UCLA biologists report how whales have changed over 35 million
years By Stuart Wolpert May 28, 2010 Category: Research Whales
are remarkably diverse, with 84 living species of dramatically
different sizes and more than 400 other species that have gone
extinct, including some that lived partly on land. Why are there
so many whale species, with so much diversity in body size? To
answer that, UCLA evolutionary biologists and a colleague used
molecular and computational techniques to look back 35 million
years, when the ancestor of all living whales appeared, to
analyze the evolutionary tempo of modern whale species and probe
how fast whales changed their shape and body size. They have
provided the first test of an old idea about why whales show
such rich diversity. "Whales represent the most spectacularly
successful invasion of oceans by a mammalian lineage," said
Michael Alfaro, UCLA assistant professor of ecology and
evolutionary biology, and senior author of the new study, which
was published this month in th