Subscribe to our free daily newsletters
  Space Travel News  




Subscribe to our free daily newsletters



A New Approach To Reconstructing The Biology Of Extinct Species

A computer reconstruction of an adult female baboon skull from high-resolution x-ray computed tomography (CT) slices. The skull is rendered transparent to show the position of the three semicircular canals and cochlea of left inner ear filled in red. The enlargement of the canals and cochlea is five times the size of the canals shown in the skull. Each canal is approximately 5 mm in diameter. Credit: Alan Walker lab, Penn State
by Staff Writers
University Park PA (SPX) Jun 20, 2007
An international research team has documented the link between the way an animal moves and the dimensions of an important part of its organ of balance, the three semicircular canals of the inner ear on each side of the skull. The team's article on its research will be published on 26 June in the print edition of the Proceedings of the National Academy of Sciences and in the journal's online early edition during the week of 18 to 22 June.

"We have shown that there is a fundamental adaptive mechanism linking a species' locomotion with the sensory systems that process information about its environment," says Alan Walker, Evan Pugh Professor of Anthropology and Biology at Penn State University, one of the team's leaders. The researchers studied 91 separate primate species, including all taxonomic families. The study also included 119 additional species, most of which are mammals ranging in size from mouse to elephant, that habitually move in diverse ways in varied environments.

The project is the first large-scale study to document the relationship of the dimensions of the semicircular canals to locomotion. These structures are filled with a fluid, which moves within the canals when the animal moves. The fluid's movement is sensed by special cells that send signals to the brain, triggering the neck and eye muscles to reflexively keep the visual image stable.

The basic hypothesis of the project was that the organ of balance -- which helps stabilize an animal's gaze and coordinate its movements as it travels through the environment -- should be irrevocably linked to the type of locomotion produced by its limbs.

"If an animal evolves a new way of moving about the world, its organ of balance must evolve accordingly," Walker explains. From the visual information, the animal tracks its position relative to stationary objects such as tree trunks, branches, rocks or cliffs, or the ground. Having a stable image of the environment is especially crucial for acrobatic animals that leap, glide, or fly.

To make the discovery, the scientists scanned skull samples of each species, measuring the size of each semicircular canal and calculating the radius of curvature. Most of the specimens were scanned at the Center for Quantitative Imaging at Penn State on the OMNI-X high-resolution x-ray CT scanner, which can resolve features approximately 1/100 the size of those detected by medical CT scanners.

In addition, experienced field workers used personal knowledge or film of animals in the wild to classify species into one of six locomotor categories ranging from very slow and deliberate to fast and agile. The scientists then compared the canal size of each species to its category of movement.

The results revealed a highly significant statistical relationship between the radius of curvature of the semicircular canals and the species' habitual way of moving. More acrobatic species consistently have semicircular canals with a larger radius of curvature than do slower-moving ones.

For example, a small, fast-moving leaper like a bushbaby has semicircular canals that are relatively and absolutely much bigger than those of the similar-sized, slow-moving loris. However, because larger animals have absolutely larger canals, the analysis had to take body size into account. The research revealed that this functional tie between the semicircular canals and locomotor pattern is evident both within the primates alone and within the entire mammalian sample.

"How an animal moves is a basic adaptation," says Walker, an expert in primate locomotion. "Now we have a way to reconstruct how extinct species moved that is completely independent of analysis of the limb structure. For the first time, we can test our previous conclusions using a new source of information."

Co-leader of the team was Fred Spoor, Professor of Anatomy at University College, London. Spoor originally studied a small number of species for his doctoral research and suggested conducting a detailed investigation using modern techniques. Other researchers on the project were Professor of Biology Theodore Garland Jr. of the University of California, Riverside; Senior Instructional Design Consultant Gail Krovitz, of the eCollege company; Research Associate in Anthropology Timothy M. Ryan of Penn State University; and Associate Professor of Anthropology Mary T. Silcox of the University of Winnipeg in Canada.

Related Links
Penn State
Explore The Early Earth at TerraDaily.com



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


When Fungi Ruled The World
Moffett Field CA (SPX) Jun 19, 2007
Starting about 420 million years ago, a bizarre cylindrical life form called Prototaxites (pro-tow-TAX-i-tees) became a prominent element of the terrestrial landscape. Up to 8 meters tall, and as much as 1 meter in diameter, Prototaxites has confounded paloebotanists for nearly a century and a half. "It's large and strange, and people have debated what it was for very long time," says C. Kevin Boyce of the University of Chicago, first author of a new paper on Prototaxites in Geology (May 2007).







  • Air Force Continues Northrop Grumman Contract For Upper Stage Engine Program
  • World's Largest Vacuum Chamber To Test Orion
  • China To Increase Payload Capacity Of Carrier Rockets
  • SpaceDev, SpaceHab And Constellation Services Sign NASA Space Act Agreements

  • 2006 Bumper Year For Satellite Launcher Arianespace
  • SES Signs For Five ILS Protons Through 2013
  • ILS Wins Arabsat-5A Contract To Launch On Proton Breeze M
  • Dawn Spacecraft Never Damaged Set To Launch July 7

  • Astronauts Set For Return To Earth On Shuttle Atlantis
  • Sharp Group Devises Tank Sander
  • Two Atlantis Space Walkers Work On ISS Solar Arrays
  • Atlantis Shuttle Mission Lengthened For Repair Job

  • Station And Shuttle Crews Close Hatches And Prep For Undocking Tuesday
  • STS-117 Shuttle Crew Conduct Fourth And Final Spacewalk About Space Station
  • Astronauts Fix Computers On ISS And Repair Shuttle Thermal Blanket
  • Computer Woes Strike International Space Station

  • NASA Nanotechnology Space Sensor Test Successful In Orbit
  • Suni Williams Sets New Record For Women In Space
  • EADS To Offer Tourist Spacecraft By 2012
  • Stardust Memories As Space Becomes The Final Frontier In Funerals

  • China To Launch Third Sino-Brazilian Satellite In September
  • China Launches Satellite To Take TV Signal Nationwide
  • China Launches Communications Satellite SinoSat-3
  • China Aims To Launch Moon Probe This Year

  • Japanese Robot Receptionists For Hire
  • Japanese Researchers Help Robots Brush Up Communication Skills
  • Guessing Robots Predict Their Environments For Better Navigation
  • Saving Robots To Save Battlefield Lives

  • Spirit Gets A Solar Panel Spring Clean
  • ESA Wants Space Pioneers For 520-Day Mars Experiment
  • An Opportunity To Take A Captain Cook At Duck Bay
  • Euopean Rover ExoMars On Target For 2013 Launch

  • The content herein, unless otherwise known to be public domain, are Copyright Space.TV Corporation. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space.TV Corp on any Web page published or hosted by Space.TV Corp. Privacy Statement