Question

Which fins are homologous with the forelimbs and hindlimbs of terrestrial vertebrates?                                                                                                                  

FORELIMBS:

HINDLIMBS:

Answer 1

Forelimbs - The pectoral fins of fish

Hindlimbs - The pelvic fins of fish

The paired pelvic fins are below the pectoral fins and are homologus to the hind limbs of the tetrapods. An example of earliest tetrapode is the amphibians. The amphibians have bony structure inside their fins that acts as legs for walking in land. The early amphibians have efficient hearts to deliver adequate oxygen to meet their increasing metabolic process. Some amphibians have internal nostrils too to function as air breathing when in land. These are certain preadaptations of fishes for their transition of life in land.