Na sua sempre interessante coluna WHAT'S NEW, o físico Bob Park informa sobre a origem do Homo Sapiens:
"Out of Africa: Determinação do ponto de partida.
A descoberta em 2003 por Tim White da Universidade de Califórnia Berkeley de um esqueleto parcial do Homo sapiens de há 160.000 anos na Etiópia foi a prova mais forte até hoje de que, de facto, viemos de África. Uma jovem antropóloga molecular da Universidade de Maryland, Sarah Tishkoff, viu que o mapeamento do genoma humano oferece uma nova ferramenta para monitorizar a migração para fora de África do Homo sapiens: estudou "pegadas" no DNA de seres humanos vivos. A equipa de Tishkoff, agora na Universidade da Pensilvânia, que incluiu linguistas e geneticistas, localizou a origem do homem moderno na inóspita fronteira entre Angola e a Namíbia. O estudo, publicado agora na revista "Science", levou investigadores a regiões remotas de África para recolher amostras de sangue de mais de 100 populações distintas. A saída de África ocorreu no Nordeste desse continente, aproximadamente a meio do Mar Vermelho."
7 comentários:
Claro que veio de Angola. E a filha está agora a comprar Portugal às postas...
Só pode.
“From the point of view of religion, polygenism is an uncommon Biblical interpretation.
Until the mid-1800s it was largely considered heretical.
It was first raised by Isaac La Peyrère, a French polymath seeking to reconcile the limited number of generations between Adam and Eve and modern day by positing "pre-Adamites".
It was not believed that the number of races could have developed within the commonly accepted Biblical timeframe.
Voltaire brought the subject up in his Essay on the Manner and Spirit of Nations and on the Principal Occurrences in History in 1756 (which was an early work of comparative history), although he made no attempt to solve the problem.
Polygenism came into mainstream scientific and religious thought due to the work of Samuel George Morton and more prominently Louis Agassiz in the United States.
The issue of race was polemical, and slave owners attempted to justify their treatment of slaves using claimed empirical science such as Morton's work.
They argued that each race was a different species, and that black Africans were mentally inferior to Caucasians. Agassiz believed that each race was unique, but could still be classified as the same species.
Contemporary geological discoveries described the earth as far older than strict interpretation of Genesis allows, and among some thinkers, polygenism was a way to reconcile the new discoveries with their faith.
In the race debates of the 1860s and 1870s, Charles Darwin and some of his supporters argued for the monogenesis of the human species, seeing the common origin of all humans as essential for evolutionary theory.
This is known as the single-origin hypothesis.
Ernst Haeckel, the major publicizer of Darwin's ideas (or his interpretation of them) to the German-speaking world, attacked this view, arguing that human beings do not form a single species but a genus divided into nine separate species that have been evolving separately since before the development of speech.
Haeckel's view remained influential until well into the 20th century.
Polygenism was heavily criticized in the 20th century Roman Catholic Church, and especially by Pope Pius XII in the encyclical Humani Generis, who felt that, although evolution was compatible with Catholicism, polygenism was seemingly incompatible with the doctrine of Original Sin.
In the late 20th century, the work of the paleoanthropologist Carleton Coon was the closest to what can be perhaps considered a "modern" polygenism by positing that the individual races of the earth separately evolved into modern Homo sapiens.
This hypothesis, called the multiregional hypothesis, was not very popular when it was presented in the mid-1960s, though there continue to be some vocal advocates for it within the scientific community.”
Criticism of Multiregionalism
“Multiregional evolution contrasts with the "Recent African Origin" (RAO) theory.
According to the latter theory, human evolution was a consequence of many cases of species replacement, as newer species replaced older ones across the human range.
Modern human origins, according to the RAO, is the most recent example of species replacement.
Aspects of multiregionalism have been criticized as not being based on objective scientific observation.
Some critics even argue that multiregionalism may be motivated by ethnocentrism and is meant to instill beliefs of purity of lineage. This implied racism has had a negative effect, causing scientists to restrict their hypothesizing to politically correct conclusions.
Multiregionalists have long claimed that modern Europeans are descended from the Neanderthals.
In 1997, testing performed on mitochondrial DNA extracted from a Neanderthal skeleton showed modern humans and Neanderthals last shared a common ancestor between 500,000 and 800,000 years ago, and furthermore that all modern humans, from the ethnic Siberians to the !Kung people of Africa, are more closely related to each other than to the Neanderthals - further evidence supporting the Out-of-Africa theory.
But old, dated to over 1 Mya, lineages in nDNA has been detected .
Peking man, (also known as "Beijing man")a Homo erectus fossil skull (possibly dated to 500,000 years ago) found in China, provides putative evidence supporting the Multiregional Theory.
Some Paleoanthropologists in China have asserted that the modern Chinese are descendants of earlier forms of humans such as Peking Man.
However criticism is based on geneticists of mtDNA.
From microsatellite analysis on the '1998 Chinese population', genetic similarities with Africans, yielding the first evidence the Chinese population is matrilineal from Africa.
A recent study undertaken by Jin Li showed no inter-breeding between modern human immigrants to East Asia and Homo erectus, contradicting the Peking Man-origin hypothesis and affirming that the Chinese descended from Africans.
In 2001, Chinese geneticists analyzed Y chromosomes in Chinese people and concluded that all Chinese samples contained a mutated gene M168G which is a marker believed to have appeared in the last 79,000 years on a number of Africans.”
Vim a este post mesmo só para ver que inanidades o Jónatas nos teria trazido. Cá estão... :)
Numa coisa os evolucionistas e os criacionistas tendem a concordar: todos os seres humanos actualmente existentes vêm de um conjunto reduzido de seres humanos.
Isto, a ciência corrobora inequivocamente.
Sucede, porém, que o DNA, os fósseis, as rochas e os isótopos não trazem uma etiqueta com a sua idade.
Eles são datados, com base nas premissas, nos modelos e nas teorias aceites pelos cientistas.
No caso da teoria da evolução, essas premissas são naturalistas e uniformitaristas.
Isto, apesar de existir ampla evidência de catastrofismo na natureza.
A teoria “out of áfrica” afirma que um grupo divergiu a partir de África e emigrou daí há cerca de 70 000 anos atrás.
Alguns evolucionistas, no entanto, defendem um modelo “out of Ásia”. Outros, ainda, defendem uma origem multiregional do homem, sustentando o carácter fragmentário e desactualizado de muita da informação paleontológica e molecular mobilizada para defender a teoria “out of África”.
Tim White, da Califórnia, defende a teoria “out of Africa”, embora seja conhecido por meter os pés pelas mãos em matéria de evolução, como sucede sempre que tenta ligar evolutivamente o Ardipiphecus, o Australopithecus e o Homo Sapiens.
No entanto, as várias teorias referidas assentam em leitura naturalistas, uniformitaristas e evolucionistas da genética molecular, dos fósseis, das rochas e dos isótopos.
Além disso eles ignoram o modo como as secções não codificadoras do DNA regulam a expressão genética.
Ainda recentemente, a revista Evolution [63 (4), 2009] publicou um estudo sustentando que a dieta alimentar, o ambiente e a plasticidade genómica podem dar rapidamente origem a diferenças cranianas significativas entre populações de humanos.
Desse modo, ela lança uma forte suspeição sobre os cálculos daqueles que as atribuíam a factores aleatórios, como as taxas de mutação genética.
Porreiro!
Com esta notícia fico muito mais descansado, não tivesse o «macacóide» provindo da zona do «Eixo do Mal»...
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