During the homecoming weekend, Colby’s biology professor Josh Martin gave a fascinating talk on the origins of brains. Starting with his own research object, praying mantises, Prof. Martin explored the neural systems of a diverse group of insects and drew connections and comparisons between insects’ brains and humans’ brains.
Category: October 27
The Human brain is something that is fascinating to me, but I also know very little about it. Though I have been lectured to about the various effects of drugs by a few different people, and therefore have a few sections of the brain, namely those that process dopamine, serotonin and other chemicals that are associated with addictive drugs. However, the little I know about the brain begins and ends with humans. Prior to this lecture, I knew nothing about insect brains. Though I assumed that they share many of the same characteristics as human brains since they are often studied, it was incredibly interesting to learn the specific differences between the human and insect brain. The brain has always captivated my attention, its nuance, its complexities, and most importantly its ability to adapt, learn and develop. As I have found with many of these lectures, I leave with more questions than when I arrive. Having known very little about the origin of anything from the universe to Italian Poetry or Novel Writing, I am repeatedly exposed to a new corner of the world which I know little to nothing about. In the brief time, it is impossible to learn the origins of anything to a satisfactory level. However, opening up these corners of the world, and shedding a bit of light on them makes me more curious, and I find myself wondering about the finer points of origins often. Can we prove the big bang? If we can prove that it happened, but we can’t prove how or why, then is this finding really significant? Does investigating this idea bring us more answers or will it lead to more questions, as the brief lecture on it has for me? How is is possible to define the first novel except by the definition used at the time when it was written? Is it possible to define the boundaries between poetry and music, or does doing so pigeon-hole a broad art form into a claustrophobically tight academic category? It was fascinating to learn so much about both a topic that I was previously very uninformed about, as well as a whole different method for investigating the topic. I was fascinated by the video that he showed of cognitive functions within insect brains, particularly given the express similarities between the human and the insect brain. It was very cool to see the brain function in this way. Given the similarities between insects and humans, it is interesting to think about how we can use the insects brain to improve upon the human brain. What diseases, mental and physical can be solved by the using the same adaptations that insect brains are able to use? By using adaptations from different animals to help solve the problems that currently plague the human brain, there are infinite possibilities to make humans smarter, happier and healthier. We could improve our physical and mental abilities by great amounts, and therefore expand the possibilities for future technological innovation.
The brain is one of the most complex organs in the human body. There have been many researches on this topic and today prof. Josh Martin brought us the exploration of the Origins of Brains.
He started the lecture with the interesting video to see the insects’ cognitive process. It gave us an idea that how a mantis recognizes a fly with his eyes and catches it with his hands. The mantis was moving smoothly using each bodies’ function effectively. Obviously it tells us that the brain of the insect has to be able to work in order to be successful of what it needs to do which is to catch the fly. As another example, I remembered the science lecture about the cognition in insects. One of the example was bumblebees. Recent experiment showed that once one bee figured out what it is necessary to do to access the reward, flower, other bees that were observing learned the string-tugging trick themselves. Furthermore it became part of the colony’s skillset, transmitted from bee to bee after the first string-pulling bee had died. In spite of the fact that bees have such a small brain, they are able to learn each other and take complex action beyond our expectation. Simultaneously when we look at the human activity, for example when we catch the ball flying towards us, it is a similar play or task the mantis does by positioning its body to be able to reach out the fly. Is there are any connections between we human beings’ brains and insects’?
The origin of brains goes back to 750 million years ago. Ediacaran Biota is considered the grand ancestor of all species. Since then many species had been branched out and took their own development by adjusting the environment they faced. So even we take an example of worms as a big category, their structure of neuron system varies depends on their genetic groups. In other words, some of their brains are close to related insects, and some are related to the group we human beings belong.
It is said that human’s adult brain is 1400 kg, the surface area is 2500 ㎤ and the number of neuron counts as 100 billion. Contrary insects, for instance a grasshopper, the brain width is less than 2mm, capacity is 6 mm3, and the number of neuron is considered as 400,000. There exists the two extremes of both big brains and small brains. However, it does not mean that human big brains developed from small ones of insects. As the chart of a phylogeny of brain which prof. Martin introduced clearly shows that the grand ancestor differentiated 500-600 million years ago into protostome which insects belong and deuterostome which human does and both took totally different paths in order to develop their own brains.
Since the brains of insects are small, they have relatively independent nerve system. They have various ganglia throughout its body to control most of the overt behaviors. Thus, even if you cut off the head of some insects, they can live for a while because the segmental ganglia still function independently. The human brain has an advantage of memory, information processing and information integration which enable us to learn complicate subjects, understand languages, do multi tasks, and to have long term memory.
It was interesting to look into the different developments in brains across different species starting from the same origin. Our origin story of brain evolution involves some of us moved forward, some of us died in that the way suits in each animals. Human and insects, in either case, we all have been making a spectacular progress and still we are.
I’ll be the first to admit that it’s hard to imagine an comparative tree of different animals’ brains. Luckily, Colby professor of Biology Josh Martin created a chart (that was easy to understand even for non-scientifically minded individuals like myself) to explain how animals have different nervous systems, and how that plays into the evolution of the human race. Continue reading