HOME >> BIOLOGY >> NEWS
Gene Study Shows Mammals Lived Before Extinction Of The Dinosaurs

Overwhelming evidence from the largest evolutionary study of gene sequences ever performed shows that the major groups of mammals emerged well before the extinction of the dinosaurs, according to Penn State researchers Sudhir Kumar, postdoctoral fellow, and S. Blair Hedges, associate professor of biology, whose research will be published in the April 30, 1998, issue of the journal Nature.

"The evolution of mammals appears to have occurred gradually by the isolation of breeding groups when the continents broke apart, not suddenly by the rapid filling of ecological niches left vacant when the dinosaurs became extinct," Hedges says. The massive gene study suggests that modern orders of mammals first evolved when the continents were separating during the Cretaceous era about 100 million years ago--much earlier than some previous estimates based on fossil studies, which link the evolutionary event to mass extinctions 65 million years ago.

"This is the first time we ever have been able to estimate when all these lifeforms appeared on Earth," Hedges says. "Fossils can't give us this information, partly because there are huge periods of Earth's history from which not enough fossils have been found to make reliable estimates."

To gauge the pace of evolution, Kumar and Hedges mined a burgeoning collection of gene sequences being accumulated at Genbank, the public genetic databases maintained by the National Institutes of Health. "During the past few years there has been a tremendous explosion in the number of known gene sequences, so we had ten times as much data to work with as we did just two years ago," says Hedges, who published a similar but much smaller study with Kumar and others in 1996.

The scientists sifted through many thousands of vertebrate gene sequences from hundreds of species to find those that develop mutations at a constant rate over time, which Kumar and Hedges
'"/>

Contact: Barbara K. Kennedy
science@psu.edu
814-863-4682
Penn State
30-Apr-1998


Page: 1 2 3 4

Related biology news :

1. Study: Emission of smog ingredients from trees is increasing rapidly
2. Study explores gene transfer to modify underlying course of Alzheimers disease
3. Study reveals why eyes in some paintings seem to follow viewers
4. Study by Israeli scientists provides insight on DNA code
5. Study reveals first genetic step necessary for prostate cancer growth
6. Study of flu patients reveals virus outsmarting key drug
7. Study in Science reveals recreational fishing takes big bite of ocean catch
8. Study suggests cell-cycle triggers might be cancer drug targets
9. Study narrows search for genes placing men at increased risk for prostate cancer
10. Study links high carbohydrate diet to increased breast cancer risk
11. Study explains spatial orientation differences between sexes

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/2/2019)... ... April 30, 2019 , ... Philadelphia intellectual ... to announce that Gunes Bender, Ph.D., a registered patent agent, has joined the ... his new role, Bender provides technical support and scientific expertise in the pharmaceutical ...
(Date:4/27/2019)... ANGELES (PRWEB) , ... April ... ... (SDi) flagship market research study " 2019 Global Assessment Report: The Laboratory ... different product categories is presented in 10 sections that include chromatography, life ...
(Date:4/25/2019)... ... , ... In recent years the neurocognitive effects of treatments ... cases the magnitude of these deficits and the long-term impact on cognitive maturation ... may impact developmental trajectories, and patients are often so unwell at the time ...
Breaking Biology News(10 mins):
(Date:4/25/2019)... ... 2019 , ... Frank is an albino, deaf Great Dane. His owners rescued him when he ... health issues. Despite his hearing impairment, he was always an active and playful pup. Frank ... day, every day. As the two grew, playtime became rougher and Frank ended up injuring ...
(Date:4/16/2019)... ... April 16, 2019 , ... Fulcrum Biometrics , a ... Bank South Pacific (BSP), the largest regionally owned bank in the South Pacific, ... contract to deliver a fingerprint-based Know Your Customer (KYC) banking solution that is ...
(Date:4/10/2019)... ... , ... After more than three months of renovation, Lajollacooks4u is set to ... appliances and modern lighting and fixtures, and will provide additional workspace for the many ... growth in the demand for our team-building events and cooking classes over the last ...
(Date:4/8/2019)... SOUTH JORDAN, Utah and BOSTON (PRWEB) , ... ... ... leader in delivering cloud-based enterprise-class unified communications and collaboration solutions, announced today the ... provides integration to an unprecedented range of business and contact-orientated applications while ...
Breaking Biology Technology:
Cached News: