SCIENCE IN THE NEWS DAILY
Did Retained Juvenile Traits Help Birds Outlive Dinosaurs?
from Scientific American
Birds are the only dinosaurs that have survived into modern times. Why is that? Of all the dinosaur species, how did they manage to make it through the catastrophic events of 65 million years ago, whereas all their fellow dinos perished? A new study, published May 27 in Nature, hints at an evolutionary phenomenon that may have played to birds' advantage: They are, it seems, baby dinosaurs whose biology prevents them from ever growing up.
Bhart-Anjan Bhullar and his doctoral advisor, Arkhat Abzhanov, posit that birds may have evolved from dinosaurs by a process known as paedomorphosis, whereby an organism retains juvenile traits even after it becomes sexually mature. "They certainly look to have some paedomorphic characteristics," says Jack Horner, a Montana State University paleontologist who studies dinosaur growth and development and was not involved in the study. Paedomorphosis "is not uncommon in evolution and speciation," he adds.
Bhullar and Abzhanov reached this conclusion by comparing the skulls of birds and dinosaurs across phylogenies, or related groups, and at different developmental stages. To quantitatively compare cranial geometries, they scanned the skulls of theropod dinosaurs (which are thought to be birds' ancestors), crocodiles and alligators (dinosaurs' cousins), early transitional birds such as Archaeopteryx, and modern birds. Then they created digitized versions of each skull and mapped out cranial landmarks, such as nostril tips, eye socket dimensions and places where bones meet.
Connect With Us:
VIDEO: The Promise and Peril of Drones
The automation of tasks at work and at home is just around the corner, including driving cars, piloting planes, delivering packages, and transporting weapons. Unmanned aerial vehicles are rapidly evolving to meet both society’s and the military’s needs in automation and better efficiency.
During her time as one of the first female fighter pilots in the US Navy, Dr. Missy Cummings observed that computers could take off and land a plane more precisely than humans. Because of this breakthrough and her fascination with this growing technology, she began human–drone interaction research.
To view all multimedia content, click "Latest Multimedia."
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.