Showing posts with label Richard Leakey. Show all posts
Showing posts with label Richard Leakey. Show all posts

Wednesday, 7 December 2016

JOSEPH TRAVELS TO OLDUPAI, THE CRADDLE OF MANKIND

Joseph in Olduvai Gorge, the cradle of mankind
Joseph de Ca'th Lon has travelled to Olduvai Gorge, in Tanzania

He wants to visit this place considered the cradle of mankind that has proven invaluable in furthering understanding of early human evolution. This place holds the earliest evidence of the existence of human ancestors.

Paleoanthropologists have found hundreds of fossilized bones and stone toots in the area dating back millions of years, leading them to conclude that humans evolved in Africa.

Joseph has joined to the paleoanthropologist team that is still working there and he wants to share with us the last reports and news about it.

More information: The Olduvai Gorge Project
 
Mary and Louis Leakey studying skull fragments 
Olduvai is a misspelling of Oldupai, a Maasai word for a wild sisal plant that grows in the area. The gorge is located in the Great Rift Valley, between the Ngorongoro Crater and the Serengeti National Park. It is 30 miles from Laetoli, another fossil-rich area. Olduvai Gorge was formed about 30,000 years ago, the result of aggressive geological activity and streams.

The steep ravine is about 48.2 km long and 89.9 meters deep, not quite large enough to be classified as a canyon. A river cuts through several layers to form four individual beds, with the oldest estimated at about 2 million years old.


Louis and Mary Leakey are often referred to as the first family of paleontology, as much of their lives, and later the lives of their children, revolved around Olduvai Gorge. The couple met on a dig in England, and both worked briefly at the Olduvai Gorge before being married in England in 1937.

Louis was born in 1903 in Kenya, where his English parents were missionaries. He would often uncover prehistoric stone tools while he was out bird watching. After graduating from University in England, he joined a fossil-finding expedition to what is now Tanzania, which sparked his interest in human origins.


More information: The Leakey Foundation

Louis and Mary Leakey
In 1930s, the Leakeys found stone tools in Olduvai and elsewhere. Among their most notable finds were several extinct vertebrates, including the 25-million-year-old Pronconsul primate, one of the first and few fossil ape skulls discovered.

Political unrest in nearby Kenya forced them to put their work on hold, but they went back to Olduvai Gorge in the late 1950s. While they had focused on tools in their previous work at the gorge, they went back to look for further evidence of human life.

One day in 1959, Mary went out to work as usual, leaving Louis behind with a headache. She discovered fossilized parts of a skull and upper teeth of a type of hominin that had not been previously identified.

More information: The Smithsonian

Over the next several weeks, the Leakeys uncovered about 400 pieces of a nearly complete skull. There were similarities to other discoveries, including those in South Africa by Raymond Dart in 1924 and by Robert Broom in 1936. However, the Leakeys classified their find as new category of hominin, dubbing it Zinjanthropus boisei.

It was not the direct ancestor of humankind that the Leakeys had hoped for, but it brought the couple some notoriety and spurred public interest in the study of human origins.

They dated the discovery as having lived 1.75 million years ago. This made it the oldest hominin discovered to that point, although a lack of fossil-dating technology made it difficult to determine the age of Dart’s and Broom’s earlier finds. The combination of the works of the Leakeys, Dart and Broom made a convincing case that humans originally evolved in Africa.


More information: National Geographic

Homo Habilis skull
By 1960, Louis Leakey had become ill and Mary took over most of the operation. There were a number of developments during this period. They uncovered a well-preserved fossil foot that had arches, giving credence to the theory that hominins walked upright.

During this time, Mary Leakey and son Jonathan Leakey found another, smaller form of hominin that they called Homo habilis, translated as handy human, because it seemed he was able to use tools. This fossil was dated at about 2 million years old. This was confirmed when another son, Richard Leakey, discovered another Homo habilis in 1972.

This 1972 discovery also supported the elder Leakey's theory that there were several lines of hominins developing simultaneously and that the Homo genus did not evolve from Australopithecus

But the Leakeys were not responsible for what some scientists term the biggest and most significant findings at Olduvai Gorge. In 1986, a team of Tanzanian and American archeologists unearthed 302 bones and teeth belonging to a female that was determined to be about 1.8 million years old.

If you live in Barcelona or you're visiting the city, you can visit a very interesting exposition in Caixa Forum about Olduvai, the cradle of mankind.

More information: Caixa Forum, Barcelona 


At Olduvai, for 20 years, Mary and I had investigated and made 
a general survey of the overall geology.
Louis Leakey

Wednesday, 14 September 2016

HOMO ERGASTER: THE WORKING MAN

Homo Ergaster
Homo Ergaster, working man, is an extinct hominid species or subspecies, according to some authorities, which lived throughout eastern and southern Africa between 1.9 to 1.4 million years ago with the advent of the lower Pleistocene and the cooling of the global climate.

Homo Ergaster is sometimes categorized as a subspecies of Homo Erectus. It is currently somewhat controversial whether Homo Ergaster or the later, Asian H. erectus was the direct ancestor of modern humans. The genetic variability among modern Homo Sapiens is greatest in Africa, which suggests strongly that this is the area where the species arose and has had most time to accumulate variation. Homo Ergaster may be distinguished from Homo Erectus by its thinner skull bones and lack of an obvious sulcus.

Derived features include reduced sexual dimorphism; a smaller, more orthognathic face; a smaller dental arcade; and a larger (700 and 850cc) cranial capacity.

More information: Brad Shaw Foundation

It is estimated that Homo Ergaster stood at 1.9m (6ft3) tall with relatively less sexual dimorphism in comparison to earlier hominins.

Remains have been found in Tanzania, Ethiopia, Kenya, and South Africa. The most complete Homo Ergaster skeleton ever discovered was made at Lake Turkana, Kenya in 1984.

Paleoanthropologists Richard Leakey, Kamoya Kimeu and Tim White dubbed the 1.6 million year old specimen as KNM-WT 15000, nicknamed Turkana Boy. The type specimen of Homo Ergaster is KNM ER 992; the species was named by Groves and Mazak in 1975.

The species name originates from the Greek Ergaster meaning Workman. This name was chosen due to the discovery of various tools such as hand-axes and cleavers near the skeletal remains of Homo Ergaster. This is one of the reasons that it is sometimes set apart distinctly from other human ancestors. Its use of advanced, rather than simple, tools was unique to this species.

Homo Ergaster tool use belongs to the Acheulean industry and first began using these tools 1.6 million years ago. Charred animal bones in fossil deposits and traces of camps suggest that the species made creative use of fire.

More information: EFossils


To investigate the history of man's development, 
the most important finds are, of course, hominid fossils.

Richard Leakey