a.What is evolution and what is natural selection? (8 marks)
The theory of evolution arises out of man's need to explain the origins of both the Universe and Life. Evolution may be defined as that continual natural process through which organisms have acquired their peculiar structure and functions. Whilst this is the generally accepted explanation to the origins of the Universe and Life in history there have been many other theories put forward, such as spontaneous generation that is the belief that living matter can be generated from non-living matter.
In layman's terms evolution is the process responsible for the changes over the extent of Earth's existence. Evolution began with the development of certain conditions on Earth which were favourable to the formation of life and the changing of these simple life forms over time into the organisms observable on earth today, including humans.
Darwin, though not the first to contribute to the idea of evolution is often credited with its development.
It was after his joint presentation with Wallace that evolution really began to gain widespread acceptance in society. In his book "Origin of Species" Darwin proposes a two-part argument to support his evolutionary theory, 'Struggle for Existence' and 'Natural Selection'.
The 'Struggle for Existence' argument proposes two principles; the principle of reproduction which states all living things are potentially able and possess the drive to reproduce at rapid rates. The second principle of dependence states that all organisms depend on natural resources such as air, water and a source of energy. To these principles three factual observations were made. The first is that there are limited numbers of places on earth where there are these natural resources exists. The second states that the locations where these natural resources exist may fluctuate over...