Sunday, May 11, 2008
In the marine biology world, there has always been an argument over a controversial issue, and that issue being whether or not whales and dolphins (cetaceans) can have a culture between themselves. Some scientists say that only humans can create a culture to live in because of what they believe in, but others look only at the facts and make their mind up that way. A culture is defined as shared variation in behavior that is generated and maintained by social learning, for example, through imitation or teaching. If you think about human culture, you can see that we live in families and our young learn their necessities to survive the rest of their lives through imitating their adult parents and through the older members' teachings.
- One example of dolphins having a culture is how they too live in families called pods. Dolphin pod sizes have been counted up to about 100+ dolphins living and hunting together in one pod. Dolphins never free-lance and live on their own, but are always with others, however they do not have life long partners, but they do enjoy having sex with each other for fun and for no apparent reason.
- Whales too live in pods but they do not nearly have as many members in their pod. When the mother gives birth to her offspring, females leave their mothers side when healthy and big/old enough to, however the male offspring stay with their mothers until death. Whales also will sometimes join pods together and create a bigger pod.
- Another way cetaceans show they have cultures in them in through communication. Communication is essential in cultures, and both humans and cetaceans have a form of communication. Human communication is obvious through writing, verbal, and touch forms of communication. And although whales and dolphins have no written forms of communication, they do exhibit forms of verbal and touch communication. They use communication for mating, defense, and hunting purposes. One example of this is how all the blue whales in the ocean have a common mating song that they sing. Even when there is a slight change in the song, the other males pick up the change and incorporate it in the new song that they sing. If you ask me, that is just like humans across the globe picking up a fad as simple as songs or clothing styles.
I strongly believe that cetaceans promote a strong culture in their existence just like we humans have in our lives.
Cetaceans have a very identical anatomy and skeletal build when compared to humans in my eyes. I think it's remarkable that we have a similar build for the very different environments that we both live in. Here are just some similarities that i have found in researching cetaceans:
- Homologous Structures: homologous structures are are characteristics which are shared by related species because they have been inherited in some way from a common ancestor, and in this case we are looking at a certain point in both organisms skeletons which is the fore-limb. As you can see in the picture to the right, the very same bones are in both of the whale and human fore-arm, they are just adapted to do different things in different ways.
- Vestigial Structures: these are structures or organs that have become useless over the period of evolution. A pelvic bone in humans connects our legs to our spinal column as well as having other purposes, but a whales pelvic bones have no function, yet they still have them, (as you can see from the picture to the right again).
- Bones and Teeth: “The bones and teeth of marine mammals, like those of other vertebrates, consist of both organic and mineral components. Because the mineral component (mostly calcium phosphate) predominates, the constituents of bones (bone and calcified cartilage) and teeth (cementum, dentine, and enamel) are referred to as ‘hard tissues.’ Each of these hard tissues is distinguished both by its composition and by its microscopic structure. Many of the histological features of marine mammal teeth are typical for all mammals…” That was said by Mary C. Mass in her study of cetacean bones and teeth.
Based on only those three examples of anatomical evidence of similarities, i would say there is a strong tie between human anatomy and cetacean anatomy.