Question

What can we learn from ancient DNA?

Answer 1

DNA and RNA- the two genetic materials are always getting changed. Mutation and variations are always going on in the base sequences and thus, the genes. When enough mutations occur in a genome, it results in evolution.

Complete answer:
Ancient DNA actually means the DNA that was present in the biosphere before the recent DNA came up.
One thing to note about learning this ancient DNA is the dominance of the RNA world. We all know that RNA is more unstable than DNA, and it came before DNA. So, RNA is more susceptible to mutations than DNA.
This draws the fact that both these genetic materials have undergone mutations in the past to look as they look today. When we search the history of evolution, and examine the ancient DNA samples collected from these organisms, we notice that they have some marked differences from the DNA structure as we see today and are accustomed to.
This opens the door of opportunity to learn new facts about the life forms of the ancient times, the genetic changes that occurred and shaped the new age organisms, and other evolutionary aspects.

Note:
It is to note that RNA is more susceptible to mutations than DNA. The DNA confers stability to the genetic material. It was because of the RNA that in the ancient world there were so many mutations that gave rise to antecedents of different organisms.