Cultures as Phenotypes .

[foodchain]

Do you think humans cultures could qualify as phenotypic difference in human organisms? I mean the relation to phenotype to genotype aside, mainly just on phenotype here to be discussed in relation to human cultures. Now I know this supposes that humans are social animals, something I tent to agree with overall, but it does not have to be taken into account overall I think to discuss the question posed.

[ecoli]

Richard Dawkins calls these memes.

[foodchain]

Richard Dawkins calls these memes.

 

I heard that brought up before in other threads, personally I thought it was some slang word in the U.K for memory really.

[ecoli]

I heard that brought up before in other threads, personally I thought it was some slang word in the U.K for memory really.

 

no, not at all.

 

http://en.wikipedia.org/wiki/Meme

[foodchain]

no, not at all.

 

http://en.wikipedia.org/wiki/Meme

 

After reading that I don’t think I am talking about that all to much. I think his idea is more out on the forefront while my question really is more based in older accepted biological terms. I also tend to disagree with his statement on the chemistry issue, I think such is just slightly more crucial overall. I just tend to wonder how much human culture influences maybe human phenotypes.

[lucaspa]

Do you think humans cultures could qualify as phenotypic difference in human organisms? I mean the relation to phenotype to genotype aside, mainly just on phenotype here to be discussed in relation to human cultures.

 

No. Phenotype as you are using it are the physical parameters of the population. Culture is the behavior of the population.

 

In evolution, behavior can lead to genetic isolation of the population. This is happening now in several cultures, but is most pronounced in the !Kung in Africa. Their culture is such that individuals who marry outside the !Kung must leave the tribe. Thus, there is gene flow out of the !Kung but no gene flow into the !Kung. The !Kung do have some unique alleles not found in any other human population.

 

So, depending on the behavior of the culture, human cultures could give rise to populations that, due to isolation, have unique phenotypes. Taken far enough, this could even lead to reproductive isolation and new species of Homo.

[CDarwin]

Do you think humans cultures could qualify as phenotypic difference in human organisms? I mean the relation to phenotype to genotype aside, mainly just on phenotype here to be discussed in relation to human cultures. Now I know this supposes that humans are social animals, something I tent to agree with overall, but it does not have to be taken into account overall I think to discuss the question posed.

 

Yes and no. On the one hand, culture is a manifestation of behavior, which is itself partially influenced by biology and partially by the environment, and is thus a manifestation of an organism's phenotype according the the Wikipedia definition at least.

 

On the other hand, culture is as Lucaspa said part of the environment that molds phenotypes.

 

It almost comes down to how you want to define culture, or even to what sense you want to use the word in. Culture is said to be both the most important and meaningless word in anthropology for its ubiquitousness of use and plethora of definitions.

[foodchain]

Yes and no. On the one hand, culture is a manifestation of behavior, which is itself partially influenced by biology and partially by the environment, and is thus a manifestation of an organism's phenotype according the the Wikipedia definition at least.

 

On the other hand, culture is as Lucaspa said part of the environment that molds phenotypes.

 

It almost comes down to how you want to define culture, or even to what sense you want to use the word in. Culture is said to be both the most important and meaningless word in anthropology for its ubiquitousness of use and plethora of definitions.

 

Well I look at culture as just another item in the environment in short, sort of maybe a hard surface to an organism possibly? Just a factor overall is what I mean by culture. I don’t think its by coincidence that humans happen to live in societies or have cultures or happen to have language for instance, but that’s little more then barely a casual connection really. What I am getting at, is that environment plays into phenotypes, the relationship of genotype to phenotype aside and simply looking at the phenotype I just sort of wonder what connection or how large a factor human cultures play on a human being.

 

Such as violence. It seems to be violence is everywhere in American culture? Now this came on gradually as being as common as it is, I mean its not like violence did not exist in the past, just now that you even have violent commercials on t.v. Is this giving some kind of violent predisposition to people, and on what level, does nature to nurture share in the phenotype? I mean if we have a culture that somewhat aligns itself with violence, what will that say about people that reject such? Will certain genes be "switched" on over others more often?

 

I think its a complex question, but I don’t know if its ever been explored in regards to humans really. I mean a culture of bacteria may be one thing, but not a culture of people, it becomes a little more complex to say the least.

[lucaspa]

What I am getting at, is that environment plays into phenotypes, the relationship of genotype to phenotype aside and simply looking at the phenotype I just sort of wonder what connection or how large a factor human cultures play on a human being.

 

The question would need to be looked at in terms of whether the culture is selecting a particular phenotype or not.

 

Such as violence. It seems to be violence is everywhere in American culture? Now this came on gradually as being as common as it is, I mean its not like violence did not exist in the past, just now that you even have violent commercials on t.v. Is this giving some kind of violent predisposition to people, and on what level, does nature to nurture share in the phenotype?

 

Is there any selection going on for violent phenotypes? IOW, are violent people producing more kids? If not, then the culture is having no effect on phenotype.

 

Will certain genes be "switched" on over others more often?

 

No. I think the confusion you have is that you are thinking evolution applies to the individual. It doesn't. Evolution happens to populations.

 

You are thinking that more individuals may decide to become more violent. There are several things you have to consider:

 

1. Reporting of violence compared to actual incidence. You can get an artifact of reporting where the phenomenon looks more prevalent because it is being reported more often. Since news organizations now report on violence all across the USA, it looks like there is more violence. But you need to look at EACH and EVERY locality over time. How many murders has Medina, OH had in the last 5 years? How many in the 5 years before that?

 

2. Normalize to numbers. If 0.01% of people will commit a murder, for instance, then that means as population increases the number of murders will increase. But the rate of murders or the frequency of murderers in the population remains the same. So, for 1 million people you have 100 murderers but for 100 million people you now have 10,000 murderers. No change in phenotype because the frequency of that phenotype in the populaton hasn't changed.

 

3. Reproductive success of the people who commit violence. This is the biggie. You have to look at birth rates. Are murderers more, or less, likely to have kids than pacifists? If less likely or the same, then culture has no effect on phenotype, because whatever genetic basis for violence is not being selected for. Ironically, this may be partly due to culture! We lock violent offenders away and prevent them from mating!

 

I think its a complex question, but I don’t know if its ever been explored in regards to humans really. I mean a culture of bacteria may be one thing, but not a culture of people, it becomes a little more complex to say the least.

 

A culture of bacteria is not the same thing as a culture of people! That seems to be a big problem: apples and oranges.

 

A culture of bacteria is a population of bacteria in an isolated geographical and genetic area -- the petri dish. A human culture is a set of ideas and behaviors that has very fuzzy boundaries both geographical and genetic. There is gene flow between human cultures. There is not gene flow between 2 culture dishes of bacteria.

 

But yes, the effect of culture on evolution has been and continues to be studied. One major reason is that you have to eliminate vagaries of culture when looking for evolution of brain and behavior modules. The modules are thought to have a genetic basis. Therefore, only those modules independent of culture -- universal in all cultures -- can be confidently identified as being the products of evolution. So the researchers have to look at culture and its possible effects on behavior -- if only as a negative control.

 

A few papers are:

 

19. J De Heinzelin, JD Clark, T White, W Hart, P Renne, G WoldeGabriel, Y Beyene, E Vrba, Enviornment and behavior of 2.5 million year old Bouri hominids. Science 284: 625-629, 1999.

1. http://www.plosbiology.org Article on baboon culture shift after aggressive males killed

3. G Vogel, DNA suggests cultural traits affect whale's evolution.Science 282: 1616, Nov. 27, 1998. Primary article is H Whitehead,Cultural selection and genetic diversity in matrilineal whales. Science282: 1708-1710, Nov. 27, 1998

 

 

This one ties into your concern of "violence" in American culture:

 

6. M Roach, Why men kill. Discover 19: 100-108, Dec. 1998. Summarizes study of Amazon tribe where half the males are murdered. looking for the evolutionary roots of violence.

 

12. DS Woodruff and NG Jablonski and G Chaplin, Chimp cultural diversity. Science 285: 836-837, Aug. 6, 1999. Social tolerance evolved among hominids.

12a. A Whiten C Boesch, The cultures of chimpanzees. Scientific American 284: 60-67, Jan. 2001. Another "unique" feature of humans turns out not to be unique.