How many times as many circles will there be at stage 21 compared to stage 20

Step-by-step explanation:

Given

Stage 20 has circles

Considering at each consecutive stage circle doubles itself

So at stage 21, there will be circles

true

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.