Andrew Robbertz
January 14, 2014
Date
of Publication: January
5, 2014
Summary:Most
teens and adults remember the time they learned how to swim and trying the
silly looking doggie paddle. Scientist, Dr. Frank Fish, set out with his
colleagues to understand how dogs themselves do the doggie paddle. Fish after
mostly studying the swimming of marine mammals not has the opportunity to look
at how many marine mammals have evolved from their walking terrestrial ancestors.
For the study Fish used eight different dogs from six different species. They
set out to a rehabilitation for horses, where they recorded the dogs swimming
from one end to the other, in order to compare the swimming movements. When
swimming the legs moved in the same style as a trot, with diagonal legs moving
together, but at a faster pace when swimming. This means that many of the dogs
use a basic function with slight modifications. Fish believed that many of the
first ancestors of swimming mammals were uncoordinated, until eventually the
limbs became more like paddles and the modern whales, dolphins, and porpoises.
These dogs can be used as a model for precursors to early swimming mammals.
Fish hopes to unravel the steps it took to form am mammal with complex swimming
locomotion from a four legged terrestrial form.
Connection:This
is relevant to our most recent unit on the evolution of life. IN this unit we
talked about homologous structures. Both Marine mammals and dogs share
homologous structures that point to them having shared a common ancestor. Watching
the dog’s clumsy swim provided Fish with an idea of how the four legged land
mammals came to be the marine mammals that they are today. This is also an
example of divergent evolution, where the single common ancestor broke into
multiple new species. We believe that the origins of wales came from hippopotamus
related species, but now we can more accurately determine how the limbs made for
walking turned into paddles and fins.
what is the goal of the research Fish is doing. is it just about the swimming of dogs or is it more to show how mammals evolved from terrestrial to aquatic.
ReplyDeleteA little bit of both. Fish knew that some dogs were born able to swim, while others eventually learned, and how some cant even swim at all. By studying how the dogs had learned to swim he connected that to how he believes mammals learned to swim in general. The first semi-aquatic mammal resembled a beaver, but it probably wasn't the first to swim.
ReplyDeleteDogs Swimming: http://animal.discovery.com/pets/do-all-dogs-know-how-to-swim.htm
First Semi-Aquatic Mammal: http://www.sciencedaily.com/releases/2006/02/060224195600.htm