|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
Member (Idle past 5183 days) Posts: 2703 From: melbourne, australia Joined: |
|
Thread Info
|
|
|
Author | Topic: Can ToE explain human Brain development? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Izanagi Member (Idle past 5470 days) Posts: 263 Joined:
|
i didnt say this mechanism is limited to humans. I said the mechanism is 'limitless' in humans.
I would like to see a site that says human memory is limitless. Before I address your point on memory, once again I would like to mention that research into human memory is ongoing and that much of what we have learned are from memory disorders. That said, long term memory storage relies on new protein construction. As you put new things into long term storage, new proteins are formed and a cellular process occurs, where certain things are inhibited. But as new memories are formed, old memories are deleted to make room for new long term memories. That's why constantly thinking about something reinforces those particular connections while not thinking about something causes the memory to degrade. This site has some information if you like to read them and links to other sites too.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Larni Member (Idle past 107 days) Posts: 4000 From: Liverpool Joined:
|
Why would we need a limitless memory when we only live for up to 100 years? You can't talk in terms of need! We did not evolve great memory because we needed it! The fact that we have an 'almost unlimited capacity to recall' is because our brains make new connections when we memorise something new. This is an inevitable consequence of how our brain evolved, not why our brains evolved! Edited by Larni, : Punctuation
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dr Jack Member (Idle past 129 days) Posts: 3514 From: Immigrant in the land of Deutsch Joined:
|
I say that becuase of what researchers have discovered about human memory. The memory has been found to have the ability to grow rather then get 'filled' They have found that its a function that is limitless. First, human memory is not limitless, it is impressively large but it's certainly not limitless. You memories are stored by changes in connection patterns between neurons, and they are finite. Secondly, there's nothing about human memory (except capacity) that makes it different from other animals. The same processes that form memories in rats and mice form memories in our brains. Hell, even the tiny nematode worm Cenorhabditis elegans with only 302 neurons in its "brain" uses only almost the same mechanisms for learning.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Otto Tellick Member (Idle past 2584 days) Posts: 288 From: PA, USA Joined: |
Hi Peg,
I wanted to thank you for mentioning this quote (I'm interested to know which source it came from):
quote: Maybe "the numbers are wonky" (as NosyNed stated), or maybe, when viewed in the context of the original source, they make sense (depending on what the source was using as the starting point for this observation). In any case, the crux of the assertion is that something quite different from typical natural selection (i.e. the effects of the environment on the propagation of particular genetic changes) has been at work in affecting the development, over many generations, of mental capacity in humans. I think there may be something to that, and I think it's quite important. In the "typical processes" of natural selection being referred to there, the less well adapted members of a species population are producing fewer offspring because they are being eaten by other species, or are not getting enough to eat, or are unable to mate, or fail to produce viable offspring after mating. But In order not to be killed, groups need to accomplish one of three alternatives: successfully avoid other groups that might kill them, kill other groups as a preemptive measure, or figure out methods that allow for coexistence without killing. In all cases, the ones who succeed must apply better intellect and memory than their competitors, as well as (or more so than) better physical strength. Once the mental capacity of a species reaches a point where individuals develop the concept and practice of killing other individuals of the same species (for whatever reason), this brings a significant transformation into the process of natural selection, with the potential effect of accelerating the rate of adaption for those features (intelligence and memory) that are most important for surviving this new environmental factor. I'm not trying to assert that any species, if it happens to develop increased mental capacity through evolution, will necessarily adopt murder as one of its behaviors. But it is clear that adopting murder (including war and genocide) has been part of human development, and the progress toward our third alternative (coexistence) has been agonizingly slow. With our population being what it is today, the first alternative (avoidance) is no longer practical. To the extent that the third alternative has been gaining ground over the second, we may conclude that the strategy of pursuing coexistence correlates with greater intelligence. Edited by Otto Tellick, : (rephrased last sentence) Edited by Otto Tellick, : struck "uniquely", in deference to bluegenes reply autotelic adj. (of an entity or event) having within itself the purpose of its existence or happening.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
bluegenes Member (Idle past 2731 days) Posts: 3119 From: U.K. Joined:
|
Otto Tellick writes: But uniquely in the case of humans (and going back some unknown amount of time among our predecessors), some groups within the population may fail to propagate because they get killed by other humans. Uniquely, Otto? There are many animals which kill within the species, including the common chimps, but not (or rarely) the bonobos. Many intelligent mammals are not particularly known for killing within their species. Bull elephants sometimes fight, but elephants in general were at very little risk of being killed by their own or by others before we came along, and the high intelligence seems to have more to do with complex and close social relationships. Whether or not dolphins kill amongst themselves, I don't know, but I can't recall hearing of it. A number of animals use, and in some cases arguably make, tools, but it is not central to their feeding processes. I think that the hypothesis that our ancestral group at some point found themselves in a situation in which basic tool use/making became central and essential might be more important. That combined with the necessity for group hunting with these tools would have driven growth in intelligence both in relation to tool making and the all important communication, what this particular ape's trying to do now. The tool use doesn't apply to dolphins, of course, so perhaps communication in social animals is the all important key, and the reason why wolves/dogs are smarter than the solitary cats. Interestingly, I think we may find that it's a surprisingly small set of genes that makes the intelligence difference between us and the other great apes, but I'm not guessing at how many yet.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Izanagi Member (Idle past 5470 days) Posts: 263 Joined:
|
The tool use doesn't apply to dolphins, of course, so perhaps communication in social animals is the all important key, and the reason why wolves/dogs are smarter than the solitary cats.
There is an argument for that. Whales and dolphins have the second "largest" brains next to humans and we know that whales and dolphins have a complex social system. The argument that increasingly complex social systems within a population require an increasingly complex brain is one that has merit considering whales and dolphins and the primates split further in the past than the human/great ape split. Then there's the argument for diet. As humans went hunting for food along the shorelines, the nutrient rich diet allowed pregnant females to have babies with larger reserves of baby fat, apparently a uniquely human trait. Additionally, a shoreline diet has nutrients rich in promoting brain function. For instance, a deficiency of iodine in the diet can result in mental slowing in humans and mental retardation in children. The truth is, while human knowledge on the brain is still incomplete, what we can surmise is that there was a complex interaction of variables that gave the earliest human ancestors the opportunity to evolve a larger brain. Understanding those variables will probably rely on what genetics discovers in the coming years. As a side-note, it would be a interesting case study to take some chimps and put them into a similar environment that we think the earliest human ancestors were in. Perhaps we could feed chimps a shoreline diet, take away the advantage of trees, as well as other things. Could humans, by doing this, eventual evolve a new sapient species? Would "Planet of the Apes" be prophetic? Edited by Izanagi, : No reason given. It's just some things you never get over. That's just the way it is. You go on through... best as you can. - Matthew Scott ---------------------------------------- This is very similar to the suggestion put forward by the Quirmian philosopher Ventre, who said, "Possibly the gods exist, and possibly they do not. So why not believe in them in any case? If it's all true you'll go to a lovely place when you die, and if it isn't then you've lost nothing, right?" When he died he woke up in a circle of gods holding nasty-looking sticks and one of them said, "We're going to show you what we think of Mr Clever Dick in these parts..." - Terry Pratchett, Hogfather ---------------------------------------- You know, I used to think it was awful that life was so unfair. Then I thought, wouldn't it be much worse if life were fair, and all the terrible things that happen to us come because we actually deserve them? So, now I take great comfort in the general hostility and unfairness of the universe. - Marcus Cole
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Perdition Member (Idle past 3492 days) Posts: 1593 From: Wisconsin Joined:
|
but it seems we have developed a brain with a capacity that is far greater then our needs. So in terms of evolution, why did it develop greater capabilities then we actually need to survive? We see in many species attributes that are more than necessary, or even detrimental to long term survival, because of sexual selection. We started getting larger brains to account for survival, seeing as how we're not fast, we don't have armor, and we don't have weapons, we need smarts to stay alive. It's just another, of the many survival mechanisms that have been tried by nature. But once we start getting larger brains that are capable of planning, forethought, even creativity (all of which are good for survival) sexual selection can lead to a sort of cascade effect, and as art and beauty appreciation advance, it just speeds up the sexual selection. For example, a primitive female hominid has the choice between a male that can run fast and quite often escape danger by running, or a male that doesn't get into danger as much, can help find food by noticing patterns, and will therefore be around longer to help care for offspring. Does it seem out of the question for the female to choose the second male over the first? And once that type of selection gets a hold, then you have an arms race fo sorts, now the females are choosing between two mmales who can avoid danger, notice patterns, etc, but instead of just bringing food, one of the males also brings pretty flowers. Once you start down the road of sexual selection, results can be incredible.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lithodid-Man Member (Idle past 3185 days) Posts: 504 From: Juneau, Alaska, USA Joined:
|
Great topic Peg, and one that should not be taken lightly. The very subject of this topic perplexed Alfred Russel Wallace and many other 'strict adaptationists'. I would need to dig for the quote, but he discussed how a 'simple' hunter-gatherer could be taught all of the science and culture of the West, demonstrating that the human brain could not have evolved as its use in the natural realm is far below its capabilities (remember when he was writing, Europeans were considered the pinnacle of human achievement). Wallace eventually adopted a brand if ID because of his insistence on pure adaptationism.
While we are far from the complete answer, we have learned quite a bit in the last 150 years. Probably most important to this discussion is the concept of spandrels. At a lecture called Daring Diversity I heard SJ Gould explain it in terms of a computer. If you want a computer for a single task, say keeping your business accounts, you might choose the most basic system there is that could perform the tasks you wish. But because of the fundamentals of architecture, that system will be capable of playing chess, displaying your photos, etc. because of the needed components. Likewise the brain architecture required for tasks that were important to our ancestors also allow us to compose music, build airplanes, etc. The portion of brain evolution that most fascinates me is that dealing with what they call 'the mind's big bang'. If I understand the concept correctly it seems that our brains reached current size long before we see evidence of cultural complexity. We see long periods of apparent stasis in stone tools for example. Then at some point something changed and we see new tool kits, and specialized tookits. I am sure part of this is an artifact of preservation. Just some thoughts! Doctor Bashir: "Of all the stories you told me, which were true and which weren't?" Elim Garak: "My dear Doctor, they're all true" Doctor Bashir: "Even the lies?" Elim Garak: "Especially the lies"
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1659 days) Posts: 20714 From: the other end of the sidewalk Joined:
|
Hi Perdition,
Once you start down the road of sexual selection, results can be incredible. One of the marks of Fisherian Runaway Sexual Selection is that a trait is pushed to the limit possible for survival. The peacock tail, for instance. With the brain we see a similar push to the limit trait - any further and the life of mother and child is endangered at birth.
But once we start getting larger brains that are capable of planning, forethought, even creativity (all of which are good for survival) sexual selection can lead to a sort of cascade effect, and as art and beauty appreciation advance, it just speeds up the sexual selection. And selection for creativity also explains the attraction of art and music and dancing. We still see this attraction today. Enjoy. by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
websnarf Junior Member (Idle past 5419 days) Posts: 9 From: San Jose, CA, USA Joined: |
quote: Starting with Australopithecus afarensis, our ancestors decided to leave their predecessors full time occupation in the trees and try out their luck on the land, as a scavenger. The one major problem they had was that they had no special adaptations for it versus hyenas, vultures or large predator cats. Now under normal circumstances, carnivorous savannah based creatures adapt to the predator-prey dynamics by gaining speed (usually via quadrapedalism), strength, claws and sharp canine teeth, like cats, hyenas and alligators. The poor australopithecines were just way too far off that to gradually attempt such adaptations (it would have taken too long, the intermediates would not have been rewarded with any substantial successes, and all the other carnivores had 10s of millions of years of evolutionary head starts.) Another thing holding us back, is that we had a defective Vitamin C enzyme. Meaning we could never leave the forest entirely -- we had to keep going back to get fruit otherwise we would die of scurvy. If you look at the phyiscal characteristics of modern humans, chimpanzees or any of our ancestors between the two, none have anything close to what is necessary in terms of pure *physical* characteristics to survive on the savannah. Yet the fossil record show that our ancestors clearly did so. Whatever their solution was, it was almost certainly the advanced capabilites of their chimpanzee-like brain that allowed them to survive (i.e., brain-power selection had already been occurring *before* our split with the chimpanzee -- probably just to successfully compete with gibbons or some other aboreal animals.) It was the only possible ace we had. Figuring out that you can eat bone marrow, for example, or that animals would die of natural causes (removing the need to hunt and kill them) might have been something our slightly clever ancestors used to survive. Just as different people have different cognitive abilities, so too would the australopithecines. The less capable probably died off before having offspring, making sure that there was at least a slow selection criteria towards improved intelligence. But the real turning point came towards the end of the Australopithecine era. Some individuals adapted, probably just by normal demographic distribution, truly superior mental abilities. They were the first to break stones in order to give them edges -- thus being the first animal to make bladed stone tools. When they found a scavenged kill, they ripped its flesh off and ate it so fast, that the other scavengers or predators simply didn't have time to steal the kill away from them. Dead alligator carcasses, that no organism (except for bacteria) could figure out how to eat (because their hides were simply too tough) became accessible to these guys with the sharp stones. This made a really significant difference in their survival and drove a limited population of the most highly intelligent representatives to adapt a permanently improved base-line of intellectual ability that allowed all of them to be clever enough to make bladed stone tools. These are represented in the fossil record as Homo habilis. What you find in the fossil record is that every significant advancement (such as the ability to migrate out of Africa, the ability to control fire, the ability to make larger tools, the development of spears, etc) corresponds to an improved mental ability and seemingly (though IMHO, the correlation is not direct, and for good reason) the *SIZE* of the brains of our ancestors increased. Going to Homo ergaster one theory is that we became bona fide hunters by walking or running animals to death (much like the Bushmen of the Kalahari, or "SAN" people do even to this day.) We had to develop the brain power to be smart enough to know that our upright walking abilities gave us the ability to outlast most animals on the savanah in any kind of marathon. The brain base-line increased yet again, but this allowed the smartest ones to figure out fire, which kept them warm at night, and gave them a very strange new weapon for warding off predators. It also allowed them to cook their meat which made it easier to digest which meant they could be actively hunting for a larger percentage of the time. So once against the brain base-line improved. This feedback loop repeated itself with superior hunting weapons including large hand axes then wooden spears and at some point clothes until finally bow and arrow, harpoons, needles and communication mechanisms (proto-language, then language) pushed us towards modern H. sapien capabilities. Each time the capability first presented itself to only the most capable of our ancestors which became a selective pressure for improved mental capabilities which improved the base-line of intelligence for the surviving ofspring.
quote: Well I've given a basic explanation above. Let us now compare this to creationism, which doesn't offer explanations. Creationism only offers conclusions and lets you fill in with whatever explanation you like. As I understand it the forbidden fruit of knowledge was something that at least one version of god specifically told us humans to avoid. It made god angry enough to punish us with the curse of sin or something like that. Sorry if I don't have it quite right, its not easy to obtain a coherent story of creationism. Talking about brain capabilities from the creationist perspective you just suggested immediately leads me to many questions. Why do we get alzheimer's disease, or parkinson's disease? Why are the elementary rules of logic and reason not built into our brains -- why does a large percentage of the population need to spend a long time learning what in digital circuits are a complete and innate triviality (things like deMorgan's laws, the law of the excluded middle, reducto ad absurdum, correlation versus causation, falsifiability, etc)? Why do we painstakingly have to learn arithmetic, probably wasting millions of neurons and many man-years for the purpose when very powerful and accurate calculators can be built in a few thousand logic gates? Why are our brains so easily fooled by optical and auditory illusions? Why do some mental talents have such a strong hereditary bias (like art skills, math skills, etc)? Its as if the "creator" knew who to bless (at birth) even before these individuals made decisions (with their "free will") about whether or not to lead sinful versus pious lives. Why does the "creator" curse some people at birth with mental retardation? Before they even get a chance to sin or not, they are denied the ability to "learn forever as God intended" as you put it. Why does the human brain have faulty memory? Serious modern scientific testing has revealed that reliability of personal testimony is nearly worthless, relative to say, useful standards of truth as desired by the US legal system. Again, the kind of logic gates required to implement static memory in actual digital circuits is quite reasonable and totally reliable by comparison. With an evolutionary explanation, all of those questions have trivial answers: none have a sufficient selective advantage which corresponds to a simple evolutionary step ladder for achieving. For example, there are examples of savants who do have some superior intellectual skills, but they are usually coupled with severe intellectual disabilities of other kinds. So its hard for the evolutionary ramp to get started there. Our brains are already way past the point of being an advantage for us over any other species of animal, so further selective intelligence can only happen through sexual selection -- and that clearly is not happening anywhere. (Intelligent people, especially intelligent women, tend to have fewer children.) When you see our developed brains as a sequence of advancements for the purpose of solving a number of problems one by one, then the kind of hodge-podge result that we have makes perfect sense. And that's what evolution tells us happened. If you say that our intellect is created, then you are left with the question as to why was created in this particular way? Why design in so many defects? Why skip over the obvious opportunities for specifically, but moderately easily designed (for an all-powerful creator that is) improvements over what we have?
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
jimgerard Junior Member (Idle past 5385 days) Posts: 2 From: ames, iowa, U.S. Joined: |
Larni writes: I understand that all animals have their own unique abilities but it seems we have developed a brain with a capacity that is far greater then our needs. So in terms of evolution, why did it develop greater capabilities then we actually need to survive? Why would excess be evidence of design? The human brain is obviously an organic development not a designed system, with newer layers over the top of older ones the way the Neocortex is a 2 inch layer of development over the R-Complex or "reptilian brain".
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
rockondon Member (Idle past 5179 days) Posts: 40 Joined: |
Now i want to pose a questions that, theoretically, the ToE should be able to answer. Which it does elegantly, yet creationism explains nothing. When one looks at the enormous biological evidence for evolution and the "mistakes" that one must accept if they have convinced themselves of design (for example, cave fish and salamanders with sightless eyes) then the only creationist explanation for what we see in biology is that God is a) a deceiver who plants evidence of the truth of evolution and b) extremely stupid.
I dont really have a premis for this discussion except to say that denying the existence of a Creator does not still man’s quest for a meaning to life. If my life was meaningless, I would probably start believing in a creator and try to convince myself that He/She/It loves me.Lucky for me I'm an atheist and my life is filled with meaning. I have hopes and dreams, I have a family and friends that love me, I have goals and desires, I have an insatiable lust for life and all its experiences, and a million more things makes life meaningful for me. This brings us back to my earlier question, Why does the human brain have such a vast intellect? What purpose does it serve in evolutionary terms. Isn't the benefits of intelligence self-evident? This is like asking why lions have strong muscles or why whales have sharp teeth.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
shalamabobbi Member (Idle past 3103 days) Posts: 397 Joined: |
Whether or not dolphins kill amongst themselves, I don't know, but I can't recall hearing of it. Hey bluegenes, Please keep the following confidential as it's an embarrassing family issue..
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
barbara Member (Idle past 5056 days) Posts: 167 Joined: |
Also how does ToE explain why most species have their own unique sensory capabilities that no two different species share exactly alike?
Hypothetically, if every species on the planet had to write a report to describe earth, none of them would see it the same way.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
jar Member (Idle past 93 days) Posts: 34140 From: Texas!! Joined: |
Also how does ToE explain why most species have their own unique sensory capabilities that no two different species share exactly alike? Simple. There is no goal. If something is just good enough to allow the critter to live long enough to reproduce it is a success. Mutations happen, if the mutation is just good enough to provide some advantage then it soon becomes the population. Anyone so limited that they can only spell a word one way is severely handicapped!
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024