Geoscience Reference
In-Depth Information
and the distances between islands was small enough that quite modest rafts or logs
would have enabled a crossing from Africa to Arabia.
A third possible migration route is across the Sahara and then along the eastern
shores of theMediterranean into southern Europe and south-west Asia. Hominid skulls
belonging to
H. erectus/H. ergaster
have been recovered fromDmanisi in Georgia and
have been dated to around 1.75 Ma (Vekua et al.,
2002
). The presence of
H. erectus
skulls at Zhoukoudian/Choukoutien near Beijing in north-east China and at Solo in
Java testify to the ability of these Lower Palaeolithic people to adapt to both temperate
regions with very cold winters and to the hot, wet tropics. Given that they had to cross
what are today vast and often waterless deserts in order to reach eastern Asia, it seems
most likely that such crossings only took place during wetter climatic intervals, when
the deserts were able to sustain permanent lakes, wetlands and rivers. By observing
flocks of semi-desert birds such as sand grouse (
Pteroclidae
), which fly to permanent
water sources to drink at regular times each day, they would have been able to locate
secure supplies of water. However, there is no evidence that the Lower Palaeolithic
peoples were ever able to occupy deserts during the arid climatic intervals, in contrast
to modern desert dwellers, such as the San people of the Kalahari or, until recently,
the Walbiri of central Australia. Desmond Clark (
1980
) used modern ethnographic
examples to suggest a model of seasonal movement of small bands of Acheulian
hunter-gatherers in North Africa in accordance with the seasonal availability of wild
foods, including honey.
The inception of the Middle Palaeolithic dates to around 500,000 years ago in
southern Africa and may have been time-transgressive, with many workers claiming
an age of around 300 ka for the ESA/MSA transition. The development of heavy-
duty choppers and other woodworking tools denotes the increasing use of wood
at this time, as does the ability to attach stone spear points to long wooden shafts
for hunting larger game. Regional specialisation becomes more evident during the
Middle Palaeolithic/MSA (Clark,
1982
; Klein,
1989
; Van Peer,
1998
), including the
appearance of tool-making traditions such as the Aterian tanged points that were in
common use across the central and northern Sahara during the Late Pleistocene (Van
Peer,
1998
; Clark et al.,
2008
). The first entry into Australia some 45,000 years ago
was by seafaring people with a stone tool-making tradition that was on the cusp
between Middle and Upper Palaeolithic but had unique elements such as edge-ground
axes, which date back to at least 25,000 years ago in northern Australia (Schrire,
1982
). Elsewhere in Eurasia, polished stone axes are considered to be diagnostic of
the Neolithic, showing that it is unwise to be too rigid when using stone typology to
determine chronology.
A persistent debate among archaeologists, paleoanthropologists and geneticists
concerns the origin of anatomically modern humans (
Homo sapiens
) and whether
or not present-day people (
Homo sapiens sapiens
) are descended from one or more
widely scattered original human groups (Van Peer,
1998
; Underhill et al.,
2001
;
