When we talk about evolution we come across the process of natural selection. Genetic variation is always required for the natural selection. A change or variation in the genes may help the individuals in a population to better adapt to the environment. Such changes may be brought by mutations or random mating in the population. Such variations help in the survival of the population by allowing them to adapt to changing environmental conditions.
Answer:
serotonin
Explanation:
Here is the complete question:. on average, those with the short form of the ________ transporter gene and a history of stressful experiences reported more than average symptoms of depression.
Serotonin is sometimes called the happy chemical, because it contributes to wellbeing and happiness. The scientific name for serotonin is 5-hydroxytryptamine, or 5-HT.
C. a green parrot has an allele for green feathers and an allele for blue feathers.
It is called a Punnett Square