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TOPIC: Homo Sapiens


L

Posts: 131433
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Neanderthal extinction
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Spanish scientists point at climate changes as the cause of the Neanderthal extinction in the Iberian Peninsula
Climate – and not modern humans – was the cause of the Neanderthal extinction in the Iberian Peninsula. Such is the conclusion of the University of Granada (Universidad de Granada [http://www.ugr.es]) research group "RNM 179 - Mineralogy and Geochemistry of sedimentary and metamorphic environments", headed by professor Miguel Ortega Huertas and whose members Francisco José Jiménez Espejo, Francisca Martínez Ruiz and David Gallego Torres work jointly at the department of Mineralogy and Petrology of the UGR and the Andalusian Regional Institute of Earth Sciences (CSIC-UGR).
Together with other scientists from the Gibraltar Museum, Stanford University and the Japan Marine Science & Technology Centre (JAMSTEC), the Spanish scientists published in the scientific journal Quaternary Science Reviews an innovative work representing a considerable step forward in the knowledge of human ancestral history.
The results of this multidisciplinary research are an important contribution to the understanding of the Neanderthal extinction and the colonisation of the European continent by Homo Sapiens.
During the last Ice Age, the Iberian Peninsula was a refuge for Neanderthals, who had survived in local pockets during previous Ice Ages, bouncing back to Europe when weather conditions improved.

The study is based upon climate reconstructions elaborated from marine records and using the experience of Spanish and international research groups on Western Mediterranean paleoceanography. The conclusions point out that Neanderthal populations did suffer fluctuations related to climate changes before the first Homo Sapiens arrived in the Iberian Peninsula. Cold, arid and highly variable climate was the least favourable weather for Neanderthals and 24,000 years ago they had to face the worst weather conditions in the last 250,000 years.
The most important about these data is that they differ from the current scientific paradigm which makes Homo Sapiens responsible for the Neanderthal extinction. This work is a contribution to a new scientific current – leaded by Dr. Clive Finlayson, from the Gibraltar Museum – according to which Neanderthal isolation and, possibly, extinction were due to environmental factors.
These studies on climate variability are part of the work of the group RNM 179, funded by the excellence project RNM 0432 of the Andalusian Regional Government’s Department for Innovation, Science and Business and by the MARCAL project of the Spanish Ministry of Education and Science, both linked to the Andalusian Environment Centre (CEAMA - Centro Andaluz de Medio Ambiente).

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L

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RE: Homo Sapiens
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Dr. Asger Hobolth, visiting professor of genetics at North Carolina State University, along with colleagues from Denmark and the United Kingdom, has put a definitive time frame on how long ago human beings and chimpanzees diverged from their common ancestor.
Based on their data, the researchers estimate that the split occurred 4 million years ago.  Current theories about the split had placed the occurrence at 5 to 7 million years ago.
Their findings were published in the Public Library of Science journal Genetics.

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When did ancient populations learn that drinking milk 'does a body good'? A team of scientists in Germany has tried to answer this question by studying ancient DNA extracted from skeletons thousands of years old.
Many adult humans can drink cow's milk — a rare feat among mammals, which usually lose the ability to digest the sugar in milk after they are weaned. Scientists have found the genetic mutations that allow many Europeans and some Africans to digest milk. Geneticists have estimated that these mutations first spread 3,000 to 7,000 years ago in eastern Africa, and slightly earlier than that in Europe.

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L

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Neanderthals
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A sharp freeze could have dealt the killer blow that finished off our evolutionary cousins the Neanderthals, according to a new study.
The ancient humans are thought to have died out in most parts of Europe by about 35,000 years ago.
And now new data from their last known refuge in southern Iberia indicates the final population was probably beaten by a cold spell some 24,000 years ago.
The research is reported by experts from the Gibraltar Museum and Spain.

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Megaladapis edwardsi
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Madagascar is, and has been, home to a wide variety of interesting primates. Once upon a time, Madagascar was the home to several species of giant primates.
Megaladapis edwardsi is one of those giants. Estimated body size was around 150 kg (about 330 pounds). Megaladapis edwardsi was folivorous (dental formula was 0:1:3:3 on maxilla and 2:1:3:3 on mandible). Based on the anatomy of the nasal region, some have suggested that it had longish prehensile lips. Megaladapis had long arms relative to its legs, a long trunk and long curved phalanges. Megaladapis was a vertical clinger and climber, although on the ground it moved quadrupedally. You may be mentally comparing Megaladapis to a sloth at this point, but a better comparison would be a koala.

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RE: Homo Sapiens
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The family tree of humans may run deeper than previously thought, stretching back millions of years to small, nimble primates that lived in ancient forests of what is now Wyoming's Bighorn Basin.
The skeleton of the earliest primate ever documented was discovered recently in limestone in the arid badlands between Cody and Powell.
The finding sheds new light on the earliest stages of human evolution, according to the authors of a new study.

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Hum,
in a case that could be likened  to Walt Disney  arguing against biologists that the Blue fairy was real...

“A prehistoric skeleton found in Kenya has sparked a new round of creation versus evolution debate between Christians and Scientists.
Kenyan evangelical leaders are demanding that Turkana boy – the most complete prehistoric human ever found – be place in a backroom with a sign cautioning that evolution is a theory during the upcoming exhibit at the famed National Museum of Kenya.”

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Prehistoric origins of stomach ulcers uncovered
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An international team of scientists has discovered that the ubiquitous bacteria that cause most painful stomach ulcers have been present in the human digestive system since modern man migrated from Africa over 60,000 years ago. The research, published online today (7 February) by the journal Nature, not only furthers our understanding of a disease causing bacteria but also offers a new way to study the migration and diversification of early humans.
The international research collaboration was led by scientists from the University of Cambridge, the Max Planck Institute in Berlin, and the Hanover Medical School. The researchers compared DNA sequence patterns of humans and the Helicobacter pylori bacteria now known to cause most stomach ulcers. They found that the genetic differences between human populations that arose as they dispersed from Eastern Africa over thousands of years are mirrored in H. pylori.
Human DNA analysis has shown that along the major land routes out of Africa human populations become genetically isolated – the further from Eastern Africa a population is the more different genetically it is compared to other human populations. Other research has shown gradual differences in European populations, presumed to be the result of Neolithic farmers moving northwards. The international H. pylori research team found almost exactly the same genetic distribution patterns in their results.
The scientists combined their genetic analysis with a computer simulation that modelled the spread of the bacteria across the globe. This showed that it migrated from Eastern Africa at almost exactly the same time as early humans, approximately 60,000 years ago.

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Homo floresiensis
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For three years researchers have feuded over the rightful classification of the Hobbit, a diminutive, 18,000-year-old specimen unearthed from the Indonesian island of Flores. Is it an entirely new species, as its discoverers have maintained, or merely a small-brained human? Last week, officials reopened the site where the Hobbit was found as well as a newly discovered cavern underneath it, raising hope that diggers might soon bring convincing new evidence to bear.
A second skull would be especially helpful. Critics of the new species theory have latched onto the Hobbit's measly 400-cubic-centimeter brain as a sure sign of an abnormality called microcephaly in which the brain does not reach normal size. Some prominent advocates of a human Hobbit say that a second skull could settle the debate.

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Turkana Boy
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Deep in the dusty, unlit corridors of Kenya's national museum, locked away in a plain-looking cabinet, is one of mankind's oldest relics: Turkana Boy, as he is known, the most complete skeleton of a prehistoric human ever found.
But his first public display later this year is at the heart of a growing storm - one pitting scientists against Kenya's powerful and popular evangelical Christian movement. The debate over evolution vs. creationism - once largely confined to the United States - has arrived in a country known as the cradle of mankind.

"I did not evolve from Turkana Boy or anything like it. These sorts of silly views are killing our faith" - Bishop Boniface Adoyo, head of Kenya's 35 evangelical denominations, which he claims have 10 million followers.

He's calling on his flock to boycott the exhibition and has demanded the museum relegate the fossil collection to a back room - along with some kind of notice saying evolution is not a fact but merely one of a number of theories.
Against him is one of the planet's best-known fossil hunters, Richard Leakey, whose team unearthed the bones at Nariokotome in West Turkana, in the desolate, far northern reaches of Kenya in 1984.

"Whether the bishop likes it or not, Turkana Boy is a distant relation of his. The bishop is descended from the apes and these fossils tell how he evolved" Leakey, who founded the museum's prehistory department.

Among the 160,000 fossils due to go on display is an imprint of a lizard left in sedimentary rock, dating back 200 million years, at a time when the Earth's continents were only beginning to separate.
Dinosaur fossils and a bone from an early human ancestor, dating back 7 million years, will also be on show along with the bones of short-necked giraffes and elephants whose tusks protrude from their lower jaws.
They provide the clearest and unrivalled record yet of evolution and the origins of man, say scientists.
But the highlight will be the 5-foot-3 Turkana Boy, who died at age 12 and whose skeleton had been preserved in marshland before its discovery.
It will form the centre stage of the exhibition to be launched in July following a $10.5 million renovation of the National Museums of Kenya, financed by the European Union. The EU says it has no concerns over the displays and that the museum was free to exhibit what it wished.

Turkana Boy or Nariokotome Boy is the designation given to fossil KNM-WT 15000, a nearly complete skeleton of an 11- or 12-year-old hominid boy who died 1.6 million years ago in the early Pleistocene. The skeleton was discovered in 1984 by Kamoya Kimeu, a member of a team led by Richard Leakey, at Nariokotome near Lake Turkana in Kenya.

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