The Dolphin Brain
Dolphins are generally friendly and popular animals to many people. Dolphins charm people with their performances in an aquarium, and dolphins are used in animal therapy to help patients with psychological problems. In addition, dolphins are very intelligent, and their abilities have been studied for a long time. Due to their large brain size, dolphins have high intelligence. Emory University researchers studied the 47 million years of evolution of brain size of dolphins and their relatives, and the researchers found some similarity of the evolution of the brains of dolphins and humans.
First, the researchers used the fossil record of the toothed whales, dolphins, porpoises, belugas, and narwhals from the order Cetacea and suborder Odontoceti. This is because the modern species, odontocetes have quite a high ratio of brain size to body size. The ratio is the second highest after modern humans. So the researchers hypothesized that there is a pattern for the ratio in toothed whales, and the solution could make odontocete brain evolution more clear. In order to study the evolution of their brains, the researchers measured the ratio of brain size to body size for 60 fossil cetacean species and 144 modern cetacean specimens with tomography to scan and measure their skulls. They used a total sample of 210 specimens from 37 families and 62 species.
From this study, the researchers found two phases in dolphins’ evolution. The first phase was that the new suborder odontocetes emerged about 39 million years ago. Their brain size gradually increased, and the body size decreased. In addition, this change started from the first cetaceans that possessed echolocation. Echolocation is a biological process that uses sound propagation under water to communicate from dolphin to dolphin, and modern dolphins and other odontocetes use echolocation. The second change of brain size occurred in the origin of Delphinoidea; oceanic dolphins, porpoises, belugas, and narwhals emerged about 15 million years ago. Also odontocetes have showed high behavioral abilities such as recognition of abstract concepts as humans have.
From these investigations, the researchers concluded that odontoces had similar features with humans in the process of brain evolution and not only humans, but also dolphins developed their brains evolutionally.
I think that further study is needed for proving the relationship between the brain evolution of dolphins and humans. This study still leaves ambiguous points. We will be able to learn new information about humans’ evolution through further study. In addition, I am especially interested in the behavioral abilities of dolphins. Their behavioral abilities include not only recognition of abstract concepts, but also self-recognition on a mirror and the comprehension of artificial, symbolic communication systems. These high behavioral abilities show dolphins’ high intelligence such as humans and great apes. I would like to research more concrete abilities of dolphins and the relationship between humans and dolphins based on the abilities.
posted by tsaori
posted by PWH @ 7:02 PM
14 comments
14 Comments:
I think is is a very fascinating study. I have had the wonderful opportunity to swim with dolphins on more than one occassion and their capabilities are just astounding. Scientifically, yes it is true that they are one of the more intelligent marine mammals. Although, I am curious if you found your original research unsatisfying because it stills leaves us hanging on the complete similarities of the dolphin and human brain, what is next? Echolocation is a huge and important discovery, so keep that in mind and maybe expand on that. Otherwise, great idea for a study and my only suggestion is wokring on the how and why?
This is a very interesting topic. I am always fascinated by the research on it. I have heard that dolphins have a very complex language like humans do. I wonder if their is any research done on the relation between this and the comparisn between the shapes of human and dolphin brains?
This article was very interesting. I think dolphins are amazing animals. I didn't realize how large their brains actually are, I knew that they are smart creatures. I wonder if their language is as complex as humans. As you stated in you blog, I am also interested to know if a dolphin and a human brain are closely related. Good job on your article.
barkley519
I am trully fascinated by studies that look further into other species intelligence. Dolophins by far are the most interesting studies I have read about thus far. Their intelligence is comprable to our own and I believe that if this topic is pursued and understood better it can ultimately help us humans understand ourselves and our own evolution of our intelligence. Great topic!
I think it is extremely fascinating that creatures from different families developed their brains in similar ways. Although they may have evolved from a common ancestor, they diverged into creatures of the land and sea but still retained some similar properties. This makes me wonder if dolphins could eventually evolve to be capable of learning things that chimpanzees do.
I'd love to read more about this subject, and see exactly which parts of the dolphin and human brains are most similar (frontal lobe, hypothalamus, etc). Good work!
This is quite an interesting topic. I believe that by and large, humans underestimate the true intelligence of dolphins. I agree that further study is needed to research the connection between the evolution of the human and dolphin brains. When we understand this connection more, we might be able to draw some striking similarities between the evolution of both the brains. Understanding the evolution of the dolphin's brain might just help us understand the evolution of our own brains.
I found this topic to be very interesting from an evolutionary standpoint. I think it could have been taken a step further in discussing some of the other research methods used, and what else was looked at. You mentioned that dolphins are friendly animals to people, but I have often heard that wild dolphins are not as friendly, and difficult to approach. Are wild dolphins in fact more aggressive than most people think? If so, in your blog are you looking at trained dolphins? It wouldn’t affect the evolutionary aspect, but would this effect the relationship between dolphins and humans?
-Morgan Lindemayer
lindema7
Your article is very interesting! You said that you are very interested in the behavioral similarities of humans and dolphins. There was a study done that showed that dolphins have some type of language. The study involved two dolphins that were each taught to press the right button when the right light came on. In addition, the second dolphin had the chance of pressing the right button only after the first dolphin pressed the correct one. The researchers blindfolded the first dolphin and they found that the second dolphin "told" the first dolphin which button to press. I find this study completely fascinating and scary at the same time. If they have the ability to tell one another of an abstract idea, such as pressing the right button, what else are they able to say?
The info re: dolphin brains is fascinating...I recently learned in another class that dolphins sleep by taking turns letting one hemisphere of the brain enter into a resting state and then the other. Apparently they do this for 8 hours a day while still swimming.
Sigh, if only this trait had survived the journey down the evolutionary tree to humans! I could just put an interested look on my face and snooze thru the next psych lecture.
CatherineS
Course Participant
I think that this is a very interesting topic. I also have a high interest in Dolphins. However, I never knew that there were studies shown to prove that dolphins could be smart as humans. Yet, you did a good job explaning this, but I think that it could be strenghten by showing more studies about this, such as finding or results, or how did this happen and why?
Very interesting choice in topic. I was aware that dolphins have high intelligences and that their brain to body size ratio was only second to humans but I was unaware of how much or what kind of research was actually put into or being put into discovering and analyzing that. I’m inspired to find out more information on this topic and since I was already thinking of studying dolphins (or possibly seals) for a career, maybe this topic will come up again a bit later in my life. And since you want to look into this same area, maybe we’ll end up working with each other some day in the future. Anyway, the article was well organized and word choice was clear so keep up with the good work!
Very interesting. It's amazing how similar humans and doliphins are, considering dolphins are aquatic.
I think this article was very well written. I do not know much about dolphins myself, but I never would have guessed that the dolphin and human brains have so many similarities. Dolphins seem to be very complex species, like ourselves, It would be fascinating to be able to undestand their language and thought processes. Good job!
I was very interested about reading more about dolphins. One thing that I knew about them before reading your post was that dolphins are one of the few animals that can recognize themselves in a mirror. (Along with us, and many primates.) I think that it is amazing to know as much as we do about the brains of animals when there are so many limitations for us to overcome while researching it. Very interesting study! Nice info.
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