Featured Research

from universities, journals, and other organizations

Discovery of 1.4 million-year-old fossil human hand bone closes human evolution gap

Date:
December 16, 2013
Source:
University of Missouri-Columbia
Summary:
Scientists have found a new hand bone from a human ancestor who roamed the earth in East Africa approximately 1.42 million years ago. The discovery of this bone is the earliest evidence of a modern human-like hand, indicating that this anatomical feature existed more than half a million years earlier than previously known.

The styloid process is a projection of bone. Ward and her team found a styloid process at the end of a wrist bone more than 1.42 million years old, indicating this anatomical feature existed more than half a million years earlier than previously known.
Credit: University of Missouri

Humans have a distinctive hand anatomy that allows them to make and use tools. Apes and other nonhuman primates do not have these distinctive anatomical features in their hands, and the point in time at which these features first appeared in human evolution is unknown. Now, a University of Missouri researcher and her international team of colleagues have found a new hand bone from a human ancestor who roamed the earth in East Africa approximately 1.42 million years ago. They suspect the bone belonged to the early human species, Homo erectus. The discovery of this bone is the earliest evidence of a modern human-like hand, indicating that this anatomical feature existed more than half a million years earlier than previously known.

Related Articles


"This bone is the third metacarpal in the hand, which connects to the middle finger. It was discovered at the 'Kaitio' site in West Turkana, Kenya," said Carol Ward, professor of pathology and anatomical sciences at MU. The discovery was made by a West Turkana Paleo Project team, led by Ward's colleague and co-author Fredrick Manthi of the National Museums of Kenya. "What makes this bone so distinct is that the presence of a styloid process, or projection of bone, at the end that connects to the wrist. Until now, this styloid process has been found only in us, Neandertals and other archaic humans."

The styloid process helps the hand bone lock into the wrist bones, allowing for greater amounts of pressure to be applied to the wrist and hand from a grasping thumb and fingers. Ward and her colleagues note that a lack of the styloid process created challenges for apes and earlier humans when they attempted to make and use tools. This lack of a styloid process may have increased the chances of having arthritis earlier, Ward said.

The bone was found near sites where the earliest Acheulian tools have appeared. Acheulian tools are ancient, shaped stone tools that include stone hand axes more than 1.6 million years old. Being able to make such precise tools indicates that these early humans were almost certainly using their hands for many other complex tasks as well, Ward said.

"The styloid process reflects an increased dexterity that allowed early human species to use powerful yet precise grips when manipulating objects. This was something that their predecessors couldn't do as well due to the lack of this styloid process and its associated anatomy," Ward said. "With this discovery, we are closing the gap on the evolutionary history of the human hand. This may not be the first appearance of the modern human hand, but we believe that it is close to the origin, given that we do not see this anatomy in any human fossils older than 1.8 million years. Our specialized, dexterous hands have been with us for most of the evolutionary history of our genus, Homo. They are -- and have been for almost 1.5 million years -- fundamental to our survival."

The study was published in the Proceedings of the National Academy of Sciences this week. Members of Ward's team who helped discover and analyze the bone include: Matthew Tocheri, National Museum of Natural History in the Smithsonian Institution; J. Michael Plavcan, University of Arkansas; Francis Brown, University of Utah; and Fredrick Manthi, National Museums of Kenya.


Story Source:

The above story is based on materials provided by University of Missouri-Columbia. The original article was written by Jerett Rion. Note: Materials may be edited for content and length.


Journal Reference:

  1. Carol V. Ward, Matthew W. Tocheri, J. Michael Plavcan, Francis H. Brown, and Fredrick Kyalo Manthi. Early Pleistocene third metacarpal from Kenya and the evolution of modern human-like hand morphology. PNAS, December 16, 2013 DOI: 10.1073/pnas.1316014110

Cite This Page:

University of Missouri-Columbia. "Discovery of 1.4 million-year-old fossil human hand bone closes human evolution gap." ScienceDaily. ScienceDaily, 16 December 2013. <www.sciencedaily.com/releases/2013/12/131216154902.htm>.
University of Missouri-Columbia. (2013, December 16). Discovery of 1.4 million-year-old fossil human hand bone closes human evolution gap. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2013/12/131216154902.htm
University of Missouri-Columbia. "Discovery of 1.4 million-year-old fossil human hand bone closes human evolution gap." ScienceDaily. www.sciencedaily.com/releases/2013/12/131216154902.htm (accessed October 24, 2014).

Share This



More Fossils & Ruins News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Oldest Bone Ever Sequenced Shows Human/Neanderthal Mating

Oldest Bone Ever Sequenced Shows Human/Neanderthal Mating

Newsy (Oct. 23, 2014) A 45,000-year-old thighbone is showing when humans and neanderthals may have first interbred and revealing details about our origins. Video provided by Newsy
Powered by NewsLook.com
Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Newsy (Oct. 23, 2014) You've probably seen some weird-looking dinosaurs, but have you ever seen one this weird? It's worth a look. Video provided by Newsy
Powered by NewsLook.com
Goofy Dinosaur Blends Barney and Jar Jar Binks

Goofy Dinosaur Blends Barney and Jar Jar Binks

AP (Oct. 22, 2014) A collection of dinosaur bones reveal a creature that is far more weird and goofy-looking than scientists originally thought when they found just the arm bones nearly 50 years ago, according to a new report in the journal Nature. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Sunken WWII U-Boat That Fired On U.S. Convoy Found

Sunken WWII U-Boat That Fired On U.S. Convoy Found

Newsy (Oct. 22, 2014) U-576, a long-lost German U-boat the U.S. sank in 1942, has been found just 30 miles off North Carolina's coast and near the wreckage of another ship. 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:

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