Reply #73: I've seen post #21.

[Jim__]

Take the case in your first citation, the peppered moth - from the review:

Consider the famous case of industrially induced melanism in the peppered moth. Supposedly, in landscapes where pollution has destroyed the lichens on the trunks of trees, melanic (black) variants of the moth are better camouflaged when they rest on tree trunks than their lighter, speckled relatives. With improved camouflage, birds and other predators are less likely to pick the moths off the tree trunks. In polluted environments, then, melanic moths are more likely to survive, and hence to leave descendants in later generations. So far, so familiar.

The essential argument made in the review is that black moths are better camouflaged than speckled moths in this environment. Our vision tells us this - we don't really need a scientific theory. The fact that black moths have a survival advantage in this environment is attested to by history. Do we call the theory that tells us that these moths turned black and thus had a survival advantage in this environment a scientific theory? Or is this a historical narrative? Scientific theories should do more than confirm what we have already observed.

From pages 20 - 21 of the book:

It's common ground that distribution of phenotypic traits in populations change over time. Having said this much, however, it must be emphasized that such shifting equilibria do not explain the distribution of phenotypes; rather they are among the phenomena that theories of evolution are supposed to explain. These days biologists have good reasons to believe that selection among randomly generated minor variants of phenotypic traits falls radically short of explaining the appearance of new forms of life. Assuming that evolution occurs over very, very long periods does not help if, as we believe, endogenous factors and multilevel genetic regulations play an essential role in determining the phenotypic options among which environmental variables can choose. Contrary to traditional opinion, it needs to be emphasized that natural selection among traits generated at random cannot by itself be the basic principle of evolution. Rather there must be strong, often decisive, endogenous constraints and hosts of regulations on the phenotypic options that exogenous selection operates on. We think of natural selection as tuning the piano, not as composing the melodies. That's our story, and we think it's the story modern biology tells when it's properly construed. We'll stick to it throughout what follows.