Mostrar mensagens com a etiqueta Homo habilis. Mostrar todas as mensagens
Mostrar mensagens com a etiqueta Homo habilis. Mostrar todas as mensagens

quinta-feira, maio 16, 2024

Somos mesmo um espécie bizarra...

Os humanos ancestrais evoluíram de forma bizarra (e diferente das outras espécies)

 

Crânios de Homo erectus, Homo floresiensis e Homo heidelbergensis

 

De acordo com um novo estudo, a competição inter-espécies nos humanos antigos registou uma tendência evolutiva completamente oposta à de quase todos os outros vertebrados.

Durante anos, os cientistas assumiram que o principal motor da ascensão e queda das espécies de hominídeos, que inclui os humanos e os nossos antepassados diretos, eram as alterações climáticas.

Sabe-se, no entanto, que a competição inter-espécies também esteve em jogo, tal como acontece na maioria dos vertebrados.

Um novo estudo, publicado na revista Nature Ecology & Evolution examinou agora o ritmo a que surgiram novas espécies de hominídeos ao longo de 5 milhões de anos.

Esta especiação na nossa linhagem, segundo os investigadores, é diferente de quase tudo o resto.

“Temos estado a ignorar a forma como a competição entre espécies moldou a nossa própria árvore evolutiva”, afirma Laura van Holstein, investigadora da Universidade de Cambridge, no Reino Unido, e autora principal do estudo.

“O efeito do clima nas espécies de hominídeos é apenas uma parte da história“, salienta a paleoantropóloga, que em 2020 descobriu que as subespécies de mamíferos desempenham um papel mais importante na evolução do que aquilo que se pensava, provando uma das teorias de Charles Darwin.

Na maioria dos vertebrados, as espécies evoluem para preencher “nichos” ecológicos. “O padrão que observamos em muitos dos primeiros hominídeos é semelhante ao de todos os outros mamíferos”, explica van Holstein, citada pela Cosmos.

“As taxas de especiação aumentam e depois estabilizam, altura em que as taxas de extinção começam a aumentar. Isto sugere que a competição entre espécies foi um fator evolutivo importante“, acrescenta a investigadora.

Mas van Holstein descreve como “bizarra” a evolução do grupo Homo, que inclui os humanos modernos e que surgiu há cerca de 2 milhões de anos com o Homo habilis. A tendência de especiação foi completamente invertida.

“Quanto mais espécies de Homo existiam, maior era a taxa de especiação. Assim, quando esses nichos foram preenchidos, algo levou ao aparecimento de ainda mais espécies. Isto é quase sem paralelo na ciência evolutiva”.

A comparação mais próxima é com as espécies de escaravelhos que vivem em ilhas, onde os ecossistemas contidos podem produzir tendências evolutivas invulgares.

“Os padrões de evolução que observamos nas espécies de Homo que conduziram diretamente aos humanos modernos estão mais próximos dos dos escaravelhos que vivem em ilhas do que dos outros primatas, ou mesmo de qualquer outro mamífero”, explica van Holstein.

 

A autora principal do estudo, Laura Van Holstein, provou em 2020 uma das teorias da evolução de Darwin

 

A investigadora criou uma base de dados de todas as espécies de hominídeos encontradas e datadas até à data: 385 registos no total, colmatando as lacunas no registo fóssil através da modelização. Isto deu-lhe novas linhas de tempo para o aparecimento e desaparecimento das espécies.

Entre as descobertas de van Holstein está o facto de várias espécies que se pensava terem evoluído através da anagénese, quando uma espécie se transforma lentamente noutra, poderem, na verdade, ter “brotado”, ou seja, a nova espécie ramificou-se da já existente.

Por exemplo, acreditava-se que a espécie de hominídeo Australopithecus afarensis tinha evoluído a partir do Australopithecus anamensis por anagénese. Mas o modelo sugere que se sobrepuseram em cerca de meio milhão de anos.

Os primeiros hominídeos podem assim ter evoluído para expandir o seu nicho. Por exemplo, o Paranthropus pode ter adaptado os seus dentes para consumir diferentes alimentos. Mas o padrão das espécies Homo sugere que a tecnologia desempenhou um papel muito mais importante na especiação.

“A adoção de ferramentas de pedra ou de fogo, ou de técnicas de caça intensiva, são comportamentos extremamente flexíveis. Uma espécie que os consiga utilizar pode rapidamente criar novos nichos e não tem de sobreviver durante vastos períodos de tempo enquanto desenvolve novos planos corporais”, conclui van Holstein.

 

in ZAP

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
  

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.

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.

sexta-feira, abril 09, 2010

Eugénia Cunha lança livro de divulgação científica

Lançado no dia 13, em Coimbra
Antropóloga portuguesa publica livro sobre como nos tornámos humanos

Eugénia Cunha é especialista em evolução humana da Universidade de Coimbra
(Paulo Ricca/PÚBLICO)


Eugénia Cunha, antropóloga forense e especialista em evolução humana. "Como nos Tornámos Humanos", publicado pela Imprensa da Universidade de Coimbra, e que vai ser lançado no próximo dia 13 (no Museu da Ciência daquela universidade, às 17h30), cabe no bolso do casaco, ou não tivesse só 17 por 12 centímetros. Mas contém tudo o que é essencial para compreender o que se lê e ouve sobre evolução humana.


Tem as descobertas importantes de fósseis, numa espécie de "quem é quem" dos protagonistas da nossa história evolutiva, sistematiza os conhecimentos, traça o "estado da arte", tudo de forma concisa e simples. Inclui referências a alguns achados portugueses, como a criança do Lapedo, com 24 mil anos ("o mais importante fóssil humano alguma vez descoberto em Portugal").

Nesta história, já sabemos como tudo acaba: somos agora a única espécie de humanos ("Homo sapiens"), mas houve muitas outras, como o "Homo habilis", o "Homo erectus" ou o "Homo neanderthalensis", algumas coexistiram, e descobrir como chegámos até aqui faz-nos continuar a ler.

"O que nos torna humanos constitui uma incrível questão científica", lê-se no início. "O destaque da imprensa à nossa história natural fundamenta-se por se tratar das nossas origens, de saber quem foi o 'big daddy', enfim compreender por que somos como somos."

Eugénia Cunha leva-nos, assim, numa viagem com início há 55 milhões de anos, quando surgiram os primatas, e, com grande parte da acção em África, conta como nos fomos tornando no que somos: bípedes, com cérebros grandes, fabricantes de ferramentas, com uma linguagem articulada e produtores de símbolos.

in Público - ler notícia



Eugénia Cunha numa palestra em Leiria (Foto: Fernando Martins)

NOTA: é sempre um prazer divulgar aqui actividades de ex-professores dos Geopedrados - até porque a Professora Doutora Eugénia Cunha tem feito imenso pela Ciência, Antropologia e Divulgação Científica no nosso país e até fora dele...

segunda-feira, fevereiro 22, 2010

Paleontologia e paleoantropologia no DN

Hobbit da Indonésia, o primeiro colonizador?


Estudos recentes apontam o 'Homo florensiensis', espécie descoberta em 2003 na Indonésia, como o primeiro a deixar África para colonizar outros pontos do globo


Cerca de um metro de altura, cérebro do tamanho de uma laranja, pés compridos e chatos. Os cientistas chamam-lhe "hobbit", mas não saiu de nenhum livro de Tolkien. Desde 2003 que a descoberta de ossadas de uma nova espécie está a ameaçar revolucionar a história da raça humana.

Quando um grupo de investigadores australianos começou a escavar o solo de Ling Bua, uma caverna de calcário na ilha das Flores, não podia adivinhar que estavam prestes a fazer uma das mais importantes descobertas arqueológicas de sempre. A ilha indonésia escondia, até há pouco mais de seis anos, a existência de uma espécie humana que não constava nos manuais de antropologia, o Homo florensiensis.

Desde essa altura que a descoberta tem causado uma acesa discussão entre cientistas sobre a origem desta espécie, que no início se pensava serem apenas humanos "modernos" que padeciam de doenças como a microcefalia, uma patologia que conduz a um desenvolvimento reduzido do crânio e do cérebro. Uma outra teoria rejeitava o "hobbit" como sendo uma nova espécie, dizendo que estas ossadas pertenceriam aos nossos antepassados Homo erectus, que teriam encolhido devido às condições de vida na ilha. Mas estudos recentes confirmam que se trata efectivamente de uma nova espécie. Desengane-se quem pensa que a discussão acaba aqui. Um artigo publicado ontem pelo editor de ciência do jornal britânico The Observer revela que as últimas pesquisas chegaram a conclusões no mínimo surpreendentes. A expedição liderada por Mike Morwood pode ter resultado na descoberta de um descendente directo do Homo habilis, espécie que apareceu pouco após a extinção do Australopithecus , correspondente ao primeiro estado de evolução da espécie humana.

A notícia está a deixar perplexa a comunidade científica, já que o Homo habilis viveu há cerca de dois milhões de anos, enquanto o "hobbit" se extinguiu apenas há 17 mil anos. São várias as questões que se levantam. Como poderá o "hobbit" ser descendente de uma espécie tão antiga? Como é possível que tenha migrado de África, onde vivia o Homo habilis, até à Indonésia? Os pés chatos e a pequena estatura tornavam a tarefa praticamente impossível. O que é certo é que as pesquisas mostram que o pequeno ser deixou África para colonizar parte do Sudeste asiático há mais de dois milhões de anos.

Esta teoria pode revolucionar a história da raça humana, já que até agora se acreditava que tinha sido o Homo erectus a primeira espécie a deixar o continente africano e a colonizar outros pontos do globo.

"Encontrámos uma ilha onde uma espécie foi separada do resto da evolução durante mais de um milhão de anos", explicou Morwood ao The Observer. O investigador acredita que, por ser uma região remota, a ilha das Flores concedeu uma protecção especial à espécie, que teve uma duração fora do comum, à semelhança de alguns animais que habitaram a ilha. "Houve , por exemplo, os elefantes-pigmeus e o dragão de Komodo, agora temos o Homo florensiensis."

in DN - ler notícia