Human phylogeography and diversity

Abstract

Homo sapiens phylogeography begins with the species’ origin nearly 200 kya in Africa. First signs of the species outside Africa (in Arabia) are from 125 kya. Earliest dates elsewhere are now 100 kya in China, 45 kya in Australia and southern Europe (maybe even 60 kya in Australia), 32 kya in northeast Siberia, and maybe 20 kya in the Americas. Humans reached arctic regions and oceanic islands last—arctic North America about 5 kya, mid- and eastern Pacific islands about 2–1 kya, and New Zealand about 700 y ago. Initial routes along coasts seem the most likely given abundant and easily harvested shellfish there as indicated by huge ancient oyster shell middens on all continents. Nevertheless, the effect of geographic barriers—mountains and oceans—is clear. The phylogeographic pattern of diasporas from several single origins—northeast Africa to Eurasia, southeast Eurasia to Australia, and northeast Siberia to the Americas—allows the equivalent of a repeat experiment on the relation between geography and phylogenetic and cultural diversity. On all continents, cultural diversity is high in productive low latitudes, presumably because such regions can support populations of sustainable size in a small area, therefore allowing a high density of cultures. Of course, other factors operate. South America has an unusually low density of cultures in its tropical latitudes. A likely factor is the phylogeographic movement of peoples from the Old World bringing novel and hence, lethal diseases to the New World, a foretaste, perhaps, of present day global transport of tropical diseases.

The history of rabies in the Western Hemisphere

“…Although these figures pale in comparison to the number of human infections by dog-maintained RABLV lineages, it is clear that bat-associated rabies is also affecting vulnerable human populations and their domestic animals. Furthermore, these data reflect the increasing frequency of interaction between domestic animals (especially dogs), bats and terrestrial wildlife under the current and evolving status of human demographics and culture ( Escobar et al, 2015 ; Harcourt, 2016 ; Lin et al, 2016 ; Liu et al, 2010 ; Yung et al, 2012 ). At the same time, several Latin American countries (Argentina, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay) with highly successful programs for the control and elimination of dog-maintained rabies have weakened or suspended canine vaccination programs, resulting in increasing numbers of rabies-susceptible dogs and cats ( Escobar et al, 2015 ; Velasco-Villa et al, 2017 in press ).…”

“…According to the most recent archeological evidence, colonization of the Americas began approximately 12,500 to 15,000 years ago by south Siberian Paleo-Indians through an unglaciated corridor at the Bering Strait ( Harcourt, 2016 ; Pedersen et al, 2016 ). Recent phylogenetic studies based on extant RABLV diversity in New World bats and skunks suggest that the presence of rabies in the WH predated the dawn of European transoceanic travel in the 15th century ( Badrane and Tordo, 2001 ; Kuzmina et al, 2013 ; Velasco-Villa et al, 2008b ).…”

The Sixth Mass Extinction: fact, fiction or speculation?

“…But when did it begin? Did it begin with the first expansion of modern humans out of Africa, 200–45 thousand years ago (kya) (Henn, Cavalli‐Sforza & Feldman, 2012; López, van Dorp & Hellenthal, 2015; Harcourt, 2016; Bae, Douka & Petraglia, 2017; Hershkovitz et al ., 2018), or 12–10 kya during the Neolithic Revolution when human populations began to increase rapidly as a result of the development of agriculture (Bocquet‐Appel, 2011; Lenton, 2019), or did it begin much more recently, even as late as during the 19th century industrial revolution? Avise et al ., (2008) characterised these as the three phases of the Sixth Mass Extinction, implicitly including all human‐caused extinctions, and considering the status of biodiversity now to have reached a crisis point.…”

β-thalassemia distribution in the old world: a historical standpoint of an ancient disease

“…Various processes (selection, mutation, migration and genetic drift) are known to determine the frequency of genetic diseases in human populations, but so far it has proved almost impossible to identify to what extent each process is responsible for the presence of a particular genetic disease. 49 – 54 …”