I would say immigration only.
emigration would theoretically reduce the genetic variation as unique individuals leave, but immigration would bring unique traits into circulation in an ecosystem.
I'm not super great at biogy tho so this might not be right... :)
Volcanos spew, ava volcano ash and gases into the environment. this is an effect on the local energy
Answer:
overreacts to an antigen
Explanation:
Allergies to substances are as a result of immunological dysfunction.
Answer:
In 2011 an estimated 1.65% of the US workforce was employed/working in the Agriculture-related sector of the economy
Explanation:
Agriculture has been a major source of jobs for most countries especially with developing/underdeveloped countries ranking in the highest percentage of their country's population working in this sector, while developed countries like the US have smaller percentage of the population working agriculture-related jobs. as of 2011 chad had an estimated 86.67% of their population involved with Agriculture-related jobs