Why does a diagram of evolution look more like a bush than a straight line

Astudent visits the beach during a very hot day she steps on the santa and jumps because it is so hot what type of heat transfer is demonstrated by the sand in this example

Joe is breeding cockroaches in his dorm room. he finds that the average wing length in his population of cockroaches is 4 cm. he chooses the six cockroaches that have the largest wings; the average wing length among these selected cockroaches is 10 cm. joe interbreeds these selected cockroaches. from earlier studies, he knows that the narrow-sense heritability for wing length in his population of cockroaches is 0.6. a. calculate the selection differential and expected response to selection for wing length in these cockroaches. b. what should be the average wing length of the progeny of the selected cockroaches?

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