In How To Create A Mind by Ray Kurzweil, the importance of the human neocortex is explored. What is important about the human neocortex? How did it evolve in our species? The answer to these questions can shed light on one of the most important evolutionary developments in the history of life on Earth.
Really nice. I wonder if it might be more correct to say that we can utilize frameworks of increasing complexity by abstraction, while not actually conceptualizing more complex ideas. That is, by encompassing a pattern into a symbol, we can then operate on that pattern in a manner that is as only complex as operating on the symbol, rather than operating on the pattern in its entirety. I think Douglas Hofstadter is really on to something with the connection between analogy and intelligence. AFAIK he now basically argues that intelligence more or less is operation by analogy. How else can you ratchet culture without biological change?Regardless, even though I have a slight disagreement with Kurzweil about the evolution of the neocortex, I think his fundamental point that the human neocortex allows for a unique type of thought, is well-grounded in current evidence and theory. Perhaps it is best summed up by Kurzweil: “[Our neocortex allows us to] understand a structure composed of diverse elements arranged in a pattern, representing that arrangement with a symbol, and then using that symbol as an element in a yet more elaborate configuration.” All evidence suggests that this occurs in our vastly expanded mammalian neocortex. As a result of this structure we are capable of building ideas that are ever more complex.
What then do you think is stopping/has stopped other animals from becoming more cognitively aware? They have the ability to analogize just as we do/did back while we were evolving. Is it due to these extra layers of neocortex? And if so then why wouldn't other mammalian types have evolved and gained the same intelligence that we have. My main question then I guess is, why are we so special.
There are two main reasons why animals have not become more "cognitively aware" and why higher intelligence is so rare on Earth (and most likely throughout the Universe): 1) The brain is expensive. The brain is 3 lbs but takes up far more than 20% of our energy expenditure. In order to have natural selection select for increased brain size the organism has to be able to fully utilize it for immediate survival and reproduction value. 2) Intelligence is not a trait that is typically beneficial on evolutionary timescales. There are other traits that are far more beneficial like speed, strength, enhanced sense or sight, echolocation etc. All of these evolutionary beneficial traits are more frequently selected for over intelligence because they are immediately useful on evolutionary timescales. If you live on the African savannah (or any other natural landscape) it doesn't matter how smart you are if there is an animal (or a group of animals) that are faster and stronger than you. In order for intelligence to be useful you have to leverage millions of years of cultural evolution. Evolution has no foresight. Intelligence is usually a hinderance for most animals, not a benefit. To sum up quickly: Energy is better spent on less expensive sensory organs and on skills that are immediately beneficial.
So with our 'ratcheting' ability to communicate our intelligence to one another it became much easier for us to learn from one generation to the next. Which expended less energy than it would have taken for other animals to learn the same thing.
"Ratcheting" isn't actually just communicating knowledge to each other (although that is a prerequisite). Cultural ratcheting is when there is generational improvement on previous cultural knowledge or technological ability. Basically the next generation is taught what is known, and then attempts to improve it in some way to benefit the entire group. This has been displayed in no other species except our own. The reason our intelligence was selected for is still a matter of intense debate among paleoanthropologists, however we do know that other key traits were selected for before larger brain size. This is key. For example, opposable thumbs and bipedalism were selected for millions of years before larger brain size. In this sense, in order for intelligence to be selected for, their must be necessary pre-adaptations. Once our ancestors were fully bipedal and able to manipulate objects with our opposable thumbs, it then became more beneficial to possess a larger brain with which to help us manipulate our environment in increasingly complex ways. Also, it is likely that we developed the ability to cook our food around the same time we experienced a surge in overall brain size. This would explain where we got our "extra energy" to fuel such an expensive organ. If you want to learn more about this check out "Catching Fire" by Richard Wrangham: http://www.amazon.com/Catching-Fire-Cooking-Made-Human/dp/04...
I definitely do want to learn more about this. Thank you for explaining all of this! Our species is extraordinarily special and learning about this adds a whole new level to our development and how we got here. I enjoy hearing about this in any form.
Here are a list of books worth reading to form a good base of knowledge about human evolution, and evolutionary theory more broadly: http://www.amazon.com/Evolution-First-Four-Billion-Years/dp/... http://www.amazon.ca/Lone-Survivors-Came-Humans-Earth/dp/080... http://www.amazon.ca/Wild-Cultures-Comparison-between-Chimpa... http://www.amazon.com/Evolution-Jean-Baptiste-Panafieu/dp/16... http://www.amazon.com/Greatest-Show-Earth-Evidence-Evolution... http://www.amazon.com/The-Ancestors-Tale-Pilgrimage-Evolutio... http://www.amazon.ca/Guns-Germs-Steel-Jared-Diamond/dp/03933... http://www.amazon.com/What-Means-98-Chimpanzee-People/dp/052... http://www.amazon.ca/Through-Window-Jane-Goodall/dp/06180567... http://www.amazon.ca/Nature-Via-Nurture-Genes-Experience/dp/... http://www.amazon.com/Maps-Time-Introduction-History-Califor...
Wow this is amazing! I've got my work cut out for me. I'll be sure to sign up for some classes pertaining to this at school as well. Thank you so much!
My best guess is that it is a combination of factors. I'd be surprised if the neocortex wasn't a big one. It is an interesting idea is that once cultural ratcheting is possible, the 'specialness' of that animal can grow very large and very quickly. Almost like the difference between birds that can fly and birds that can't. They are very similar, but just a small physical difference makes for very distinct behavioral possibilities. Perhaps the analogy enabled brain can simply take off.My main question then I guess is, why are we so special.
Our neocortex is certainly the main reason that we are "special". What is interesting though is the number of "pre-adaptation" that needed to be in place before such a development could take place. However, as I hypothesized in the article, I don't believe that once an animal possesses some type of cultural ratcheting that it starts to progress very quickly. Since ratcheting seems to be an exponential phenomenon, I believe the process likely starts off with an unnoticeable beginning. If you were to study the first australopithecines, you would likely not notice any type of cultural ratcheting, even if you observed them for thousands of years. In fact, you would hardly notice any cultural ratcheting in Homo erectus. They used the exact same tool technology for 1 million years! However, in retrospect we can observe the archaeological record and see that in fact the technology was improving in complexity exponentially, and it had yet to really hit an explosive curve.
What's just as interesting is the disparity that we see in humans with the same biological potential. How far do we have to go back in our own ancestry until ratcheting is unlikely? And why did some parts of the world like Europe and the Middle East see a technological and cultural explosion whereas others like Aboriginals of Australia didn't? If it's just environmental, then how long did humans possess the potential before the environment gave them the kick they needed? I have a feeling that epigenetics might be involved. The potential to ratchet might ebb and flow as stressors rise and fall.
As far as we know modern humans have been around for ~ 150,000-200,000 years. During this time until ~11,000 the Earth was in an Ice Age. Release from that Ice Age is correlated with the development of settled agricultural city-states, which dramatically increased our ability to ratchet. I believe, as Jared Diamond outlined in "Guns, Germs, and Steel" that the disproportionate ratcheting seen in different areas of the world was a product of several environmental factors. The most importan of those factors being a) domesticatable animals and plants, b) a continent w a large east-west axis (as opposed to north-south which impedes diffusion on domesticated plants and animals), and c) the development of a large network of civilizations which feed off of each others growth.
Here's a crackpot thought (but a thought-provoking one, nonetheless). I was talking with a couple colleagues a few minutes ago about the role of epigenetics in the obesity epidemic in America, which is an unexplored, but certainly important dimension. But let's back up a minute. Wallace discovered natural selection independent of Darwin, and may have been the catalyst for Darwin to finally publish Origin of Species. But, one great difference between Wallace and Darwin was that Wallace was a God-fearing man. He held the view that God must actively intervene in the word to some extent, because human culture is evident, and could not have happened by natural selection. He held such a rigid view of selection that he believed that all traits of an organism must serve some biological purpose. Thus, he reasoned, that when you listen to the beauty of an aria, you are hearing the work of God, because there is no natural reason for a soprano to exist, in fact no reason one could exist. Let's get back to obesity. There was an interesting study published several months ago wherein the authors showed that obese rats give birth to pups with distinct miRNA profiles that predispose the rats to being obese themselves. One wonders if there is a similar thing at work in cultural development. Agricultural societies are always the ones that developed cities and ratcheted cultures, the thinking being that people were more sedentary when fed, and therefore had more time to explore engineering, etc. But I wonder if there is a biological component to cultural proclivity. What if eating cultivated grains as a staple changes our epigenetics in a way that affects our ability to think and produce culture? This is highly speculative, but I think worth investigating. Maybe a positive feed back exists between thinking and nutrition that has finally reached its point of collapse, as all positive feedback loops eventually do, given that nothing can grow infinitely.
Honestly, I can't say that there isn't some epigenetic factor that has contributed to development in ratcheting over the past 10,000 years, but it seems that a persons ability to continue this process is more dependent on socio-cultural factors, as opposed to ancestry. But there will probably need to be a lot of research to make the case that epigenetics played a role. Personally, I don't think it's possible that it played a larger role than environmental factors. How do you suppose you could test for that?
Certainly, it would be foolish to argue that epigenetics are a bigger piece of the puzzle than environment alone. But, I think that Lamarkian evolution has found a place in epigenetics, and Lamarkian evolution, while subtler, can work orders of magnitude faster than its Darwinian cousin. I would be surprised if epigenetics played no role in culture formation. It has been shown that epigentic changes can predispose rats to aggression. It stands to reason that the opposite could be true. The less war-like we become, the less-warlike our progeny may be. Hence, we can build bridges (literally and figuratively).
Very cool to have you answer me, thank you. I don't really have much technical knowledge about things like this, but I have an immense curiosity. Also, I'm new to the site so thank you for a place to discuss things like this as well!