What is meant by the common descent with modification a clas

What is meant by the common descent with modification (a classical principle of Darwinian evolution)? Why it was a new idea compared to evolutionary theories which existed before Darwin? What mechanism did Darwin propose for this process?

Illustrate with real examples involving at least 5-6 animal groups.

(Answer in 6-7 sentences).

Solution

Answer:

Common descent with modifications indicates that, in the offsprings there will be sharing of common genetic resources from parents but it can not be a phenotypic copy of each parent. Many factors have been postulated in the event. Such events are mutation, genetic drift, migration and natural selection. Pre Darwinism claims that parents features will be recapitulated in offsprings, however the modifications of the features if the common descent is the new finding if Darwin\'s theory.