The 30 million years ago, because its the closest one to us. Wait is there a picture to it ?
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... :)
Answer: During vigorous exercise your breathing rate increases in order to intake more oxygen
Explanation: during vigorous exercise / activity the body needs more oxygen in order to produce energy so your breathing rate increases in order to reach the demand of more intake of oxygen , and your muscles work harder due to an increase in oxygen demand and how much oxygen the muscles take from the blood during vigorous exercises , BUT during rest we have normal rate of oxygen intake because your body is at rest at that moment .
HOPE THIS HELPS!!!!!!!!!!!!!!!!!!!!!!!!!
It is cow chicken pig poop