Founder Mutation

Founder Mutation

            Medical researchers, geneticist, and scientist have recently been able to come to the conclusion that it is possible to trace a person’s ancestry through their DNA. In genetic mutations that are hereditary these genes will be passed on to all of their future generations. This person with the initial mutation is called the founder and their genetic legacy is called the founder mutation. Many founders are identified for carrying hereditary disease like sickle-cell anemia, cystic fibrosis, and other deficiencies. This disease is created in the founder’s genes and can be shown in their DNA as well as all of their descendants. Most changes in people’s DNA are eliminated at birth, but these natural diseases are created by germ-line mutation, which survive after birth and are able to be passed on.

            There are also hot-spot mutations, which cause things like dwarfism. Hot-spot mutations occur in DNA base pairs that are prone to mutations.  People with hot-spot mutations usually have no relation to one another besides the mutation in the base pair. This is unlike founder mutations which are passed on through generations, and with founder mutations the length of the damaged DNA is shortened every generation. The stretch of damaged DNA is called the haplotype, and people with the same haplotype share a common ancestor. Tracing haplotypes is how geneticists have been able to trace the founder of the mutation and track certain populations. Disease mutations exist at a very small rate while founder mutations can be found by percent in a population.

            The article along with many people often question, “Why does evolution preserve rather than weed out such seemingly detrimental mutations”? The reason is that in order to receive the disease from the founder mutation, the offspring must receive the mutation from both parents. A person that receives it from only one parent is called a carrier. Carriers will never receive the disease, and they also receive certain advantages for carrying the mutations. A great example is sickle-cell anemia. Carriers will survive malaria infections, but a person with two copies of the mutation is prone to pain and a short life. Sickle-cell anemia has five different haplotypes meaning it was born naturally five different times showing the profitability of the mutation.

            With this information geneticist have been able to piece together the human past. They have been able to determine that humans started in Africa and that about 75,000 years ago a subgroup left Africa. This is shown in the PTC gene which the humans that left developed a mutation from a founder that allowed them not to taste certain bitterness in certain chemicals and plants. Geneticist were able to conclude that the subgroup left Africa around 75,000 years ago by studying the length of the haplotype. This is just one example for the many benefits geneticist have learned to study in our DNA to develop human evolution.