Answer:
Knowing the evolutionary relationships among species allows scientists to choose appropriate organisms for the study of diseases, such as HIV. Scientists are even using the principles of natural selection to identify new drugs for detecting and treating diseases such as cancer. Environmental change and isolation of groups of organisms play an important role in evolution. Environmental change is any change in an environment to which an organism must adapt. Change can be gradual, such as when mountains or deserts form, other species die out, or new species evolve.
Explanation:
Some agree its in the billions range somewhere close to 3 billion.
In Mendel's experiment, he basically crossed purebred genes and observed the outcome. The product showed how dominant genes controlled the variation of the offspring more than recessive traits, but it also showed how the two, recessive and dominant, worked together to create offspring with variation.
I believe the appropriate answer is a cooling-off period. The cooling off period us described as the state of returning to the offender's usual way of life between homicides. The key distinction between the serial killers and mass or spree killers is this emotional cooling off period in which the killer blends back into his/her normal life.
