Evolutionary biologist develops insights at HUB

Man is not the pinnacle of evolution, according to an Oxford University evolutionary biologist who spoke at the University last night.

Current models of evolution which place Homo sapiens at the top of an evolutionary ladder are too human chauvinistic, Richard Dawkins told the crowd gathered in the HUB Ballroom for his lecture entitled "Is Evolution Progressive."

"Evolution is a densely branching tree. Our species is just one twig," he said.

As a result, Dawkins said, "It has become unfashionable to regard evolution as progressive."

But Dawkins, a reader in zoology, said that the passion to discount progressive evolution has gone too far. Progressive evolution makes sense, he said, if we redefine progress to be less biased against species other than Homo sapiens.

Progress is best described as an overall improvement in an adaptation of a specific lineage of a species, he said.

Dawkins attacked an assumption of Stephen Jay Gould, professor of earth science at Harvard University. More complex species are more advanced than simple species, Gould contends.

But Dawkins has a theory of his own. A lobster, for example, is only more complex than a millipede in the sense that a book about lobsters could be much longer than a book about millipedes written at the same level of detail, Dawkins said.

The complexity of life presents evolutionary biologists like Dawkins with a dilemma. The scientists question how natural processes manage to cobble together something as perfect as the vertebrate eye.

The creation of life by natural selection is analogous to a hurricane sweeping through a junkyard and assembling a 747, said one evolutionary critic.

"Natural selection is cumulative," Dawkins said in response to the analogy. "It does not assemble the 747 in one blow."

In the sense that natural selection constantly creates fitter "survival machines," Dawkins said, "it is essential to this argument that evolution should be progressive."

Matt Davis (sophomore-premedicine) said he does not believe we descended from the apes. But Davis, who describes himself as a "literal creationist," does agree in part with Dawkins.

"Species-level adaptations definitely happen," he said.

Dawkins also attacked Gould's theory of punctuated equilibrium. Gould contends that the Cambrian period was a fertile evolutionary time, producing new phyla and classes. Later on, evolution became gradual, producing only occasional new species.

But there could have been no phylum-level leaps, Dawkins said. A mutation producing an entirely new phylum is analogous to a tree that for years produces no new boughs, and new growth occurs entirely on the twig level, an explanation one student found interesting.

Toby Morales (junior-wildlife and fisheries science) said Dawkins "helped give me new thoughts about the phylogenic tree and the pre-Cambrian period."

Dawkins also touched on the apparent exponential evolution of the human brain, comparing its ascent to the rapid growth of computer technology. He described a system of co-evolution between software (complex instructions and concepts) that require ever greater hardware processing power, in the form of faster central processing units and larger human brains. The increased computational capacity, in turn, makes possible new software innovations. Verbal language may have developed this way, he said.

Dawkins promotes computer modeling as "an extremely powerful technique." Using computers, he said, we can create increasingly sophisticated models of the universe.

"Before we die, we have the power to understand why we were ever born in the first place," he said.

Elif Ertekin (sophomore-engineering science) said she gained a new perspective on the evolutionary debate.

"I've read a lot of Gould's books," she said. "I appreciated it."