Featured Research

from universities, journals, and other organizations

New theory on origin of birds: Enlarged skeletal muscles

Date:
July 2, 2011
Source:
New York Medical College
Summary:
A new theory of the origin of birds, traditionally believed to be driven by the evolution of flight, is now being credited to the emergence of enlarged skeletal muscles in birds. Their upright two-leggedness, he says, led to the opportunity for other adaptive changes like flying or swimming.

Ostriches in South Africa's Kruger National Park. A developmental biologist is proposing a new theory of the origin of birds, which traditionally has been thought to be driven by the evolution of flight. The new theory credits the emergence of enlarged skeletal muscles as the basis for their upright two-leggedness, which led to the opportunity for other adaptive changes like flying or swimming.
Credit: © David Garry / Fotolia

A developmental biologist at New York Medical College is proposing a new theory of the origin of birds, which traditionally has been thought to be driven by the evolution of flight. Instead, Stuart A. Newman, Ph.D., credits the emergence of enlarged skeletal muscles as the basis for their upright two-leggedness, which led to the opportunity for other adaptive changes like flying or swimming. And it is all based on the loss of a gene that is critical to the ability of other warm-blooded animals to generate heat for survival.

Dr. Newman, a professor of cell biology and anatomy, studies the diversity of life and how it got that way. His research has always centered on bird development, though this current study, "Thermogenesis, muscle hyperplasia, and the origin of birds," also draws from paleontology, genetics, and the physiology of fat.

Dr. Newman draws on earlier work from his laboratory that provided evidence for the loss, in the common dinosaur ancestors of birds and lizards, of the gene for uncoupling protein-1 (UCP1). The product of this gene is essential for the ability of "brown fat," tissue that protects newborns of mammals from hypothermia, to generate heat. In birds, heat generation is mainly a function of skeletal muscles.

"Unlike the scenario in which the evolution of flight is the driving force for the origin of birds, the muscle expansion theory does not require functionally operative intermediates in the transition to flight, swimming, or winglessness, nor does it require that all modern flightless birds, such as ostriches and penguins, had flying ancestors. It does suggest that the extinction of non-avian dinosaurs may have been related to a failure to evolve compensatory heat-generating mechanisms in face of the loss of UCP1," says the scientist


Story Source:

The above story is based on materials provided by New York Medical College. Note: Materials may be edited for content and length.


Journal References:

  1. Stuart A. Newman. Thermogenesis, muscle hyperplasia, and the origin of birds. BioEssays, 2011; DOI: 10.1002/bies.201100061
  2. Nadejda V Mezentseva, Jaliya S Kumaratilake, Stuart A Newman. The brown adipocyte differentiation pathway in birds: An evolutionary road not taken. BMC Biology, 2008; 6 (1): 17 DOI: 10.1186/1741-7007-6-17

Cite This Page:

New York Medical College. "New theory on origin of birds: Enlarged skeletal muscles." ScienceDaily. ScienceDaily, 2 July 2011. <www.sciencedaily.com/releases/2011/06/110622115317.htm>.
New York Medical College. (2011, July 2). New theory on origin of birds: Enlarged skeletal muscles. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2011/06/110622115317.htm
New York Medical College. "New theory on origin of birds: Enlarged skeletal muscles." ScienceDaily. www.sciencedaily.com/releases/2011/06/110622115317.htm (accessed September 17, 2014).

Share This



More Fossils & Ruins News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) — Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Museum Traces Fragments of Star-Spangled Banner

Museum Traces Fragments of Star-Spangled Banner

AP (Sep. 12, 2014) — As the Star-Spangled Banner celebrates its bicentennial, Smithsonian curators are still uncovering fragments of the original flag that inspired Francis Scott Key's poem. (Sept. 12) Video provided by AP
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. Video provided by Newsy
Powered by NewsLook.com
Meet Spinosaurus, the First-Known Water Dinosaur

Meet Spinosaurus, the First-Known Water Dinosaur

AFP (Sep. 11, 2014) — Spinosaurus aegyptiacus was adapted for both land and water, and an exhibit featuring a life-sized model, based on new fossils unearthed in eastern Morocco, opens at the National Geographic Museum in Washington on Friday. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins