Download Dezham 1 Arsalan Dezham 1/30/13 Biology 1010 Professor Hardy

Dezham 1
Arsalan Dezham
1/30/13
Biology 1010
Professor Hardy
“Founder Mutations” – Summary
I read the article Founder Mutations, by Dennis Drayna. The article talked
about how some special groups of genetic mutations that cause human diseases, can
now be traced back to the migration and growth of the specific population arising
thousands of years ago. Biology deals with DNA, and genetic mutations where a
normal sequence is disrupted randomly and the mutation forms. Most of the
damage of mutations gets repaired or eliminated at birth and doesn’t get passed
down to generations. But in some mutations, called germ-line mutations, are passed
down their offspring and can cause serious medical problems. One rule contributing
to the founder mutations (mutations arising from an ancestor generations ago) is
that different mutations in the same gene usually cause the same disease. In a few
other disorders however, the same mutation can be seen over in generations passed
down. Every human who is exposed to the founder mutation has the same damaged
DNA as the founder. The entire length of DNA is called a haplotype, therefor the
more geneticists study the DNA, the more information they can obtain of where the
mutation started. The age of the mutations can be estimated by seeing how long the
haplotype is, because they get shorter over time. Something I found very interesting
in reading that article is that in some cases, the founder mutation may be proved
beneficial. The mutation is always recessive, only a person with two copies of the
affected gene, one from each parent will suffer from the disease. But when they are
carrying one copy of the mutation, they are called carriers. The single copy of the
mutation allows the carrier of the advantage to survival of the fittest. For example,
carriers of hemochromatosis mutations is said to be protected from iron-deficiency,
because part of their DNA is encoded with proteins that allows the person to absorb
iron more effectively then someone who is carrying the full founder mutation of two
copies. The founder mutation says that if someone has two copies of the mutation,
they will probably die before reproducing, therefor the humans with single copies of
the mutation will learn to adapt in the environment better, and help benefit in
certain diseases. The starting of mutation occurred as people migrated mainly from
Europe and Africa around the world. For example a condition called Cystic fibrosis
began in Southeast Europe/Middle East and migrated west and north across
Europe, the specific gene affected by the mutation is called CFTR, yet if you have the
single copy of the gene you can be protected from diarrhea. With the help of
anthropologists, historians, and archeologists, scientists can trace the exact
locations and time of when the mutations began. Studies show that specific
populations with the same disease generally always have the mutation in the exact
same gene. This article allows me to believe that in some way all of our ancestors
are rooted together and their genes are constantly traveling from one another.
Dezham 2
Works Cited:
Drayna, Dennis. "Founder Mutations." Current Issues in Biology. 4. (2005): 1-8.
Print.