Science Assessment

Assume that some type of forelimbs were present in the common ancestor of pigs, crocodiles, whales, and birds, and that those ancient forelimbs evolved into the arms, fins, and wings of animals that exist today. What would be true about the genes that code for forelimbs in these different animals that evolved from the forelimbs of the common ancestor?

1. Exactly the same genes would code for forelimbs in all of these animals.
2. Many of the same genes would code for forelimbs in all of these animals.
3. Many of the same genes would code for arms in pigs and crocodiles, but these genes would be completely different from the genes that code for wings in birds or fins in whales.
4. Completely different sets of genes would code for forelimbs in these different kinds of animals.