Featured Research

from universities, journals, and other organizations

Fossils of horse teeth indicate 'you are what you eat'

Date:
March 4, 2011
Source:
New York Institute of Technology
Summary:
Fossil records verify a long-standing theory that horses evolved through natural selection. Scientists arrived at the conclusion after examining the teeth of 6,500 fossil horses representing 222 different populations of more than 70 extinct horse species.

Horses. Fossil records verify a long-standing theory that horses evolved through natural selection.
Credit: iStockphoto

Fossil records verify a long-standing theory that horses evolved through natural selection, according to groundbreaking research by two anatomy professors at New York College of Osteopathic Medicine (NYCOM) of New York Institute of Technology.

Working with colleagues from Massachusetts and Spain, Matthew Mihlbachler, Ph.D., and Nikos Solounias, Ph.D. arrived at the conclusion after examining the teeth of 6,500 fossil horses representing 222 different populations of more than 70 extinct horse species. The records, spanning the past 55 million years, indicate a "critical" lag time between the evolution of horse teeth and dietary changes resulting from climate change.

The breakthrough findings were published in the March 4 issue of the journal Science.

"One of the advantages of studying extinct creatures like prehistoric horses is we can look at how animals responded to their environments over millions of years -- something that biologists who study living species cannot do," Mihlbachler said, adding that the biggest surprise of the study was that while some of the extinct populations they examined had extremely abrasive diets, much of the time, it seemed horses had it surprisingly easy. This suggests that "strong natural selection" for different types of teeth only happened occasionally during brief intervals in horse history.

Solounias helped develop a methodology known as dental mesowear analysis to reconstruct the diets of extinct species by measuring food-related wear and tear on fossil teeth. He and Mihlbachler used the process to investigate wear patterns on the molars of thousands of fossil horses. They later analyzed their data alongside records of North American climate changes that would have shifted the animals' diets from rainforest fruits and woody, leafy vegetation to the more abrasive diets found in grasslands.

"Lag time in the evolution of horse teeth in comparison to dietary changes is critical," Mihlbachler explained. "We found that evolutionary changes in tooth anatomy lag behind the dietary changes by a million years or more."

While paleontologists have long held horses as classic examples of evolution through natural selection, the theory has been difficult to test because the majority of horse species are extinct. However, Mihlbachler and Solounias' observation that dental changes in horses follow their dietary changes is consistent with evolution due to adaptation.

"'You are what you eat': we hear this all the time, but now we know it is true," explained Thomas Scandalis, Dean of NYCOM. "This study shows that the evolutionary path of horses as we know them today was affected by the food available to their prehistoric ancestors."

The duo's research shows that not only has the number of horse species been greatly reduced in the past few million years, but also that the diets of horses have been narrowly restricted. "Living horses are anything but typical examples of the dietary ecology of this once great group of mammals," Solounias said.


Story Source:

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


Journal Reference:

  1. Matthew C. Mihlbachler, Florent Rivals, Nikos Solounias and Gina M. Semprebon. Dietary Change and Evolution of Horses in North America. Science, 4 March 2011: Vol. 331 no. 6021 pp. 1178-1181 DOI: 10.1126/science.1196166

Cite This Page:

New York Institute of Technology. "Fossils of horse teeth indicate 'you are what you eat'." ScienceDaily. ScienceDaily, 4 March 2011. <www.sciencedaily.com/releases/2011/03/110303141542.htm>.
New York Institute of Technology. (2011, March 4). Fossils of horse teeth indicate 'you are what you eat'. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2011/03/110303141542.htm
New York Institute of Technology. "Fossils of horse teeth indicate 'you are what you eat'." ScienceDaily. www.sciencedaily.com/releases/2011/03/110303141542.htm (accessed July 22, 2014).

Share This




More Plants & Animals News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
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