Two roads r1 and r2 and the streets between them s1 s2 s3 and s4 are shown. The intersections, represented by the points, lie on a circle, with the intersection of the four streets at the center of the circle shown. What is the measure of angle a between the two roads A 15
B 30
C 38
D 54
E 68

step-by-step explanation:

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.