Friday, October 05, 2007

Dolphins Provide Further Evidence that Woman Do, In Fact, Belong in the Kitchen.

Ok, that was a joke, and probably one in bad taste; but, hey, the point was to get your attention. So I should start first by stating that in no way do I believe the title of this blog to be an accurate indication of the female capacity. Dolphins, found in Shark Bay, Australia, on the other hand, seem incapable of understanding, and indifferent towards the Woman’s Rights Movement. It appears there have been no Dolphin equivalents to Susan B. Anthony or Eleanor Roosevelt in this Dolphin community. Here, only female dolphins use sponges, while male dolphins, as stated by Dr. Michael Krützen, “apparently have better things to do.” What things you ask? It seems socializing and fraternizing with other Dolphins takes up too much of their time to be bothered with sponges. (Oh, the connection to the joke was sea sponges vs. household sponges found in kitchens; it’s probably not a good sign for the joke if I felt I had to add this explanation.)

Now, to diverge from my extraordinary comedic wit, I shall address the biological application of this study, as it presents a topical application to issues discussed in class. Bottle-nose dolphins found in Shark Bay, off the coast of Australia, have recently been observed repeating a strange behavior; carrying portions of sea-sponges over their snouts. No other dolphins on Earth are known to exhibit this odd behavior. Naturally, marine biologists were intrigued to discover the purpose and origin of this behavior.

Observations revealed that the sponge is actually used for protection when foraging for food in the rough substrate of the bay. Essentially, it is worn like a glove…..or oven mitt, to protect the sensitive snouts of the dolphins from cuts as well as stings from prey. A scientific experiment performed in Shark Bay revealed that of a sample population 1 male dolphin and 12 females exhibited the “sponging” behavior, and 172 dolphins did not. Of the thirteen dolphins who exhibited sponging only one dolphin did not share markers in the DNA of their mitochondria, which are cellular organelles inherited strictly from mothers. Was genetics, then, responsible for the spread of the sponging behavior in Shark Bay? Extensive DNA mapping of the test dolphins revealed that there is no coded “sponging” gene in the dolphins. The genetic relatedness among dolphins is a reflection that daughter dolphins descended from a particularly pioneering female dolphin learned the sponging technique by observation and interaction, thus exhibiting cultural transmission. It can only be hypothesized why male dolphins do not routinely learn the behavior. However, studies of bottlenose dolphins reveal males generally allocate their time to social interaction, and sponging is a relatively solitary behavior.

The evidence of “sponging” in Shark Bay further demonstrates the exceptional intelligence of bottlenose dolphins, marking the first instance of tool application of any cetacean (order including porpoises, dolphins, and whales). The behavior is evident almost exclusively in females as a result of intelligence and cultural transmission.

"Posted by David Mahoney"


At 10:58 AM, Blogger PWH said...

First, great blog! Second, this reminds me of the macaques in Japan ding the potato washing. I would assume that since this is a learned behavior eventually the entire dolphin population in Shark Bay will acquire this behavior.
"Posted by Jennifer McGrath"


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