The questions has a set of four sentences marked A to D. Identify the arrangement of these sentences which makes a logical sequence.
(A) fossil evidence suggests that the mammals underwent adaptive radiation to produce the range of mammal types 1 extant today.
(B) Adaptive radiation, in the life sciences, refers to the differentiation (or anagenesis) of one or a few species into many to fill a large number of related ecological niches by adaptation.
(C) Thus the first bird species may have given rise many more bird species by adaptive radiation.
(D) Typically, a species adapts to colonize a new habitat and, this adaptation opening up a new range of niches, adapts again to fill the new niches which are presented.