Search results
Results from the WOW.Com Content Network
Common name Scientific name Range Comments Pictures North African elephant: Loxodonta africana pharaoensis: North Africa: Neolithic rock art indicates that the African bush elephant inhabited much of the Sahara desert and North Africa at the beginning of the Holocene, and Ancient authors wrote that it was present in the Atlas Mountains, the Red Sea coast, and Nubia until the first few ...
Beginning of animal evolution. [54] [55] 720–630 Ma Possible global glaciation [56] [57] which increased the atmospheric oxygen and decreased carbon dioxide, and was either caused by land plant evolution [58] or resulted in it. [59] Opinion is divided on whether it increased or decreased biodiversity or the rate of evolution. [60] [61] [62 ...
Extinction through human hunting has been supported by archaeological finds of mammoths with projectile points embedded in their skeletons, by observations of modern naive animals allowing hunters to approach easily [147] [148] [149] and by computer models by Mosimann and Martin, [150] and Whittington and Dyke, [151] and most recently by Alroy.
Mass extinctions are characterized by the loss of at least 75% of species within a geologically short period of time (i.e., less than 2 million years). [18] [51] The Holocene extinction is also known as the "sixth extinction", as it is possibly the sixth mass extinction event, after the Ordovician–Silurian extinction events, the Late Devonian extinction, the Permian–Triassic extinction ...
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...
Of insects, Africa has many thousand different kinds; of these the locust is the proverbial scourge of the continent, and the ravages of the termites are almost incredible. The spread of malaria by means of mosquitoes is common. The tsetse fly, whose bite is fatal to all domestic animals, is common in many districts of South and East Africa. It ...
Many kingdoms and empires came and went in all regions of the continent. Most states were created through conquest or the borrowing and assimilation of ideas and institutions, while some developed through internal, largely isolated development. [7] Some African empires and kingdoms include:
By 5000 BC, Africa entered a dry phase, and the climate of the Sahara region gradually became drier. The population trekked out of the Sahara region in all directions, including towards the Nile Valley below the Second Cataract, where they made permanent or semipermanent settlements. A major climatic recession occurred, lessening the heavy and ...