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DIE BONTEBOK
CONTINENTAL DRIFT AND ITS EFFECT ON THE EVOLUTION OF SPECIES together depending on which way the plates on which they are attached are moving. The continents have all been one big landmass at least twice in the history of the earth. These supercontinents were called Rodinia and Pangaea. Rodinia was the first super-continent that formed about 1.3 billion years ago and started breaking up about 900 million years ago.
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By: Dr Kas Hamman
revious articles focused on the interesting phenomena of Island or isolation evolution and how it gave rise to unique forms of lifeadaptations on Islands such as Madagascar, New Zealand, Australia, the Galápagos Islands and many others. Scientists concur that the earth is about 4.6 billion years old. There is also no doubt that for long periods of time, the earth has undergone some drastic changes. Over millions of years various forms of life on earth has had to adapt to ever changing environmental conditions in order to survive. These physical changes to our planet are without doubt strong drivers of evolution as the species that live on our planet in that particular period of time have to adapt to change as the planet itself changes. These changes can come from internal or external sources and are part of ongoing natural processes. Continental Drift The ground that we stand and live on every day may feel stationary and solid, but in reality, it is not the case. The continents on earth are divided up into large “plates” that move and float on the liquid-like rock that makes up the mantle of the earth. These plates are like rafts that move as the convection currents in the mantle move below them and are called tectonic plates. The actual movement of these plates can now be measured quite accurately by sensitive instruments on geostationary satellites. Some plates move faster than others, but all are moving, although at a slow rate of only a few centimetres, on average, per year. The continual movement of these tectonic plates leads to what scientists refer to as “continental drift”. Continents move apart and come back
Theoretical reconstruction of the Rodinia super continent 900 million years ago
The second super-continent, Pangaea formed about 300 million years ago and started breaking up about 200 million years ago.
The original Pangea Continent about 300 million years ago
The southern part of Pangaea is known as Gondwana, which also started braking up over the following 100 million years.
