Issues related to genetic diversity
Genetic diversity pdf
The field is notable for clear examples of associations between gene variants and disease susceptibility or resistance, for which excellent epidemiological evidence, often backed up by laboratory studies, exists. In this review we discuss recent developments in the study of human genetic diversity in general, driven by the availability of large data sets on global samples, and then move on to address evidence for pathogen, climatic, dietary and cognitive genetic adaptation, many of which have consequences for disease susceptibility today. Relevance of evolution: conservation : Low genetic variation Genetic variation is the raw material of evolution. There are both pessimistic and optimistic versions of the argument. Social spiders have large populations, but their social biology is so extreme that their actual population size the number of individuals has no effect on their effective population size. Some have made the argument that the out of Africa migration entailed novel challenges that favoured the selection of enhanced cognitive ability, and have supported this using comparisons of IQ and brain size The most obvious response is in pigmentation, due to the quantity, type, and distribution of melanin. Nonetheless, much or most of the international controversy over collecting genes to study human genetic variation would disappear if the patenting of genes and gene sequences were outlawed. Some human demes have fewer internal barriers to gene flow—created by stratification by class, caste, ethnic group, or clan affiliation—within the population than others.
I will discuss these concerns below. Commercialization And Reciprocity Agreements Some proponents of human genetic variation research argue that it will be essential to negotiate arrangements regarding possible commercial benefits with the subject groups in advance of research, to make the participating groups "partners" with scientists in the research North American Committee.
Also available is the alteration of parent gametes in order to eliminate the possibility of passing on genetic disease to their offspring. A less-comprehensive, mutually agreeable strategy would be to require that all such patent applications include an agreement to share a set proportion of the resulting net proceeds or profits with the person whose body was the source of the DNA or, at that person's election, with the community of which he or she is a member. Genetic homogeneity may be an unintended consequence of a population sharing common values Resnik , For example, eight panthers from Texas were introduced to the Florida panther population, which was declining and suffering from inbreeding depression. Studies using these samples have shown the power of a geographically explicit approach 9—12 to explain global patterns. Where sunlight is low, depigmentation may be favoured because UV penetration is necessary for vitamin D synthesis In vivo and in vitro conservation is complementary: when you do both, you guarantee flexibility of breeding programs by safeguarding rare breeds and have the possibility to use them for present activities. How many individuals of a given species are needed to maintain genetic diversity in the long run? This element could pose a serious problem for this type of research. Selection for or against a trait can occur with changing environment — resulting in an increase in genetic diversity if a new mutation is selected for and maintained or a decrease in genetic diversity if a disadvantageous allele is selected against. Proposals for human genome diversity research that do not adequately anticipate the issues raised by the proposers' population focus have already proved capable of generating a remarkable amount of public controversy. I address one of the pragmatic ethical concerns, the potential loss of genetic diversity. On the other hand, global sample sets, like the CEPH-HGDP panel, are universally available and typed with many markers, but completely lack phenotypic information. Perhaps the most contentious issue in the short history of human genetic diversity research is the growing practice of patenting cell lines and gene sequences. C Selected migrations and subsequent admixture in the last three thousand years, including consequences for infectious and other diseases in the New World arrows indicate migrations; KYA: thousand years ago; C: century; figure based on material included in 1.
Genetic diversity of a population can be assessed by some simple measures. The concept of community approval is not well articulated in contemporary research policies, but it is similar to some forms of community consultation already used in some population-level research.
Issues related to genetic diversity
This practice is called doping, and it frequently involved such substances as erythropoietin, steroids, and growth hormones Filipp, From that information, parents can decide to destroy the embryo, alter the embryo, or leave the embryo unmodified and risk that the child will develop a genetic disease. The field is notable for clear examples of associations between gene variants and disease susceptibility or resistance, for which excellent epidemiological evidence, often backed up by laboratory studies, exists. Glover and W. Cognitive adaptation? The type of human experiment that would produce the evidence is incompatible with present ethical codes of conduct. The smallest populations ten individuals lost the most genetic diversity, the medium sized population 50 individuals lost a little less, while the larger populations individuals retained the most diversity. The fact that a group name exists for political purposes can be scientifically misleading. To clarify the inference, one should be reminded of what is at stake with respect to genetic diversity. The known variants still do not account for all of lactase persistence; so further examples are likely to exist. The trustee organization, in turn, would be required to ensure that the revenue benefited the participating populations, which would be represented in the trustee organization. Occupation of new environments had adaptive consequences for skin pigmentation, and possibly for cognition. Richard Lankau, "If any one type is removed from the system, the cycle can break down, and the community becomes dominated by a single species.
Similarly, to the above example, monoculture agriculture selects for traits that are uniform throughout the plot. Also available is the alteration of parent gametes in order to eliminate the possibility of passing on genetic disease to their offspring.
Nonetheless, the most important ethical question in research is always whether the research is worth doing.
A major factor in whether these reproductive technologies will increase or decrease genetic diversity is what model they are implemented under, free market or state control.
This habit, of course, long predates scientific thinking about human genetics.
Genetic diversity examples
This allows the drinking of milk without adverse effects, and the distribution of the phenotype correlates well with that of populations with a history of cattle domestication and milk drinking Many people wonder whether positive diagnosis of an impending untreatable disease will harm the at-risk individual by creating undue stress and anxiety. A more-sophisticated and more-complicated approach would be to form an international organization to serve as a trustee and fundholder for all the sampled populations. Relevance of evolution: conservation : Low genetic variation Genetic variation is the raw material of evolution. These technologies pose the clearest threat to genetic diversity of human populations. Like fruit flies, most spiders are solitary, which means that they live most of their lives alone without having to cooperate with each other. However, translating the kinds of protections that medical geneticists have adopted for individuals and family-research subjects into protections for entire social groups might require more radical changes in the traditional professional practices of biologic anthropologists and population geneticists than the ones that medical geneticists had to face. The committee heard testimony from John Moore, whose spleen was used as a source of a cell line that was immortalized and patented without his knowledge or permission. Societal pressures and obligations may also produce conformity. A major factor in whether these reproductive technologies will increase or decrease genetic diversity is what model they are implemented under, free market or state control. Similar epidemics could sweep through other vulnerable species with low genetic variation, increasing their chance of extinction.
Nevertheless, confounding factors such homogeneity of desirable characteristics makes the above inference much more dubious than it first appears.
There is an ethical duty to prevent decreases in the genetic diversity of populations because of its importance in the survivability of those populations. Lincoln St Washington, PA Abstract Recent advances in reproductive technologies, especially those that alter the germ-line, raise many ethical and theological concerns.
There has been argument over whether these patterns could be explained by demographic processes rather than selection 56 Chapter Excavating these genetic strata is not easy, but it is reasonable to suppose that early events when populations were small had disproportionately large effects on modern diversity.
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