Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study of Ancient Primate Counters "Darwinus" Discovery

23.10.2009
A scientific analysis of a recently discovered adapiform, an ancient primate, reveals that the fossil, called Afradapis, is not on the evolutionary lineage of anthropoids (Old World Monkeys and higher primates, including humans) but instead more closely to lemurs and lorises.

Led by Stony Brook University paleontologist Erik R. Seiffert, Ph.D., the research supports the more commonly held theory on adapiform evolution and refutes a claim earlier in 2009 by scientists that described another adapiform, called Darwinius, as a direct link to the lineage leading to higher primates. The study findings are reported in the October 22 issue of Nature.

The study of Afradapis, recently discovered in northern Egypt, involves a complete analysis of the jaw and teeth that reconstructs the most likely evolutionary tree of the 37 million year-old fossil. Dr. Seiffert and colleagues used a scientific method called parsimony evidence that compares Afradapis’ jaw and teeth across 117 living and extinct primates.

“Our analysis is the first to incorporate evidence from all the key players in the anthropoid origins debate, that is all of the fossil species that have been proposed as possible early anthropoids, including a large sampling of adapiform primates,” says Dr. Seiffert, Assistant Professor in the Department of Anatomical Sciences, Stony Brook University. “The adapiform lineage that includes Darwinius and Afradapis has been particularly controversial, and we are finding new evidence that allows us to be increasingly confident that the anatomical features that these adapiforms share with anthropoids are due to convergent evolution and not common ancestry.”

The controversy on the adapiform evolutionary line escalated when a team of European and American paleontologists reported in the May 19, 2009, online edition of PloS One that their two-year analysis of Darwinius indicates the adapiform is the first link to all humans, supporting a common ancestry theory. Some media publicized their finding that the “missing link” to anthropoids had been found.

Conversely, Dr. Seiffert and colleagues’ analysis of Afradapis, and thus ancient adapiforms, supports the convergence evolutionary theory and contributes to a growing body of evidence that indicates that convergent evolution was a common phenomenon in early primate evolution. Convergent evolution is a process in which organisms and animals become similar in shape or structure, in response to similar environmental conditions, despite that their evolutionary lineage is different.

Dr. Seiffert explains that the common ancestry theory of adapiforms linking them more closely to higher primates than lemurs hinges on features such as fusion of the two halves of the jaw, reduction and loss of the first frew premolar teeth, and the presence of front teeth (incisors) that are shaped like a spatula. However, he points out that the study of Afradapis shows the fusion of the two halves of the jaw clearly evolved convergently in adapiforms and anthropoids, as even the earliest anthropoids have unfused mandibles.

“Incisor teeth that are shaped like a spatula might have been present in the last common ancestor or all primates, and so would not specifically support a link between adapiforms and anthropoids,” adds Dr. Seiffert. “Our analysis also indicates that the reduction and/or loss of the first few premolars must have evolved convergently in adapiforms and anthropoids because of some of Afradapis’ close relatives retain a full complement of four premolars on each side of the jaw, as in many other early mammalian relatives of primates.”

In the anatomical analysis published in Nature titled “Convergent evolution of anthropoid-like adaptations in Eocene adapiform primates,” the authors point out that at the very least Afradapis, the largest non-anthropoid primate ever documented in Afro-Arabia, provides surprising new evidence for primitive primate diversity in the Eocene era of Africa. They also contend that their findings raise the possibility that ecological competition between adapiforms and higher primates, based on environmental and geography changes, led to anatomical adaptations by both and played an important roles during early primate evolution.

The research for the study was supported by the Research Foundation of the State University of New York, and grants from the U.S. National Science Foundation and The Leakey Foundation.

In addition to Dr. Seiffert, co-authors of the study include: Jonathan M. G. Perry, Department of Anatomy, Midwestern University; Elwyn L. Simons, Division of Fossil Primates, Duke Lemur Center, Duke University; and Doug M. Boyer, Department of Ecology & Evolution, Stony Brook University.

The Department of Anatomical Sciences is one of 25 departments within Stony Brook University School of Medicine. The department includes graduate and doctoral programs in Anatomical Sciences. Fields of study include research on human evolutionary anatomy, morphology and vertebrate paleontology. Many faculty members in the department are also participants in an interdepartmental graduate program in anthropological sciences that is recognized worldwide for its faculty and research strengths in functional morphology and human evolution.

Greg Filiano | Newswise Science News
Further information:
http://www.stonybrook.edu
http://commcgi.cc.stonybrook.edu/artman/publish/index.shtml

More articles from Earth Sciences:

nachricht NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center

nachricht The melting ice makes the sea around Greenland less saline
16.10.2017 | Aarhus University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>