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Science Frontiers ONLINE No. 95: Sep-Oct 1994 |
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The urge to replicate: part ii
In an earlier issue (SF#46), we related how the morphology of the megabats (the "flying foxes") displays primate overtones. The very idea that bats of any kind could be closely related to humans and apes was quickly dismissed by most zoologists. Flying mammals -- the bats -- evolved only once according to mainstream theory; later the Order Chiroptera ("hand-wings") split into the small, mainly insect-eating microbats and the large, fruit-eating megabats. It was all pretty obvious; how could such complex, specialized animals have evolved twice?
But in Science Frontiers, there is ever the "however":
"Arnd Schreiber, Doris Erker and Klausdieter Bauer of the University of Heidelberg have looked at the proteins in the blood serum of megabats and primates and found enough in common to suggest a close taxonomic relationship between the two groups. (Biological Journal of the Linnean Society, 51:359)"
An explanation might be that the similarities between the microbats and megabats represent adaptations to similar environmental niches rather than a common ancestry.
(Timson, John; "Did Bats Evolve Twice in History?" New Scientist, p. 16, June 4, 1994.)
Comment. Does the black box labelled EVOLUTION contain a special subprogram for converting hands into membaneous wings whenever it seems profitable to do so? Or are we somehow missing a different sort of evolutionary process, perhaps something akin to the "directed evolution" suggested by some experiments with bacteria? (SF#64)
The possible separate evolutions of micro- and megabats is covered in more detail in BMA41 and BME1 in Biological Anomalies: Mammals I and II, respectively. To order, visit here.