peter@baylor.UUCP (Peter da Silva) (08/29/85)
Oh boy, an easy one... > 1) Fossils of whales which prelived today's whales did not have said > organs (at least not in the currently developed mode). Zeuglodon and relatives did not have a melon, and the nostrils were in a position similar to that of most mammals: at the front of the head, on the beak/snout/rostrum. Modern whales have the nostrils on top of the head, a position which facilitates breathing. > 2) Present whales could not survive or at least would be severely > hampered without said organs. When a whale breathes only the very top of the head surfaces, which (a) cuts down the time a whale must spend on the surface, and (b) cuts down the whale's visible profile. Near the surface there is greater drag, so anything that cuts down the time spent there has a positive evolutionary advantage (a). Now (b) is probably much less important, since there were very few surface hunters until about 50,000 years ago when we arrived in the scene, and whales have been in approximately their present form for several million years. -- Peter (Made in Australia) da Silva UUCP: ...!shell!neuro1!{hyd-ptd,baylor,datafac}!peter MCI: PDASILVA; CIS: 70216,1076