn at December 19, 2004 7:26 AM


As always, you start by going too far and end by making no sense.

The question of existence is unanswerable. The only existence worth having faith in is one with God, else human life is fungible.

Posted by: oj at December 19, 2004 8:17 AM


You should clean your finger before pointing out someone else's spots.

Believers in God have an impeccable track record of treating human life as fungible, and very dispensable in the quest for admission to heaven.

Posted by: Jeff Guinn at December 19, 2004 3:17 PM

Killing for religious purposes takes life seriously.

Posted by: oj at December 19, 2004 4:36 PM