Re: tufa umana ie foarte stufoasa

On Aug 8, 4:53 pm, x terminator <manassetecs...@xxxxxxxxx> wrote:
Study finds twist in human evolution By SETH BORENSTEIN, AP Science
Writer
Wed Aug 8, 1:32 PM ET

WASHINGTON - Surprising fossils dug up in Africa are creating messy
kinks in the iconic straight line of human evolution with its knuckle-
dragging ape and briefcase-carrying man.

The new research by famed paleontologist Meave Leakey in Kenya shows
our family tree is more like a wayward bush with stubby branches,
calling into question the evolution of our ancestors.

The old theory was that the first and oldest species in our family
tree, Homo habilis, evolved into Homo erectus, which then became us,
Homo sapiens. But those two earlier species lived side-by-side about
1.5 million years ago in parts of Kenya for at least half a million
years, Leakey and colleagues report in a paper published in Thursday's
journal Nature.

In 2000 Leakey found an old Homo erectus complete skull within walking
distance of an upper jaw of the Homo habilis, and both dated from the
same general time period. That makes it unlikely that one evolved from
the other, researchers said.

It's the equivalent of finding that your grandmother and great-
grandmother were sisters rather than mother-daughter, said study co-
author Fred Spoor, a professor of evolutionary anatomy at the
University College in London.

The two species lived near each other, but probably didn't interact
with each other, each having their own "ecological niche," Spoor said.
Homo habilis was likely more vegetarian and Homo erectus ate some
meat, he said. Like chimps and apes, "they'd just avoid each other,
they don't feel comfortable in each other's company," he said.

They have some still-undiscovered common ancestor that probably lived
2 million to 3 million years ago, a time that has not left much fossil
record, Spoor said.

Overall what it paints for human evolution is a "chaotic kind of
looking evolutionary tree rather than this heroic march that you see
with the cartoons of an early ancestor evolving into some intermediate
and eventually unto us," Spoor said in a phone interview from a field
office of the Koobi Fora Research Project in northern Kenya.

That old evolutionary cartoon, while popular with the general public,
keeps getting proven wrong and too simple, said Bill Kimbel, who
praised the latest findings. He is science director of the Institute
of Human Origins at Arizona State University and wasn't involved in
the research team.

"The more we know, the more complex the story gets," he said.
Scientists used to think Homo sapiens evolved from Neanderthals, he
said, but now know that both species lived during the same time period
and that we did not come from Neanderthals.

Now a similar discovery applies further back in time.

Leakey's team spent seven years analyzing the fossils before
announcing their findings that it was time to redraw the family tree -
and rethink other ideas about human evolutionary history, especially
about our most immediate ancestor, Homo erectus.

Because the Homo erectus skull Leakey recovered was much smaller than
others, scientists had to first prove that it was erectus and not
another species nor a genetic freak. The jaw, probably from an 18- or
19-year-old female, was adult and showed no signs of any type of
malformations or genetic mutations, Spoor said. The scientists also
know it isn't Homo habilis from several distinct features on the jaw.

That caused researchers to re-examine the 30 other erectus skulls they
have and the dozens of partial fossils. They realized that the females
of that species are much smaller than the males - something different
from modern man, but similar to other animals, said study co-author
Susan Anton, a New York University anthropologist. Scientists hadn't
looked carefully enough before to see that there was a distinct
difference in males and females.

Difference in size between males and females seem to be related to
monogamy, the researchers said. Primate species that have same-sized
males and females, such as gibbons, tend to be more monogamous.
Species that are not monogamous, such as gorillas and baboons, have
much bigger males.

This suggests that our ancestor Homo erectus reproduced with multiple
partners.

The Homo habilis jaw was dated at 1.44 million years ago. That is the
youngest ever found from a species that scientists originally figured
died off somewhere between 1.7 and 2 million years ago, Spoor said. It
enabled scientists to say that the two species lived at the same time.

All the changes to human evolutionary thought should not be considered
a weakness in the theory of evolution, Kimbel said. Rather, those are
the predictable results of getting more evidence, asking smarter
questions and forming better theories, he said.
.........................

hahaha !
din craca'n craca.
piticus gogulis erectus.

Daca bunica si strabunica erau surori atuncea bunelu' cu strabunelu'
cum erau'~ai?

.

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