The Story of Life & the Environment
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The Story of Life & the Environment  an African perspective
The Story of Life and the Environment
A distant galaxy photographed from the Hubble telescope.
A group of women fishing with baskets in the Okavango River, Botswana
A hawksbill turtle swimming over a coral reef off Zanzibar, Tanzania
Californian coast redwoods, the largest trees on Earth

Life on Land

Land comprises less than 30% of the surface of the Earth, but supports the highest biodiversity on the planet, of which a large proportion is found on the African continent. Africa is the second largest continent and covers an area of about 30 million km2, representing about 20% of the total land surface.

The fly agaric, genus Amanita, probably the icon of fungi, is associated with pine trees and has dispersed all over the world where pines grow    The African Pygmy Goose    Artiodactyla: hippopotamus, the third-largest land mammal

The geology of Africa is complex and unique because of a rich variety of rock types that also conceal an enormous richness of mineral wealth. The entire African continent is situated on a relatively stable tectonic plate bordered on all sides, except to the north, by mid-oceanic ridges. Except for the volcanoes in the vicinity of the East African Rift Valley, volcanism and earthquakes are almost nonexistent on the continent due to the absence of subduction zones.
The stability of the continent has had a dual effect on its composition: the land underwent long and continuous periods of chemical weathering, which resulted in nutrient-poor soils from the leaching of soil minerals. On the other hand, the same weathering formed rich deposits of minerals such as bauxite, iron and manganese.

Life on land depends on complex interactions between geology, climate, landscapes, organisms and community structures that are shaped by these features, but which themselves also contribute to the evolution of the ecosystem structure. Thus, a strong association exists between habitat shifts and species diversification. A high-energy event such as the impact of an asteroid or volcanic eruption could trigger a series of events, from change in climatic conditions to collapse of certain ecosystems and species extinction. These high-impact events modified the course of evolution as they gave the living world the opportunity to reorganise itself. Such catastrophes would have ripped apart the evolutionary process and, in so doing, may have helped new biological forms to establish themselves.

Story of Life