Her performance markedly improved after she switched coaches and began training with Brian Orser.

how do the limbs of a pig differ markedly from those of humans?

You could use the word "substantially" instead. Say you saw someone after a lot of years, you could say they had changed markedly. Or if someone did something good or bad that affected someone else a lot you would say that it had affected them markedly.

In markedly the ed is prounounced mark- ed-ly.

Marked is pronounced as though there is only a d on the end 'markd'

markedly