A couple visit your genetic counseling clinic worried suspecting that they may be second cousins and that their marriage will be consanguineous. You give them a DNA test checking for allele-sharing at 1000 independent markers and find that they are identical by descent at 10 of them. What is the couple's probability of sharing 10 or fewer of 1000 markers if they are second cousins? If they are third cousins? (Use the pbinom(...) function with the prob parameter equal to the expected fraction of DNA shared by the relatives. To compute these probabilities, draw a family tree a multiply by one half for every sibling or parent-child relationship on the path between the relatives.)