All about genetics .:D

All about genetics .:D

BLAME YOUR PARENTS Genetics are what makes up look different from other peopleThe Male determining gene is in the y chromosome and the female determining gene is in the x chromosome. Blue eyed people carry the same mutation in their OCA2 gene. The first blue eyed person originated from the Black Sea around 600 000 10 000 years ago. EYCL1 determines blue vs. green eye colour and EYCL2 determines blue vs brown eye colour. This is why blue eyed couples rarely have brown eyed children. There are over 50 genes that contribute to the variation in eye colour and pattern. There is less genetic variation in 7 billion humans than there are in 300,000 chimps. To explain this, we need to look at the recent evolutionary history and migration patterns. Genetic evidence suggests that some of the brown eyed ancestors left Africa) around 100,000 years ago and began to travel in 2 main directions, Asia and Europe. Human migration started around 74,000 years ago with the eruption of the Toba super-volcano. Scientists believe that this catastrophic effect reduced the human population into 10,000 breeding individuals. The genetic bottleneck may explain why humans have similar genetics today and could also explain why 90% of living human variations are the same in each population and must have originated from Africa. Only 10% of variation in human DNA is population specific, i.e. African-only, Asian-only or European-only, if to do with eye colour.You might wonder why chimpanzees were less affected than the humans , it is because chimps were exclusively in Africa whilst human were in Asia as well and therefor more affected. Genetics and their functionsGenetics are what makes up look different from other peopleThe male determining gene is in the y chromosome and the female determining gene is in the x chromosome. So for females, there would be XX chromosomes and for males, there would be XY chromosomes. Blue eyed people carry the same mutation in their OCA2 gene. The first blue eyed person originated from the Black Sea around 600 000 10 000 years ago. EYCL1 determines blue vs. green eye colour and EYCL2 determines blue vs brown eye colour; this is why blue eyed couples rarely have brown eyed children. There are over 50 genes that contribute to the variation in eye colour and pattern. Nature vs. nurtureVariation in genes will affect how muscles and nerves are built and function. Sprinting is a good example of this; researchers have found that small genetic differences in several genes have contributed to our sprinting ability. But each of these variation genes contributes less than 1% to our speed. Clearly diet and training are critical; environment contributes to our sprinting ability. (Show video). Today 74 men have run 100m in under 10 seconds. Those nine are from Jamaica. 12.2% of the fastest men on Earth are from a country that comprises 0.04% of the worlds population. http://www.youtube.com/watch?v=jmvtwjqYZcY Genetics in twinsTwins usually share the same genes, but there are two types of twins Monozygotic twins who share their entire DNA would be expected to look very similar Dizygotic twins who share 50% of their DNA will be less similar in appearance. Alternatively, if characteristics were primarily environmental; the differences between twins will be the same for both sets of twins. Rare instances of twins in the adoption system, who grew up with difference families in different environments are even more informative