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Benvenuti in queste pagine dedicate a scienza, storia ed arte. Amelia Carolina Sparavigna, Torino

Showing posts with label genome. Show all posts
Showing posts with label genome. Show all posts

Thursday, January 5, 2012

Chimeras

"The world's first monkeys to be created from the embryos of several individuals have been born at a US research centre. Scientists at the Oregon National Primate Research Centre produced the animals, known as chimeras, by sticking together between three and six rhesus monkey embryos in the early stages of their development....The first chimeric animals were created by researchers in the 1960s, when experiments with mouse embryos showed they could combine to form a single mouse of normal size. Since then, scientists have created chimeric versions of rats, rabbits, sheep and cattle."
More http://www.guardian.co.uk/science/2012/jan/05/chimera-monkeys-combining-several-embryos

Friday, January 14, 2011

Human, All Too Human - 4 - Lifespan

"A new study by a Washington University in St. Louis suggests life expectancy was probably the same for early modern and late archaic humans and did not factor in the extinction of Neanderthals. Our species, Homo sapiens, is the only surviving lineage of the genus Homo. Still, there once were many others, all of whom could also be called human. One puzzle was the lack of elderly individuals. It was therefore suggested that early hominins might have had a shorter life expectancy than early modern humans, with our lineage ultimately outnumbering Neanderthals, contributing to their demise." But  Neanderthals and early modern humans had same lifespan.

Wednesday, December 29, 2010

Human, All Too Human - 3 - Denisova

The Denisova hominin is the name given to the remains of a member of the genus Homo that may be a previously unknown species. The discover is based on the analysis of mitochondrial DNA, obtained from a bone of a juvenile that lived about 41,000 years ago. The find happened in  the Denisova Cave (Altai Krai, Russia), a region also inhabited at about the same time by Neanderthals and modern humans. From
http://en.wikipedia.org/wiki/Denisova_hominin

Red-headed Neanderthals

Probably this fact is already well-known...
BBC reported that a research team  extracted DNA from the remains of two Neanderthals and retrieved part of a gene called MC1R. In modern people, a mutation in this gene causes red hair. Until this discovery, no one knew what hair colour our extinct relatives had: by analysing a version of the gene in Neanderthals, the scientists found that they were flame-haired.

Human, All Too Human - 2 - DNA

Researchers compared the Neanderthal DNA to the DNA of three modern people (French, Han Chinese, Polynesian). The team found that all three had inherited between 1 and 4 percent of their DNA from Neanderthals. They also compared the Neanderthal sequence to two African individuals (Yoruba, San) and found no indication that they had inherited genes from Neanderthals, who evolved outside Africa. The research supports the idea that Neanderthals interbred with Homo sapiens between 100,000 and 80,000 years ago as our anatomically modern ancestors left Africa and spread across the globe, as we can read from http://www.archaeology.org/1101/topten/germany.html
See also http://stretchingtheboundaries.blogspot.com/2010/12/human-all-too-human.html

Friday, December 24, 2010

Human, All Too Human - 1 - New

The sequencing of the nuclear genome from an ancient finger bone found in a Siberian cave shows that the cave dwellers were neither Neanderthals nor modern humans.
An international team of researchers led by Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) has sequenced the nuclear genome from a finger bone of an extinct hominin that is at least 30,000 years old and was excavated by archaeologists from the Russian Academy of Sciences in Denisova Cave in southern Siberia, Russia, in 2008.

Read more
http://www.pasthorizons.com/index.php/archives/12/2010/siberian-human-sheds-new-light-on-our-origins