Surviving Evolution: The Ongoing Battle Between Pathogens and Human Immunity

[BigRed11]

I have been thinking of the evolution of the human race over time. Obviously, environmental factors have prevented those with detrimental traits from passing them on, bringing us to our current form. However, with the amount of technological advances in our current time and in the near future that allow those with these traits to live and often reproduce, would it not be true that the evolution we have undergone has either slown to a creeping pace or stopped alltogether? On the other hand, one might say that we are evolving into a species of extremely attractive and intelligent beings (because those with the genetic predisposition for these traits are the ones to most often reproduce). However, if this is true, in the distant future when everyone is attractive, what would be the new definition of beauty?

Sorry for the half-bio half-psych thread, but it's been on my mind.

 

[Mk]

Definitions of beauty have changed greatly over time, and depending on the society in which you live. Ancient Chinese liked small-footed women, in Myanmar there is a tribe that prefers longer-necked women, and in old Europe, the fatter you were, the hotter you were. In many paintings and sculptures of the Roman god Venus, she is rather chubby.

From this I conclude, beauty more depends on sociology, and instinct of the organism. Humans have always liked larger breasts, larger penises, etc. (I think) This tells another how well they can take care of themselves.

I was reading a study how body ratios affect different age group's sense of beauty. The research team presented different pictures of males and females with different upper-torso:waist width ratios. Around nine years old the boys started recognizing the ratios that the adults liked. Whereas the females, it eleven years old. Under those ages, the young children tended to think people with body ratios closer to their own were more attractive.

 

[scott1]

Definitions of beauty have changed greatly over time, and depending on the society in which you live. Ancient Chinese liked small-footed women, in Myanmar there is a tribe that prefers longer-necked women, and in old Europe, the fatter you were, the hotter you were. In many paintings and sculptures of the Roman god Venus, she is rather chubby.

From this I conclude, beauty more depends on sociology, and instinct of the organism. Humans have always liked larger breasts, larger penises, etc. (I think) This tells another how well they can take care of themselves.

I was reading a study how body ratios affect different age group's sense of beauty. The research team presented different pictures of males and females with different upper-torso:waist width ratios. Around nine years old the boys started recognizing the ratios that the adults liked. Whereas the females, it eleven years old. Under those ages, the young children tended to think people with body ratios closer to their own were more attractive.

Is this were the getting fat genes come from If someone built a time machine a brought a Roman to the futre,He would think were all crazy when where fat and were trying to get thin.
I think the Reason why back then the fatter you were the hotter you are is because back then you had be really rich to get good food and If your fat that ment you had good food.

 

[matthyaouw]

Evolution is one part natural selection, and one part genetic variation (through mixing and mutation). Natural selection isn't as prominent as it used to be in humans, but this just means that more genetic variation can occur.

There have been quite a few discussions on this here. Do a search for "human evolution".

 

[somasimple]

and in old Europe, the fatter you were, the hotter you were

It is a bull****! Fatty people were simply able to eat more than poor ones. Being a fatty person was only a way to recognize richs/middle class from those whom haven't money.
We have a maxim saying: "wearing richness on the belly"
But of course, women were normally attracted by such males because it was a certainty of future.

 

[Mk]

You mean you're offering a different explanation for why excess cellulite was a sign of beauty?

 

[somasimple]

Not really, MK,

The fatty persons were beautiful because they represented, also, a life style.

 

[Phobos]

However, with the amount of technological advances in our current time and in the near future that allow those with these traits to live and often reproduce, would it not be true that the evolution we have undergone has either slown to a creeping pace or stopped alltogether?

Selection forces may have been dampened by technology, but human evolution still goes on. From generation to generation, the statistics of the human gene pool changes...any particular gene or combiantion of genes can be expressed in a larger or smaller percentage of the population; new gene combinations appear (the biological purpose of sex); our immune system has to adapt to whole new pathogens; etc.

On the other hand, one might say that we are evolving into a species of extremely attractive and intelligent beings (because those with the genetic predisposition for these traits are the ones to most often reproduce).

I'm not sure the statistics bears this out (weren't there some recent stats indicating that people with higher levels of education tended to have fewer children?)

 

[selfAdjoint]

I'm not sure the statistics bears this out (weren't there some recent stats indicating that people with higher levels of education tended to have fewer children?)

I think the latest results in the ongoing story of the demographic collapse suggest that the attribution of low birthrate to educated people was just a temporary thing; the true attribution is that women of whatever class who have become self-motivated tend to have fewer children. The only countries left with high birthrates are those with unreconstructed patriarchal social systems. And straws in the wind out of Saudi Arabia suggest that they aren't a long way from collapsing either.

 

[newp175]

Remember that evolution is not just getting stronger/ smarter or whatever, but getting adapted to a specific environment. In that sense, evolution never stops.

 

[selfAdjoint]

Remember that evolution is not just getting stronger/ smarter or whatever, but getting adapted to a specific environment. In that sense, evolution never stops.

Quite right. And in this spirit we should recall that the environment too is a moving target. And in fact the ongoing evolution of a species in an environment can modify the environment, so there is feedback too. Consider the "Red Queen's Race" between predator and prey, or between parasite and host.

No modern environment is over 200 years old, and we have no high expectation that any modern environment will endure more than a century. Meanwhile the mode of reproduction of humans is varying rapidly. We will just have to wait and see how this all shakes out.

 

[jim mcnamara]

Let's look at one smallpoint of action in the Natural Selection process. Surviving illnesses.

When Bubonic plague hit Europe en masse in the 14th C, mortaility rates were very high. There were people who had some degree of immunity.
They survived in affected areas. Subsequent waves of plague in those same areas had lesser levels of mortaility because gene frequency for "surviving plague alleles" increased over time. This is Natural Selection in action.

Applying this to modern times - think of the avian flu. The reason it's causing a scare is because of a high mortality rate. Sound familiar? If there were a pandemic, then the same sort of thing would happen again as happened during plague years.

Look at disease virulence/resistance as an ongoing arms race. The pathogen changes genetically to a "new" strain, and is able to spread more effectively than before. It wins for a while. However if it kills all of it's hosts it loses completely.

Ther next move is: hosts spread "avian flu immunity genes" through the population over time. The pathogen becomes less of threat, and it has a harder time moving through the population. Then the pathogen undergoes change... It goes on ad nauseum. And don't think of it as a linear process, it really isn't. My example just looks linear.