Reporting in this week’s PLoS ONE in a study funded by the National Geographic Society Mission Programs, Lee Berger and colleagues from the University of the Witwatersrand, Rutgers University and Duke University, describe the fossils of small-bodied humans from the Micronesian island of Palau. These people inhabited the island between 1400 and 3000 years ago and share some – although not all – features with the H. floresiensis specimens.
Palau is situated in the Western Caroline Islands and consists of a main island of Babeldaob, with hundreds of smaller rock islands to the south west, colloquially known as the ‘‘rock islands.” These rock islands contain caves and rock shelters, in many of which, fossilized and subfossilized human remains have been found. The specimens described by Berger and colleagues came from two such caves, Ucheliungs and Omedokel, which appear to have been used as burial sites. In both caves, they found skeletons of individuals who would have been small even relative to other such populations and are approximately the size of H. floresiensis or small members of the genus Australopithecus. These fossils were radiocarbon dated to between 1410 and 2890 years ago. The entrance to Omedokel cave also contained the remains of larger individuals dated to between 940 and 1080 years ago.
These two caves have provided and will continue to provide a wealth of specimens, which will need more intensive study. However, preliminary analysis of more than a dozen individuals including a male who would have weighed around 43 kg and a female of 29 kg, show that these small-bodied people had many craniofacial features considered unique to H. sapiens. These include: a distinct maxillary canine fossa, a clearly delimited mandibular mental trigone (in most specimens), moderate bossing of the frontal and parietal squama, a lateral prominence on the temporal mastoid process, reduced temporal juxtamastoid eminences and an en maison cranial vault profile with the greatest interparietal breadth high on the vault. Thus, these individuals are likely to be from a human population who acquired reduced stature, for some reason.
It is well established that populations living on isolated islands often consist of individuals of smaller stature than their mainland cousins – a phenomenon known as island dwarfism. This is true not just for humans but for many animals including extinct mammoths and elephants from islands off Siberia, California and even in the Mediterranean. Alternatively, the island may have been colonized by a few small individuals, between 3,000 and 4,000 years ago who, through extensive inbreeding, and other environmental drivers, produced a small-bodied population, which continued to inhabit Palau until at least 1400 years ago.
As well as having characteristics of H. sapiens, the Palau fossils also have features seen in H. floresiensis, such as their small bodies and faces, pronounced supraorbital tori, non-projecting chins, relative megadontia, expansion of the occlusal surface of the premolars, rotation of teeth within the maxilla and mandible, and dental agenesis. Berger and colleagues do not infer from these features any direct relationship between the peoples of Palau and Flores; however, these observations do suggest that at least some of the features which have been taken as evidence that the Flores individuals are members of a separate species, may be a common adaptation in humans of reduced stature.
Detailed analysis of the Palau specimens is unlikely to settle arguments over the status of H. floresiensis as there are features of Flores man, such as small brain size, not found in the people of Palau. Nevertheless, they do suggest that at least some of the unusual features seen in Flores are a result of environment rather than ancestral heritage. Above all, the skeletons from Palau should greatly increase our understanding of the process of island dwarfism in human populations and of the ancient colonizations of Oceania.
A documentary on Professor Lee Berger's findings, "Mystery Skulls of Palau" premieres Monday, March 17 at 10 PM on the National Geographic Channel in the U.S.
Rebecca Walton | alfa
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences