doc_simon
May 15, 2007, 03:28 AM
Linky (http://www.livescience.com/animals/070514_tiny_brain.html)
Oh, and by human ancestor they mean "29-million-year-old fossilized skull [that] belonged to a common ancestor of humans, monkeys and apes." So not really all that close to us! But none the less an apparently important find:
Tiny enough to fit into the palm of your hand, the skull comes from a female Aegyptopithecus zeuxis, which means "linking Egyptian ape." This early monkey lived about 33 million years ago, a time when primates were evolving rapidly. The cat-size primate ate fruits and leaves in a tropical rainforest in what is now the Fayum in Egypt.
The discovery, published online this week in the journal Proceedings of the National Academy of Sciences, sheds light on the evolution of human-like brains .
"The reason Aegyptopithecus is so important is that it's at the base of the family tree of the Old World higher primates, the group that we're in," Simons told LiveScience. "So this is telling us something about the chapter in our own ancestry."
The article has a few other interesting factoids too.
The team estimates the female weighed about five and a half pounds, or half the weight of the male. This size difference between males and females, called "sexual dimorphism," is comparable to that in gorillas, whose genes make them our second-closest relatives next to chimpanzees.
The stark size difference indicates the monkey-like animals were social and hung out in multi-male and multi-female troops of 15 to 20 individuals. "If we infer that an Aegyptopithecus had a large social group, that suggests it had enough sense to tell all of those members apart from nonmembers," Simons said.
...
Other features also point to an evolving primate. The skull shows features similar to other higher primates, including a developed visual cortex, suggesting Aegyptopithecus had acute vision. "So the visual sense, which is regarded as a very important feature of anthropoids, or higher primates, had already expanded," Simons said.
And unlike the prosimians, which run around at night, the animal had small eye sockets and was likely diurnal (awake during daylight) like modern and ancient higher primates.
Oh, and by human ancestor they mean "29-million-year-old fossilized skull [that] belonged to a common ancestor of humans, monkeys and apes." So not really all that close to us! But none the less an apparently important find:
Tiny enough to fit into the palm of your hand, the skull comes from a female Aegyptopithecus zeuxis, which means "linking Egyptian ape." This early monkey lived about 33 million years ago, a time when primates were evolving rapidly. The cat-size primate ate fruits and leaves in a tropical rainforest in what is now the Fayum in Egypt.
The discovery, published online this week in the journal Proceedings of the National Academy of Sciences, sheds light on the evolution of human-like brains .
"The reason Aegyptopithecus is so important is that it's at the base of the family tree of the Old World higher primates, the group that we're in," Simons told LiveScience. "So this is telling us something about the chapter in our own ancestry."
The article has a few other interesting factoids too.
The team estimates the female weighed about five and a half pounds, or half the weight of the male. This size difference between males and females, called "sexual dimorphism," is comparable to that in gorillas, whose genes make them our second-closest relatives next to chimpanzees.
The stark size difference indicates the monkey-like animals were social and hung out in multi-male and multi-female troops of 15 to 20 individuals. "If we infer that an Aegyptopithecus had a large social group, that suggests it had enough sense to tell all of those members apart from nonmembers," Simons said.
...
Other features also point to an evolving primate. The skull shows features similar to other higher primates, including a developed visual cortex, suggesting Aegyptopithecus had acute vision. "So the visual sense, which is regarded as a very important feature of anthropoids, or higher primates, had already expanded," Simons said.
And unlike the prosimians, which run around at night, the animal had small eye sockets and was likely diurnal (awake during daylight) like modern and ancient higher primates.