the evolution of fin morphology in harp seals

• The harp seal’s lineage:– Phylum: Chordata– Class: Mammalia– Order: Carnivora– Family: Phocidae– Genus: Phoca– Species: Phoca

groenlandicahttp://www.youtube.com/watch?v=1hT8DtfriYU

• Fish’s research studied how once quadrupedal, terrestrial mammals evolved into fully aquatic mammals.

• He studied the differences in propulsion of terrestrial, semiaquatic, and full aquatic mammals.

• He found harp seals to use pelvic oscillations as their mode of locomotion and to use thrust force for lift.

Figure 1 is showing: • The major forces associated with propulsion modes. •Note the third animal figure. This is the harp seal and its propulsive mode of pelvic oscillation shown. Also, the harp seal uses its hind flippers (i.e. back fins) lift-based propulsion.

Note the back fin anatomy on the harp seal above.

http://www.youtube.com/watch?v=rZVtecticP0

• While some research has been done on harp seals (as seen in the previous video), not a lot of supporting research has been done.

• With recent discoveries, more research is being conducted on the harp seals, but we do not have access to these findings yet.