We know a lot more about animals and plants than darwin did, and still, not a single case is known to me of a complex organ that could not have been formed by numerous successive, slight modifications. i do not believe that such a case will ever be found. if it is i shall cease to believe in darwinism.
a) true
b) false

The given statement is True.

Explanation:

The Charles Darwin developed the theory called Darwinism theory of evolution. The theory states that all the species of the organisms arises and developed through the small, inherited variations in the organisms that increase the individual ability to complete the survive and reproduce.

The individual species are not having identical traits that  are passed from the generation to generation. The offspring are born that can survive, only the survive of the completion for resources will reproduce; he describes how the species can change in shape and character through the selective breeding.

d. making up measurements to record.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation