The random variable X is exponentially distributed, where X represents the waiting time to receive a custom ordered package from a company. If X has an average value of 15 days, what is the probability that the wait time is greater than 11 days

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.