Post by Kukul-Kan on Dec 6, 2003 15:14:29 GMT -5
In this thread the conversation deviated to the topic of the pros and cons of Race mixing.
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Race mixing can be either good or bad from a physical point of view depending on the races involved, the climatic circumstances the place and time where it takes place etc. There you have the example of Annamite-French hybrids who in childhood were inferior physically to both French and pure Vietnamese but in youth they were both taller and stronger than both previous groups. Plus their women were described as extremely beautiful by French travelers. On the contrary Amerindian/Black hybrids were described as both intellectually and physically inferior to both pure Negroids and Amerindians in colonial Mexico. The Scottish wife of the second Spanish Ambassador to Mexico, Count Calderón de la Barca, mentioned there wasn’t a race as ugly as those “zamboes(Negroid/Amerindian mix)”<br>
Hybridization, Advantages and Disadvantages
By Stanley M. Garn, Human Races.
In the last century race-mixture was viewed as totally bad, with dire consequences visited upon the hybrid progeny. Plant Genetists, however, discovered the phenomenon of hybrid vigor, thus pointing to a possible advantage of hybridization though such has no means been conclusively demonstrated in man. What can we say now about the advantages and disadvantages of hybridization, or race-crossing in Homo sapiens?
Taking the long view and centering our attention on the population, hybridization may be considered as advantageous. By increasing genetic variability, there is a greater range of genotypes to work from, a greater likelihood of adaptive genotypes and far better prospects for long-term survival. In the long run, the more different genes the better, and race-crossing enhances genetic diversity. A hybrid race has superior long-range prospects.
The short-range view, however, centering attention upon individuals rather than the population can be somewhat different. If a population is optimally adapted to the environment, the introduction of new genes will lower average individual fitness, until the balance is restored by natural selection. But this answer itself needs qualification and emendation, as shown in the following example.
Take an East African population constantly beset by malaria and with a high incidence of the sickling gene. This population is optimally adapted to its circumstances. Admixture with nonsickling peoples would result in decreased average fitness, until such time as the balance is restored by selection. For this particular example, admixture is bad for the individuals concerned.
If we move this African population (or control malaria with DDT, ditch drainage and quinine) the situation may become quite different. The "hybrids" with a lower incidence of the sickling disease would exhibit increased fitness, relative to the original population.
So the "fitness" of hybrids depends very much upon circumstances. Given a population highly adapted to particular circumstances, and an intrusive population not, the hybrids would be less fit than one parental group (though more than the second). Change the circumstances and the hybrids may be superior in fitness to the first group but not the second In a third set of circumstances hybrid fitness may be superior to both parental groups.
Race mixture, the coalescence of distinct micro-races, local races or geographical races is an old human accomplishment resulting in increased genetic diversity, more rapid natural selection and (usually) new adaptive peaks.
Apart from the advantages accruing to scientific investigation, race-mixture raises the problem of population and individual fitness. No hard and fast rule can be drawn. In some cases decreased individual fitness ensues, and in other cases increased individual fitness will eventuate. From a population point of view, increased genetic diversity is of ultimate value.
Dire predictions about race mixture voiced in last-century Europe have not proved correct. Decreased fertility in particular has failed to evidence itself in hybrid human populations. Hybrid vigor, suggested by plant experiments, remains to be demonstrated in man.
That race-mixture has been an important race-making mechanism goes without doubt. Studies in populations of recent, hybrid origin hold many advantages and there are many opportunities to investigate fitness under purely local circumstances.
dodona.proboards24.com/index.cgi?board=guess&action=display&thread=1070591715
Race mixing can be either good or bad from a physical point of view depending on the races involved, the climatic circumstances the place and time where it takes place etc. There you have the example of Annamite-French hybrids who in childhood were inferior physically to both French and pure Vietnamese but in youth they were both taller and stronger than both previous groups. Plus their women were described as extremely beautiful by French travelers. On the contrary Amerindian/Black hybrids were described as both intellectually and physically inferior to both pure Negroids and Amerindians in colonial Mexico. The Scottish wife of the second Spanish Ambassador to Mexico, Count Calderón de la Barca, mentioned there wasn’t a race as ugly as those “zamboes(Negroid/Amerindian mix)”<br>
Hybridization, Advantages and Disadvantages
By Stanley M. Garn, Human Races.
In the last century race-mixture was viewed as totally bad, with dire consequences visited upon the hybrid progeny. Plant Genetists, however, discovered the phenomenon of hybrid vigor, thus pointing to a possible advantage of hybridization though such has no means been conclusively demonstrated in man. What can we say now about the advantages and disadvantages of hybridization, or race-crossing in Homo sapiens?
Taking the long view and centering our attention on the population, hybridization may be considered as advantageous. By increasing genetic variability, there is a greater range of genotypes to work from, a greater likelihood of adaptive genotypes and far better prospects for long-term survival. In the long run, the more different genes the better, and race-crossing enhances genetic diversity. A hybrid race has superior long-range prospects.
The short-range view, however, centering attention upon individuals rather than the population can be somewhat different. If a population is optimally adapted to the environment, the introduction of new genes will lower average individual fitness, until the balance is restored by natural selection. But this answer itself needs qualification and emendation, as shown in the following example.
Take an East African population constantly beset by malaria and with a high incidence of the sickling gene. This population is optimally adapted to its circumstances. Admixture with nonsickling peoples would result in decreased average fitness, until such time as the balance is restored by selection. For this particular example, admixture is bad for the individuals concerned.
If we move this African population (or control malaria with DDT, ditch drainage and quinine) the situation may become quite different. The "hybrids" with a lower incidence of the sickling disease would exhibit increased fitness, relative to the original population.
So the "fitness" of hybrids depends very much upon circumstances. Given a population highly adapted to particular circumstances, and an intrusive population not, the hybrids would be less fit than one parental group (though more than the second). Change the circumstances and the hybrids may be superior in fitness to the first group but not the second In a third set of circumstances hybrid fitness may be superior to both parental groups.
Race mixture, the coalescence of distinct micro-races, local races or geographical races is an old human accomplishment resulting in increased genetic diversity, more rapid natural selection and (usually) new adaptive peaks.
Apart from the advantages accruing to scientific investigation, race-mixture raises the problem of population and individual fitness. No hard and fast rule can be drawn. In some cases decreased individual fitness ensues, and in other cases increased individual fitness will eventuate. From a population point of view, increased genetic diversity is of ultimate value.
Dire predictions about race mixture voiced in last-century Europe have not proved correct. Decreased fertility in particular has failed to evidence itself in hybrid human populations. Hybrid vigor, suggested by plant experiments, remains to be demonstrated in man.
That race-mixture has been an important race-making mechanism goes without doubt. Studies in populations of recent, hybrid origin hold many advantages and there are many opportunities to investigate fitness under purely local circumstances.