Geoscience Reference
In-Depth Information
Other physiological adaptations are the ability to drink large amounts of water when
needed and the ability to excrete solids and liquids in highly concentrated form with
minimal loss of water. Dingoes in the Australian desert can also obtain water from
solids excreted by their puppies and by other animals. The most obvious behavioural
adaptation seen in marsupials, rodents and carnivores is to remain dormant in shady
places by day and to hunt or seek food by night. The big cats of the Africa savannas are
nocturnal hunters, as are the jackals and hyenas, although they are capable of daytime
activity if required. Smaller animals, including scorpions, lizards and beetles, will
seek refuge in burrows, where the relative humidity is higher than the ground outside
during the day and the temperature much cooler. Desert snakes, including the various
desert vipers like the African saw-scaled viper
Echis carinatus
, can burrow rapidly
into sand and remain almost invisible by day. Snakes and other reptiles can lower
their body temperature and metabolic rates during times of cold and increase them
gradually on contact with warm surface rocks or soils.
4.5 Adaptations of humans to life in deserts
Human societies that have lived in desert areas for many hundreds of years have
practised four main lifestyles: hunting and gathering; pastoralism; rain-fed cultivation;
and irrigated farming. For the sake of clarity, these lifestyles are considered separately,
but they should not be seen as mutually exclusive, given that pastoral nomads may
practise some cultivation, and sedentary farmers may resort to hunting.
The hunter-gatherer lifestyle of the San people of the Kalahari relies on an intimate
knowledge of plants and animals across a wide area, as well as an ingenious method
of procuring water from sip wells and storing it in ostrich eggshells (Lee and DeVore,
1976
). Whether the San people are really what Marshall Sahlins (
1968
)termedthe
'original affluent society' is highly debatable. Indeed, as Carmel Schrire remarked,
tartly but aptly, the affluence may reside more in the mind of the anthropologist than
in the belly of the hunter (pers. comm., Cape Town, June 1979). Until about 100 to
200 years ago, the Aboriginal desert dwellers of Australia relied on an intricate and far
flung network of trading and social contacts to enable them to survive in unusually dry
years by moving into the lands of their neighbours and using their natural resources
(Gould,
1980
;Veth,
2005a
;Veth,
2005b
; Hiscock and O'Connor,
2005
). This reliance
broke down after the arrival of Europeans on the continent, just as it has done with
many other indigenous peoples in the deserts of the Old and New Worlds (Paterson,
2005
; Kinahan,
2005
).
The hunter-gatherer way of life remained universal until the advent of Neolithic
plant and animal domestication, which began more than 11,000 years ago in the
semi-arid 'Fertile Crescent' region of the Near East (modern Turkey, Syria, Lebanon
and Iraq) and then spread into other dry regions like the Nile Valley. Elsewhere,
early agriculture developed quite independently, as in several parts of South America,
