Friday, July 04, 2008

Suspicions

Granted the story about bird evolution investigated by genetic analysis is very ill-reported. Compare these two statements: Point 2 "Perching birds ... are closely related to parrots and falcons." Point 8 "Owls, parrots and doves have few, if any, living intermediate forms linking them to other well-defined groups of birds".

The sweeping conclusions they draw about relationships leave me dubious. The shape of a creature will relate to its occupation, so scions of different families occupying the same niche are going to look similar. So classification by morphology is open to some hazards. Still, such sweeping reorganizations make me hunger for some predictive power to the techniques. Is there anything we can say about members of the same family--that transplants are more reliable, or that specific body structures will be more similar to each other than to non-family species?

Without that, I'm not sure how much more accurate genetic taxonomy is going to be than morphological taxonomy. The theory sounds good, but where can we find some cross-checking?

Obscure. OK: morphological taxonomy is figuring out what species are related to each other by looking at details of the organs and seeing which have parts more like others.

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