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Homo antecessor is believed to have left them roughly 800,000 years ago, footprints are oldest found in Europe

Professor Martin Bates, a professor of history and anthropology at Trinity Saint David University in Lampeter, Wales, UK made a fascinating discovery last year that is shedding new light the path of one of mankind's potential ancestors. Thanks to the follow-up work of a team of top European museum scholars and university researchers, these new findings cast light on the footsteps of the hominid nearly a million years ago on the coast of England.
 
I. Footprints in the Sand
 
The footsteps were located on the Southeast coast of England, in the village of Happisburgh.  Professor Bates spotted them while on a walk in May 2013.  He and other researchers had been investigating sites in the area where 850,000-950,000 year old flint tools, believed to be created by a recent hominid, were found.
 
The incredible discovery promised to corroborate the tools collected in dig sites in the village's vicinity, which were dated to roughly the same era.  But Mother Nature threatened to destroy the discovery as quickly as it laid it bare.

Britain footprints site
The site lies by the sea. [Image Source: PloS One/The British Museum]

The tracks appeared as pits in the rock-hard sediments at the bottom of a cliff base.  Exposed by rain and driving tides, the footprints weren't expected to last long.  Knowing time was of the essence; Professor Bates contacted colleagues at The British Museum to further investigate the exciting find.

Britain footprints
The location was at risk due to the same erosion that exposed the prints -- rain and tides.
[Image Source: PloS One/The British Museum]

Researchers were able to race against the clock, and over the next two weeks obtain a set of high-resolution 3D photograph images of the 12 square-meter site.  They also used standard dating procedures to determine that the sediments were between 780,000 and 1 million years old.

It was a good thing the researchers found the site and were able to work so quickly -- by the end of May driving water had etched away the semi-hard rock containing the footprints as quickly as it had exposed it.

Britain Hominid footprints
Toes were visible in some prints. [Image Source: PloS One/The British Museum]

To the skeptics who might suspect contamination from modern man as a source of the prints, Nicholas Ashton, a curator at The British Museum, writes in a blog post on the discovery:

I imagine that there will be plenty of sceptics out there, as were we initially, but the more we eliminated the other possibilities, the more convinced we became. The sediments are hard and compacted – you can jump on them today and leave little impression. And there are no erosional processes that leave those sort of hollows.

Using a technique called photogrammetry, Professor Isabelle de Groote from Liverpool John Moores University analyzed the data from Professors Ashton and Bates.  The technique stitched together the collected 3D images, producing a 3D model of the finding ready for analysis.
 
II. Computer Analysis Gives Clues to Human Ancestor's Appearance
 
From there the discoveries began.
 
Histogram and regression analysis of the prints suggested that the group likely stood up to 5.6 feet (1.7 meters) tall and weighed up to 53 kg (~117 lb).  In total 49 footprints were used for some of the histogram analyses, but twelve of the footprints were selected for more detailed study, based on their clarity.  In some of these specimens, toe prints were even seen.

Stitched together image
hominid footprints
footprint analysis
Top to bottom: Top -- stitched together raw image of printed terrain; middle -- colorized image showing located prints; bottom -- gender highlighted prints and graph of estimated age of group members [Image Source: PloS One/The British Museum]

The research indicated the group was travelling southward along the ancient estuary (riverbed flowing into the ocean).  The group is believed to have consisted of at least five adults, including males and females, plus juveniles of both genders.  The group walked with an upright posture and gait similar to modern man.
 
The footprints found were narrower than most modern humans, although they were similar to Native Americans, which were geographically isolated from Eurasian Homo Sapiens an estimated 12,000 years ago.  The footprints are believed to belong to Homo antecessor, a recent hominid, which humans (Homo sapiens) and their close relative, the Neanderthals (Homo neanderthalis) are believed to have descended from.
 
The team in February published their findings in PloS One, a prestigious peer-reviewed journal which top paleoanthropology discoveries have been published in.
 
III. Much Work Remains
 
While the footprints did offer some valuable clues to the ancient tribe, they left much mystery to discover.  The researchers are the first to admit there's much that's uncertain.
 
Blogs Mr. Ashton:

We actually know very little else about the people who left these prints, but from the plant and animal remains at Happisburgh we know that they were able to survive winters colder than today. We’re still asking questions of whether they had clothing and shelter or controlled the use of fire. Some of this evidence will be on display in a major exhibition, Britain: One Million Years of the Human Story opening at the Natural History Museum on Thursday 13 February 2014.

Researchers are still holding out hope that fossil specimens will be found, but fragments of past Homo antecessor skeletons carried cutting marks indicating cannibalism, perhaps of a ceremonial nature.  In that regard, it's very possible that few remains were left behind that would allow for analysis.

The discovery is the oldest fossil footprints in England, but not the first ones to be found there.  The research team had previously cut its teeth on a younger set of prints from early humans.  Those prints -- on the Welsh coast near Aberystwyth -- are located relatively near to those discovered in May, but in sediments that date back only a few thousand years.

Footprint sites
Fossilized hominid footprints have only been found in a handful of locations in Europe and Africa. [Image Source: PloS One/The British Museum]

Footprints are a rare type of fossil, both in hominids and in other species, as they need highly specialized types of sedimentary deposition to be preserved.  The footprints found in the new work are the oldest hominid footprints to be found outside of Africa.
 
Other younger European prints have been found in The Vârtop Cave in Romania (62,000-97,000 years ago) and the volcanic sediment of Roccamonfina, Italy (~350,000 years ago).  Older prints have previously been found been at two Central African, and two South African sites.  These African sites date around 3.6 and 1.5 million years ago, placing them in the Early Pleistocene.  These sites showed mankind's development of a modern gait.
 
IV. The New Family Tree
 
Thanks to discoveries like the one made at the Happisburgh site, scientists are beginning to have a clearer picture on the hominids that evolved immediately prior to modern man.  Researchers now believe that mankind -- along with its closest relative species Homo neanderthalis -- is derived from one or two distinct subspecies, Homo heidelbergensis (formerly known as Homo rhodesiensis, "the Rhodesian man") and Homo antecessor
 
These species are together often referred to by the somewhat misleading title "the missing link", which came in to the popular vernacular on account to their somewhat later discovery.  They "link" modern hominids (Neanderthals, man) to older species like Homo erectus and Australopithecus afarensis.
 
Because of limited fossil evidence, researchers aren't quite sure how these two hominids species fit in the family tree.  It's possible that Homo heidelbergensis and Homo antecessor hominids -- both of which were prevalent in European, Africa, and the Middle East between 1.2 million and 250,000 years ago -- are the same species; others think they were two separate species which possibly interbred; others still think that Homo heidelbergensis evolved into Homo antecessor.

Mankind's evolution
A prospective evolutionary roadmap is seen here.  Recent evidence suggests that Homo antecessor may be more closely related to modern man and Neanderthals as previously believed (and as seen in this chart).  [Image Source: Nature]

Fossil and genetic evidence may eventually elucidate the relationships between the most recent hominids -- modern man (Homo sapiens) and Neanderthals -- and late Pleistocene hominids (Homo heidelbergensis and Homo antecessor).  In the meantime discoveries regarding their impact on Eurasia are continuing to be made.
 
While researchers have began to delve into the evolutionary path of early primates, who gave rise to the hominid line, much of the most exciting work examines the evolution of hominids in more recent terms.  Modern genetics and new paleoanthropology discoveries are combining to give us a rich, and at times surprising picture of how our species evolved into its current form over the last several million years.
 
V. Discoveries Reinvent our View of Mankind's Place in History
 
Among the recent discoveries include genetic indications that Neanderthals may have been capable of speech.
 
Other traits observed in the finished Neanderthal genome and correlated to occurrence in humans shed intriguing new light on the early differences in looks between early humans and Neanderthals.  Early humans were shown to have darker pigment (similar to that found in modern Africans).  By contrast, analysis of the Neanderthal and modern human genomes suggests the species was fair skinned and hairier than their human counterparts of the time.  Neanderthals are also believed to have hair red and blond, genes not seen in humans at the time.
 
Some ethnicities of modern humans are believed to have acquired these Neanderthal traits thanks to interbreeding between the species in Europe.  Mankind also is believed to have gained other mutations from the Neanderthals, including more facial and body hair (Homo sapiens are believed to have initially only had a light amount of hair).

Neanderthal Red haired
Red hair and fair skin are also thought to have been inherited from Neanderthals.
[Image Source: BBC News]

This is a pleasing finding from an intuitive perspective.  The last locations where Neanderthals are thought to have actively cohabited with humans were northern England, Ireland, and Scandinavia.  The fact that these regions now have the highest incidence of Neanderthal traits -- fair skin and blond/red hair -- now appears to be anything but coincidence.
 
Blue eyes were suggested in another new study to be a recent evolution in modern man, first occurring around 100,000 years ago.
 
Elsewhere in Asia, a second recent counterpart species, the Denisovans (Denisova hominins), is believed to have interbred with other groups of early humans, passing along certain traits.  Breeding with both Denisovans and Neanderthals is believed to have made Eurasians have more robust immune systems.
 
In that light, the recent genetic research suggest modern man to be highly diverse, consisting of a mixture of DNA from different hominid species.  And thanks to globalization the entire human race is slowly intermixing, spreading the contributions of the Neanderthals and Denisovans around the globe.
 
The picture is far from complete, but it's exciting to see these surprises that are coming at a growing pace each year as genetics and paleoanthropology mesh beautifully to give us insight into the history of mankind, and into what directions future human evolution might head in.

Sources: PloS One [abstract], The British Museum



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RE: So much conjecture
By geddarkstorm on 2/11/2014 6:28:05 PM , Rating: 2
Err, of course we share some DNA, if we are from the same lineage. That is, if any genes survived from the last common ancestor without much change, then they can be said to be "shared".

One needs to look at the much larger scientific research, that's why I linked that Review article from the primary lit. The mitochondrial DNA for instance has been strongly against interbreeding between our two groups to any substantial amount. More over, if we -did- interbreed, we'd expect similarity in DNA far above 2-4%.

Even worst, that metric is misleading. Humans and chimpanzees share about 97% of our DNA. This is why I am skeptical of these sort of conjections. The evidence supports much simpler population genetic explanations. This is also why you don't get clustering of human ethnic groups in most genetic analysis, and certainly not Europeans away from everyone else, as would happen if they had a unique amount of interbreeding with hominids outside our species (again, nevermind that for two individuals to breed and have viable offspring, they must by most conventions be the same species).


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