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Path of human evolution continues to be enriched and elucidated by growing trove of fossil evidence

In comments to the media, renowned paleoanthropologist Richard Leakey opined that the evolution debate "would soon be over" thanks to a growing wealth of fossil evidence.  The latest piece of the puzzle comes courtesy of Professor Leakey's wife, Meave Leakey, and his mother, Louise Leakey, who are busy working on the excavation of a site east of Lake Turkana.

I. Two New Branches on the Evolutionary Tree

Located in Eastern Africa, specifically in the north of Kenya and south of Ethiopia, the Turkana Basin has been the site of some of many astonishing and fortunate fossil discoveries that have given mankind a glimpse of its evolutionary ancestors.  In fact the region proved so fruitful that the Leakey family of famed anthropologists raised funds to open Turkana Basin Institute (TBI), a special research institution devoted to studying the region's fossils and human evolution.

The recent discoveries were made by Professors Louise and Meave Leakey, along with other TBI researchers and researchers from the Koobi Fora Research Project (KFRP) -- a evolutionary research team funded by the National Geographic Society.

Lake Turkana Basin
The Turkana basin is located in Eastern Africa. [Orig. Image Source: Google Maps]

Unearthed between 2007 and 2009, the find includes a face, a remarkably complete lower jaw, and part of a second lower jaw.  Researchers believe that the fossils belong to not one, but two genus Homo species, which lived beside mankind's direct ancestor, Homo erectus.

II. Solving a Big Mystery

The find solves the mystery of KNM-ER 1470 -- the research designation given to a mysterious hominid skull fossil found four decades ago.  The KNM-ER 1470 specimen featured a striking long, flat-face -- à la the pop culture depiction of an alien -- and a large brain size.

Researchers were unsure if the fossil was truly a different species or simply an unusual variant of Homo erectus.

Professor Meave Leakey enthuses, "For the past 40 years we have looked long and hard in the vast expanse of sediments around Lake Turkana for fossils that confirm the unique features of 1470's face and show us what its teeth and lower jaw would have looked like.  At last we have some answers."

Complete specimen
The stellar jaw specimen (bottom) fits perfectly on the restored KNM-ER 1470 skull (top).  
[Image Source: Fred Spoor]

The new finds left little doubt among researchers that KNM-ER 1470 was indeed a separate species, and as an added surprise, they also indicated that one of the two specimens dug up during the various excavations was a second relative.

Comments Fred Spoor who led the analysis of the specimens unearthed by the Leakey team, "Combined, the three new fossils give a much clearer picture of what 1470 looked like.  As a result, it is now clear that two species of early Homo lived alongside Homo erectus. The new fossils will greatly help in unraveling how our branch of human evolution first emerged and flourished almost two million years ago."

The KNM-ER 1470 look alike was found in 2008.  Dubbed KNM-ER 62000, the individual is thought to have lived between 1.78 million and 1.95 million years ago (placing it in the early Pleistocene era), according to isotopic dating techniques.  

Hominid Jaw
The semi-complete skull and upper jaw provided promising clues. [Image Source: Nature]

The find included a complete skull with most of the cheek teeth present in the well-preserved upper jaw, allowing researchers to infer the shape of the lower jaw.

Hominid jawHominid Jaw
The KNM-ER 60000 jaw was the best lower jaw specimen recovered to date. [Image Source: Nature]

The skull allowed a 2007 partial lower jaw discovered by Robert Moru, dubbed KNM-ER 62003, to be confirmed as a member of the new species.  Likewise, another jaw discovered in 2009 by Cyprian Nyete -- KNM-ER 60000 -- further enriched the picture.  The 60000 specimen was the most complete hominid lower jaw ever discovered by researchers to date.

III. Much Work Remains

The discovery was truly a breathtaking process, beginning with geological analysis of probable sites for preserved remains, funded by the Leakey Foundation.  With promising dig sites pinpointed, the National Geographic Society provided funding for the successful fieldwork, a half decade ago.  And the Max Plank Society also chipped in, funding the laboratory work on the unearthed fossils.

The finished paper [abstract] on the groundbreaking work was published in the prestigious peer-reviewed journal Nature.  Its authors include Christopher Kiarie (TBI), who carried out the laboratory preparation of the fossils, Craig Feibel (Rutgers University), who studied the age of the fossils, and Susan Antón (New York University), Christopher Dean (UCL, University College London), Meave and Louise Leakey (TBI, Kenya; and Stony Brook University, New York) and Fred Spoor (Max Planck Institute for Evolutionary Anthropology, Leipzig and UCL), who analyzed the fossils.

Leakeys
The Leakey ladies with their outstanding find. [Image Source: National Geographic]

While the terrific find solves many unanswered questions about hominid evolution, it raises yet others.  These species clearly have not survived to the present day, but it is unclear what their true fate is.

Recent sequencing of the Neanderthal genome revealed that humans surprisingly interbred with this co-existing species, allowing some of its genetic material to be preserved even after it was displaced by Homo sapiens and went extinct.  Likewise, these new hominids could have interbred with Homo erectus, contributing scraps of valuable DNA that helped create the creature that we today know as a "human".

There's much work to be done on the eve of this discovery.

Sources: Nature, National Geographic Society



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RE: Voyager
By othercents on 8/10/2012 10:10:13 AM , Rating: 1
There is no dispute the evolution happens, however the dispute has always been evolving between two distinctly different species (IE. fish to monkey). Also no one has proven where the spark of life came from. There are theories that don't stand up to the evidence. For example primordial soup theory would have some lingering chemicals that don't exist in our atmosphere besides the fact the chemicals required can't sustain life they actually have been proven to kill the life it creates.

BTW. Who says Adam and Eve were not more ape like and we have evolved from them?

Other


RE: Voyager
By morob05 on 8/10/2012 9:51:50 PM , Rating: 2
You're mixing together different theories and hypothesis. The theory of evolution does not concern itself with how life came into being. Abiogenesis is concerned with that and so far there are only different hypotheses, but no theories. Primordial soup is a hypothesis, NOT a theory!

By examining and comparing the genetics of different human populations around the globe we can trace our way back along the paternal lines of the family tree to what we call mitochondrial Adam and mitochondrial Eve. Those are the latest male and female that every human living today are related to. We can't give a very precise estimate though. Mitochondrial Adam lived between 140000 and 60000 years ago and mitochondrial Eve is older having lived about 200000 to 190000 years ago...


RE: Voyager
By Jeffk464 on 8/11/2012 3:14:59 PM , Rating: 2
Pretty sure they have a fossil record of transition animals moving from water to land.


RE: Voyager
By woody1 on 8/12/2012 2:40:42 PM , Rating: 2
Adam and Eve? What do they have to do with anything? You can't really talk about science if you mix in mythology. If you want to make claims that biblical myths have scientific validity, then you have to explain talking snakes and the concept that the planet is only about 6000 years old.

You also have to explain how all of the species on the planet were packed onto a hand-made boat.

No point in introducing Adam and Eve unless you're prepared to provide scientific explanations for everything in the Bible.


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