Quote:Pleistocene Occupation of Oceania: Into Sahul
According to archaeological evidence, New Guinea and Australia were settled by anatomically modern humans very early in human history; sites from around 50 thousand years ago (kya) are known from Australia [3], and of around 40 kya from New Guinea [4], although the exact timing is still debated [5]. It often is assumed that the occupation of Sahul represents the results of the first exodus episode of modern humans out of Africa [6,7]. The time period of at least 40 kya of potentially shared contacts between New Guinea and Australia, until both regions became separated by rising sea levels about 8 kya, might seem to suggest that the human occupation of Sahul stems from a common origin. This view may be supported by a number of at least superficially similar phenotypic traits, such as their exterior appearance, between these two populations. However, many of these traits are expected to be influenced by selective processes that can be of independent origin in different geographic regions while resulting in similar phenotypic outcomes because of similar environmental factors to which people genetically adapted. However, population-based mitochondrial DNA (mtDNA) studies, mostly based on the non-coding control region, either found no similarities between Aborigines from New Guinea and Australia (Figure 1), and distant positioning of both groups in phylogenetic analyses, or they revealed that, although most of the mtDNA variation differs between both regions (Figure 1), some very few Australians clustered closer to New Guineans than to any other worldwide samples [8–10]. Similar results were obtained from more recent studies using whole mtDNA genomes [11,12]. However, one study based on complete mtDNA genomes and using lineage-based (but not population-based) phylogenetic analyses argued for a single founder group having settled in Australia and New Guinea about 50 kya [13]. Studies on the non-recombining part of the Y-chromosome (NRY) revealed that no major lineages are shared between Australia and New Guinea [14–16] (Figure 2). Moreover, the major Australian NRY lineage (C-DYS390.1del/M347) is not only restricted to but also appears highly frequent across Australia [13,14,17,18]. Together with low diversity of lineage-associated Y-chromosomal short tandem repeat (Y-STR) haplotypes, this lineage provides evidence for a somewhat recent founder or bottleneck event in the Australian history as well as subsequent population expansion [14]. This may be in line with archaeological data indicating a mid-Holocene ‘intensification’ — beginning about 4 kya new tool types occur, many sites were occupied for the first time, whereas other sites show a higher density of materials [19]. However, the reduced Australian NRY diversity contrasts sharply with strong mtDNA heterogeneity [11,12], implying that the assumed founder/bottleneck event and subsequent population expansion concerned mainly males. Hence, overall, most NRY and mtDNA studies either failed to establish the degree of genetic relationship expected under the common-origin hypothesis, or, alternatively, suggest that if a common ancestry did exist, it must have been well before the entry into Sahul about 50 kya. Notably, also linguists failed so far to detect similarities between the many languages spoken by Australian and New Guinean Aborigines [20]. Currently available autosomal DNA data from single locus (such as α-globin genes or HLA genes) studies have been used to support both a common-origin hypothesis as well as a different-origin model [21–23].
[
Source]
So we're all Aboriginal then .... Yes?
Forum
Pages: 
Spot the Aboriginal.. (Read 31223 times)
