A group of field biologists goes out to mark beetles living in an area around a local pond in order to estimate population size. They capture 500 beetles on the first day. They return the following day and catch a total of 400 individuals, 200 of which are marked. What is the estimated population size for the beetles?

Question

Quizplus · Accepted Answer

This problem can be solved using the Lincoln-Petersen index, which assumes that the proportion of marked individuals in the second sample (M/N) is equal to the proportion of marked individuals in the overall population (m/N). The equation for this index is N = (M * n) / m, where N is the population size, M is the size of the first sample, n is the size of the second sample, and m is the number of marked individuals in the second sample. Plugging in the values from the problem, we get N = (500 * 400) / 200 = 1000. Therefore, the estimated population size for the beetles is 1000.

A Group of Field Biologists Goes Out to Mark Beetles