Hi steemit community,
today I am going to talk about The Future Of Human Variation.
Laboratory fertilisation, subsequent transplantation of the embryo, and successful birth have been accomplished with humans and nonhumans. The exact reproduction of an individual from cellular tissue, has been achieved with frogs and sheep. And genetic engineering, the substitution of some genes for others, is increasingly practised in nonhuman organisms.
Indeed, genetic engineering is now used in humans to eliminate certain disorders that are produced by defective genes.
What are the implications of such practices for the genetic future of humans? Will it really be possible someday to control the genetic makeup of our species? If so, will the effects be positive or negative?
It is interesting to speculate on the development of "perfect human." Aside from the serious ethical question of who would decide what the perfect human should be like, there is the serious biological question of whether such a development might in the long run be detrimental to the human species, for what is perfectly suited to one physical or social environment may be totally unsuited for another.
The collection of physical, emotional, and intellectual attributes that might be "perfect" in the early 21st century might be appropriate in the 22nd century. Even defects such as the sickle-cell trait may confer advantages under certain conditions, as we have seen.
In the long run, the perpetuation of genetic variability is probably more advantageous than the creation of a "perfect" and invariable human being. In the event of dramatic changes in the world environment, absolutely uniformity in the human species might be an evolutionary dead end.
Such uniformity might lead to the extinction of the human species if new conditions favoured genetic or cultural variations that were no longer present in the species.
Perhaps our best hope for maximising our chances of survival is to tolerate, and even encourage, the persistence of many aspects of human variation, both biological and cultural.
Summary
- Physical variation is the variation in frequencies of physical traits, that is to say, from one human population to another is the result of one or more of the following factors that is;
- adaptation,
- acclimatisation,
- and the influence of the social or cultural environment
- Some physical variations in human populations involve genetic variation, that is to say, other variations, including;
- body build,
- facial construction,
- and skin color,
may be adapted to variation in climate. Still other variations, such as the ability to make lactase, may be adapted partially to variation in cultural environment.
- Most people agree that "race" is not a useful way of referring to human biological variation because human populations do not unambiguously fall into discrete groups defined by a particular set of biological traits.
Physical traits that are adaptive vary clinally, which makes it meaningless to divide humans into discrete "racial" entities. Rather it is suggested that "racial" classifications are mostly social categories that are presumed to have biological basis.
- Perhaps, the most controversial aspect of racial discrimination is the relationship supposed between "racial" categories and intelligence. Attempts have been made to show, by IQ tests and other means, the innate intellectual superiority of one "racial" category over another.
But there is doubt that IQ tests measure intelligence fairly. Because evidence indicates that IQ scores are influenced by both genes and environment.