Posted on 10/29/2012 2:12:45 PM PDT by SunkenCiv
Despite the ability to walk upright, early relatives of humanity represented by the famed "Lucy" fossil likely spent much of their time in trees, remaining very active climbers, researchers say.
Humans are unique among living primates in that walking bipedally -- on two feet -- is humans' chief mode of locomotion. This upright posture freed their hands up for using tools, one of the key factors behind humans' domination of the planet.
Among the earliest known relatives of humanity definitely known to walk upright was Australopithecus afarensis, the species including the famed 3.2-million-year-old "Lucy." Australopithecines are the leading candidates for direct ancestors of the human lineage, living about 2.9 million to 3.8 million years ago in East Africa.
Although Lucy and her kin were no knuckle-draggers, whether they also spent much of their time in trees was hotly debated...
The researchers found these bones had several details in common with those of modern apes, suggesting they lived part of the time in trees. For instance, the socket for the shoulder joint was pointed upward in both Selam and today's apes, a sign of an active climber. In humans, these sockets face out to the sides.
Lucy's adult shoulder sockets also faced upward, suggesting that, like modern apes, her species was equipped for tree-climbing throughout its life span. Humans, on the other hand, are born with a somewhat downward-facing socket that gradually moves to face outward as people mature.
(Excerpt) Read more at livescience.com ...
To help resolve this controversy, scientists looked at two complete shoulder blades from the fossil "Selam," an exceptionally well-preserved skeleton of a 3-year-old A. afarensis girl dating back 3.3 million years from Dikika, Ethiopia. The arms and shoulders can yield insights on how well they performed at climbing. (Shown here, Selam's cranium, face and mandible.) CREDIT: Image courtesy of Zeray Alemseged / Dikika Research Project
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Maybe because Lucy *was* an ape.
Is this the one that BJ wanted to date ?
Now, I thought that evolutionary theory was such that a trait that was beneficial would always overpower, or at least remain neutral to, those traits that were detrimental, or otherwise of negligible benefit. So, even after 3 million years, one might expect that a trait for more powerful shoulders, would be more of a survival imperative than proportionally weaker ones. In point of fact, there are many characteristics of early hominid development that would increase survivability over what the human race has inherited.
She’s got some ‘splainin’ to do!
What a bunch of BS!
I spent half of my life before age fifteen in trees. Maybe I’m a throwback?
Exactly, Jack, what fun Satan has with this nonsense. He hates us so. To have serious men in serious robes discuss our ancestors swinging from trees. Such a mockery.
Apparently he didn't understand the point and ignored me. However, let me expand on it a bit ~ humans have finger nails. The hardness is controlled by genes. About half have hard nails. The other half have soft nails.
It's been that way for hundreds of thousands of years, and probably even millions of years ~ all the way back to the first dude to have fingernails,
Evolutionary theory always said this about that ~ the fingernail type most advantageous to the survival of the species is the type each individual should have.
In the case of important features ~ to wit: fingernails ~ that have 2 variations, and which persist through geologic time ~ the traditionalists would say "see, neither type has survival advantage so both survive". Yet, we can look back up the line to the forebears and some of them have claws ~ well, actually, at some point going back they all had claws, and all claws are hard ~ that's because claws need to be hard. Fingernails that replaced them obviously had more survival advantage so presumably they started off hard as well ~ then what? Well, another type with no clear advantage we can see, the soft ones, came into existence, and now we have some people with hard and some people with soft fingernails.
By now you've probably gotten to the question ~ how is it soft fingernails have an advantage over claws? Your friendly neighborhood bears would probably like to know that answer as well ~ did you know they can open doors using the knobs and levers? Their mothers teach them now to do that. They open your door; go in; raid your refrigerator; and close it.
They'll be back!
Bears have hard claws and can gut you in a NY sec. They can peel oranges if you let them.
So, why nails? Why soft nails?
Nothing like climbing a tree for pure pleasure.
There are a few rogue scientists out there who speculate that mankind has been around for up to a billion years.
Lucy is a joke, by a desperate professor, at the end of his tour and funding.
Parts found half a mile and depths apart, yet attributed to same critter, and WaLa! It’s transitional!
we have fingernails because they are easier to trim to enable us to keep them short so we can use tools with utmost dexterity. ever see a lady with 4 inch nails work? they are basically useless. its an evolving trait that the body uses to expel dead cells.
So true.
http://www.youtube.com/watch?v=z4Ep6U0EN1g
http://t2.gstatic.com/images?q=tbn:ANd9GcSl2_5zcqqdDNBiHqxZflUAHxP3EU5ApqPbKlMf6HxQDADAHrvn ~ MONKEY FINGERNAILS and then http://universalspectrum.org/forum/attachment.php?attachmentid=189&d=1336375640 Baby marmoset claws ~ world’s smallest monkey.
Is there something I'm missing in this story?
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