In order for speciation (formation of a new species) to occur, why is it necessary to prevent the populations from interbreeding (breeding together)?

Describe five factors that influence the value of fuel

The allele for curly hair is incompletely dominant. if a mother is homozygous for curly hair and the father is homozygous for straight hair, what percentage of the offspring will exhibit characteristics of both parents? 25 percent 50 percent 75 percent 100 percent

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?