What is Darwin's evolution theory?
2 Answers
Darwin's theory of evolution is the idea of descent with modification.
this means that all living things have come about by natural causes from a common ancestor.
Explanation:
Darwin observed that living organisms have variations in their offspring.
Darwin realized that not all the offspring could survive. (that there would be a struggle for survival)
Darwin made a comparison with artificial selection where farmers would select the animals best suited to their priorities to survive and breed. Darwin called this idea natural selection.
Darwin looked at the changes that artificial selection could make in pigeons and extrapolated that these changes over a vast period of time could result in the formation of a totally new species which would not be a pigeon.
Darwin Then extrapolated backwards and theorized that over time natural selections could account for all the variations in living things that are observed today.
Darwin based his theory on the assumptions of
A. everything happens by uniform natural causes observable today
B. There is an infinite possibility of variation in the offspring of living things.
C. There is a vast period of time for these slow uniform changes to take place.
D. That these slow uniform changes could result in an increase of beneficial changes resulting in new and better organisms.
E. All life started as a "simple one cell organism that with descent with modification resulted all life on earth
Descent with Modification states that all life came from a single common ancestor totally by slow gradual natural causes.
Explanation:
When people use the term evolution or organic evolution they are usually referring to Darwin's theory of Descent with Modification.
Darwin's theory was the " tree of life" that all life descended from a common ancestor, some "simple " primate cell.
Darwin believed that there was infinite possibilities of variations in all organisms. Natural selection would then favor the variations that were more "advanced" than the other variations causing an inevitable progress of improvement in living things.
Neo Darwinism modified Darwin's theory with the idea of mutations being the source of infinite variation after Mendel's experiments on genetics proved that there were only a finite and conservative variations in living things.
Darwin used Lyell's theory of geological uniformtarism and applied it to biological systems. Darwinian evolution is based on the idea that everything can be explains through slow uniform small changes in living things that by extrapolation can explain eventual large changes in living things. t
The beauty of descent with modification in the culture of the Enlightenment was that it explained life without reference to God or any supernatural causes. Everything could be explain by natural causes, supporting the philosophy of material realism.
Note evolution can also refer to adaptive evolution ( micro evolution) punctuated equilibrium, forms of guided evolution as well as the standard Neo Darwinian synthesis. Descent with Modification remains a theory because there is no empirical evidence that random mutations can result in an "advance" in genetic information.
