something strange about the evolution of man?

hello all it is me, the man who tried to disprove time, now i come to you with an odd realization and potential query about mans origins. as many of us well know according to the doctrines of a one charles darwin creatures change their physiology to survive, this is known as the common principle of evolution, now hold up a sec im getting to my point, lets take a species like the bird for example. now any woodland bird is bound to have predators so therefore it would need to change some physical charecteristic to keep itself alive or die, so lets say our hypothetical bird became smaller and more streamlined allowing it to have more speed and therefore survive, and with this speed it could live comfortably out of the reach of its predators and continue its existence by reproducing. now their are several factors that may become accentuated in evolution in order for a species to survive...
strength, speed, size, durabiblity, or even versatility like amphibians.
but a select few species have their intelligence heightened in order to survive. dolphins, bonobos, chimpanzees, and even some domesticated animals have aquired a decent level of brillianceto the point of allowing them to comfortably survive. but humans are a far different story, early in our history we developed tools to help us escape our enemies and eat certains foods, we could at this point easily survive but instead continued to change. we developed better tools like spears, and clothing to protect us from the elements, and subtley developed languages. but even then we kept on gaining intelligence, and even now if i am correct the global i.q. raises at least 3 points every year. but my question is how did we humans develop such drastically changed intelligence and leave all other species in the dust when their is really no practical need for it to continue to raise?

I guess sexual selection has a part to play. I know some think the human cognitive abilities (language, creativity etc) are a sort of Peacock's tale.

There is also a good correlation between a measure of brain size and social group size/complexity in carnivores, primates, and cetaceans. So, that may be another possible influence.

We outstripped other primates because we became dedicated meat eaters. Moving out of the trees to have access to meat led to physical changes to prevent our becoming meat ourselves, such as true bipedalism to see predators coming.

Intelligence from larger brains from eating meat led to even more increase in intelligence because it was obviously a fantastic survival mechanism, so successful we have overpopulated our planet.

That's the answer, a four letter word: meat.

There is a diet-related hypothesis regarding human brain evolution, MM. But this is focusing on the effect of a fishy based nutrition:

Something Fishy: How Humans Got So Smart
By Corey Binns, Special to LiveScience

posted: 20 February 2006 10:20 am ET

ST. LOUIS-Human brains are bigger and better than any of our closest living or dead non-human relatives in relation to body weight. Scientists say we have fish and frogs to thank for this.

When early humans started to fish, they also began feeding their hungry brains.

The arrival of language and tool-making tend get all the credit for the big brain phenomenon. But before language or tools, a healthy diet was a brain's first fertilizer, said Stephen Cunnane, a metabolic physiologist at the University of Sherbrooke in Quebec.

"Something had to start the process of brain expansion and I think it was early humans eating clams, frogs, bird eggs and fish from shoreline environments," Cunnane said.

www.livescience.com...

I'd heard that one before, melatonin, but thanks for the link anyway.

I think the likeliest start we had out of the trees was as scavengers of other animals' prey. The beach life probably came later and accelerated what was started with the land animals.

Tell ya what, though, this thread is making me hungry!

Aye, cool.

I think what's obvious is that there are lots of ideas about what underlies our expansive cortex, and that the truth is probably a mix of them.I do favour the social brain hypothesis, but that's just my academic bias, heh.

I'm pining for my bed at the moment, so off I go.

MM and melatonin - you are talking about this as if it is so logical and simple. Your Watchmaker is blind-remember? Random mutation followed by selection then genetic stability. You have to be more specific before making sweeping statements. Please give me a scenario where, at each step, you can select for stability of genes for different nutrition in a human ape. I will even concede that you have mutations in regulator genes which have a wide-ranging/global effect, e.g. transcriptional regulators. I'd love to find out more.

Originally posted by Heronumber0
MM and melatonin - you are talking about this as if it is so logical and simple. Your Watchmaker is blind-remember?

Thing is though, hero, i'm not trying to explain exactly why and how we evolved such a remarkable brain.

The OP stated that they thought predation would have been of little consequence for human brain evolution. Therefore, I provided a few of the real hypothesis floating about.

All are possible influences. Thus, there are relationships between people who express creativity and sexual selection (i.e. artists and creatives get laid), there is also a strong relationship between social group complexity and neocortical size across many mammal groups (see Dunbar, 1998). It is also likely that diet was important.

Lots of explanations. No real certainty. Possible that numerous influences were acting on brain evolution.

Now, myself, I prefer the complexity based social explanations. As a major region of the brain, the frontal lobe, has undergone massive expansion. This region underpins complex and flexible behaviour. And I'm also involved in social neuroscience, so it speaks to me

[edit on 28-7-2007 by melatonin]

The answer is real simple... opportunism. If you look at all of the animals that are the top intellects of their species you will find that they are not specialized but are opportunists, usually omniivores and need a wider ranging intellect than more specialized creatures...say crows for example over hummingbirds.

Like has been said, we will never know for sure but there are a large number of hypotheses out there. Invariably, the development would be down to numerous factors that have affected the evolving species during the last few million years.

I for one believe that instead of adopting a short term adaptation to a specific problem, the larger cranium was developed as a longer term 'investment'. i.e. a solution to a multitude of environmental challenges. To operate a large brain is a more 'expensive' adaptation than, for example, developing stronger legs to give more speed.

Like for example; i believe that climate change drove our ancestors gradually out of the trees and on to a 'plains' style of life - this lead to being able to forage - which in turn lead to scavenging - which in turn lead to migration (following prey on their own migration and frightening off their predators once a kill had been made) - which lead to the ocean diet for accelerated brain development......

its like a multiplier effect. We eat better food - we develop more brain power - we eat even better food - we develop social groups, and better brain power.....

Once a successfully adapted brain emerged, it follows logically that the bloke who can find better food can share it with females with whom he desired to mate with. He would mate more often and at the same time provide better food to his offspring.....this lead to the sexual selection of these good providers and IMO also to the realisation that living in groups means that more food is provided for everyone.

One does not have to be 'creative' in order to attract mates but has to be able to adequately 'provide' food, protection etc to his desired mates. (I know that this sounds horribly sexist but thats how is was). If 'creative' means would do something out of the ordinary, then i agree.

On a lighter note, i wonder how we figured out what berries were good and what were bad.......sometimes being the 'creative' one had its downfalls!

Originally posted by Heronumber0
MM and melatonin - you are talking about this as if it is so logical and simple. Your Watchmaker is blind-remember?

We don't believe in a watchmaker, remember? That's the fantasy of creationists.

Natural selection. Look it up. It'll tell you everything you want to know, should you actually choose to try to understand it.

We don't believe in a watchmaker, remember? That's the fantasy of creationists.

Natural selection. Look it up. It'll tell you everything you want to know, should you actually choose to try to understand it.

I'd love to understand better. I want you to tell me for example, at the epigenetic/molecular level how a particular organ function can be changed and then be stabilised by natural selection. I just want to know how a small mutation may be beneficial and then selected for. Obviously you read widely, so enlighten me please.

I'm not sure exactly what you are asking, hero, but here is a possible answer to my interpretation of the second part of your post.

Evolution Occurs in the Blink of an Eye
By Jeanna Bryner, LiveScience Staff Writer

posted: 12 July 2007 02:05 pm ET

A population of butterflies has evolved in a flash on a South Pacific island to fend off a deadly parasite.

The proportion of male Blue Moon butterflies dropped to a precarious 1 percent as the parasite targeted males. Then, within the span of a mere 10 generations, the males evolved an immunity that allowed their population share to soar to nearly 40 percent—all in less than a year.
“We usually think of natural selection as acting slowly, over hundreds or thousands of years," said study team member Gregory Hurst, an evolutionary geneticist at the University College London. "But the example in this study happened in a blink of the eye, in terms of evolutionary time."

The scientists think the males developed genes that hold a male-killing microbial parasite, called Wolbachia, at bay.

The results, detailed in the July 13 issue of the journal Science, illustrate the power of positive natural selection on “suppressor” genes that thwart the lethal bacteria, allowing the male butterflies to bounce back.

Although this is different from where the OP was going (i.e. this is a sort of co-evolution arms race type scenario), it shows how a particular trait can be selected for. In this case, the mutation increases the reproductive potential of the males by protecting against the effect of the parasite, and the gene spreads through population.

The same would apply to other scenarios. If we focus on sexual selection, then the Peacock's tail is a suitable example (i.e. hens progressively select those males with exaggerated tail feathers as a sort of health indicator).

In most scenarios, the gene will increase reproductive potential, and those with these genes come to dominate the species - possibly to the extent it becomes fixed within the population. However, genes can also become fixed through other means (e.g. drift).

[edit on 28-7-2007 by melatonin]

Although this is different from where the OP was going (i.e. this is a sort of co-evolution arms race type scenario), it shows how a particular trait can be selected for. In this case, the mutation increases the reproductive potential of the males by protecting against the effect of the parasite, and the gene spreads through population.

The same would apply to other scenarios. If we focus on sexual selection, then the Peacock's tail is a suitable example (i.e. hens progressively select those males with exaggerated tail feathers as a sort of health indicator).

In most scenarios, the gene will increase reproductive potential, and those with these genes come to dominate the species - possibly to the extent it becomes fixed within the population. However, genes can also become fixed through other means (e.g. drift).

[edit on 28-7-2007 by melatonin]

Melatonin thanks for the example. I have no problem with natural selection really - I consider it to be a Scientific Law which has been sufficiently reproduced even under laboratory conditions e.g. with the selection of polypeptide lengths from the QB virus.

I think some of the important answers will come from your field of neuroscience in regard to development of consciousness and social evolution (and I suppose language as an outcome of social behaviour). The development of neocortex size in particular seems important from Dunbar's review. If the Penrose Hamerof Orch OR model could be applied to the development of consciousness, it would make quite a good story...

Originally posted by MajorMalfunction
Intelligence from larger brains from eating meat led to even more increase in intelligence because it was obviously a fantastic survival mechanism, so successful we have overpopulated our planet.

That's the answer, a four letter word: meat.

I'll do you one better. when man learned how to use fire to cook meat. When meat is cooked to certain temperatures, harmful parasites are killed. If eaten raw, these parasites can make you very sick, even kill you.

Before man could reap the many benefis of meat, he had to be able to survive it. Discovering fire, learning to cook meat killed these parasites, and we certainly reaped the rewards from that.

Originally posted by The Cyfre
I'll do you one better. when man learned how to use fire to cook meat. When meat is cooked to certain temperatures, harmful parasites are killed. If eaten raw, these parasites can make you very sick, even kill you.

Before man could reap the many benefis of meat, he had to be able to survive it. Discovering fire, learning to cook meat killed these parasites, and we certainly reaped the rewards from that.

That's certainly true the case of fowl and certain mammals, like pigs. But fish, beef, lamb, deer, etc can be eaten raw.

What I find interesting is that, given the number of carnivores around, that animals such as bears (they loves their fish) and the great cats haven't evolved brains the way we did. Perhaps it's their natural defenses and strength that made it unneccessary.

But even something as advanced as flight has been independently developed at least four times: insects, pterosaurs, birds and bats. Long necks have been independently developed in giraffes, llamas, ostraches and emus, brachiosaurs, etc. But large, human-like brain growth has happened only once.

Maybe having to do with a high protein diet combined with the neccessity to think our way out of trouble due to our relatively empty arsenal of natural physical defenses.

I dunno. Food for thought though. Nice high protein thread we got goin' here.

wow alot of interesting poinst especially nerevar good one

i don't believe that human beings evolved naturally, but evolved through external help possible from a higher intelligence.
The possibility of the brain, the heart, the nervous system and the eyes evolving and developing through the natural progression of time to accomodate our environment is not possible as the organs are far too complex to ned up as good as they are.

That's baloney. Our eyes, etc. evolved from lower systems, just like everything else on the planet. Man is not so special he needed supernatural or extra terrestrial help.

Take the eye, for example. On our planet, right now, this very moment, you can see eyes in the animal kingdom that represent the full spectrum of the evolution of our own eyes.

Light-sensing cells to light-sensing eyespots (as in starfish). Then you have a whole gamut of eye types from the simple camera eye, black and white vision, color vision. You also have compound eyes as in insects and night-seeing eyes as in the cats. All these evolved from simple cells that were light-sensitive (such as in plants) that helped an organism move towards sunlight when needed.

It was done over BILLIONS of years. No extra help necessary.

Evolution is a beautiful thing. Embrace it for what it is, instead of selling it short. I know it's hard for some people to grasp that it takes place glacially slowly over timeframes our brains can't really conceive of, but with a healthy imagination and an open mind, one can at least intellectually grasp the concept if not completely understand it and feel the truth of it.

To Meurig and MajorMalfunction both,

Let's consider this:

What if "intelligent design" doesn't assign authorship to a "supreme being", but, rather, to "intelligence", itself?

I don't believe for one moment that an eye can evolve from random mutations because "random mutation" implies that it's all haphazard and goal-less.

So let's suppose, for a moment, that a living organism is capable of KNOWING what it needs to do to survive. Not consciously (as we normaly understand consciousness), mind you. But that it "knows" what it needs to do to itself in order to survive.

I think, (and this is just speculation -- I'm not a biologist by any means) that life has a way of preserving itself in ways that we cannot yet get a grasp on. I'm supposing, for the purpose of this thread, that even the most primitive automata have, within them, a way of decerning their environment and are equipped -- by virtue of simply being alive -- to deal with perceived changes and threats in their environment.

I submit for your humble analysis the hypothesis that life itself is intelligent, by nature, and that evolution is the result of life knowing how to cope with beginning itself, experiencing itself and, amazingly enough, with ending itself.


Flame on!





[edit on 29-7-2007 by Tuning Spork]