Question

Evidence suggests that there is a relationship between ancient dinosaurs and modern birds. Through time, each occurrence of a new trait MOST likely resulted from which of the following?
mutation of genes

hybridization of species

alteration of the environment

extinction of populations

Answer 1

The answer is mutation of genes.  The mutations were beneficial and gave the individuals of  the population advantage and hence increased their survival. The classic features of birds evolved one by one and gave birds advantage over their dinosaurs counterparts, especially the feature of small size.

Answer 2

A is the answer ......