Tag: Africa

Did Humans Almost Go Extinct? | Random Thursday

70,000 years ago, the human population hit a major bottleneck, and scientists aren’t exactly sure why.

One of the more popular explanations has been the Toba explosion, the massive explosion of the Toba supervolcano that occurred at roughly that same time, but has been mostly disproven.

DNA evidence shows that African populations, especially the ancient Khoi and San people of Africa, show far more genetic diversity than those who came out of Africa according to the “out of Africa” theory. The study showed that those that came out of Africa descended from between 1000 and 10,000 breeding pairs.

The reason for this remains a mystery.

A Newly Discovered Skull Reveals What The Common Ancestor Of Humans And Apes May Have Looked Like

An infant ape cranium named as “Alesi”, excavated from the site of an archaeological dig at Napudet, west of Lake Turkana in Kenya.

Scientists have named a new species of ape based on a 13-million-year-old skull fossil.

It belonged to a new species called Nyanzapithecus alesi that was closely related to the common ancestor of people and modern apes although that ancestor likely was even older, University College London paleontologist Fred Spoor said.




The sole specimen is that of an infant that would have grown to weigh about 11 kilogrammes (24 pounds) in adulthood. Its adult brain volume would have been nearly three times larger than that of known African monkeys from the same time, the researchers estimate.

If you compare to all living things, it looks most like a gibbon“, study co-author Isaiah Nengo of the Stony Brook University in NY told AFP. The same probably held for N. alesi, making it an unlikely direct ancestor of living gibbons, they conclude.

The skull may answer a long-standing question about the origin of the lineage that led to people and modern apes such as chimpanzees, gorillas, orangutans and gibbons, indicating their common ancestor evolved in Africa, not Eurasia, the scientists said.

The lemon-sized skull was found in Kenya by an global team of researchers, and was dated to the middle of the Miocene era, a little-understood time when many species of ape arose in Africa, including common ancestors of both modern apes and humans.

With this we put the root of the hominoidea in Africa more firmly“, said Nengo.

Scientists assigned it to a new species, Nyanzapithecus alesi. If an evolutionary relationship existed with the older N. alesi, the first members of the Oreopithecus genus probably originated in Africa, Nengo proposes.

That group, which has no official name yet, lived and died millions of years ago.

As well as dating to the “dark ages” of human origins, it is also the most complete extinct ape skull in the fossil record.

Alesi is the one that has allowed us to. know who is in that group. and when we take a close look we see that most of the group are found in Africa“.

The record of African fossil hominoids (primates that include apes, humans and their ancestors) lacked a almost complete cranium from between 17 million and 7 million years ago, the study notes.

We have a handsome ape cranium from a period that we knew virtually nothing about and this is one of those wonderful cases where discovery leads to all sorts of new and interesting perspectives“, Craig Feibel, who chairs Rutgers’ Department of Anthropology and is a professor of geology and anthropology, said in a statement.

The skull resembles a baby gibbon’s. But the balance organ inside its inner ear differed from gibbons and suggested Alesi’s species moved through trees more cautiously and had shorter arms than gibbons, which swing through trees with acrobatic ease.

Growth lines on the adult teeth showed Alesi was one year and four months old at death.

Commenting on the study, anthropologist Brenda Benefit of the New Mexico State University described this as a fossil find “that I never thought would be made during my lifetime“.

It’s a major finding that fills a large gap in the evolutionary record“.

This is an exceptional discovery“, agreed Paul Tafforeau of the European Synchrotron Radiation Facility in Grenoble, France, who helped examine the skull.

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Oldest Fossils Of Homo Sapiens Found in Morocco

jaw

Fossils discovered in Morocco are the oldest known remains of Homo sapiens, scientists reported, a finding that rewrites the story of mankind’s origins and suggests that our species evolved in multiple locations across the African continent.

Until now, the oldest known fossils of our species dated back just 195,000 years. The Moroccan fossils, by contrast, are roughly 300,000 years old.




Remarkably, they indicate that early Homo sapiens had faces much like our own, although their brains differed in fundamental ways.

Today, the closest living relatives to Homo sapiens are chimpanzees and bonobos, with whom we share a common ancestor that lived over six million years ago.

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Indian Stone Tools Could Dramatically Push Back Date When Modern Humans First Left Africa

We are all children of Africa. As members of the hominin species Homo sapiens, you and I are the product of millions of years of shared evolutionary history of life on Earth.

But as a species we are relatively recent, emerging between 400,000 and 300,000 years ago in East Africa from indigenous archaic populations.

Currently, some of the biggest questions facing palaeoanthropology involve trying to work out how and when early humans left the continent. Was it a single dispersal? Or multiple?

A recent discovery of a jawbone fossil in Israel suggests that there could have been a migration as early as about 180,000 years ago.




But a new study, published in the journal Nature, suggests early humans may have left Africa much earlier than that.

The new research reports the discovery of tools from the Middle Palaeolithic (200,000 to 40,000 years ago) in Tamil Nadu, India.

Surprisingly, the tools date back to 385,000 years ago – which is around the same time as this technology is thought to have first developed by archaic or possibly modern humans in Africa.

This challenges the view, backed by most researchers, that modern humans brought these technologies to India less than 140,000 years ago.

Attirampakkam site

Attirampakkam is located on the banks of a stream of the Kortallaiyar River in northeast Tamil Nadu.

Excavations by a team of Indian researchers revealed abundant layers of stone tools trapped within sediments deposited by streams which ran through the area in prehistory.

The site appears to have been sporadically occupied by apes and early hominins predating Homo sapiens from as far back as 1.7m years ago.

Using a dating technique called infrared-stimulated luminescence – which pinpoints the last time that sediment grains were exposed to light – the authors determined that the silts and gravels which contain the tools date to between 385,000 and 172,000 years ago.

These tools chart the transition from the Acheulean handaxe culture, created by archaic humans of the Lower Palaeolithic, to smaller tools.

The latter were produced by a more sophisticated technique called Levallois – involving the production of stone points and blades.

The tools push the date back for the origins of Middle Palaeolithic technology in India.

Previous studies have suggested that this occurred between 140,000 years and 46,000 years ago, possibly as Homo sapiens migrated into the subcontinent.

But what is perhaps more important, is what these dates mean for the emergence of Homo sapiens and our species’ migrations into the rest of the Old World.

And to understand those implications we need to consider fossils from North Africa and how they are associated with hominin species and technology.

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Scientists Find Jawbone Fossil From Oldest Modern Human Out Of Africa In A Cave In Israel

Scientists on Thursday announced the discovery of a fossilized human jawbone in a collapsed cave in Israel that they said is between 177,000 and 194,000 years old.

If confirmed, the find may rewrite the early migration story of our species, pushing back by about 50,000 years the time that Homo sapiens first ventured out of Africa.

Previous discoveries in Israel had convinced some anthropologists that modern humans began leaving Africa between 90,000 and 120,000 years ago. But the recently dated jawbone is unraveling that narrative.

This would be the earliest modern human anyone has found outside of Africa, ever,” said John Hawks, a paleoanthropologist from the University of Wisconsin, Madison who was not involved in the study.




The upper jawbone — which includes seven intact teeth and one broken incisor, and was described in a paper in the journal Science — provides fossil evidence that lends support to genetic studies that have suggested modern humans moved from Africa far earlier than had been suspected.

Dr. Hawks and other researchers advised caution in interpreting the discovery.

Although this ancient person may have shared some anatomical characteristics with present-day people, this “modern human” would have probably looked much different from anyone living in the world today.

Early modern humans in many respects were not so modern,” said Jean-Jacques Hublin, director of the department of human evolution at the Max Planck Institute for Evolutionary Anthropology in Germany.

Dr. Hublin said that by concluding the jawbone came from a “modern human,” the authors were simply saying that the ancient person was morphologically more closely related to us than to Neanderthals.

 

That does not mean that this person contributed to the DNA of anyone living today, he added. It is possible that the jawbone belonged to a previously unknown population of Homo sapiens that departed Africa and then died off.

That explanation would need to be tested with DNA samples, which are difficult to collect from fossils found in the arid Levant.

The upper jawbone, or maxilla, was found by a team led by Israel Hershkovitz, a paleoanthropologist at Tel Aviv University and lead author of the new paper, while excavating the Misliya Cave on the western slopes of Mount Carmel in Israel.

The jawbone was discovered in 2002 by a freshman on his first archaeological dig with the group.

The team had long known that ancient people lived in the Misliya Cave, which is a rock shelter with an overhanging ceiling carved into a limestone cliff.

By dating burned flint flakes found at the site, archaeologists had determined that it was occupied between 250,000 to 160,000 years ago, during an era known as the Early Middle Paleolithic.

Evidence, including bedding, showed that the people who lived there used it as a base camp. They hunted deer, gazelles and aurochs, and feasted on turtles, hares and ostrich eggs.

Dr. Hershkovitz and Mina Weinstein-Evron, an archaeologist at the University of Haifa, felt that the jawbone looked modern, but they needed to confirm their hunch.

The Misliya finding is just the latest in a series of discoveries that are changing the story of our evolutionary past.

One study, not yet confirmed, suggested that modern humans may have interbred with Neanderthals in Eurasia about as far back as 220,000 years ago.

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The Origins Of Our Species Might Need A Rethink

On the outskirts of Beijing, a small limestone mountain named Dragon Bone Hill rises above the surrounding sprawl.

Along the northern side, a path leads up to some fenced-off caves that draw 150,000 visitors each year, from schoolchildren to grey-haired pensioners.

It was here, in 1929, that researchers discovered a nearly complete ancient skull that they determined was roughly half a million years old.

Dubbed Peking Man, it was among the earliest human remains ever uncovered, and it helped to convince many researchers that humanity first evolved in Asia.

Since then, the central importance of Peking Man has faded. Although modern dating methods put the fossil even earlier at up to 780,000 years old the specimen has been eclipsed by discoveries in Africa that have yielded much older remains of ancient human relatives.




Such finds have cemented Africa’s status as the cradle of humanity the place from which modern humans and their predecessors spread around the globe and relegated Asia to a kind of evolutionary cul-de-sac.

But the tale of Peking Man has haunted generations of Chinese researchers, who have struggled to understand its relationship to modern humans.

It’s a story without an ending,” says Wu Xinzhi, a palaeontologist at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing.

They wonder whether the descendants of Peking Man and fellow members of the species Homo erectus died out or evolved into a more modern species, and whether they contributed to the gene pool of China today.

Keen to get to the bottom of its people’s ancestry, China has in the past decade stepped up its efforts to uncover evidence of early humans across the country.

It is reanalysing old fossil finds and pouring tens of millions of dollars a year into excavations. And the government is setting up a US$1.1-million laboratory at the IVPP to extract and sequence ancient DNA.

In its typical form, the story of Homo sapiens starts in Africa. The exact details vary from one telling to another, but the key characters and events generally remain the same. And the title is always ‘Out of Africa’.

In this standard view of human evolution, H. erectus first evolved there more than 2 million years ago.

Then, some time before 600,000 years ago, it gave rise to a new species: Homo heidelbergensis, the oldest remains of which have been found in Ethiopia.

About 400,000 years ago, some members of H. heidelbergensis left Africa and split into two branches: one ventured into the Middle East and Europe, where it evolved into Neanderthals; the other went east, where members became Denisovans a group first discovered in Siberia in 2010.

The remaining population of H. heidelbergensis in Africa eventually evolved into our own species, H. sapiens, about 200,000 years ago.

Then these early humans expanded their range to Eurasia 60,000 years ago, where they replaced local hominins with a minuscule amount of interbreeding.

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Could Aquaculture Solve Africa’s Fishing Crisis?

Marine fisheries in Africa are over-exploited, but with the right type of fish and support from NGOs, smallholders could help bring about growth.

Fish is a critical source of dietary protein in sub-Saharan Africa, providing an estimated 22% of protein intake.

But with marine fisheries over-exploited, African fish production is failing to keep up with rising populations.

How should that gap be filled to protect this vital source of nutrition?

Aquaculture can do it, according to experts from the UN’s Food and Agriculture Organisation and the WorldFish research organization.




But it will only work if there’s a shift away from decades-old approaches to aquaculture development, which uses farm ponds.

For real impact on overall fish production and access, they say, there needs to be a greater emphasis on smallholders joining forces and helping to develop a commercial fish farming sector.

Per capita fish supplies in Africa are dwindling,” says Malcolm Beveridge, director for aquaculture and genetic at WorldFish, one of the CGIAR research centres.

In Malawi, they fell from 10kg to 6kg per person between 1986 and 2006. Aquaculture has the potential to increase supplies of this affordable nutritious food for poor and vulnerable consumers.

Historically, aquaculture development in Africa has targeted the poorest people to address hunger through small on-farm ponds.

This has proven valuable for household food and nutrition security and will continue to have a place.

But on-farm aquaculture isn’t meeting the overall supply gap now, and isn’t likely to do so in future for a rapidly growing and increasingly urbanised population.

Small ponds reliant on meagre household scraps and on-farm waste will produce only a few kilograms of fish per year,” says Beveridge.

This is often important for the family and worth supporting as part of building livelihood diversification strategies. But the benefits rarely extend beyond the household and immediate neighbours.

This partly explains why, to date, African aquaculture has remained insignificant in global terms. Total production was 1,288,320 tonnes in 2010, representing just 2.2% of global production.

Discount Egypt (Africa’s major producer) and the figure for sub-Saharan Africa on its own was just 359,790 tonnes for 2010 – a mere 0.6% of world production.

But things are already changing. It may be starting from a low base, but aquaculture in sub-Saharan Africa is growing: in 2000, production was just 55,690 tonnes, so it saw almost seven-fold growth between then and 2010.

Much of this growth is taking place in countries including Ghana, Nigeria, Uganda, Kenya, and Namibia, thanks partly to initiatives such as the FAO’s Special Programme for Aquaculture in Africa and the Nepad action plan for the development of African fisheries and aquaculture, which are providing policy and technical support to a groundswell of aquaculture enterprises.

Spada, established in 2007, stated an aim of increasing aquaculture in Africa by 200% over the next decade. But the extent to which that will impact upon food security depends on how it is achieved.

In theory, more fish should mean lower prices and greater access, but that isn’t guaranteed if production is concentrated amongst a small number of large-scale producers near urban centres, or if the fish is exported.

It’s therefore essential that smallholders help drive the growth, according to Rohana Subasinghe, senior aquaculture officer at the FAO.

This will help ensure that the most food insecure benefit from increased production. But smallholders can’t do it individually, because entry costs can be prohibitive for small-scale producers, who tend to be risk-averse.

Smallholders are extremely important in Africa, but you have to operate on a certain scale in aquaculture,” says Subasinghe.

So smallholders will need to work together in clusters, so they can be more empowered and operate as a group with better market access.

“These SMEs – made up of smallholders – will help keep the ultimate objective of agriculture in mind, which is alleviating poverty and improving food security.

Another factor to get right is the type of fish produced. The vast majority of farmed fish in Africa is freshwater, mainly the Nile tilapia and sharptooth catfish.

These omnivorous fish are relatively easy to raise, and there is strong demand for them. New strains of the Nile tilapia released this year Egypt, Ghana and Malawi are also up to 30% faster-growing than traditional strains, and have been heralded as a leap forward for African aquaculture.

But bigger is not always better, in food security terms.

For development actors, then, the challenge is to provide the right kind of support to aquaculture in different places.

On the one hand, on-farm ponds will remain important and can be developed further to improve household food security.

For the very poorest, this is crucial. Work in Malawi, for example, has shown how successful Integrated Agriculture-Aquaculture can be at the farm level, providing not just the protein from fish but raising overall agricultural productivity.

On the other hand, NGOs can also play a vital role in developing and fostering networks of aquaculture SMEs formed of smallholders, and helping the sector develop in such a way that it contributes to wider food and nutrition security.

Governments have already demonstrated political will, says Subasinghe. Kenya has made aquaculture a core priority in its fisheries department. But it is NGOs who can really help make things happen.

Much of Africa already has the right conditions in terms of soils, water, temperatures and market demand to farm fish successfully.

What’s important now is to shape growth in such a way that it has real impacts on hunger and undernutrition.

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According To Scientists, Europe Was The Birthplace Of Mankind And Not Africa

The history of human evolution has been rewritten after scientists discovered that Europe was the birthplace of mankind, not Africa.

Currently, most experts believe that our human lineage split from apes around seven million years ago in central Africa, where hominids remained for the next five million years before venturing further afield.

But two fossils of an ape-like creature which had human-like teeth have been found in Bulgaria and Greece, dating to 7.2 million years ago.

The discovery of the creature, named Graecopithecus freybergi, and nicknameded ‘El Graeco’ by scientists, proves our ancestors were already starting to evolve in Europe 200,000 years before the earliest African hominid.




An international team of researchers say the findings entirely change the beginning of human history and place the last common ancestor of both chimpanzees and humans – the so-called Missing Link – in the Mediterranean region.

At that time climate change had turned Eastern Europe into an open savannah which forced apes to find new food sources, sparking a shift towards bipedalism, the researchers believe.

This study changes the ideas related to the knowledge about the time and the place of the first steps of the humankind,” said Professor Nikolai Spassov from the Bulgarian Academy of Sciences.

Graecopithecus is not an ape. He is a member of the tribe of hominins and the direct ancestor of homo.”

The food of the Graecopithecus was related to the rather dry and hard savannah vegetation, unlike that of the recent great apes which are living in forests.  Therefore, like humans, he has wide molars and thick enamel.

To some extent this is a newly discovered missing link. But missing links will always exist , because evolution is infinite chain of subsequent forms. Probably  El Graeco’s face will resemble a great ape, with shorter canines.”

The team analysed the two known specimens of Graecopithecus freybergi: a lower jaw from Greece and an upper premolar tooth from Bulgaria.

Using computer tomography, they were able to visualise the internal structures of the fossils and show that the roots of premolars are widely fused.

The lower jaw, has additional dental root features, suggesting that the species was a hominid.

The species was also found to be several hundred thousand years older than the oldest African hominid, Sahelanthropus tchadensis which was found in Chad.

Professor David Begun, a University of Toronto paleoanthropologist and co-author of this study, added: “This dating allows us to move the human-chimpanzee split into the Mediterranean area.

During the period the Mediterranean Sea went through frequent periods of drying up completely, forming a land bridge between Europe and Africa and allowing apes and early hominids to pass between the continents.

The team believe that evolution of hominids may have been driven by dramatic environmental changes which sparked the formation of the North African Sahara more than seven million years ago and pushed species further North.

They found large amounts of Saharan sand in layers dating from the period, suggesting that it lay much further North than today.

Retired anthropologist and author Dr Peter Andrews, formerly at the Natural History Museum in London, said: “It is possible that the human lineage originated in Europe, but very substantial fossil evidence places the origin in Africa, including several partial skeletons and skulls.”

I would be hesitant about using a single character from an isolated fossil to set against the evidence from Africa.

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