Turns out it’s not bad being top dog, or in this case, top baboon.
Results of a study by University of Notre Dame biologist Beth Archie and colleagues from Princeton University and Duke University finds that male baboons that have a high rank within their society recover more quickly from injuries, and are less likely to become ill than other males.
The finding is somewhat surprising, given that top-ranked males also experience high stress, which should suppress immune responses. (more…)
UD’s McCarthy part of group that films rare striped rabbit in Sumatra
With cameras set up in Sumatra looking for medium- and small-sized wild cats, such as leopards, a research group involving the University of Delaware’s Kyle McCarthy, found images of something else entirely — a rabbit. Not just any ordinary rabbit, but a Sumatran striped rabbit, one of the world’s rarest species and one that had been captured on film only three times before.
Environmental change is the selective force that preserves adaptive traits in organisms and is a primary driver of evolution. However, it is less well known that evolutionary change in organisms also trigger fundamental changes in the environment.
Yale University researchers found a prime example of this evolutionary feedback loop in a few lakes in Connecticut, where dams built 300 years ago in Colonial times trapped a fish called the alewife.
In a study published May 23 in the journal Proceedings of the Royal Academy B, the Yale team describes how this event fundamentally changed the structure of the alewife and, with it, the water flea that the alewife feeds upon and the food chain that supports them both. (more…)
Pollination could be a chaotic disaster. With hundreds of pollen grains growing long tubes to ovules to deliver their sperm to female gametes, how can a flower ensure that exactly two fertile sperm reach every ovule? In a new study, Brown University biologists report the discovery of how plants optimize the distribution of pollen for successful reproduction.
PROVIDENCE, R.I. [Brown University] — Next Mother’s Day, say it with an evolved model of logistical efficiency — a flower. A new discovery about how nature’s icons of romance manage the distribution of sperm among female gametes with industrial precision helps explain why the delicate beauties have reproduced prolifically enough to dominate the earth.
In pollination, hundreds of sperm-carrying pollen grains stick to the stigma suspended in the middle of a flower and quickly grow a tube down a long shaft called a style toward clusters of ovules, which hold two female sex cells. This could be a chaotic frenzy, but for the plant to succeed, exactly two fertile sperm should reach the two cells in each ovule — no more, no less. No ovule should be left out, either because too many tubes have gone elsewhere, or because the delivered sperm don’t work. (more…)
Picture a turtle the size of a Smart car, with a shell large enough to double as a kiddie pool. Paleontologists from North Carolina State University have found just such a specimen – the fossilized remains of a 60-million-year-old South American giant that lived in what is now Colombia.
The turtle in question is Carbonemys cofrinii, which means “coal turtle,” and is part of a group of side-necked turtles known as pelomedusoides. The fossil was named Carbonemys because it was discovered in 2005 in a coal mine that was part of northern Colombia’s Cerrejon formation. The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby – and is believed to belong to the same species – measures 172 centimeters, or about 5 feet 7 inches, long. That’s the same height as Edwin Cadena, the NC State doctoral student who discovered the fossil. (more…)
Marine science majors conduct field research with horseshoe crab census
Wearing sneakers and rain boots, University of Delaware freshmen got their feet wet as marine biologists recently while counting horseshoe crabs along the Delaware Bay. The students participated in a monitoring effort to gain firsthand experience in field research with their fellow marine science majors.
“Where else can you go on a Saturday night to count horseshoe crabs?” freshman Will Goldman said. (more…)
Using the latest satellite tracking technology, conservationists from the Wildlife Conservation Society, the University of Exeter and the Government of Mexico have completed a ground-breaking study on a mysterious ocean giant: the manta ray.
The research team has produced the first published study on the use of satellite telemetry to track the open-ocean journeys of the world’s largest ray, which can grow up to 25 feet in width.
Researchers say the manta ray—listed as ‘Vulnerable’ by the International Union for the Conservation of Nature (IUCN)—has become increasingly threatened by fishing and accidental capture and now needs more protection. (more…)
Brittle stars and people have something in common: They move in fundamentally similar ways. Though not bilaterally symmetrical like humans and many other animals, brittle stars have come up with a mechanism to choose any of its five limbs to direct its movement on the seabed. It’s as if each arm can be the creature’s front, capable of locomotion and charting direction. Results appear in the Journal of Experimental Biology.
PROVIDENCE, R.I. [Brown University] — It appears that the brittle star, the humble, five-limbed dragnet of the seabed, moves very similarly to us.
In a series of first-time experiments, Brown University evolutionary biologist Henry Astley discovered that brittle stars, despite having no brain, move in a very coordinated fashion, choosing a central arm to chart direction and then designating other limbs to propel it along. Yet when the brittle star wants to change direction, it designates a new front, meaning that it chooses a new center arm and two other limbs to move. Brittle stars have come up with a mechanism to choose any of its five limbs to be central control, each capable of determining direction or pitching in to help it move. (more…)
