The grand canyon was carved out by the colorado river. this caused the separation of members of a squirrel species. abert’s squirrel lives on the southern side of the canyon and in other parts of the united states. a subspecies, the kaibab squirrel, is found around the northern rim of the canyon and nowhere else in the country. as shown here, the two squirrels differ in body and tail coloration. their ears are also different. these variations are the result of

When a person is exercising the body needs to deliver increased amounts of oxygen to the muscles which component of blood ensures that the muscles will receive it

Cold case files recently began re-investigating an old murder case. the murder took place in the park; a young man, james, was hit over the head with a brick and killed. police suspected the jealous former boyfriend of james' wife, karen. whoever killed james may have washed their hands in a near-by bird bath as detectives found blood in the bird bath. since the murder took place before dna fingerprinting was available, the suspected killer, ronnie, went free. detectives are now reviewing the blood evidence using dna fingerprinting. based on the dna fingerprints of all possible suspects, who is james' killer?

Why do oceanic plates tend to subduction when colliding with a continental plate