PhD student Naoki Morimoto, member of the Computer-Assisted Paleoanthropology group of Ch. Zollikofer and M. Ponce de León, and junior author of the study, was surprised by his own findings. Although humans are bipeds, and chimps are quadrupeds, muscle attachment sites at their thighbones are quite similar.
Great ape virtopsy: virtual preparation of skin, muscles, and bone of a young chimpanzee. UZH
Muscle attachment areas on the right thighbone (seen from lateral-posterior): During human-chimp evolution, the hip extensor muscle glutaeus maximus (GM) has «moved» from below to above a conspicuous bony crest (black arrowheads). In gorillas the GM muscle is situated below the crest, together with the vastus lateralis (VL) muscle. UZH
Attachment sites differ substantially, however, between chimpanzees and gorillas, although these great apes species move similarly. Interestingly, Morimoto’s results are in line with insights from genetics: humans and chimps are evolutionary sister species, while gorillas are more distant relatives, like cousins. Morimoto explains the seeming paradox of his results: this is not «form follows function», but «form follows family».
Functional inferences: a cautionary tale
The new findings have far-reaching implications for the interpretation of fossil hominin remains. Fossil thighbone shafts are often well preserved, but it now appears that inferences about locomotor behavior must be drawn with caution, while inferences about the fossil’s evolutionary relationships might be more straightforward. Anthropologist Ch. Zollikofer explains: «the transition from great-ape-like quadrupedal to human-like bipedal locomotion is accompanied by several changes in the hip and thighbones, but currently we cannot infer functional change from structural change with any certainty.» And he asks the next big question of paleoanthropology: «Why did the last common ancestor of humans and chimps, who might have lived 7-8 million years ago, evolve novel thighbone features?»
To get a detailed look at great ape musculoskeletal anatomy, the research team combined high-resolution computed tomography with computer-assisted virtual dissection. Great ape bodies are a scarce and valuable resource for scientific studies, and anthropologists are increasingly reluctant to «sacrifice» them for anatomical dissections. Virtual autopsy – or Virtopsy – is the method of choice. Virtopsy was pioneered by Michael Thali (Institute of Forensic Science, UZH), and is now used in forensic institutes worldwide. Anthropological virtopsy has enormous potential, as it permits virtual dissection of one single specimen by many different researchers, and according to many different criteria, without actually deteriorating the orginal body. Moreover, great ape virtopsy gives an immediate picture of the spatial relationships between soft and hard tissues (bones) of one and the same individual. Traditionally, bone morphology was studied on dry-skeleton specimens, and subsequently combined with muscle data obtained from dissections of other animals.
Acquiring 3D tomographic data of great ape bodies, however, is a complex endeavor, which requires collaboration across disciplines. To reach these goals, the «Visible Ape Consortium» was established, which has become an example of efficient transdisciplinary research at UZH (see below).
Naoki Morimoto, Marcia S. Ponce De Leόn, Takeshi Nishimura and Christoph P.E. Zollikofer: Femoral Morphology and Femoropelvic Musculoskeletal Anatomy of Humans and Great Apes: A Comparative Virtopsy Study, in: The Anatomical Record, 294:1433–1445 (2011), DOI 10.1002/ar.21424The Visible Ape Consortium:
Beat Müller | idw
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
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...
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....
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...
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...
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...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research