domingo, 26 de agosto de 2007

PROGRAMA FORMACION ASISTENTE CAMPO ETOLOGIA PRIMATES

Apreciados amigos y amigas,

Os hacemos llegar información sobre el próximo PROGRAMA DE FORMACIÓN DE ASISTENTE DE CAMPO EN ETOLOGÍA DE PRIMATES que Fundación Mona comenzará a impartir a partir del próximo mes de enero de 2008, en su Centro de Recuperación de Primates de Riudellots de la Selva (Girona – España).

A través del programa de formación se pretende dotar a los asistentes de las herramientas necesarias para el trabajo como asistente de campo en la investigación sobre el comportamiento de los primates.

La formación de una duración total de 6 meses es fundamentalmente práctica, con una carga de 500 horas lectivas distribuidas en un mínimo de 3 días a la semana. Los alumnos participarán en proyectos reales de investigación y aprenderán a diseñar y confeccionar proyectos propios dentro del estudio de la conducta de los primates no humanos.

El proceso de solicitud de plaza para la formación del primer semestre finaliza el próximo 15 de octubre de 2007. Se llevará a cabo una selección entre todas las solicitudes presentadas que más se ajusten a los requisitos demandados.

La formación se ofrecerá en español, catalán e inglés.

Para más información y solicitudes de plazas dirigirse a:

Miquel Llorente

Unitat de Recerca i Laboratori d’Etologia

Fundació Mona

recerca@fundacionmona.org

(00 34) 972 477 618

Dear friends,

We send you information about the next TRAINING PROGRAMME FOR PRIMATE ETHOLOGY FIELD ASSISTANT that Mona Foundation will impart from the next month of January of 2008, in its Primate Rescue Center of Riudellots de la Selva (Girona - Spain).

Through the programme of training it is intended to endow to the assistants of the necessary tools for the work like field assistant in research about the behavior of the primates.

The training of a total duration in 6 months is fundamentally a practice, with a load of 500 school hours distributed in a minimum of 3 days per week. The pupils will participate in real projects of research and will learn to design and to make own projects in the study of the behavior of the non-human primates.

Deadline of applications of the first semester will finish next 15th October of 2007. A selection will be carried out among all presented requests that fit more to the demanded requirements.

The training will be offer in Spanish, Catalan and English.

For further information and applications contact with:

Miquel Llorente

Unitat de Recerca i Laboratori d’Etologia

Fundació Mona

recerca@fundacionmona.org

(00 34) 972 477 618

jueves, 23 de agosto de 2007

New Fossil Ape May Shatter Human Evolution Theory


Nick Wadhams in Nairobi, Kenya
for National Geographic News
August 22, 2007

Fossil teeth found in Ethiopia might represent a previously unknown species of great ape that lived in Africa ten million years ago, paleontologists report.

The find not only fills an important gap in the fossil record, the Japanese and Ethiopian team says, but could also demolish a working theory of human evolution.


The teeth—eight molars and a canine—come from Ethiopia's fossil-rich Afar region, a valley made famous by the 1974 discovery of the early human ancestor known as Lucy. (What was Lucy?)

For years scientists have been unable to find fossils of direct ancestors of modern great apes in Africa dating back to between 8 million and 14 million years ago.

But the fossil record of great apes—including gorillas, chimpanzees, and bonobos—is abundant in Asia and Europe during this time (see related pictures of an ancient great ape found in Spain).

Experts had speculated that the common ancestor of all apes and humans had left Africa and split off into separate species.

Among the new species was the ancestor of African apes and humans, which returned to Africa sometime around seven million years ago. Molecular analyses of fossils from Europe and later African species seemed to back up this hypothesis.

The recent fossil discovery, however, means that ancient gorillalike apes lived in Africa as far back as ten million years ago.

"Based on this fossil, that means the split is much earlier than has been anticipated by the molecular evidence," said Berhane Asfaw, a study co-author at the Rift Valley Research Service in the Ethiopian capital of Adis Abeba (Addis Ababa).

"That means everything has to be put back."

Diet Clues

Writing in tomorrow's issue of the journal Nature, lead study author Gen Suwa of the University of Tokyo and colleagues dub the new creature Chororapithecus abyssinicus.


An assistant named Kampiro picked the fossil out of the rocky terrain after the team had done surveys by foot over about 62 miles (100 kilometers).

The team found the molars during a second dig in 2007.

"When I saw the first big molar in the March survey, wow, was I surprised," said Yonas Beyene, a member of the research team.

In terms of size and proportion, it's impossible to tell the difference between the teeth from these "proto-gorillas" and teeth belonging to some modern gorilla subspecies, the researchers write.

The team believes the C. abyssinicus fossils represent a great ape ancestor because the molars suggest that the animal had started to adapt toward eating a highly fibrous diet similar to that of today's gorillas.

Richard Potts, director of the Human Origins Program at the Smithsonian Institution, said it is possible that the teeth belonged to another type of ape ancestor whose eating habits simply resemble a gorilla's.

"They have a really good case that this has a gorillalike diet," Potts said. "The question is: Is it a gorilla?

"Maybe the similarities of the tooth are due to the similarities of a diet of a different line of ape."

Other researchers agree that the data Suwa's team has right now are very limited.

Nonetheless, the experts say, the find does seem poised to overturn old ideas that were based on the lack of a fossil record rather than on solid evidence.

"We just can't use the absence of evidence as an evidence of absence," said Yohannes Haile-Selassie, a paleontologist with the Cleveland Museum of Natural History.

It's possible Suwa and his colleagues will accumulate more fossils that might support the theory of an earlier evolutionary split between apes and humans, Haile-Selassie said.

"It's just a matter of dedicated work and spending a lot of time and energy in looking for those tiny fossils."

Better Tools

The newfound ape species is the latest in a spate of new fossil announcements to come out of East Africa in recent months.

In July researchers found a roughly 3.5-million-year-old jawbone in Ethiopia that helps bridge a gap between two human ancestors.

And earlier this month researchers in Kenya found fossils that suggest the two human ancestors Homo habilis and Homo erectus—previously believed to have lived at different times—actually coexisted for half a million years.

(Read "Kenyan Fossils May Add New Branch to Human Family Tree" [August 8, 2007].)

Researchers say the finds are partly coincidence and partly the result of better fossil-hunting techniques coupled with better access to the region.

"In the old days we had to depend on aerial photographs, and some of the areas were not covered by aerial photographs," study co-author Asfaw said. "We were working totally blind."

lunes, 20 de agosto de 2007

Científics d'Oxford identifiquen un gen decisiu en els esquerrans


  1. També l'associen amb l'esquizofrènia, però diuen que s'ha d'estudiar a fons
  2. El descobriment ajudarà a descobrir els secrets de la asimetria cerebral
 Pablo Picasso.
Pablo Picasso.
IDOYA NOAIN
NOVA YORK
S'anomena LRRTM1, és un gen i, d'acord amb un estudi de la Universitat d'Oxford, un dels factors que contribueixen a determinar que una persona sigui esquerrana. El descobriment, publicat a la revista Molecular Psychiatry, suposa un avanç en la comprensió de la asimetria al cervell i el seu funcionament. L'estudi que l'ha identificat pot alarmar els esquerrans, ja que demostra que aquest gen també està associat a un risc més gran de tenir malalties psicòtiques com és ara l'esquizofrènia; per això els científics han fet una crida a la calma.
"Hi ha molts factors que fan que els individus siguin més proclius a desenvolupar esquizofrènia, i la majoria dels esquerrans mai patiran el problema", ha afirmat per tranquil.litzar el públic el doctor Clyde Francks, principal investigador de l'equip d'Oxford, que ha liderat un grup internacional de científics. "No coneixem encara el paper precís d'aquest gen".

EL CERVELL DEL MICO
Els descobriments derivats d'aquest estudi poden ajudar a comprendre més bé com es va desenvolupar la asimetria al cervell, condició que va ser un factor important en l'evolució de les espècies, ja que el cervell del mico és més simètric. Al cervell humà, en la majoria dels casos, la part esquerra controla determinades funcions específiques com el llenguatge i la parla, mentre que la dreta alberga les emocions. En el cas dels esquerrans --aproximadament un 10% de la població-- és al contrari.
Francks i el seu equip van descobrir l'LRRTM1 en el marc d'un estudi de centenars de famílies amb fills dislèxics. En realitat, el que buscaven era un nexe entre la dislèxia i el fet que una persona sigui esquerrana; quan van començar l'anàlisi de les mostres genètiques van trobar un cromosoma que semblava determinant en aquest segment de població. "Llavors vam començar a estudiar a fons el cromosoma i vam trobar el gen", diu Francks.

PREJUDICIS PASSATS
No ha passat gaire més de mig segle des que va desaparèixer d'Espanya la pràctica d'obligar els nens esquerrans a fer servir la mà dreta. Hi tenia molt a veure la Bíblia, que aporta més d'un centenar de comentaris favorables a la mà dreta i alguns de desfavorables a l'esquerra, habitualment associada al diable. Esquerrans famosos són i van ser Franz Kafka, Picasso, Fidel Castro, Nicole Kidman, Maradona i fins i tot la granota Gustavo, segons es va deduir d'una entrevista que va concedir alguna vegada.

jueves, 9 de agosto de 2007

Fossils in Kenya Challenge Linear Evolution


Two fossils found in Kenya have shaken the human family tree, possibly rearranging major branches thought to be in a straight ancestral line to Homo sapiens.

Scientists who dated and analyzed the specimens — a 1.44 million-year-old Homo habilis and a 1.55 million-year-old Homo erectus — said their findings challenged the conventional view that these species evolved one after the other. Instead, they apparently lived side by side in eastern Africa for almost half a million years.

If this interpretation is correct, the early evolution of the genus Homo is left even more shrouded in mystery than before. It means that both habilis and erectus must have originated from a common ancestor between two million and three million years ago, a time when fossil hunters had drawn a virtual blank.

Although the findings do not change the relationship of Homo erectus as a direct ancestor of Homo sapiens, scientists said, the surprisingly diminutive erectus skull implies that this species was not as humanlike as once thought.

Other paleontologists and experts in human evolution said the discovery strongly suggested that the early transition from more apelike to more humanlike ancestors was still poorly understood. They also said that this emphasized the need to search more widely for fossils from the critical period at the still unknown dawn of our own genus, Homo.

The challenge to the idea of a more linear succession of the three Homo species is being reported today in the journal Nature. The lead author is Fred Spoor, an evolutionary anatomist at University College London. Other authors include Meave G. Leakey and her daughter Louise Leakey, the Kenyan paleontologists who are co-directors of the Koobi Fora Research Project that made the discovery. The fieldwork was supported by the National Geographic Society.

The fossils were found east of Lake Turkana in Kenya in 2000. It took years to prepare the specimens, encased in hardened sediment, for study and to be sure of the identification of the species, the scientists said. University of Utah geologists determined the dates of the fossils from volcanic ash deposits.

The most recent fossils of the habilis species known before now were 1.65 million years old or older. Some fragments of fossils with apparent habilis attributes have been dated as early as 2.33 million years old.

In recent years, scientists not involved in the project said, discoveries were hinting at possible overlap between the habilis and erectus species. But the implications were considered so profound that little was said about these dates, pending more conclusive evidence.

“The oldest Homo habilis we had known of was about the same age as erectus,” said Daniel Lieberman, a professor of biological anthropology at Harvard University. “Now we have extended the duration of the habilis species, and there’s no doubt that it overlaps considerably with erectus.”

In their report, Dr. Spoor and his colleagues wrote, “With the discovery of the new, well dated specimens, H. habilis and H. erectus can now be shown to have co-occurred in eastern Africa for nearly half a million years.”

The fact that the two hominid species lived together in the same lake basin for so long and remained separate species, Dr. Meave Leakey said in a statement from Nairobi, “suggests that they had their own ecological niche, thus avoiding direct competition.” For example, the two may have had foraging and dietary differences.

In any case, Dr. Leakey said, “Their co-existence makes it unlikely that Homo erectus evolved from Homo habilis.”

Dr. Spoor, speaking by satellite phone from a field site near Lake Turkana, said the evidence clearly contradicted previous ideas of human evolution “as one strong, single line from early to us.” The new findings, he added, support the revised interpretations of “a lot of bushiness and experimentation in the fossil record,” rather than a more linear succession of species.

But Dr. Spoor said the second fossil, the 1.55 million-year-old erectus skull, was probably the more surprising discovery. The bones are unusually well preserved.

“What is truly striking about this fossil is its size,” he said. “It is the smallest Homo erectus found thus far anywhere in the world.”

The scientists reported that the individual was a young adult or “a late subadult.” Its size was closer to that of a habilis than previously known erectus fossils. But the distinctive ridge on the cranium, the jaw and teeth and the shape of the neck are all characteristic of erectus rather than habilis or other human ancestors.

From the skull’s small size, the scientists concluded that Homo erectus was, in one important respect, less humanlike than had been previously assumed. Other erectus skull and skeletal fossils had seemed to show erectus to be the first human ancestor that was like us in so many ways, except for a smaller brain.

Susan Anton, an anthropologist at New York University and one of the report’s authors, said that the small skull pointed up a significant variation in the sizes of erectus specimens, particularly differences between the male and female of the species, or sexual dimorphism.

Such a characteristic is thought to be a primitive stage in evolution. In humans, males average about 15 percent larger than females, and the same is true for chimpanzees. Sexual dimorphism is much more striking in gorillas, and apparently also in erectus.

“The new Kenyan fossil suggests that contrary to common belief, this may have been true of Homo erectus,” Dr. Anton said, implying that erectus was not as humanlike as once thought.

Dr. Lieberman of Harvard said, “The small skull has got to be a female, and my guess is that all the previous erectus we have found turned out to be male.”

The new findings, Dr. Lieberman said, highlight the need for obtaining more fossils that are more than two million years old. In addition, he said, they show “just how interesting and complex the human genus was and how poorly we understand the transition from being something much more apelike to something more humanlike.”

August 9, 2007 New York Times