Ascientist finds what she thinks is a new species of rodent on a small pacific island. however, some similar-looking rodents inhabit some nearby islands. she mates the new rodent with the nearby rodents and gets viable but infertile offspring. why? a) the new rodents probably derive from fairly recent ancestors that experienced dispersive allopatric speciation
b) the old and new rodents underwent vicariance, and they hybrid offspring were sterilized by adaptive radiation
c) the new and old rodents are both allopolploid are undergoing sympatric speciation
d) none of the above

Aresearcher designed an investigation to test what effect eating different types of food would have on blood insulin levels. she selected 10 male subjects who were all 25 years of age and in good health. the experiment took place over 3 days. at 8: 00 a.m. on each day, the subjects ate a meal consisting of only 1 type of food. they had their blood insulin levels measured after consuming the meal. on day 1 they ate a high fat diet, on day 2 they ate a high protein diet, and on day 3 they ate a high sugar diel what is the independent variable in this experiment? a the age of the subjects b the blood insulin level c the type of food consumed d the time of day the meal was consumed

Which is not a type of symmetry? a. asymmetryb. radial symmetryc. bilateral symmetryd. lateral symmetry

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review