Evolution of modern humans: evidence from nuclear DNA polymorphisms

1992 ◽  
Vol 337 (1280) ◽  
pp. 159-165 ◽  
Keyword(s):  
Dna Sequences ◽  
Nuclear Dna ◽  
Point Of View ◽  
Dna Polymorphisms ◽  
Modern Humans ◽  
Marker Allele ◽  
Archaeological Data ◽  
Tropical Environments ◽  
Anatomically Modern Humans ◽  
Single Allele

Previously we have described studies of the evolution of modern humans based upon data for classical genetic markers and for nuclear DNA polymorphisms. Such polymorphisms provide a different point of view regarding hum an evolution than do mitochondrial DNA sequences. Here we com pare revised dates for major migrations of anatomically modern humans, estimated from archaeological data, with separations suggested by a genetic tree constructed from classical marker allele frequencies. Analyses of DNA polymorphisms have now been extended and com pared with those of classical markers; genetic trees continue to support the hypothesis of an initial African and non-African divergence for modern humans. We have also begun testing non-hum an primates for a set of human DNA polymorphisms. For most polymorphisms tested so far, humans share a single allele with other primates; such shared alleles are likely to be ancestral. Populations living in humid tropical environments have significantly higher frequencies of ancestral alleles than do other populations, supporting the hypothesis that natural selection acts to maintain high frequencies of particular alleles in some environments.

scholarly journals When didHomo sapiensfirst reach Southeast Asia and Sahul?

2018 ◽  
Vol 115 (34) ◽  
pp. 8482-8490 ◽  
Author(s):  
James F. O’Connell ◽  
Jim Allen ◽  
Martin A. J. Williams ◽  
Alan N. Williams ◽  
Chris S. M. Turney ◽  
...  
Keyword(s):  
Southeast Asia ◽  
South China ◽  
Homo Sapiens ◽  
Region Of Interest ◽  
New Guinea ◽  
Archaeological Site ◽  
Southwest Asia ◽  
Modern Humans ◽  
Archaeological Data ◽  
Anatomically Modern Humans

Anatomically modern humans (Homo sapiens, AMH) began spreading across Eurasia from Africa and adjacent Southwest Asia about 50,000–55,000 years ago (ca. 50–55 ka). Some have argued that human genetic, fossil, and archaeological data indicate one or more prior dispersals, possibly as early as 120 ka. A recently reported age estimate of 65 ka for Madjedbebe, an archaeological site in northern Sahul (Pleistocene Australia–New Guinea), if correct, offers what might be the strongest support yet presented for a pre–55-ka African AMH exodus. We review evidence for AMH arrival on an arc spanning South China through Sahul and then evaluate data from Madjedbebe. We find that an age estimate of >50 ka for this site is unlikely to be valid. While AMH may have moved far beyond Africa well before 50–55 ka, data from the region of interest offered in support of this idea are not compelling.

Neanderthals and modern humans

2017 ◽  
Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde
Keyword(s):  
Genetic Differentiation ◽  
Nuclear Dna ◽  
Homo Sapiens ◽  
Whole Genome ◽  
Upper Palaeolithic ◽  
Modern Humans ◽  
Homo Neanderthalensis ◽  
Modern Mind ◽  
Similarities And Differences ◽  
Mode 3

This chapter deals with the similarities and differences between Homo neanderthalensis and Homo sapiens, by considering genetic, brain, and cognitive evidence. The genetic differentiation emerges from fossil genetic evidence obtained first from mtDNA and later from nuclear DNA. With high throughput whole genome sequencing, sequences have been obtained from the Denisova Cave (Siberia) fossils. Nuclear DNA of a third species (“Denisovans”) has been obtained from the same cave and used to define the phylogenetic relationships among the three species during the Upper Palaeolithic. Archaeological comparisons make it possible to advance a four-mode model of the evolution of symbolism. Neanderthals and modern humans would share a “modern mind” as defined up to Symbolic Mode 3. Whether the Neanderthals reached symbolic Mode 4 remains unsettled.

scholarly journals The Role of Mitochondria in Carcinogenesis

2021 ◽  
Vol 22 (10) ◽  
pp. 5100
Author(s):  
Paulina Kozakiewicz ◽  
Ludmiła Grzybowska-Szatkowska ◽  
Marzanna Ciesielka ◽  
Jolanta Rzymowska
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Polymorphisms ◽  
Gene Encoding ◽  
Dna Mutations ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Gene Coi ◽  
The Impact

The mitochondria are essential for normal cell functioning. Changes in mitochondrial DNA (mtDNA) may affect the occurrence of some chronic diseases and cancer. This process is complex and not entirely understood. The assignment to a particular mitochondrial haplogroup may be a factor that either contributes to cancer development or reduces its likelihood. Mutations in mtDNA occurring via an increase in reactive oxygen species may favour the occurrence of further changes both in mitochondrial and nuclear DNA. Mitochondrial DNA mutations in postmitotic cells are not inherited, but may play a role both in initiation and progression of cancer. One of the first discovered polymorphisms associated with cancer was in the gene NADH-ubiquinone oxidoreductase chain 3 (mt-ND3) and it was typical of haplogroup N. In prostate cancer, these mutations and polymorphisms involve a gene encoding subunit I of respiratory complex IV cytochrome c oxidase subunit 1 gene (COI). At present, a growing number of studies also address the impact of mtDNA polymorphisms on prognosis in cancer patients. Some of the mitochondrial DNA polymorphisms occur in both chronic disease and cancer, for instance polymorphism G5913A characteristic of prostate cancer and hypertension.

scholarly journals Stochastic models support rapid peopling of Late Pleistocene Sahul

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Corey J. A. Bradshaw ◽  
Kasih Norman ◽  
Sean Ulm ◽  
Alan N. Williams ◽  
Chris Clarkson ◽  
...  
Keyword(s):  
Stochastic Models ◽  
Ecological Model ◽  
New Guinea ◽  
Emergent Properties ◽  
Modern Humans ◽  
Global Migration ◽  
Early Settlement ◽  
Anatomically Modern Humans ◽  
Settlement Event ◽  
Initial Entry

AbstractThe peopling of Sahul (the combined continent of Australia and New Guinea) represents the earliest continental migration and settlement event of solely anatomically modern humans, but its patterns and ecological drivers remain largely conceptual in the current literature. We present an advanced stochastic-ecological model to test the relative support for scenarios describing where and when the first humans entered Sahul, and their most probable routes of early settlement. The model supports a dominant entry via the northwest Sahul Shelf first, potentially followed by a second entry through New Guinea, with initial entry most consistent with 50,000 or 75,000 years ago based on comparison with bias-corrected archaeological map layers. The model’s emergent properties predict that peopling of the entire continent occurred rapidly across all ecological environments within 156–208 human generations (4368–5599 years) and at a plausible rate of 0.71–0.92 km year−1. More broadly, our methods and approaches can readily inform other global migration debates, with results supporting an exit of anatomically modern humans from Africa 63,000–90,000 years ago, and the peopling of Eurasia in as little as 12,000–15,000 years via inland routes.

Review Feature: A review of The Mind in the Cave: Consciousness and the Origins of Art by David Lewis-Williams. London: Thames & Hudson, 2002. ISBN 0-500-05117-8 hardback £18.95 & US$29.95; 320 pp., 66 figs., 29 colour plates

2003 ◽  
Vol 13 (2) ◽  
pp. 263-279 ◽  
Author(s):  
David Lewis-Williams ◽  
E. Thomas Lawson ◽  
Knut Helskog ◽  
David S. Whitley ◽  
Paul Mellars
Keyword(s):  
Rock Art ◽  
David Lewis ◽  
Modern Human ◽  
Hominid Evolution ◽  
Modern Humans ◽  
Radiocarbon Dates ◽  
Anatomically Modern Humans ◽  
The Mind ◽  
Cave Art ◽  
West European

David Lewis-Williams is well-known in rock-art circles as the author of a series of articles drawing on ethnographic material and shamanism (notably connected with the San rock art of southern Africa) to gain new insights into the Palaeolithic cave art of western Europe. Some 15 years ago, with Thomas Dowson, he proposed that Palaeolithic art owed its inspiration at least in part to trance experiences (altered states of consciousness) associated with shamanistic practices. Since that article appeared, the shamanistic hypothesis has both been widely adopted and developed in the study of different rock-art traditions, and has become the subject of lively and sometimes heated controversy. In the present volume, Lewis-Williams takes the argument further, and combines the shamanistic hypothesis with an interpretation of the development of human consciousness. He thus enters another contentious area of archaeological debate, seeking to understand west European cave art in the context of (and as a marker of) the new intellectual capacities of anatomically modern humans. Radiocarbon dates for the earliest west European cave art now place it contemporary with the demise of the Neanderthals around 30,000 years ago, and cave art, along with carved or decorated portable items, appears to announce the arrival and denote the success of modern humans in this region. Lewis-Williams argues that such cave art would have been beyond the capabilities of Neanderthals, and that this kind of artistic ability is unique to anatomically modern humans. Furthermore, he concludes that the development of the new ability cannot have been the product of hundreds of thousands of years of gradual hominid evolution, but must have arisen much more abruptly, within the novel neurological structure of anatomically modern humans. The Mind in the Cave is thus the product of two hypotheses, both of them contentious — the shamanistic interpretation of west European Upper Palaeolithic cave art, and the cognitive separation of modern humans and Neanderthals. But is it as simple as that? Was cave art the hallmark of a new cognitive ability and social consciousness that were beyond the reach of previous hominids? And is shamanism an outgrowth of the hard-wired structure of the modern human brain? We begin this Review Feature with a brief summary by David Lewis-Williams of the book's principal arguments. There follows a series of comments addressing both the meaning of the west European cave art, and its wider relevance for the understanding of the Neanderthal/modern human transition.

scholarly journals Phylogenetic relationships of Cranichidinae and Prescottiinae (Orchidaceae, Cranichideae) inferred from plastid and nuclear DNA sequences

2009 ◽  
Vol 104 (3) ◽  
pp. 403-416 ◽  
Author(s):  
Gerardo A. Salazar ◽  
Lidia I. Cabrera ◽  
Santiago Madriñán ◽  
Mark W. Chase
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Nuclear Dna
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