published Friday, September 9th, 2011

‘Game-changer’ in evolution from South African bones

By RANDOLPH E. SCHMID

AP Science Writer

WASHINGTON — Two million-year-old bones belonging to a creature with both apelike and human traits provide the clearest evidence of evolution’s first major step toward modern humans — findings some are calling a potential game-changer.

An analysis of the bones found in South Africa suggests Australopithecus sediba is the most likely candidate to be the ancestor of humans, said lead researcher Lee R. Berger of the University of Witwatersrand in South Africa.

The fossils, belonging to a male child and an adult female, show a novel combination of features, almost as though nature were experimenting. Some resemble pre-human creatures while others suggest the genus Homo, which includes Homo sapiens, modern people.

“It’s as if evolution is caught in one vital moment, a stop-action snapshot of evolution in action,” said Richard Potts, director of the human origins program at the Smithsonian Institution. He was not among the team, led by South African scientists, whose research was published online Thursday in the journal Science.

Scientists have long considered the Australopithecus family, which includes the famous fossil Lucy, to be a primitive candidate for a human ancestor. The new research establishes a creature that combines features of both groups.

The newly studied bones were found in 2008 in the fossil-rich cave region of Malapa near Johannesberg. Berger’s then 9-year-old son, Matthew, found a bone that was determined to belong to the child. Two weeks later Berger uncovered the fossils of the female.

The journal published five papers detailing the findings, including separate reports on the foot, hand, pelvis and brain of A. sediba.

Berger said the brain, hand and foot have characteristics of both modern and early pre-human forms that show a transition under way. It represents a bona fide model that could lead to the human genus Homo, Berger said.

Kristian J. Carlson, also at Witwatersrand, said the brain of A. sediba is small, like that of a chimpanzee, but with a configuration more human, particularly with an expansion behind and above the eyes.

This seems to be evidence that the brain was reorganizing along more modern lines before it began its expansion to the current larger size, Carlson said in a teleconference.

“It will take a lot of scrutiny of the papers and of the fossils by more and more researchers over the coming months and years, but these analyses could well be ‘game-changers’ in understanding human evolution,” according to the Smithsonian’s Potts.

So, does all this mean A. sediba was the “missing link”?

Well, scientists don’t like that term, which Berger calls “biologically unsound.”

This is a good candidate to represent the evolution of humans, he said, but the earliest definitive example of Homo is 150,000 to 200,000 years younger.

Scientists prefer the terms “transition form” or “intermediary form,” said Darryl J. DeRuiter of Texas A&M University.

“This is what evolutionary theory would predict, this mixture of Australopithecene and Homo,” DeRuiter said. “It’s strong confirmation of evolutionary theory.”

But it’s not yet an example of the genus Homo, he said, though it could have led to several early human forms, including Homo habilis, Homo rudolfensis or Homo erectus — all considered early distant cousins to man, Homo sapiens.

These articles “force a rethinking of how traits are coupled together in human evolution,” the Smithsonian’s Potts said in an email from Kenya, where he is doing research.

“For example, in previous definitions of our genus, the leading edge in the emergence of Homo has been brain enlargement. The sediba bones show, however, that reorganization of the brain and pelvis typically connected with the evolution of Homo need not have involved brain enlargement,” he noted.

“The more we learn about human evolution, the more we see that traits” that must have happened together could occur separately, Potts said.

For example, the study of the hand shows that major changes in the thumb usually associated with toolmaking “did not imply abandoning life in the trees. In the foot article, we’re introduced to a unique and previously unknown combination of archaic and advanced traits in sediba,” Potts explained.

The researchers reported that the fingers of A. sediba were curved, as might be seen in a creature that climbed in trees. But they were also slim and the thumb was long, more like a Homo thumb, so the hand was potentially capable of using tools, though no tools were found at the site.

The fossil provides the first chance for researchers to evaluate the function of a full hand this old, said Tracy Kivell of the Max Planck Institute for Evolutionary Anthropology in Germany. Previously, hand bones older than Neanderthals have been isolated pieces rather that full sets.

The heel bone seems primitive, the researchers said. Yet its front is angled, suggesting an arched foot for walking on the ground, and there is a large attachment for an Achilles tendon as in modern humans, they said.

The pelvis is short and broad like a human pelvis, creating more of a bowl shape than in earlier Australopith fossils like the famous Lucy, explained Job Kibii of the University of the Witwatersrand.

That may force a re-evaluation of the process of evolution because many researchers had previously associated development of a human-like pelvis with enlargement of the brain, but in A. sediba the brain was still small.

The name Australopithecus means “southern ape,” and “sediba” means natural spring, fountain or wellspring in the local Sotho language.

After the bones were discovered, the children of South Africa were invited to name the child, which they called “Karabo,” meaning “answer” in the local Tswana language. The older skeleton has not yet been given a nickname, Berger said.

The juvenile would have been aged 10 to 13 in terms of human development; the female was in her 20s and there are indications that she may have given birth once. The researchers are not sure if the two were related.

———

Online:

http://www.sciencemag.org

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librul said...

Science marches on, Glory!

September 9, 2011 at 8:51 a.m.
lkeithlu said...

Indeed-my family saw the new human origins exhibition at the Smithsonian Natural History Museum this past month. Wow-what an improvement over the old exhibit! This fossil was already added to the display with room for updating its information as more is learned. My spouse, whose area of research and teaching is related, thought the exhibit was terrific, though the tool use area could use expanding. There were interactive and educational exhibits, but at the core was the effort to show multiple fossil examples of each organism known. Even floresiensis was well documented.

September 9, 2011 at 9:42 a.m.
XGSBoss said...

Just like the "dinosaur" bones, they were put there by the devil to try and fool us!!

September 9, 2011 at 10:22 a.m.
7Seventeen said...

Hurricane hits New Orleans: "God is clearly expressing his anger at sin!"

More fossils found supporting evolution: "God sure works in mysterious ways!"

September 9, 2011 at 10:51 a.m.
una61 said...

Interestingly, did A.sediba have a consciousness and did they communicate with a language? What about a "soul" that survived death? When did "souls" evolve? With the evolution of our consciousness and the development of our languages that allowed the accumulation of knowledge, we enjoy Braves' baseball and the descendent apes and chimps, without a language, still hunt termites with a stick.

September 9, 2011 at 11:47 a.m.
lkeithlu said...

The existence of "soul" cannot be shown physically, neither in current humans nor in the past. The soul lies outside the realm of science. We are not the only organism capable of language, but we are the only one capable of spoken language. Chimps and gorillas can use sign language very well. There are several mammals that are self aware, including porpoises, elephants and great apes. They also have culture, tool use, and at least some understanding of death and mourning.

September 9, 2011 at 11:56 a.m.
riverstronghold said...

Are we really the only organism capable of spoken language? All those critters from dogs to dolphins and whales are really just making random noises? Humans are amazing in our capacity to ignore the obvious.

As a species, we stand out more for our other tendencies, Braves baseball notwithstanding, than in our obvious spiritual advancement beyond other creatures. We put one another in situations from which hunting termites with a stick would be a big step up.

Twain said that the distinctive feature of humanity is that we are "the only animal that blushes -- or needs to."

September 9, 2011 at 3:12 p.m.
lkeithlu said...

Are we really the only organism capable of spoken language? All those critters from dogs to dolphins and whales are really just making random noises?

To our knowledge, yes. That does not mean that the noises these animals make are random, it's just that they don't constitute "spoken language" as far as we know. Animals communicate. Some animals have dozens of sounds that represent different things. But this isn't language.

September 9, 2011 at 3:24 p.m.
btn128 said...

Some animals have dozens of sounds that represent different things. But this isn't language.

Maybe you can tell me what language is exactly if it is not sounds representing things.

September 9, 2011 at 4:43 p.m.
lkeithlu said...

Sounds combined to form unique sentences. Usually with action (verb) subject (noun) object (noun) and sometimes with indication of time (past or present, one event or ongoing).

Animals can make two different sounds to represent two different things (like avian predator vs ground predator-one provokes a dive to cover, the other a climb to heights). However, apes taught sign language can form unique sentences, even combine words to get a unique meaning or to express abstract ideas for which they have no terms. Clearly apes have the cognitive ability to use language, but lack the vocal ability and have not to our knowledge evolved a way past that obstacle. We on the other hand developed verbal communication first, followed by symbolic (art) and written.

September 9, 2011 at 5:01 p.m.
btn128 said...

I agree with everything you have said except that it has to form unique sentences for it to be a language. If a specific sound represents a specific unique meaning that others understand and also use, then why would it not be considered language? Even if a very basic and limited one?

September 9, 2011 at 5:10 p.m.
lkeithlu said...

Not according to scientific definition of language. What you are talking about is "communication". I guess science distinguishes between them because of the big cognitive leap it takes to use language. Even fairly primitive animals communicate.

September 9, 2011 at 5:16 p.m.
una61 said...

ik: With a background in math and physics I understand what Science is (rational, secular explanations of the physical, material world.). I mentioned "souls" satirically for comments from religonists. Your posts defending science are very good. btn: We've been a species for about 200,000 years but civilized for only about the last 10,000 years or so. Language allows the accumulation of knowledge from generation to generation which other animal species don't do. The evolution of our conscientiousness is also important. The proverbial goose wakes up in a new world every day. Witness the following Ted Talk. http://www.ted.com/talks/mark_pagel_how_language_transformed_humanity.html?utm_source=newsletter_weekly_2011-08-03&utm_campaign=newsletter_weekly&utm_medium=ema (20 minutes).

September 9, 2011 at 5:36 p.m.
lkeithlu said...

Thanks, una! I love Ted talks!

PS sometimes I am not able to recognize when someone is making a joke. Not that smart I guess...

September 9, 2011 at 5:41 p.m.
rolando said...

Here's a question:

According to Darwin's evolution hypothesis as I understand it, small advances or improvements -- one at a time -- in a lifeform, that tend to improve the overall function of the lifeform, improve its chances of survival and the passing of those improvements to its "offspring".

So. How does the newly discovered longer thumb of a tree-dwellers hand serve to advance the lifeform?

Since modern orangs, chimps, other monkeys, etc seem to function perfectly well with their typical tree-dwellers hand with truncated thumb, why didn't they evolve too? They were under the same stress, subject to the same improvements as sibida.

Couldn't have been tool using because they didn't have the tools that would cause an improved thumb to develop into an advantage. Chicken/egg thing. The thumb evidently would not be of particular advantage to tree-dwelling, so it wouldn't have developed for that reason.

Same thing for the developing brain pan. If it had no advantage to survival, according to Darwin it wouldn't be passed on. Further, what caused it to develop in the first place?

Single-step evolution is much more logical than simultaneous multi-step. I am surprised that the scientists were surprised. The odds of one improvement happening is rather high, the odds of two or three required to occur at the same time to ensure survival must be astronomical. Each step must improve the lifeform in order to ensure survival.

Answers/comments?

September 9, 2011 at 9:25 p.m.
rolando said...

Here are a few more points garnered here and there. Mind you, I am not a specialist in any of this, other than being a trained researcher and investigator, but am just an inquiring -- and open -- mind.

Darwin's theory was that a process of random mutation, sex and death, allowing the "fittest" to survive and reproduce, and the less fit to die without reproducing, would, over the course of billions of years, produce millions of species out of inert, primordial goo.

The vast majority of mutations are deleterious to the organism, so if the mutations were really random, then for every mutation that was desirable, there ought to be a staggering number that are undesirable.

Otherwise, the mutations aren't random, they are deliberate -- and then you get into all the hocus-pocus about "intelligent design" and will probably start speaking in tongues and going to NASCAR races.

We also ought to find a colossal number of transitional organisms in the fossil record -- for example, a squirrel on its way to becoming a bat, or a bear becoming a whale. (Those are actual Darwinian claims.)

To explain away the explosion of plants and animals during the Cambrian Period more than 500 million years ago, Darwiniacs asserted -- without evidence -- that there must have been soft-bodied creatures evolving like mad before then, but left no fossil record because of their squishy little microscopic bodies.

Then in 1984, "the dog ate our fossils" excuse collapsed, too. In a discovery The New York Times called "among the most spectacular in this century," Chinese paleontologists discovered fossils just preceding the Cambrian era.

Despite being soft-bodied microscopic creatures -- precisely the sort of animal the evolution cult claimed wouldn't fossilize and therefore deprived them of crucial evidence -- it turned out fossilization was not merely possible in the pre-Cambrian era, but positively ideal.

And yet the only thing paleontologists found there were a few worms. For 3 billion years, nothing but bacteria and worms, and then suddenly nearly all the phyla of animal life appeared within a narrow band of five million to 10 million years.

Even the eye simply materializes, fully formed, in the pre-Cambrian fossil record.

Jan Bergstrom, a paleontologist who examined the Chinese fossils, said the Cambrian Period was not "evolution," it was "a revolution."

Personally, and with little theoretical evidence but lots of the empirical variety, I suspect we will eventually learn the sediba fossils were a hoax or some such thing. And yes, I cut and pasted...from townhall.com

September 9, 2011 at 9:40 p.m.
lkeithlu said...

It's a good question, rolando, and it reveals some confusion with the theory. Variation occurs in all populations, due to a variety of causes-drift, sexual reproduction, mutations, etc. These differences get passed on to subsequent generations. Most have little effect on survival rates or reproduction rates especially when the environment is not changing rapidly.

Over a large span of generations, shorter if there is great environmental change, some variations are a little more successful at survival and reproduction. These variations increase in frequency as others diminish. Each generation changes little from the previous, but given enough time, and especially enough pressure from environmental factors, competition for resources, or predation, the changes can be significant.

Single step is most likely, as you say, although competition can favor several attributes at once, especially if they provide advantages. I don't know the order in which certain features appeared in the fossil record: bipedal locomotion was quite early for example, before major brain development. How early changes influenced later changes of course is of great interest. A combination of features evolve together: brain size, cooperative living, longer childhood, tool use, communication; these work together to enhance lifespan and survival. A lot of the smaller details may never be known with great certainty, but it is surprising how much is known already.

September 9, 2011 at 9:45 p.m.
librul said...

"It is not the strongest of the species that survives, nor the most intelligent that survives, it is the one most adaptable to change." Charles Darwin

September 9, 2011 at 9:52 p.m.
lkeithlu said...

Here are a few more points garnered here and there. Mind you, I am not a specialist in any of this, other than being a trained researcher and investigator, but am just an inquiring -- and open -- mind.

It doesn't take a specialist, but it does take a lot of time and it helps to have people in the field to ask questions of, something I do enjoy.

Darwin's theory was that a process of random mutation, sex and death, allowing the "fittest" to survive and reproduce, and the less fit to die without reproducing, would, over the course of billions of years, produce millions of species out of inert, primordial goo.

Darwin's theory does not address the origin of life, just the diversity.

The vast majority of mutations are deleterious to the organism, so if the mutations were really random, then for every mutation that was desirable, there ought to be a staggering number that are undesirable.

This is incorrect-the vast number of mutations have no effect whatsoever on the organism.

Otherwise, the mutations aren't random, they are deliberate Nope, they are random -- and then you get into all the hocus-pocus about "intelligent design" and will probably start speaking in tongues and going to NASCAR races. Strange thing to say, but Intelligent Design is not science.

We also ought to find a colossal number of transitional organisms in the fossil record -- for example, a squirrel on its way to becoming a bat, or a bear becoming a whale. (Those are actual Darwinian claims.)

This is cut and pasted from Coulter. Squirrels are not predecessors to bats, and we now know that the closest living relatives to whales are hippos, not bears, though it wasn't a bad theory at the time given what Darwin had to work with. He changed his mind about this connection. As for fossils-we are lucky that anything manages to get fossilized, and there are many examples of transitional fossils, some even predicted before they were discovered.

September 9, 2011 at 10:02 p.m.
lkeithlu said...

To explain away the explosion of plants and animals during the Cambrian Period more than 500 million years ago, Darwiniacs asserted -- without evidence -- that there must have been soft-bodied creatures evolving like mad before then, but left no fossil record because of their squishy little microscopic bodies. Another cut and paste from Coulter. The Cambrian wasn't and "explosion" in a sense that these fossils developed over tens of millions of years, a rather short time relative to other diversification events. There is nothing from the Cambrian that evolution can't explain.

Then in 1984, "the dog ate our fossils" excuse collapsed, too. In a discovery The New York Times called "among the most spectacular in this century," Chinese paleontologists discovered fossils just preceding the Cambrian era.

This is also from Coulter, and it is not surprising, nor does it present a problem for evolution.

Despite being soft-bodied microscopic creatures -- precisely the sort of animal the evolution cult claimed wouldn't fossilize and therefore deprived them of crucial evidence -- it turned out fossilization was not merely possible in the pre-Cambrian era, but positively ideal.

Again from Coulter, who does not understand that the chances of fossilization of animals without hard body parts is very low, and the chances of us finding them are lower still; that we see them at all confirms the theory all the better.

And yet the only thing paleontologists found there were a few worms. For 3 billion years, nothing but bacteria and worms, and then suddenly nearly all the phyla of animal life appeared within a narrow band of five million to 10 million years.

This also presents no problems with evolution.

Even the eye simply materializes, fully formed, in the pre-Cambrian fossil record.

The eye has evolved many different ways over the eons. Not surprising, as sight confers HUGE advantage if finding prey or avoiding predators. Current eye configurations represent several completely different and separate evolutionary paths.

Jan Bergstrom, a paleontologist who examined the Chinese fossils, said the Cambrian Period was not "evolution," it was "a revolution." It was still evolution. Remarkable yes, but not outside the capabilities of Darwin's theory.

Might I suggest that you take some time to (really) learn about evolution, and avoid discredited crackpots like Coulter, who is an attorney, not a scientist.

Personally, and with little theoretical evidence but lots of the empirical variety, I suspect we will eventually learn the sediba fossils were a hoax or some such thing. And yes, I cut and pasted...from townhall.com

It shows. You are out of your element completely on this topic. That can be remedied but you've got work to do.

September 9, 2011 at 10:03 p.m.
rolando said...

Thank you for the cogent response to both posts, lkeithlu.

You find nothing significant in the billion-year long period of Pre-Cambrian stasis? If mutations occurred continuously, as Darwinism proposes, those should appear in the fossil record as well. If a step-by-step process to final improvement is required -- say, 15 steps -- and a competitor mutates into only 10 of those and then branches off [and is consequently unsuccessful] that record of failure should be found...it survived -- and multiplied -- through two-thirds of the steps, after all. But they don't appear.

A missing record [or records, billions of them] cannot be shrugged off. This applies to everything, of course, not just the pre-Cambrian. Where are the records of "squirrels mutating into bats" [or whatever], for instance.

I am not anti-evolution -- the preponderance of evidence indicates it happened, after all. Nor am I anti-ID. Indications are it happened, too.

I find it very hard to accept that major mutations occurred simultaneously -- and were required to occur simultaneously -- before a human could result. The brain development, the tool-using thumb, and the foot, the pelvis, etc for instance. What of those creatures that developed them one at a time -- like sediba? Where are the rest of them?

If I read your response correctly, you said that as early humans developed from the tree-dwellers, their communal efforts, tool using, etc -- their psychological development -- caused their physical evolution. Again, chicken/egg. Many, many steps required from a "squirrel to a bat"...or a tree-dweller into a human. Out of those millions, perhaps billions of individuals evolving from a whatever to a Cro-Mag, where are they? Sediba is perhaps a first step...or a failed one.

You, by the way, are an excellent source of information...hence my questions...and my return. Hopefully you have the time.

September 10, 2011 at 6:40 a.m.
lkeithlu said...

You find nothing significant in the billion-year long period of Pre-Cambrian stasis? If mutations occurred continuously, as Darwinism proposes, those should appear in the fossil record as well. If a step-by-step process to final improvement is required -- say, 15 steps -- and a competitor mutates into only 10 of those and then branches off [and is consequently unsuccessful] that record of failure should be found...it survived -- and multiplied -- through two-thirds of the steps, after all. But they don't appear.

This is an answer for geology. There is very little strata remaining undisturbed and available for us to see that is that old. Given that these animals dwelt in the ocean and required very specific conditions to be preserved, it's surprising we have any record at all, and silly to think that we should have a complete record.

A missing record [or records, billions of them] cannot be shrugged off. This applies to everything, of course, not just the pre-Cambrian. Where are the records of "squirrels mutating into bats" [or whatever], for instance.

Much of the fossil record is missing, as much of the strata laid down over the last 600 million years is missing, destroyed by geological forces or buried. As for transitions (except for squirrels to bats-didn't happen) are found all the time. The recent sequence of terrestrial precursors to whales is well represented in the fossil record. Google Carl Zimmer on Whale fossil record.

I am not anti-evolution -- the preponderance of evidence indicates it happened, after all.

Correct

Nor am I anti-ID. Indications are it happened, too.

Incorrect-there is no evidence whatsoever. ID proponents only try to find so called "gaps" in evolution and insert God. They don't do any science.

September 10, 2011 at 7:13 a.m.
lkeithlu said...

I find it very hard to accept that major mutations occurred simultaneously -- and were required to occur simultaneously --

No one claims that they did occur simultaneously

The brain development, the tool-using thumb, and the foot, the pelvis, etc for instance. What of those creatures that developed them one at a time -- like sediba? Where are the rest of them?

The difficulty with understanding evolution is grasping the immense time scale. Thousands and thousands of generations. We are able to do quite a bit in only a few generations with animal husbandry. Fossils are simply moments in a very long time, with millions of individuals and their variations.

If I read your response correctly, you said that as early humans developed from the tree-dwellers, their communal efforts, tool using, etc -- their psychological development -caused their physical evolution.

Never said caused. But these small changes can work together and enhance the selection of other changes given enough time. Also, an animal that already exhibits certain behavior is more likely to evolve in that direction. Social beings like humans are more likely to evolve from social, group living animals rather than solitary animals.

Many, many steps required from a "squirrel to a bat"...or a tree-dweller into a human. Out of those millions, perhaps billions of individuals evolving from a whatever to a Cro-Mag, where are they?

A surprising number of hominid fossils have been found, and they can be accurately dated. I recommend a basic physical anthropology text from someone such as Clark Larsen, or start with the internet (such as talkorigins.org)and find their secondary sources such as popular books and intro college texts. Avoid the town hall and Coulter-they use arguments that even Creationists have abandoned because science has addressed them so thoroughly.

Sediba is perhaps a first step...or a failed one

It may be a human ancestor or on a dead end branch. That does not diminish the robustness of evolutionary theory, nor is it evidence for ID.

Hope that helps.

You, by the way, are an excellent source of information...hence my questions...and my return. Hopefully you have the time.

That's very kind. This is an area I have spent years researching and reading and asking questions. Mileage really helps.

September 10, 2011 at 7:26 a.m.
LibDem said...

Thanks, lkeithlu and rolando. Nicely done.

September 10, 2011 at 9:53 a.m.
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