Rogue finger gene got bats airborne

Jeff Hecht

19:00 10 November 04

A change to a single gene allowed bats to grow wings and take to the air, a
development that may explain why bats appeared so suddenly in the fossil
record some 50 million years ago.

Bats have been an evolutionary enigma. That's because the oldest fossil bats
look remarkably like modern ones, each having wings formed from membranes
stretched between long fingers, and ear structures designed for
echolocation. No fossils of an animal intermediate between bats and their
non-flying mammal ancestors have been found.

Now Karen Sears, at the University of Colorado Health Sciences Center in
Denver, has discovered why intermediate forms may be missing in the fossil
record. In a bid to understand where bats' specialised finger digits evolved
from, Sears compared their embryological development with that of the finger
digits of mice.

In both animals, digits form from cartilage cells which divide and mature
into bone in regions called growth plates. But in bats, a key region of the
growth plate called the hypertrophic zone is much larger than in mice, which
allows their digits to grow much longer. That difference is controlled by a
single gene known as BMP2, one of a family of genes important for limb
development in mammals.

Full text at NewScientist
http://www.newscientist.com/news/news.jsp?id=ns99996647

Posted by
Robert Karl Stonjek
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