Date: September 24, 2016
Source: University of Washington
Biologists of all stripes attest
to evolution, but have debated its details since Darwin's day. Since changes
arise and take hold slowly over many generations, it is daunting to track this
process in real time for long-lived creatures.
"We know that evolution
occurs -- that species change," said Dee Boersma, a University of
Washington professor of biology. "But to see this process in long-lived
animals you have to look at generations of individuals, track how traits are
inherited and detect selection at work."
Boersma studies one particularly
intriguing long-lived species, the Magellanic penguins of South America. She
has spent 34 years gathering information about their lifespan, reproduction and
behavior at Punta Tombo, a stretch of Argentine coast that serves as their
largest breeding site. Boersma and her colleagues combed through 28 years'
worth of penguin data to search for signs that natural selection -- one of the
main drivers of evolution -- may be acting on certain penguin traits. As they
report in a paper published Sept. 21 in The Auk: Ornithological Advances,
selection is indeed at work at Punta Tombo.
"This is the first
decades-long study to measure selection in penguins, and only the second one
for birds overall," said lead author Laura Koehn, a graduate student in
the UW School of Aquatic and Fishery Sciences who worked with Boersma as an
undergraduate.
