The findings were discovered in the Qesem Cave, a pre-historic site located near Rosh Ha'ayin that was first excavated in 2000. Prof. Avi Gopher and Dr. Ran Barkai of Tel Aviv University's Department of Archaeology, who run the excavations, and Prof. Israel Hershkowitz of the university's Department of Anatomy and Anthropology and Sackler School of Medicine, together with an international team of scientists, performed a morphological analysis on eight human teeth found in the Qesem Cave.
This analysis, which included CT scans and X-rays, indicates that the size and shape of the teeth are very similar to those of modern humans. The teeth found in the Qesem Cave are very similar to other evidence of modern humans from Israel, dated to around 100,000 years ago, discovered in the Skhul Cave in the Carmel and Qafzeh Cave in the Lower Galilee near Nazareth. The results of the researchers' findings are being published in the American Journal of Physical Anthropology.
Reading the past
Qesem Cave is dated to a period between 400,000 and 200,000 years ago, and archaeologists working there believe that the findings indicate significant evolution in the behavior of ancient humans. This period of time was crucial in the history of humankind from cultural and biological perspectives. The teeth that are being studied indicate that these changes are apparently related to evolutionary changes taking place at that time.
Prof. Gopher and Dr. Barkai noted that the findings related to the culture of those who dwelled in the Qesem Cave -- including the systematic production of flint blades; the regular use of fire; evidence of hunting, cutting and sharing of animal meat; mining raw materials to produce flint tools from subsurface sources -- reinforce the hypothesis that this was, in fact, innovative and pioneering behavior that may correspond with the appearance of modern humans.
An unprecedented discovery
According to researchers, the discoveries made in the Qesem Cave may overturn the theory that modern humans originated on the continent of Africa. In recent years, archaeological evidence and human skeletons found in Spain and China also undermined this proposition, but the Qesem Cave findings because of their early age is an unprecedented discovery.
Excavations at Qesem Cave continue and the researchers hope to uncover additional finds that will enable them to confirm the findings published up to now and to enhance our understanding of the evolution of humankind -- especially the emergence of modern man.
history and science
Tuesday, February 1, 2011
New Appreciation of the Ecology-Evolution Dynamic
A classic example of ecology influencing evolution is seen in a Galápagos ground finch, Geospiza fortis. In this species, larger beaks dominated the population after dry years when large seeds were more abundant. After wet years, the direction of natural selection reversed, favoring smaller beaks that better handled the small seeds produced in the wet environment.
Environmental factors had given birds with certain genes a survival advantage.
But does evolution affect ecology over similar time scales? Scientists are increasingly thinking that the answer is yes, says Schoener, who points toward numerous examples of organisms evolving rapidly. This sets the stage for the possibility that evolutionary dynamics routinely interact with ecological dynamics.
Schoener writes: "If ecology affects evolution (long supported) and evolution affects ecology (becoming increasingly supported), then what? The transformed ecology might affect evolution, and so on, back and forth in a feedback loop."
Still to be discovered in this emerging field of "eco-evolutionary dynamics," he concludes, is just how much evolutionary changes substantially affect ecological traits such as species populations and community structure. Schoener calls for a major research effort to find out.
The study was supported by grants from the National Science Foundation.
In an unusual occurrence, Schoener is a co-author of a second paper in the same issue of Science. His former doctoral student, Jonah Piovia-Scott, is that paper's lead author.
Environmental factors had given birds with certain genes a survival advantage.
But does evolution affect ecology over similar time scales? Scientists are increasingly thinking that the answer is yes, says Schoener, who points toward numerous examples of organisms evolving rapidly. This sets the stage for the possibility that evolutionary dynamics routinely interact with ecological dynamics.
Schoener writes: "If ecology affects evolution (long supported) and evolution affects ecology (becoming increasingly supported), then what? The transformed ecology might affect evolution, and so on, back and forth in a feedback loop."
Still to be discovered in this emerging field of "eco-evolutionary dynamics," he concludes, is just how much evolutionary changes substantially affect ecological traits such as species populations and community structure. Schoener calls for a major research effort to find out.
The study was supported by grants from the National Science Foundation.
In an unusual occurrence, Schoener is a co-author of a second paper in the same issue of Science. His former doctoral student, Jonah Piovia-Scott, is that paper's lead author.
Subscribe to:
Comments (Atom)