Human Evolution site

[Suezoled]

Originally posted by Eos of the Eons As a result of our accomplishments we are seeing some evolution. A lot of people need their wisdom teeth pulled because our lower jaws are getting smalller. We normally would die of infections and such, but our intelligence allows this "mutation" to flourish.

As I understood it, it's not the jaw that's getting smaller, it's better dental hygiene that allows for the wisdom teeth to become superfluous. People lost teeth more as adults and the wisdoms were kind of "back ups" for to allow a person to still be able to eat adequate amounts of food... if they can catch it.

Aren't we also getting taller as a species? Women generally (not me) prefer tall men, and seem more likely to have children with them. At least we still have short people around in case this trait is selected for some day from some environmental stressor.

It's not that I prefer tall men, it's just that 99.999999% of the males are taller than me anyway. This includes many 11 year olds, too.

As a whole, humanity may still evolve very very slowly, but I can't see any other species branching off for any reason. There aren't really any populations in isolation, etc. I can't see us evolving so much that we could become a different species. What we have now "works".
(snipped) , but a different species may have died off because of survival of the fittest. The present form won out.

(snipped)

or got really really dang lucky. maybe the same thing.

 

[Eos of the Eons]

As I understood it, it's not the jaw that's getting smaller, it's better dental hygiene that allows for the wisdom teeth to become superfluous. People lost teeth more as adults and the wisdoms were kind of "back ups" for to allow a person to still be able to eat adequate amounts of food... if they can catch it.


It's not that I prefer tall men, it's just that 99.999999% of the males are taller than me anyway. This includes many 11 year olds, too.

or got really really dang lucky. maybe the same thing.

Thanks Suez, I'm really feeling out of it since I haven't been to school for over 10 years. So, what is superfluous? Overdeveloped? Or yes, now we simply have too many teeth. I do remember something about smaller jaws though...maybe some silly misinterpretation though.

Edited to add link about warrior types, etc.

http://www.hsperson.com/files/sample.pdf

99.999999% are taller than me too. My 13 year old is taller than me (he's 13 in a couple of weeks). I seem more attracted to men 5' 7" or shorter for some reason. Most women seem to want men 6' or more. There was this study done on TV, and women wouldn't date a "short guy" even if he was incredibly smart and/or wealthy. Had a huge debate on some forum about it, maybe here too.

I'll try to dig up some links on the "bigger brain/more intelligence" "better survival" for humans a few thousand years back that brought us to our present form.

 

[Eos of the Eons]

Each population bottleneck temporarily exaggerated the importance of such traits as cooperation, altruism and hunting abilities. Even if each episode changed the inborn predilections of the hominids by only a small amount, the hundreds of repetitions of this scenario may explain some of the differences between human abilities and those of our closest relatives among the great apes. It is tempting to say that the abrupt coolings pumped up brain size, but what makes for better survival is something much more specific: hunting abilities and perhaps altruism. What might they have to do with intelligence?

...Let us consider how these principles might apply to the evolution of an intelligent guess inside the brain. Thoughts are combinations of sensations and memories -- in a way, they are movements that haven't happened yet (and maybe never will). They take the form of cerebral codes, which are spatiotemporal activity patterns in the brain that each represent an object, an action or an abstraction. I estimate that a single code minimally involves a few hundred cortical neurons within a millimeter of one another, either keeping quiet or firing in a musical pattern.

...Why aren't there more species with such complex mental states? There might be a hump to get over: a little intelligence can be a dangerous thing. A beyond-the-apes intelligence must constantly navigate between the twin hazards of dangerous innovation and a conservatism that ignores what the Red Queen explained to Alice in Through the Looking Glass: "...it takes all the running you can do, to keep in the same place." Foresight is our special form of running, essential for the intelligent stewardship that Stephen Jay Gould of Harvard University warns is needed for longer-term survival: "We have become, by the power of a glorious evolutionary accident called intelligence, the stewards of life's continuity on earth. We did not ask for this role, but we cannot abjure it. We may not be suited to it, but here we are."

http://williamcalvin.com/1990s/1998SciAmer.htm
Intelligence is but one of many adaptations that may or may not be beneficial in any particular case. Pit humans against the great apes though, and we find it is a great advantage. Pit one human agains a bear and you'll quickly realize what advantage there is to size and teeth and claws.

Put together all advantages of any group and you'll find so many factors that must be considered. Intelligence allows us to exploit many skills of individuals within a group. It is truly mind boggling to think of how we got as we are. It did take a long time.

High intelligence appears less useful in a nomadic band that frequently relocates. The burden of carrying artifacts from camp to camp prevents the development of any but minimal handicrafts. A highly specialized tool used for a single purpose may not be worth carrying (making the intelligence needed to invent and use such a tool of little value). Any shelters built must be of a simple form, since they will soon be abandoned. [para 13]

...Colder temperatures increase the advantages of a well built permanent home over a simple shelter, and are hence more likely to lead to permanent settlement. In colder climates permanent houses and fancier clothing are needed for protection from the cold. The construction of these require higher spatial intelligence. It is necessary to visualize how different building materials will fit together to provide a house, or to visualize how different pieces of material will fit together to make a garment. Tests of the ability to visualize how such pieces can be combined to make designated objects are frequently used in intelligence tests, creating a presumption that intelligence (and visual and spatial abilities in particular) would be an asset in the construction of such artifacts.

...the genes that determine differences in intelligence appear to be many more than those that determine brain size. However, differences in the frequencies of the genes that determine brain size may be good indicators of the extent to which populations have been selected for intelligence. [para 16]

http://cas.bellarmine.edu/tietjen/images/climate_and_intelligence.htm

 

[Suezoled]

Thanks Suez, I'm really feeling out of it since I haven't been to school for over 10 years. So, what is superfluous? Overdeveloped? Or yes, now we simply have too many teeth. I do remember something about smaller jaws though...maybe some silly misinterpretation though.

Too many teeth, not enough room. Since dental decay was a lot more common (so it says in some textbooks), extra teeth were an asset so if some of the adult teeth were lost, the wisdoms could take over. Until they rotted and fell out too.