Why Siblings Can Get Different Results From DNA Ancestry Tests

In modern times, it has become fashionable to get your ancestry checked with the help of DNA tests. These commercial testing kits have become the rage, especially among young people. They are affordable, easy to use and satisfy your curiosity boundlessly., Most of us think that getting an ancestry dna test done will reveal a lot of genetic similarities of ourselves and our siblings. However, we are generally stunned to see that there are numerous differences that we have with our siblings as far as our genetic makeup is concerned., Now the question arises that why does this happen? There are many explanations that can be given for this. Most people don’t acknowledge this fact and they either start doubting the veracity of the genetic testing kit or they begin to think that there are certain skeletons in the closet as far as their family tree is concerned., This article examines the reasons behind this phenomenon and tries to find out its influence in the minds of people who use them. It deconstructs the fallacies that people tend to make when faced with such situations and finds alternative solutions that are more logical and plausible to accept., Read on to find out why DNA ancestry tests can throw up different results even for siblings. This will help you get a clearer picture of the way in which genetics works.,

DNA Reshuffling

, Recent research has shown that siblings only share about 50 % of their genes. This is true even for identical twins. Now the question pops up that why does this happen? As their parents are the same, they should naturally share a higher percentage of genes. This is what is commonly believed., However, this is not the case. What is stunning is that even identical twins who look the same still share only 50% of the genes. Normal logic would lead us to believe that they should have 90% of genes in common but unfortunately, this is far from the truth., There is a scientific explanation for this. A human embryo is formed due to the union of an egg from the mother and a sperm from the father. This clearly shows that half of the genes come from the mother and half of them come from the father., When the egg and the sperm are formed in the ovary and the testes respectively, the DNA of each of them gets reshuffled due to their mode of formation. There is a very interesting way in which this happens. Normally, each autosomal or normal cell has 46 chromosomes. But eggs and sperms have only half that amount, which is 23 chromosomes., This is because the egg and the sperm will combine to form 46 chromosomes which will give birth to a new baby. Hence, when the chromosomes are getting divided, at that time, there will be DNA reshuffling., Hence, no two eggs and sperms will have the same chromosomes. This explains clearly that even two identical brothers or sisters will not have the same genetic material. In other words, the eggs and the sperms forming them will carry different genes that are a result of genetic reshuffling., This process takes place in all kinds of siblings and there is no need to jump into fallacious conclusions should your DNA testing kit exhibit different results with the rest of your siblings. The reason that our genes behave like this is to protect the offspring of a particular species., Recent biological research has also revealed that the more diverse the genes of a particular species are, the higher the chances of survival of that offspring. Hence, as humans are the most evolved species of animals, it goes without saying that our genes will be more widely scattered when compared with other animals.,

A Limited Gene Pool

, Another reason why this phenomenon can take place is that DNA testing companies have a limited gene pool that makes their findings not free from being just random checks. This happens because of the fact that DNA testing companies don’t make use of the entire set of the data that is available to them., They just publish the results after conducting random checks on a particular sample of the population and then extrapolating the results to a diverse group of people. Hence, we should not really take the results seriously even though what they say is more or less true., The point we are making here is that it’s quite ok to use these DNA testing kits to get a general overall level of information but that doesn’t mean that they are not without faults. Hence, it is best for us if we don’t jump to conclusions from these results as none of them are foolproof., Another thing that needs to be stated is that most of the research has been done on the European and North American gene pool and very little has been done on the Asian and African varieties. Hence, it is clear that until we expand the gene pool to include people from all over the world, it will not be possible for us to get a better understanding of the human genome., This amply makes it clear that we are working on a limited gene pool that needs to be expanded for us to get better and more reliable results.,

Selective Differentiation

, The process of selective differentiation is an evolutionary step that has been taken to ensure the survival of the species. This is why no two human beings carry the same genetic information even though they share around 99 % of the autosomes., It is this 1 % that holds the key to how we are as a person. All the differences that make us different from other human beings are contained in it. This makes the study of human genetics both fascinating and mind-boggling., Selective differentiation also protects us from various diseases and illnesses due to the fact that they scatter out the genes that facilitate these disorders. Without this process, we would be more vulnerable to fall prey to them quickly. Hence, they perform an important evolutionary function.,

Conclusion

, From the above, it is clear why siblings can get different results from DNA ancestry tests. This amply shows the prudent ways in which we need to interpret these findings.