Featured Research

from universities, journals, and other organizations

Decoding slowness: How sloths perfected energy saving

Date:
July 20, 2011
Source:
Friedrich Schiller University Jena
Summary:
Zoologists have discovered how sloths move and how their locomotive system adapted to their unhurried lifestyle in the course of evolution.

Sloth Julius is accustomed by John Nyakatura to the climbing pole while being fed.
Credit: Image courtesy of Friedrich Schiller University Jena

Zoologists of the Friedrich Schiller University Jena (Germany) have discovered how sloths move and how their locomotive system adapted to their unhurried lifestyle in the course of evolution.

Related Articles


Sloths spend most of their lives hanging in trees upside down. If they have to move, they do so only slowly. Very slowly. But why are sloths so 'lazy'? And how has the locomotive system of these creatures adapted to their unhurried lifestyle in the course of evolution? Zoologists of the Friedrich Schiller University Jena (Germany) have looked into the matter comprehensively.

"To our great surprise the locomotion of the sloths is basically not so different from the locomotion of other mammals, like monkeys for instance, which instead of hanging from tree branches, balance along them," says Dr. John Nyakatura. In his doctoral thesis at the Institute of Systematic Zoology and Evolutionary Biology with Phyletic Museum the evolutionary biologist analyzed the locomotion of sloths with X-ray video equipment. That was not so easy at the beginning, as the first sloth stepping in front of the camera for the Jena scientist simply refused to work. "Mats, the sloth, just didn't want to co-operate," Nyakatura remembers, smiling. Therefore it was given to a zoo and made headlines around the globe as the 'laziest animal in the world'.

In comparison, the two-toed sloths Evita, Julius and Lisa appeared to be more co-operative. They brachiated along the provided pole in the X-ray tube. "The position of their legs and the bending of their joints matches exactly those of other mammals in the process of walking," Nyakatura explains. Hence one could imagine the locomotion of sloths actually as 'walking' under a tree. Just much slower than other quadrupeds.

However, the evolutionary biologist found distinct differences in the anatomical structure of the animals. "Sloths have very long arms, but only very short shoulder blades (scapulae), being able to move freely on top of a narrow, rounded chest. This lends them a maximum radius of movement." Moreover a dislocation of certain muscular contact points occurred which enabled them to keep their own body weight with a minimum of energy input. "In the evolution of the sloths the adaptation to the slow, energy saving way of movement occurred solely through their anatomy," John Nyakatura sums up. What was even more astonishing, this principle developed in two cases independent of each other: in the two-toed sloths and in the three-toed sloths. But although the outward appearance and lifestyle of the animals may lead to the assumption of them being related to each other, these two families are, from an evolutionary point of view, only distant relations.

"With their mode of life the sloths are filling an ecological niche," adds Prof. Dr. Martin S. Fischer, who oversaw John Nyakatura's doctoral thesis. "Sloths lead their lives in energy saving mode." Their usage of energy saving food in connection with an unobtrusive lifestyle turns them into complete 'models of energy saving' among the mammals, according to the Jena Professor of systematic zoology and evolutionary biology. And this was a well-known recipe for success -- completely unrelated to 'laziness'.

Meanwhile John Nyakatura and his colleagues are not analyzing sloths any more -- those have returned to the Zoo in Dortmund. Now the Jena researchers are applying themselves to the movement of birds.


Story Source:

The above story is based on materials provided by Friedrich Schiller University Jena. Note: Materials may be edited for content and length.


Cite This Page:

Friedrich Schiller University Jena. "Decoding slowness: How sloths perfected energy saving." ScienceDaily. ScienceDaily, 20 July 2011. <www.sciencedaily.com/releases/2011/07/110719072721.htm>.
Friedrich Schiller University Jena. (2011, July 20). Decoding slowness: How sloths perfected energy saving. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2011/07/110719072721.htm
Friedrich Schiller University Jena. "Decoding slowness: How sloths perfected energy saving." ScienceDaily. www.sciencedaily.com/releases/2011/07/110719072721.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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