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Homo sapiens vieillit au moins de 100 000 ans. Dans le registre fossile actuel, les tous premiers H. sapiens – Omo 1 et Omo 2 – sont éthiopiens et vieux d’environ 200 000 ans.

Homo sapiens vieillit au moins de 100 000 ans

Cela va changer toutefois, puisque les nouveaux fossiles que l’équipe internationale dirigée par Jean-Jacques Hublin de l’Institut Max-Planck d’anthropologie évolutionniste, à Leipzig, a découverts et datés augmente de 100 000 ans au moins l’ancienneté de notre espèce. Ces fossiles récemment mis au jour et toute une série d’autres anciennement découverts au même endroit, mais mal datés, proviennent du site marocain de Jebel Ihroud. Dès 1961, les exploitants d’une mine de barytine y avaient découvert un crâne humain quasi complet dans le remplissage d’une grotte.

Plus tard une boîte crânienne fragmentaire et une mandibule d’enfant avaient été trouvés dans le même site. Ce matériel était associé à des restes de faune et à des outils de pierre débités par la méthode Levallois (caractéristique de tout le Paléolithique moyen). Chromosome cooperation is long-distance endeavor. Multiple genomic elements work cooperatively and over long distances in order to ensure the proper functioning of chromosomes, a team of scientists has found.

Chromosome cooperation is long-distance endeavor

Its research offers new insights into the complexity of gene regulation. CRISPR controversy raises questions about gene-editing technique. Why Is Synaptic Pruning Important for the Developing Brain? One of the grand strategies nature uses to construct nervous systems is to overproduce neural elements, such as neurons, axons and synapses, and then prune the excess.

Why Is Synaptic Pruning Important for the Developing Brain?

Scientists jump hurdle in HIV vaccine design. Scientists at The Scripps Research Institute (TSRI) have made another important advance in HIV vaccine design.

Scientists jump hurdle in HIV vaccine design

The development was possible thanks to previous studies at TSRI showing the structures of a protein on HIV's surface, called the envelope glycoprotein. How dinosaurs may have evolved into birds. Evolutionary biologists have suspected that anatomical differences within and between species are caused by cis-regulatory elements (CREs).

How dinosaurs may have evolved into birds

CREs are regions of genome DNA that do not code for proteins, and control morphology and other traits by regulating genes. The international group of researchers analyzed the genomes of 48 avian species that represent the evolutionary history of modern birds and compared them to many other vertebrates to find DNA sequences specific to avians. They identified millions of genomic regions named 'avian-specific highly conserved elements' (ASHCEs) that appeared to function as CREs. Large study uncovers genes linked to intelligence.

Exactly what constitutes intelligence, and to what extent it is genetic, are some of the most controversial questions in science.

Large study uncovers genes linked to intelligence

But now a new study of nearly 80,000 people, published in Nature Genetics, has managed to identify a number of genes that seem to be involved in intelligence. According to a dictionary definition, intelligence is “the ability to learn, understand or deal with new situations” or “the ability to apply knowledge to manipulate one’s environment or to think abstractly”. Our 'selfish' genes contain the seeds of our destruction – but there might be a fix. The human race is in so much trouble that it needs to colonise another planet within 100 years or face extinction.

Our 'selfish' genes contain the seeds of our destruction – but there might be a fix

So says the physicist Stephen Hawking in an upcoming BBC documentary, Stephen Hawking: Expedition New Earth. According to Hawking, “with climate change, overdue asteroid strikes, epidemics and population growth, our own planet is increasingly precarious”. If this makes you nervous, it should. Colonising another planet will be much easier said than done, and lots of people would likely be left behind to face whichever disaster comes first. Knowledge gap on the origin of sex. There are significant gaps in our knowledge on the evolution of sex, according to a research review on sex chromosomes from Lund University in Sweden.

Knowledge gap on the origin of sex

Even after more than a century of study, researchers do not know enough about the evolution of sex chromosomes to understand how males and females emerge. Mapping the proteome. Tiny shells indicate big changes to global carbon cycle: Future conditions not only stress marine creatures but also may throw off ocean carbon balance. Experiments with tiny, shelled organisms in the ocean suggest big changes to the global carbon cycle are underway, according to a study from the University of California, Davis.

Tiny shells indicate big changes to global carbon cycle: Future conditions not only stress marine creatures but also may throw off ocean carbon balance

For the study, published in the journal Scientific Reports, scientists raised foraminifera -- single-celled organisms about the size of a grain of sand -- at the UC Davis Bodega Marine Laboratory under future, high CO2 conditions. D'où vient la couleur des yeux ? C'est la quantité de mélanine contenue dans l'iris qui détermine la couleur des yeux.

D'où vient la couleur des yeux ?

A new T-cell population for cancer immunotherapy. Scientists at the University of Basel in Switzerland have, for the first time, described a new T cell population that can recognize and kill tumor cells. The open access journal eLife has published the results. T lymphocytes (short T cells) are a special type of cells that recognize germs and protect our body from infections. Their second important job is to ride the body of harmed cells, such as tumor cells. Birds, bees and other critters have scruples, and for good reason. Humans are not the only species to show a strong work ethic and scruples.

UC Berkeley researchers have found evidence of conscientiousness in insects, reptiles, birds, fish and other critters. Cookies are Not Accepted - New York Times. Feather Fancy - Video. DNA vaccine protects against toxic proteins linked to Alzheimer's. A new DNA vaccine when delivered to the skin prompts an immune response that produces antibodies to protect against toxic proteins associated with Alzheimer's disease -- without triggering severe brain swelling that earlier antibody treatments caused in some patients. Two studies from the Peter O'Donnell Jr. Brain Institute demonstrate in animals how a vaccine containing DNA of the toxic beta-amyloid protein elicits a different immune response that may be safe for humans.

The vaccine, which will likely be tested further by the U.S. Un virus géant contrôle à distance le noyau de son hôte. Avec plus de dix membres, la famille des virus géants continue de s’agrandir. Découverts en 2003, ces organismes sont hors-norme par leur taille, supérieure à 200 nanomètres, et par le nombre de paires de bases de leur ADN. Un nouveau venu, Nouméavirus, découvert en Nouvelle-Calédonie, semble en outre se répliquer selon une stratégie tout à fait originale qui ne ressemble à aucune autre connue. C'est ce qu'a mis en évidence l’équipe de Jean-Michel Claverie et Chantal Abergel, du CNRS et de l’université Aix-Marseille. Dans un organisme eucaryote, l’ADN est confiné dans le noyau de la cellule, ainsi que la machinerie nécessaire à sa transcription en ARN (les enzymes ARN polymérases). L’ARN obtenu sort alors du noyau pour être « traduit » en protéines dans le cytoplasme. Par ailleurs, des observations au microscope confirment que l’ADN du virus ne pénètre pas dans le noyau.

Comment les cyanobactéries ont commencé à respirer.