Behavior May Influence Evolution

eldavojohn writes "Pending your beliefs about evolution, National Geographic is running an interesting article on the influences of behavior on evolution. The study supports the controversial idea that an animal's behavior in response to environmental change can spur evolutionary adaptations. By adding a predator to an island where a species of lizards lived with no predators, they witnessed a quick shift in the average length of legs on the lizards. Long legs meant to escape were useless against the new larger predators while short legs became the dominant feature since they increased climbing ability (to trees the predators could not reach). For the finer details on the research, visit the Losos Lab Research Page."

Comments

Article is wrong - Study misinterpreted.

[Esteanil]

I'm hijacking a higher thread since pretty much everything written below is just plain wrong.
Not the submitters' fault, they simply read the article and based what they wrote on it.

Let me explain:
The article is claiming that "Evolution's Driving Force Shifts Based on Behavior"
Go to the actual research site (linked in submission), scroll down to the end, and you will find that what they're saying is:
"... another alternative is that lizards growing in different environments grow different length legs. To test this hypothesis, we raised baby anoles on two different surfaces at the St. Louis Zoo--either on 2x4's or on narrow (1/4") dowels. At the end of three months, the lizards raised on broader surfaces had longer limbs than the lizards on narrower surfaces! This suggests that the results observed in the field may be the result of a phenotypic plasticity in limb growth, rather than genetic differentiation."

Phenotypic plasticity is a term some of you may be unfamiliar with, a good example of it is found in ants.

In any given hill, there are different castes of ants. Warriors, workers, etc. They are all quite different.
However, the differences are not genetic; they arise during development and depend on the manner of treatment of the eggs by the queen and the workers, who manipulate such factors as embryonic diet and incubation temperature. The genome of each individual contains all the instructions needed to develop into any one of several 'morphs', but only the genes that form part of one developmental program are activated.

This is what the study suggests is happening to these lizards.
They're saying there are at least two different 'morphs', one with long legs and one with short ones, in the genome of the lizards.
These are then selected between (through some so far unknown mechanism) based on the environment of the lizards.

"These findings suggest the intriguing possibility that phenotypic plasticity may play an important role in adaptive differentiation by permitting lizards to occupy different habitats; once subsequent mutations arise, these differences can then be elaborated upon by natural selection."

Now, let the ghosts of Lamarckism the article has raised from their graves go to rest.