|
 
Darah Oxford
|
Student
Scientists:
Darah Oxford
By Charles Reineke
When H. Carl Gerhardt, a professor of biological
sciences at MU, wanted to learn more about changes in
gray tree frog vocalizations — signals made by the
sticky-footed amphibians to repel competitors and attract
mates — he turned
to Darah Oxford, a 20-year-old biology major from Columbia. Together
they designed an experiment to determine whether females
came equipped with a pre-existing bias in favor of certain
male calls.
Designing an experiment is one thing, getting
frogs to the lab is quite another. Oxford and her husband, Jon,
also a biology student researcher, spent long nights at area
ponds rounding up tree frog couples. “When the female
chooses a male, she walks up to him and he jumps on her back,” Oxford
explains. After giving the male a piggyback ride to the pond — a
position called amplexus — the female lays eggs and her
mate fertilizes them. “We catch them before they go to
lay their eggs,”
she says.
Oxford and her husband next hauled the frogs
back to MU’s
Tucker Hall, then chilled them to keep the egg-filled female
from laying (“Once she lays her eggs she doesn’t
care what the male has to say,” Oxford says). Testing
involved adding a mix of “advertisement” and “aggression”
calls to digitalized tree frog sounds, then watching as the female
picked the one she found most compelling.
“We put the
[warmed up] female in the middle of our testing chamber, between
two speakers, and played one call out of one speaker and a different
one out of the other,” Oxford
says. The female frog continually hopped toward the call she
liked, eventually earning, with her boyfriend, a trip back
to the pond. Oxford says the data collected so far indicates,
surprisingly, that tree frog communications may not change
in the gradual way most researchers supposed — that,
in fact, frog vocalizations seem to evolve in, well, leaps
and bounds.
As for her own evolution, Oxford, who plans
to attend medical
school, says that’s moving forward too.” I’d
never been allowed to actually control a project myself,”
she says. “It was a great experience.”
« Back
to Student Scientists Feature Story
Archives
| Comments | Home SUBSCRIPTIONS
Subscribe
| Change Your
Address | Unsubscribe
Copyright © 2007 — Curators of the University of Missouri
DMCA and other copyright information.
All rights reserved.
An equal opportunity/ADA institution.
Published by the Mizzou Alumni Association
Questions? Comments? E-mail comments@mizzoualumni.org
Last Update:
March 12, 2007
|
