To estimate the number of foxes in an area, a researcher conducted a mark-recapture survey. In the first survey, he caught and marked N number of foxes. In his second survey a week later, he caught 120 foxes of which 90 were unmarked (recaptures). If you are told that the actual number of foxes in this area is 400, what is value of N in this area?

#Question id: 11978

#Section 1: Ecology

#Question id: 4700

#Section 2: Evolution

Which of the following is not an observation or inference on which natural selection is based?

#Question id: 4620

#Section 2: Evolution

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?

#Question id: 16869

#General Aptitude

#Question id: 10631

#Section 2: Evolution

To estimate the number of foxes m an area, a researcher conducted a mark-recapture survey. In the fast survey, he caught and marked 90 foxes. In his second survey a week later, he caught 120 foxes of which 40 were marked (recaptures). If you are told that the actual number of foxes in this area is 400, which of the following is a plausible explanation for the anomaly in the researcher's data?