4 workers build a walk in 18 days . How many more workers should be added to build it in 12 days?

2

Step-by-step explanation:

figure it in "worker days"

4 builders times 18 days= 72 worker days

72 days/ 12= 6 workers

have 4 workers now, so you need 2 more

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.