What ideas were changing in the scientific community at the time darwin travels

One Idea was the appreciation that the age of the Earth was much greater than had hitherto for been imagined.

before it leaves the nucleus of a eukaryotic cell, mrna is altered in the following ways: - a cap is added to the 5' end of the mrna molecule; - a poly a tail is added to the 3' end; - introns are removed and exons are spliced together.