Mostrar mensagens com a etiqueta Australopithecus. Mostrar todas as mensagens
Mostrar mensagens com a etiqueta Australopithecus. Mostrar todas as mensagens

terça-feira, fevereiro 06, 2024

Mary Leakey nasceu há cento e onze anos...

 

Mary Leakey (London, 6 February 1913 – Nairobi, 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai Gorge. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.

   


Replica of an Australopithecus boisei skull discovered by Mary Leakey in 1959
     
Replica of Laetoli footprints, exhibit in the National Museum of Nature and Science, Tokyo, Japan

   

segunda-feira, fevereiro 06, 2023

Mary Leakey nasceu há cento e dez anos

   

Mary Leakey (London, 6 February 1913 – Nairobi, 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai Gorge. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.

   

Replica of an Australopithecus boisei skull discovered by Mary Leakey in 1959
     
Replica of Laetoli footprints, exhibit in the National Museum of Nature and Science, Tokyo, Japan

   

domingo, fevereiro 06, 2022

Mary Leakey nasceu há 109 anos

   

Mary Leakey (London, 6 February 1913 – Nairobi, 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai Gorge. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.

   

Replica of an Australopithecus boisei skull discovered by Mary Leakey in 1959
     
Replica of Laetoli footprints, exhibit in the National Museum of Nature and Science, Tokyo, Japan

   

sábado, fevereiro 06, 2021

Mary Leakey nasceu há 108 anos

Mary and Louis Leakey at Olduvai Gorge

  

Mary Leakey (London, 6 February 1913 – Nairobi, 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai Gorge. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.

   

Replica of an Australopithecus boisei skull discovered by Mary Leakey in 1959
     
Replica of Laetoli footprints, exhibit in the National Museum of Nature and Science, Tokyo, Japan

   

quarta-feira, fevereiro 06, 2019

Mary Leakey nasceu há 106 anos

Mary Leakey (London, 6 February 1913 – Nairobi, 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai Gorge. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.
Replica of an Australopithecus boisei skull discovered by Mary Leakey in 1959
  
Replica of Laetoli footprints, exhibit in the National Museum of Nature and Science, Tokyo, Japan

 

terça-feira, fevereiro 06, 2018

Mary Leakey nasceu há 105 anos

Mary Leakey (London, 6 February 1913 – Nairobi9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.
Mary Leakey was born Mary Douglas Nicol on 6 February 1913 in London, England to Erskine Edward Nicol and Cecilia Marion (Frere) Nicol. Since Erskine worked as a painter, specializing in watercolor landscapes, the Nicol family would move from place to place, visiting numerous locations in the USA, Italy, and Egypt, where Erskine painted scenes to be sold in England. Erskine Nicol developed an amateur enthusiasm for Egyptology during his travels. Mary Leakey was a direct descendant of antiquarian, John Frere, and cousin to archaeologist, Sheppard Frere, on her mother's side. The Frere family had been active abolitionists in the British colonial empire during the nineteenth century and established several communities for freed slaves. Three of these communities remained in existence as of Mrs. Leakey's 1984 autobiography: Freretown, Kenya, Freretown, South Africa, and Freretown, India. She also was a distant relative of baronet Henry Bartle Frere.
The Nicols spent much of their time in southern France. Mary became fluent in French. She identified more with the adventurous spirit of her father, going for long walks and explorations with him and having long talks. She disliked her governess and had less sympathy for her mother.
In 1925, when Mary was 12, the Nicols stayed at Les Eyzies at a time when Elie Peyrony was excavating one of the caves there. Peyrony did not understand the significance of much of what he found, and was not excavating scientifically during that early stage of archaeology. Mary received permission to go through his dump. It was there that her interest in prehistory was sparked. She started a collection of points, scrapers, and blades from the dump and developed her first system of classification.
That winter, the family moved to Cabrerets, a village of Dordogne, France. There she met Abbé Lemozi, the village priest, who befriended her and became her mentor for a time. The two toured Pech Merle cave to view the prehistoric paintings of bison and horses.
Through Gertrude, Mary met Louis Leakey, who was in need of an illustrator for his book, Adam's Ancestors. While she was doing that work they became romantically attached. They shared common interests and values: a love of freedom and dislike for rules, an egalitarian frame of mind extending even to animals, a desire for adventure, and a passion for archaeology. Louis was still married when he started living with Mary, which caused a scandal that ruined his career at Cambridge University. They were married when Louis' wife Frida divorced him in 1936.
From then until about 1962 Louis and Mary faced trying circumstances together. Early in their relationship he nursed her through double pneumonia. They had three sons: Jonathan in 1940, Richard in 1944, and Philip in 1949. The boys received much of their early childhood care at various anthropological sites. Whenever possible the Leakeys excavated and explored as a family. The boys grew up with the same love of freedom their parents had. Mary would not even allow guests to shoo away the pet hyraxes that helped themselves to food and drink at the dinner table. She smoked very much, first cigarettes and then cigars, and dressed as though on excavation.
Louis was not always faithful to Mary, as he had not been to Frida. In 1960 they agreed that Mary would become director of excavations at Olduvai. From then on she operated more or less independently, taking over the dig. After Louis became known as a womanizer the intimate side of the marriage was effectively over. For example, Louis became briefly involved with Dian Fossey. Meanwhile, Mary's life consisted mainly of her children, her dogs, and her archaeology. Louis died on 1 October 1972 of a heart attack. Mary continued the family's archaeological work.
Mary carried on after Louis, becoming a powerful and respected figure. By then Richard had decided to become a palaeoanthropologist. She helped his career significantly. Her other two sons opted to follow other interests.

Replica of an Parantropus (Australopithecus) boisei skull, discovered by Mary Leakey, in 1959
Mary died on 9 December 1996 at the age of 83, a renowned palaeoanthropologist, who had not only conducted significant research of her own, but had been invaluable to the research careers of her husband Louis Leakey and their sons Richard, Philip and Jonathan.
  
Leakey served her apprenticeship in archaeology under Dorothy Liddell at Hembury in Devon, England, 1930-1934, for whom she also did illustrations. In 1934 she was part of a dig at Swanscombe where she discovered the largest elephant tooth known up to that time in Britain, but needed assistance to identify it.
The years 1935 to 1959, spent at Olduvai Gorge in the Serengeti plains of Northern Tanzania, yielded many stone tools from primitive stone-chopping instruments to multi-purpose hand axes. These finds came from Stone Age cultures dated as far back as 100,000 to two million years ago.
The Leakeys unearthed a Proconsul africanus skull on Rusinga Island, in October 1948.
Their next discovery, in 1959, was a 1.75 million-year-old Australopithecus boisei skull, catalogued as OH 5. They also found a less robust Homo habilis skull and bones of a hand. After reconstructing the hand, it was proven the hand was capable of precise manipulation. Many more remains were found at this site. In 1965 the husband and wife team uncovered a Homo erectus skull, dated at one million years old.
After Mary's husband died, she continued her work at Olduvai and Laetoli. It was here, at the Laetoli site, that she discovered Hominin fossils that were more than 3.75 million-years-old. She also discovered fifteen new species of other animals and one new genus.
From 1976 to 1981 Leakey and her staff worked to uncover the Laetoli hominid footprint trail which was left in volcanic ashes some 3.6 million years ago. The years that followed this discovery were filled with research at Olduvai and Laetoli, the follow-up work to discoveries and preparing publications.
 
Replica of Laetoli footprints, exhibit in the National Museum of Nature and Science, Tokyo, Japan
  

quinta-feira, fevereiro 06, 2014

Mary Leakey nasceu há 101 anos

Mary Leakey (6 February 1913 – 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai Gorge. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.

Replica of an Australopithecus boisei skull discovered by Mary Leakey in 1959

quarta-feira, fevereiro 06, 2013

Mary Leakey nasceu há um século


Mary Leakey (6 February 1913 – 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.
Mary Leakey was born Mary Douglas Nicol on 6 February 1913 in London, England to Erskine Edward Nicol and Cecilia Marion (Frere) Nicol. Since Erskine worked as a painter, specializing in watercolor landscapes, the Nicol family would move from place to place, visiting numerous locations in the USA, Italy, and Egypt, where Erskine painted scenes to be sold in England. Erskine Nicol developed an amateur enthusiasm for Egyptology during his travels. Mary Leakey was a direct descendant of antiquarian, John Frere, and cousin to archaeologist, Sheppard Frere, on her mother's side. The Frere family had been active abolitionists in the British colonial empire during the nineteenth century and established several communities for freed slaves. Three of these communities remained in existence as of Mrs. Leakey's 1984 autobiography: Freretown, Kenya, Freretown, South Africa, and Freretown, India. She also was a distant relative of baronet Henry Bartle Frere.
The Nicols spent much of their time in southern France. Mary became fluent in French. She identified more with the adventurous spirit of her father, going for long walks and explorations with him and having long talks. She disliked her governess and had less sympathy for her mother.
In 1925, when Mary was 12, the Nicols stayed at Les Eyzies at a time when Elie Peyrony was excavating one of the caves there. Peyrony did not understand the significance of much of what he found, and was not excavating scientifically during that early stage of archaeology. Mary received permission to go through his dump. It was there that her interest in prehistory was sparked. She started a collection of points, scrapers, and blades from the dump and developed her first system of classification.
That winter, the family moved to Cabrerets, a village of Dordogne, France. There she met Abbé Lemozi, the village priest, who befriended her and became her mentor for a time. The two toured Pech Merle cave to view the prehistoric paintings of bison and horses.
Through Gertrude, Mary met Louis Leakey, who was in need of an illustrator for his book, Adam's Ancestors. While she was doing that work they became romantically attached. They shared common interests and values: a love of freedom and dislike for rules, an egalitarian frame of mind extending even to animals, a desire for adventure, and a passion for archaeology. Louis was still married when he started living with Mary, which caused a scandal that ruined his career at Cambridge University. They were married when Louis' wife Frida divorced him in 1936.
From then until about 1962 Louis and Mary faced trying circumstances together. Early in their relationship he nursed her through double pneumonia. They had three sons: Jonathan in 1940, Richard in 1944, and Philip in 1949. The boys received much of their early childhood care at various anthropological sites. Whenever possible the Leakeys excavated and explored as a family. The boys grew up with the same love of freedom their parents had. Mary would not even allow guests to shoo away the pet hyraxes that helped themselves to food and drink at the dinner table. She smoked very much, first cigarettes and then cigars, and dressed as though on excavation.
Louis was not always faithful to Mary, as he had not been to Frida. In 1960 they agreed that Mary would become director of excavations at Olduvai. From then on she operated more or less independently, taking over the dig. After Louis became known as a womanizer the intimate side of the marriage was effectively over. For example, Louis became briefly involved with Dian Fossey. Meanwhile, Mary's life consisted mainly of her children, her dogs, and her archaeology. Louis died on 1 October 1972 of a heart attack. Mary continued the family's archaeological work.
Mary carried on after Louis, becoming a powerful and respected figure. By then Richard had decided to become a palaeoanthropologist. She helped his career significantly. Her other two sons opted to follow other interests.

Replica of an Parantropus (Australopithecus) boisei skull discovered by Mary Leakey in 1959

Mary died on 9 December 1996 at the age of 83, a renowned palaeoanthropologist, who had not only conducted significant research of her own, but had been invaluable to the research careers of her husband Louis Leakey and their sons Richard, Philip and Jonathan.

Leakey served her apprenticeship in archaeology under Dorothy Liddell at Hembury in Devon, England, 1930-1934, for whom she also did illustrations. In 1934 she was part of a dig at Swanscombe where she discovered the largest elephant tooth known up to that time in Britain, but needed assistance to identify it.
The years 1935 to 1959, spent at Olduvai Gorge in the Serengeti plains of Northern Tanzania, yielded many stone tools from primitive stone-chopping instruments to multi-purpose hand axes. These finds came from Stone Age cultures dated as far back as 100,000 to two million years ago.
The Leakeys unearthed a Proconsul africanus skull on Rusinga Island, in October 1948.
Their next discovery, in 1959, was a 1.75 million-year-old Australopithecus boisei skull, catalogued as OH 5. They also found a less robust Homo habilis skull and bones of a hand. After reconstructing the hand, it was proven the hand was capable of precise manipulation. Many more remains were found at this site. In 1965 the husband and wife team uncovered a Homo erectus skull, dated at one million years old.
After Mary's husband died, she continued her work at Olduvai and Laetoli. It was here, at the Laetoli site, that she discovered Hominin fossils that were more than 3.75 million-years-old. She also discovered fifteen new species of other animals and one new genus.
From 1976 to 1981 Leakey and her staff worked to uncover the Laetoli hominid footprint trail which was left in volcanic ashes some 3.6 million years ago. The years that followed this discovery were filled with research at Olduvai and Laetoli, the follow-up work to discoveries and preparing publications.

sexta-feira, julho 13, 2012

Novidades paleoantropológicas

Evolução humana
Fóssil de australopiteco achado no laboratório 
Fóssil encontrado em 2008 do Australopithecus sediba  

Fóssil encontrado em 2008 do Australopithecus sediba 

Não foi necessário voltar ao terreno para aparecer o terceiro fóssil do australopiteco que se conhece há menos tempo. Há três anos que o esqueleto de um indivíduo da espécie Australopithecus sediba estava num laboratório na África do Sul, mas passou despercebido por estar preso numa rocha de um metro de diâmetro. Só recentemente é que os investigadores do Instituto Wits para a Evolução Humana, em Joanesburgo, o encontraram e ontem divulgaram a sua existência.
"Descobrimos partes de uma mandíbula e o que parece ser um fémur completo, costelas, vértebras e outros elementos dos membros, alguns que nunca foram vistos de uma forma tão completa em fósseis [de hominídeos]", disse Lee Berger, paleoantropólogo do instituto, citado num comunicado.

O cientista foi um dos responsáveis pela investigação dos dois primeiros fósseis de Australopithecus sediba, encontrados no local arqueológico de Malapa, na África do Sul, em 2008, e cujos resultados foram publicados em 2010. A nova rocha é proveniente do mesmo local. Este australopiteco viveu há dois milhões de anos. Por ter características comuns ao australopiteco e ao género a que pertence o homem, veio baralhar os cientistas em relação à sua importância e lugar na árvore da evolução humana.

As ossadas novas podem fazer com que a espécie passe a ter o registo fóssil mais completo de sempre de um antepassado humano. A preparação do fóssil, retirando-o da rocha, vai ser transmitida na Internet. E quem quiser vai poder visitar o laboratório e ver a investigação ao vivo.

segunda-feira, fevereiro 06, 2012

A matriarca da família Leakey nasceu há 99 anos

Mary Leakey (6 February 1913 – 9 December 1996) was a British archaeologist and anthropologist, who discovered the first fossilized Proconsul skull, an extinct ape now believed to be ancestral to humans, and also discovered the robust Zinjanthropus skull at Olduvai. For much of her career she worked together with her husband, Louis Leakey, in Olduvai Gorge, uncovering the tools and fossils of ancient hominines. She developed a system for classifying the stone tools found at Olduvai. She also discovered the Laetoli footprints. In 1960 she became director of excavation at Olduvai and subsequently took it over, building her own staff. After the death of her husband she became a leading palaeoanthropologist, helping to establish the Leakey tradition by training her son, Richard, in the field.
Mary Leakey was born Mary Douglas Nicol on 6 February 1913 in London, England to Erskine Edward Nicol and Cecilia Marion (Frere) Nicol. Since Erskine worked as a painter, specializing in watercolor landscapes, the Nicol family would move from place to place, visiting numerous locations in the USA, Italy, and Egypt, where Erskine painted scenes to be sold in England. Erskine Nicol developed an amateur enthusiasm for Egyptology during his travels. Mary Leakey was a direct descendant of antiquarian, John Frere, and cousin to archaeologist, Sheppard Frere, on her mother's side. The Frere family had been active abolitionists in the British colonial empire during the nineteenth century and established several communities for freed slaves. Three of these communities remained in existence as of Mrs. Leakey's 1984 autobiography: Freretown, Kenya, Freretown, South Africa, and Freretown, India. She also was a distant relative of baronet Henry Bartle Frere.
The Nicols spent much of their time in southern France. Mary became fluent in French. She identified more with the adventurous spirit of her father, going for long walks and explorations with him and having long talks. She disliked her governess and had less sympathy for her mother.
In 1925, when Mary was 12, the Nicols stayed at Les Eyzies at a time when Elie Peyrony was excavating one of the caves there. Peyrony did not understand the significance of much of what he found, and was not excavating scientifically during that early stage of archaeology. Mary received permission to go through his dump. It was there that her interest in prehistory was sparked. She started a collection of points, scrapers, and blades from the dump and developed her first system of classification.
That winter, the family moved to Cabrerets, a village of Dordogne, France. There she met Abbé Lemozi, the village priest, who befriended her and became her mentor for a time. The two toured Pech Merle cave to view the prehistoric paintings of bison and horses.
Through Gertrude, Mary met Louis Leakey, who was in need of an illustrator for his book, Adam's Ancestors. While she was doing that work they became romantically attached. They shared common interests and values: a love of freedom and dislike for rules, an egalitarian frame of mind extending even to animals, a desire for adventure, and a passion for archaeology. Louis was still married when he started living with Mary, which caused a scandal that ruined his career at Cambridge University. They were married when Louis' wife Frida divorced him in 1936.
From then until about 1962 Louis and Mary faced trying circumstances together. Early in their relationship he nursed her through double pneumonia. They had three sons: Jonathan in 1940, Richard in 1944, and Philip in 1949. The boys received much of their early childhood care at various anthropological sites. Whenever possible the Leakeys excavated and explored as a family. The boys grew up with the same love of freedom their parents had. Mary would not even allow guests to shoo away the pet hyraxes that helped themselves to food and drink at the dinner table. She smoked very much, first cigarettes and then cigars, and dressed as though on excavation.
Louis was not always faithful to Mary, as he had not been to Frida. In 1960 they agreed that Mary would become director of excavations at Olduvai. From then on she operated more or less independently, taking over the dig. After Louis became known as a womanizer the intimate side of the marriage was effectively over. For example, Louis became briefly involved with Dian Fossey. Meanwhile, Mary's life consisted mainly of her children, her dogs, and her archaeology. Louis died on 1 October 1972 of a heart attack. Mary continued the family's archaeological work.
Mary carried on after Louis, becoming a powerful and respected figure. By then Richard had decided to become a palaeoanthropologist. She helped his career significantly. Her other two sons opted to follow other interests.

Mary died on 9 December 1996 at the age of 83, a renowned palaeoanthropologist, who had not only conducted significant research of her own, but had been invaluable to the research careers of her husband Louis Leakey and their sons Richard, Philip and Jonathan.

Leakey served her apprenticeship in archaeology under Dorothy Liddell at Hembury in Devon, England, 1930-1934, for whom she also did illustrations. In 1934 she was part of a dig at Swanscombe where she discovered the largest elephant tooth known up to that time in Britain, but needed assistance to identify it.
The years 1935 to 1959, spent at Olduvai Gorge in the Serengeti plains of Northern Tanzania, yielded many stone tools from primitive stone-chopping instruments to multi-purpose hand axes. These finds came from Stone Age cultures dated as far back as 100,000 to two million years ago.
The Leakeys unearthed a Proconsul africanus skull on Rusinga Island, in October 1948.
Their next discovery, in 1959, was a 1.75 million-year-old Australopithecus boisei skull, catalogued as OH 5. They also found a less robust Homo habilis skull and bones of a hand. After reconstructing the hand, it was proven the hand was capable of precise manipulation. Many more remains were found at this site. In 1965 the husband and wife team uncovered a Homo erectus skull, dated at one million years old.
After Mary's husband died, she continued her work at Olduvai and Laetoli. It was here, at the Laetoli site, that she discovered Hominin fossils that were more than 3.75 million-years-old. She also discovered fifteen new species of other animals and one new genus.
From 1976 to 1981 Leakey and her staff worked to uncover the Laetoli hominid footprint trail which was left in volcanic ashes some 3.6 million years ago. The years that followed this discovery were filled with research at Olduvai and Laetoli, the follow-up work to discoveries and preparing publications.

sábado, fevereiro 04, 2012

O cientista que descobriu o Australopithecus africanus nasceu há 119 anos

Raymond Dart com o crânio do bebé de Taung

Raymond Arthur Dart (4 de fevereiro de 1893 - 22 de novembro de 1988) foi um anatomista e antropólogo australiano que descreveu, em 1924 uma nova espécie de hominídeo, o Australopithecus africanus, a partir dum crânio fóssil encontrado em Taung na Bechuanalândia (antigo nome do actual Botswana).
Nascido em Toowong, Brisbane, na Austrália, ele estudou nas universidades de Queensland, Sydney e no University College de Londres. Em 1922 Dart foi nomeado chefe do novo departamento de anatomia da Universidade de Witwatersrand em Johannesburg, na África do Sul.
Em 1924, um aluno trouxe-lhe o crânio fossilizado de um babuíno descoberto numa pedreira perto da Universidade, em Taung. Isto despertou o interesse de Dart que solicitou que novas descobertas similares lhe fossem trazidas. A primeira a chegar foi o rosto e um maxilar de um crânio fossilizado cravado na rocha. Inicialmente pensou que os ossos pertencessem a um símio mas depois concluiu que os dentes e o maxilar pareciam humanos. Dart demorou 73 dias a remover os ossos incrustados na rocha. Um exame mais minucioso levou-o a concluir que se tratava de um jovem. Dart atribuiu ao fóssil o nome Australopithecus africanus, que significa "macaco do Sul da África" e alcunhou-o de "Bebé de Taung".
Embora o crânio tivesse o tamanho do de um macaco, Dart estava convencido, pela forma como este assentava sobre a coluna vertebral, que a criatura deveria ter caminhado sobre duas pernas, sendo assim um hominídeo. Portanto, Dart considerou o Australopithecus africanus uma espécie nova e, possivelmente o "elo perdido" da evolução entre os símios e os seres humanos, devido ao pequeno volume do seu crânio, mas com uma dentição relativamente próxima dos humanos e por ter provavelmente uma postura vertical.
Esta revelação foi muito criticada pelos cientistas da época, entre os quais Sir Arthur Keith, que postulava que o “crânio infantil de Taung” não passava do crânio de um pequeno gorila. Como o crânio era realmente dum jovem, havia espaço para várias interpretações e, mais importante, nessa altura não se acreditava que o "berço da humanidade" pudesse estar em África.
As descobertas de Robert Broom em Swartkrans, na década de 1930 corroboraram a conclusão de Dart, mas algumas das suas ideias continuam a ser contestadas, nomeadamente a de que os ossos de gazela encontrados junto com o crânio podiam ser instrumentos daquela espécie.
Raymond Dart continuou como director da Escola de Anatomia da Universide de Witwatersrand, até 1958 e, em 1959 escreveu a suas memórias, a que chamou “Aventuras com o Elo Perdido”. O Instituto para o Estudo do Homem em África foi fundado na Wits em sua honra.

quinta-feira, junho 02, 2011

Notícia sobre Paleoantropologia no Público

Paleontologia
Na vida dos hominídeos eles ficavam, elas vinham, sugere estudo da Nature

O Australopithecus africanus viveu há 2,2 milhões de anos na actual África do Sul

Há mais de um milhão de anos, na savana situada no que é hoje a África do Sul, os grupos de hominídeos teriam uma história de vida diferente consoante fossem machos ou fêmeas. Um estudo publicado esta quarta-feira na Nature sugere que enquanto os hominídeos masculinos mantinham-se no mesmo habitat desde que nasciam até à morte, as fêmeas teriam crescido num local diferente e acabavam por morrer noutra região.

A descoberta não foi feita a partir de fósseis novos encontrados. O trabalho de uma equipa internacional de cientistas dos Estados Unidos, da Alemanha, Suiça, Inglaterra e da África do Sul utilizou técnicas diferentes para recolher esta informação.

O estudo focou-se nos fósseis de dentes de duas espécies de hominídeos. O Australopithecus africanus, viveu há 2,2 milhões de anos e foi possivelmente antepassado directo do Homem, e o Paranthropus robustus, que viveu há 1,8 milhões de anos, e foi um primo.

Os fósseis de cada espécie foram encontrados em duas grutas no Noroeste da África do Sul, que estão a poucos quilómetros de distância uma da outra. A equipa analisou a quantidade relativa de um metal chamado estrôncio, que existe no esmalte dos dentes.

Este elemento químico está nos minerais e é absorvido pelas plantas, entrando assim nos ecossistemas. Durante o crescimento dos animais, o estrôncio acumula-se no esmalte dos dentes. A percentagem relativa de isótopos deste metal que existe no ambiente vai ficar registada nos dentes e serve de assinatura do local onde os hominídeos cresceram.

“Um dos nossos objectivos foi tentar encontrar algo sobre o uso da paisagem dos primeiros hominídeos”, disse em comunicado Sandi Copeland, primeira autora do artigo da "Nature", que trabalha no Instituto Max Planck, em Leipzig, Alemanha. “Aqui, tivemos um vislumbre directo dos movimentos geográficos dos primeiros hominídeos, e parece que as fêmeas moviam-se preferencialmente para longe dos grupos onde residiam.”

A equipa analisou fósseis de oito indivíduos de Australopithecus africanus e 11 de Paranthropus robustus. A percentagem relativa de isótopos de estrôncio nos dentes das fêmeas, que por norma são mais pequenos, mostrava que pelo menos metade tinham vindo de outro sítio. Enquanto nos machos esta percentagem era apenas de dez por cento.

“O que os resultados mostram é que as fêmeas vinham mais de fora da região do que os machos. Não vinham de muito longe, mas não era o mesmo grupo natal onde cresceram”, disse à BBC News Julia Lee-Thorpe, investigadora da Universidade de Oxford que fez parte da equipa. “Não sabemos se as fêmeas derivaram de outro grupo, se vieram de propósito, ou se foram sequestradas; não temos forma de saber esse tipo de detalhes, mas na generalidade, a maioria das fêmeas veio de outro lugar.”

Este comportamento é o que acontece nos chimpanzés, onde os machos ficam no mesmo sítio onde nascem e as fêmeas são obrigadas a abandonar o grupo para não haver consanguinidade. Algo que não acontece, por exemplo nos gorilas, onde tanto os machos como as fêmea migram do grupo onde nasceram.

sexta-feira, fevereiro 11, 2011

Notícia sobre a mais famosa austalopiteca

Estudo publicado na Science
Australopiteco Lucy já estava adaptado para caminhar de pé

O osso visto em diferentes posições

O andar bípede não é só atitude. Os ossos dos pés, dos joelhos, das ancas, da coluna e dos braços permitem ao Homem andar com duas pernas sem esforço, ao contrário dos chimpanzés ou gorilas. Agora, através do estudo de um único osso do pé de um australopiteco parente da carismática Lucy, uma equipa de cientistas provou que este hominídeo já tinha o pé arqueado, próprio de quem está totalmente adaptado ao bipedismo. A descoberta é publicada hoje na revista Science.

As adaptações ao andar bípede foram feitas ao longo da evolução. Os fósseis do Homo habilis, que apareceu há 2,3 milhões de anos, já denunciavam um esqueleto bípede, mas nunca tinha sido provado que o Austrolopithecus afarensis, a espécie da Lucy, tinha completado estas adaptações ou se, por outro lado, ainda partilhava o dia-a-dia com as árvores.

O fóssil foi encontrado em 2000, em Haida, no Sudão, num local onde já foram descobertos mais de 250 fósseis da espécie. A Lucy e os seus congéneres viveram entre 3,7 e 2,9 milhões de anos no continente Africano em África, antes do género Homo ter aparecido (do qual nós, humanos, somos a única espécie sobrevivente). O fóssil estudado pela equipa dos EUA chama-se AL 333-160 e tem 3,2 milhões de anos. É o quarto dos cinco ossos que compõem o metatarso – que no pé faz a ligação entre os ossos do calcanhar e dos dedos.

Segundo o artigo, o quarto metatarso “é o elemento chave ao longo da coluna lateral do pé que difere entre os símios superiores e os humanos” e que testa a presença da dobra do pé e do bipedismo.

“As dobras do pé são um componente chave para o andar humano porque absorvem o choque [quando se caminha] e proporcionam uma plataforma rija que dá o apoio para começar um novo movimento do nosso pé andar para a frente”, disse em comunicado Carol Ward, a primeira dos três autores do artigo, que pertence à Universidade do Missouri. Segundo a investigadora, quando as pessoas têm o pé chato e falta-lhes esta dobra têm vários problemas a nível das junções ósseas.

Nunca se tinha encontrado este osso de A. afarensis preservado. Quando a equipa estudou o fóssil verificou que o osso é arqueado como na espécie humana e como noutras espécies do género Homo. No caso de primatas como o gorila ou chimpanzé, o metatarso é muito mais direito.

“Isto afecta muito do que sabemos sobre [Lucy e os seus parentes], desde onde eles viviam, o que é que comiam até como é que evitavam os predadores”, explicou a cientista. “O desenvolvimento da dobra do pé foi fundamental para a mudança em direcção à condição humana, porque significa que houve uma desistência na utilização do dedo grande [do pé] para agarrar os ramos das árvores, o que mostra que os nosso antepassados finalmente trocaram a vida nas árvores pela vida no chão.”