What can scientists look at to help them prove that our modern-day animals evolved from extinct animals?

i think that they can help like teaching the World a lesson for the good of all of us in this planet.

Their skeletal structure and possibly how they look but usually not. You can also look at the way they live and the biomes they live in.

Explanation:

1. dermis

2. chemical

3. urine

4. viruses

5. antibodies

haploid cells;