Tag Archives: archaeology

Ancient Australians and the Americas

There has been a theory during the past decade that stated that the ancient Olmecs of Mexico were descended from Africans or Australians because of statuary that was left over from their civilization.

Now there has been a discovery of a skeleton of an ancient woman that may provide an important link to the puzzle:

Cranial features distinctive to Australian Aborigines are present in hundreds of skulls that have been uncovered in Central and South America, some dating back to over 11,000 years ago.

Evolutionary biologist Walter Neves of the University of São Paulo, whose findings are reported in a cover story in the latest issue of Cosmos magazine, has examined these skeletons and recovered others, and argues that there is now a mass of evidence indicating that at least two different populations colonised the Americas.

He and colleagues in the United States, Germany and Chile argue that first population was closely related to the Australian Aborigines and arrived more than 11,000 years ago.

Cranial morphology

The second population to arrive was of humans of ‘Mongoloid’ appearance – a cranial morphology distinctive of people of East and North Asian origin – who entered the Americas from Siberia and founded most (if not all) modern Native American populations, he argues.

“The results suggest a clear biological affinity between the early South Americans and the South Pacific population. This association allowed for the conclusion that the Americas were occupied before the spreading of the classical Mongoloid morphology in Asia,” Neves says.

Until about a decade ago, the dominant theory in American archaeology circles was that the ‘Clovis people’ – whose culture is defined by the stone tools they used to kill megafauna such as mammoths – was the first population to arrive in the Americas.

Clovis culture

They were thought to have crossed the Bering Strait from Siberia into Alaska at the end of the last Ice Age, some 10,000 or so years ago, following herds of megafauna across a land bridge created as water was locked up in glaciers and ice sheets.

But in the late 1990s, Neves and his colleagues re-examined a female skeleton that had been excavated in the 1970s in an extensive cave system in Central Brazil known as Lapa Vermelha.

The skeleton – along with a treasure trove of other finds – had been first unearthed by a Brazilian-French archaeological team that disbanded shortly after its leader, Annette Laming-Emperare, died suddenly. A dispute between participants kept the find barely examined for more than a decade.

The oldest female skeleton, dubbed Luzia, is between 11,000 and 11,400 years old. The dating is not exact because the material in the bones used for dating – collagen – has long since degraded; hence, only the layers of charcoal or sediment above and below the skeleton could be dated.

“We believe she is the oldest skeleton in the Americas,” Neves said.

Luzia has a very projected face; her chin sits out further than her forehead, and she has a long, narrow brain case, measured from the eyes to the back of the skull; as well as a low nose and low orbits, the space where the eyes sit.

These facial features are indicative of what Neves calls the ‘generalised cranial morphology’ – the morphology of anatomically modern humans, who first migrated out of Africa more than 100,000 years ago, and made it as far as Australia some 50,000 years ago, and Melanesia 40,000 years ago.

New finds in seven sites

When Neves first announced his discovery of Luzia in the late 1990s, he faced criticism from a number of archaeologists, who claimed the dating was not accurate. He has since returned to excavate four other sites, and is still cataloguing skeletons from the most recent dig.

In total, there are now hundreds of skeletons with the cranial morphology similar to Australian Aborigines, found in seven sites – as far north as Florida in the United States to Palli Aike in southern Chile.

In 2005, he published a paper in the U.S journal,Proceedings of the National Academy of Sciences, analysing the characteristics of a further 81 skeletons he recovered from one of four sites, in which he said strengthened his argument that there were migrations to the Americas from at least two major populations.

Not related to Native Americans

In June 2010 in the journal PLoS ONE, Neves and colleagues Mark Hubbe of Chile’s Northern Catholic University and Katerina Harvati from Germany’s University of Tübingen, showed that it was not possible for the Aborigine-like skeletons to be the direct ancestors of the Native Americans.

Nor was it possible for the two populations to share a last common ancestor at the time of the first entrance into the continent, they argued, based on the 57 cranial measurements that can be made on a skull.

So far, almost all DNA studies of Native Americans points to a single entry from Siberia. This may mean that the original population died out, or simply that DNA studies have been too narrow, argue a number of archaeologists.

I’m also curious as to why DNA studies have failed to trace the genetic ancestry of some of these tribes. Perhaps they have been too narrow in scope.

After all, to find otherwise would upset the known paradigm.

Did Australian Aborigines reach America first?

hat tip

The Ethics of Neanderthal Cloning

For a break from space stuff, I would like to put forth an ethical conundrum of science; “Should we clone Neanderthals?”

Neanderthals were a branch of humanity (according to mainstream science) that existed for over 450,000 years and coexisted with our homo sapien ancestors 50-60,000 years ago.

They supposedly were less intelligent than homo sapiens and one prevailing theory up until recently said that our ancestors wiped out the less aggressive Neanderthals.

Now there seems to be proof that both branches of humanity where able to interbreed (viva la differance!) and instead of being wiped out, the Neanderthals were absorbed into the larger homo sapien gene pool.

With the advances in genetic engineering, it has become possible to resurrect the Neanderthal race of homo sapiens, but that has started an interesting problem and the the question posed at the beginning of the post:

[…]The Neanderthals broke away from the lineage of modern humans around 450,000 years ago. They evolved larger brains and became shorter than their likely ancestor, Homo heidelbergensis. They also developed a wider variety of stone tools and more efficient techniques for making them. On average, Neanderthals had brains that were 100 cubic centimeters (about 3 ounces) larger than those of people living today. But those differences are likely due to their larger overall body size. Those large brains were housed inside skulls that were broader and flatter, with lower foreheads than modern humans. Their faces protruded forward and lacked chins. Their arms and the lower part of their legs were shorter than modern humans’, making them slower and less efficient runners, but they also had more muscle mass. Their bones were often thicker and stronger than ours, but they typically show a lot of healed breaks that are thought to result from hunting techniques requiring close contact with large game such as bison and mammoths. They had barrel-shaped chests and broad, projecting noses, traits some paleoanthropologists believe would have helped Neanderthals breathe more easily when chasing prey in cold environments.

Recent studies comparing Neanderthal and modern human anatomy have created some surprising insights. “Neanderthals are not just sort of funny Eskimos who lived 60,000 years ago,” says Jean-Jacques Hublin, a paleoanthropologist at Max Planck. “They have a different way to give birth to babies, differences in life history, shape of inner ear, genetics, the speed of development of individuals, weaning, age of puberty.” A study comparing Neanderthal and modern children showed Neanderthals had shorter childhoods. Some paleoanthropologists believe they reached physical maturity at age 15.

As different as Neanderthals were, they may not have been different enough to be considered a separate species. “There are humans today who are more different from each other in phenotype [physical characteristics],” says John Hawks, a paleoanthropologist at the University of Wisconsin. He has studied differences in the DNA of modern human populations to understand the rate of evolutionary change in Homo sapiens. Many of the differences between a Neanderthal clone and a modern human would be due to genetic changes our species has undergone since Neanderthals became extinct. “In the last 30,000 years we count about 2,500 to 3,000 events that resulted in positive functional changes [in the human genome],” says Hawks. Modern humans, he says, are as different from Homo sapiens who lived in the Neolithic period 10,000 years ago, as Neolithic people would have been from Neanderthals.

Clones created from a genome that is more than 30,000 years old will not have immunity to a wide variety of diseases, some of which would likely be fatal. They will be lactose intolerant, have difficulty metabolizing alcohol, be prone to developing Alzheimer’s disease, and maybe most importantly, will have brains different from modern people’s.

Bruce Lahn at the University of Chicago studies the evolutionary history of the genes that control human brain development. One gene that affects brain size particularly interests him, a variant of the microcephalin gene, which Lahn thinks may have entered the human gene pool through interbreeding with Neanderthals. If that turns out to be true, roughly 75 percent of the world’s population has a brain gene inherited from Neanderthals. Lahn is excited to see what the Neanderthal microcephalin gene sequence looks like. “Is the Neanderthal sequence more similar to the ancestral version or the newer, derived version of the gene?” Lahn asks. “Or is the Neanderthal yet a third version that is very different from either of the two human versions? No matter how you look at it, it makes that data very interesting.”

The Neanderthals’ brains made them capable of some impressive cultural innovations. They were burying their dead as early as 110,000 years ago, which means that they had a social system that required formal disposal of the deceased. Around 40,000 years ago, they adopted new stone-tool-making traditions, the Châttelperronian tradition in Western Europe and the Uluzzian in Italy, that included a greater variety of tools than they had used in hundreds of thousands of years. But even if they were as adaptable as Homo sapiens, the question remains–if they were so smart, why are they dead? Chris Stringer of London’s Natural History Museum believes our species hunted and gathered food so intensively that there simply was not enough room for the Neanderthals to make a living. In other words, they had the same problem as many species facing extinction today–they were crowded out of their ecological niche by Homo sapiens. Finding a place in the world for a Neanderthal clone would be only one dilemma that would have to be solved.

Bernard Rollin, a bioethicist and professor of philosophy at Colorado State University, doesn’t believe that creating a Neanderthal clone would be an ethical problem in and of itself. The problem lies in how that individual would be treated by others. “I don’t think it is fair to put people…into a circumstance where they are going to be mocked and possibly feared,” he says, “and this is equally important, it’s not going to have a peer group. Given that humans are at some level social beings, it would be grossly unfair.” The sentiment was echoed by Stringer, “You would be bringing this Neanderthal back into a world it did not belong to….It doesn’t have its home environment anymore.”

There were no cities when the Neanderthals went extinct, and at their population’s peak there may have only been 10,000 of them spread across Europe. A cloned Neanderthal might be missing the genetic adaptations we have evolved to cope with the world’s greater population density, whatever those adaptations might be. But, not everyone agrees that Neanderthals were so different from modern humans that they would automatically be shunned as outcasts.

“I’m convinced that if one were to raise a Neanderthal in a modern human family he would function just like everybody else,” says Trenton Holliday, a paleoanthropologist at Tulane University. “I have no reason to doubt he could speak and do all the things that modern humans do.”

“I think there would be no question that if you cloned a Neanderthal, that individual would be recognized as having human rights under the Constitution and international treaties,” says Lori Andrews, a professor at Chicago-Kent College of Law. The law does not define what a human being is, but legal scholars are debating questions of human rights in cases involving genetic engineering. “This is a species-altering event,” says Andrews, “it changes the way we are creating a new generation.” How much does a human genome need to be changed before the individual created from it is no longer considered human?

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Legal precedent in the United States seems to be on the side of Neanderthal human rights. In 1997, Stuart Newman, a biology professor at New York Medical School attempted to patent the genome of a chimpanzee-human hybrid as a means of preventing anyone from creating such a creature. The patent office, however, turned down his application on the basis that it would violate the Constitution’s 13th amendment prohibition against slavery. Andrews believes the patent office’s ruling shows the law recognizes that an individual with a half-chimpanzee and half-human genome would deserve human rights. A Neanderthal would have a genome that is even more recognizably human than Newman’s hybrid. “If we are going to give the Neanderthals humans rights…what’s going to happen to that individual?” Andrews says. “Obviously, it won’t have traditional freedoms. It’s going to be studied and it’s going to be experimented on. And yet, if it is accorded legal protections, it will have the right to not be the subject of research, so the very reasons for which you would create it would be an abridgment of rights.”

[image]

Human rights laws vary widely around the world. “There is not a universal ban on cloning,” says Anderson. “Even in the United States there are some states that ban it, others that don’t.” On August 8, 2005, the United Nations voted to ban human cloning. It sent a clear message that most governments believe that human cloning is unethical. The ban, however, is non-binding.

The legal issues surrounding a cloned Neanderthal would not stop with its rights. Under current laws, genomes can be patented, meaning that someone or some company could potentially own the genetic code of a long-dead person. Svante Pääbo, who heads the Neanderthal genome sequencing project at Max Planck, refused to comment for this article, citing concerns about violating an embargo agreement with the journal that is going to publish the genome sequence. But he did send ARCHAEOLOGY this statement: “We have no plans to patent any of the genes in the Neanderthal.”

The ultimate goal of studying human evolution is to better understand the human race. The opportunity to meet a Neanderthal and see firsthand our common but separate humanity seems, on the surface, too good to pass up. But what if the thing we learned from cloning a Neanderthal is that our curiosity is greater than our compassion? Would there be enough scientific benefit to make it worth the risks? “I’d rather not be on record saying there would,” Holliday told me, laughing at the question. “I mean, come on, of course I’d like to see a cloned Neanderthal, but my desire to see a cloned Neanderthal and the little bit of information we would get out of it…I don’t think it would be worth the obvious problems.” Hublin takes a harder line. “We are not Frankenstein doctors who use human genes to create creatures just to see how they work.” Noonan agrees, “If your experiment succeeds and you generate a Neanderthal who talks, you have violated every ethical rule we have,” he says, “and if your experiment fails…well. It’s a lose-lose.” Other scientists think there may be circumstances that could justify Neanderthal cloning.

“If we could really do it and we know we are doing it right, I’m actually for it,” says Lahn. “Not to understate the problem of that person living in an environment where they might not fit in. So, if we could also create their habitat and create a bunch of them, that would be a different story.”

“We could learn a lot more from a living adult Neanderthal than we could from cell cultures,” says Church. Special arrangements would have to be made to create a place for a cloned Neanderthal to live and pursue the life he or she would want, he says. The clone would also have to have a peer group, which would mean creating several clones, if not a whole colony. According to Church, studying those Neanderthals, with their consent, would have the potential to cure diseases and save lives. The Neanderthals’ differently shaped brains might give them a different way of thinking that would be useful in problem-solving. They would also expand humanity’s genetic diversity, helping protect our genus from future extinction. “Just saying ‘no’ is not necessarily the safest or most moral path,” he says. “It is a very risky decision to do nothing.”

Hawks believes the barriers to Neanderthal cloning will come down. “We are going to bring back the mammoth…the impetus against doing Neanderthal because it is too weird is going to go away.” He doesn’t think creating a Neanderthal clone is ethical science, but points out that there are always people who are willing to overlook the ethics. “In the end,” Hawks says, “we are going to have a cloned Neanderthal, I’m just sure of it.”

I’m not sure I agree with Hawk’s rational of cloning the Neanderthal genome, just because we can clone the mammoth’s genome, we should clone the Neanderthals’.

In my view, just because we can, doesn’t necessarily mean we should.

And the ethics of bringing another race of potentially intelligent beings back into existence should be considered. What of their ‘rights?’ Should they be afforded the same as other human beings? What of their ‘nationality?’ Does that influence what rights of being they have?

To me, the legalities of this act should be considered before any ‘resurrection’ is performed.

What do you think?

Should We Clone Neanderthals?

hat tip

Ancient Abu Dhabi, out of Africa and wither men?

Most of the outside world attributes the success of the UAE to the murky fluid beneath its soil, but thousands of years ago, long before oil was of any use, a culture existed here that built a foundation for the UAE’s civilisation…

…During the last two years archaeologists have discovered solid evidence of very ancient communities that were living in different places in the UAE. The most ancient community known so far is the one that lived around Jebel Baraka in the Western Region of Abu Dhabi, at least 150,000 years ago. The Arabian Gulf by then was still a dry land ripped by the Tigris and the Euphrates which debouched at the strait of Hormuz.

Hmmm, 150,000 years ago is given as the time homo sapiens left Africa and started to settle other areas, including the Middle East. If I read the article right, these early communities were already established 150,000 years ago.

Maybe Michael Cremo has a point?

Communities lived here 150,000 years ago

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But not so fast now…

MITOCHONDRIAL DNA is a remarkable thing. Itself the remnant of a strange evolutionary event (the merger of an ancient bacterium with the cell ancestral to all plant and animal life), it also carries the imprint of more recent evolution. In many species, humans included, it passes only from mother to child. No paternal genes get mixed into it. That makes it easy to see when particular genetic mutations happened, and thus to construct a human family tree.

The branches of that tree are now well studied. Humans started in Africa, spread to Asia around 60,000 years ago, thence to Australia 50,000 years ago, Europe 35,000 years ago and America 15,000 years ago. What have not been so well examined, though, are the tree’s African roots. The genetic diversity of Africans probably exceeds that of the rest of the world put together. But the way that diversity evolved is unclear.

The time frames don’t jibe here at all, communities in the United Arab Emirates that date back 150,000 years, or a branch of humanity just hiking out of Africa 70,000 years ago?

DNA research can be a powerful tool indeed to find the truth. But like all tools, it can be subverted for political, societal and religious gain.

Before the exodus

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Uh-oh, speaking of DNA, this doesn’t bode well for the male gender:

Imagine a world without men: Lauren Bacall but no Bogie, Hillary Clinton but no Bill, no Starsky or Hutch.

This isn’t just an unlikely sci-fi scenario. This could be reality, according to Bryan Sykes, an eminent professor of genetics at Oxford University and author of “Adam’s Curse: A Future Without Men.”

“The Y chromosome is deteriorating and will, in my belief, disappear,” Sykes told me. A world-renowned authority on genetic material, Sykes is called upon to investigate DNA evidence from crime scenes. His team of researchers is currently compiling a DNA family tree for our species.

In 125,000 years there won’t be anymore men. Good news for radical feminists and women of the same sex proclivity.

But c’mon now, who will women blame for wars, drunken barroom brawls and failing to take out the trash?

Envisioning a World Without Men