Posts Tagged ‘Genetics’
Posted on January 10, 2009 - by Khaled
Since the day scientists were able to sequence the human genome there were some huge leaps in the human genetics field. Many human characteristics and body functions are now directly linked to their genes. For instance there’s probably an intelligence gene! So what if we apply our current knowledge to more precise goal? i.e. are there any genes that predispose a human to be a sports champion? If yes, why not try and find them and be able to test our children since their youngest age?
Don’t just want to know if your child can be the next Roger Federer? Michael Jordan? Tiger woods? or may be Tom Brady? What about Michael Phelps? Heather O’reilly? Nadia Comaneci? What if you could tell if this might happen even before your child learns to walk? Well may be you can!
For less than $200 (even lower some times) companies like Atlas Sports Genetics, CyGene and Australian Genetic technologies will analyse the DNA of children as young as 1 and the results of the analysis can help predicting wether or not they genetically predisposed to be sporting champions.
All what is needed is a swab taken from inside the child’s cheek to obtain sufficient DNA. After 10-15 days the results are dispatched and may even come with a signed certificate attesting , with details, the potential “Genetic Advantage” of the child. They summarise all you need to know about physiological strengths and probable suitability of the child for certain types of sports.
These tests may have some advantages if used wisely. An implication of higher instances, like sports ministries, seem to be necessary to avoid any excesses. Such studies seem to be pushing the limits of the current scientific knowledge. The day where we will be able to predict the sanitary future and predispositions of humans for certain jobs or activities seems to be around the corner. Such situation may lead to some dramatic events though. Telling a child that he will never be able to be as good as his favorite athlete no matter how hard he tries is a problem! and might have terrible psychological effects on the child!! Should we tell him/her in such cases? should we let them try and waste their try knowing that they will probably fail? On the other hand, does knowing that a kid is predisposed to be a sports champion dive us the right to push him towards sports and performance pressuring him to give his best even though he does not like sports? This may lead to depression, a general feeling of melancholy and may, in some extreme cases, push the child to commit suicide! We, as intelligent humans, must be very careful on how to deal with such issues! How someone will live his life knowing that he will have some cardiac problems or diabetic disorders? Again should we tell him? And, for instance, will any company hire someone that is predisposed to be ill with some chronic disease? or someone who has “bad” intelligence genes? Should these kinds of tests be prohibited? Discovery is good! But should always be used wisely!
Posted on January 8, 2009 - by Khaled
Hybridization is a natural process happening with or without human intervention. It is an important evolutionary phenomenon that helps understanding complex mechanisms such as speciation. Hybrid zones between related species are thus regarded as “natural laboratories”. So mating between genetically divergent species or populations is quite common in nature.
Key insights into the process of speciation can be provided by comparing the genes flow rates throughout the whole genome and therefore underlie reproductive isolation. Some recent studies (2008) led by Geraldes et al., reported the geographical distribution of Y chromosome lineages in wild populations of rabbits from Iberia and southern France. This revealed that Y chromosomes showed a high level of differentiation between rabbit subspecies on either side of the existing hybrid zone. This was in clear contradiction with the evident gene flow detected at other loci from other chromosomes. This suggests that the Y chromosome might play a key role in reproductive isolation. This a new case species with mosaic patterns of differentiation across their genomes.
Comparisons of introgression levels between the Y chromosome, the X chromosome, the autosomes, and mitochondrial DNA are essential to the knowledge of speciation genetics. Particularly, the important role of the sex chromosomes in reproductive isolation predicts that genetic markers found on these chromosomes will often show restricted gene flow compared to other loci.
An alternative explanation can also be suggested. Relative levels of differentiation might simply echo the rate of ancestral lineage sorting (due to differences in effective population size) which is expected to be fastest for the Y and the mitochondrial DNA, followed by the X chromosome, and finally the non-sexual chromosomes. Crossing test can be useful to assess the validity of either hypothesis.
Multilocus surveys of population differentiation will be increasingly used in the speciation research nascent field. Soon we will be witnessing entire genomes scanned for introgression in hybridizing species. However this method will still be challenged by the fact that we still ignore what does an outlier locus look like? In fact, this is a common problem with other genomic researches….