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Mutations

Mutations are random changes in the genetic information of an organism. These lead to new varieties and traits in an organism. Most are harmful, but a few are neutral or even beneficial.
There are two main types of genetic mutations: a point mutation and a frameshift mutation. In a point mutation, one of the bases(chemicals) in the chain of DNA is replaced by a different base. In a frameshift mutation, one base pair is "deleted," so it throws off all of the codons(triplets) in the DNA sequence, leading to different proteins that are usually useless or harmful.

Mutations-Beneficial or Harmful?

There are many examples in nature that show how mutations are beneficial or harmful in the context of their environment. A beneficial or neutral mutation can quickly become harmful when the environments change. The environment greatly affects an organism’s ability to survive, and even a small change can be harmful to some organisms. A few organisms that show this are the panda, kokapo, penguin, and naked mole rat.
The panda’s "thumb" is actually an enlarged bone of the wrist. In the panda’s environment, bamboo is the main food source. It is difficult to handle and break the hard stalks, so an enlarged wrist bone helps to grasp the bamboo. In another environment where the food source is not plants, an extra ‘finger’ would have little benefit, perhaps even be cumbersome. The mutated hands of pandas have been beneficial only because of their need for a better grip on bamboo.
The kokapo is a strange flightless parrot that lives in the brush on the mountains of New Zealand. Before man reached its shores, the island was almost mammal-free, with no ground predators of birds. As a result, the many ground dwelling birds lost the ability to fly, because there was no need. Their wings are small and useless. When man did come they brought mammals, such as cats and weasels. The kokapo was easy prey for them, and is now nearly extinct. This happened to several other birds, including the kiwi. These birds inability to fly quickly caught up to them when the environment changed, showing how their mutation of bad wings was harmful in a different environment.
The penguin has a similar situation, living in the waters of Antarctica and surrounding places. They have evolved into flightless birds that are cumbersome and ineffective on land, but are masters of the water. In Antarctica, the sea is the best place to get food, so that is where the penguin has hunted. It has gradually lost its ability to fly, attained huge amounts of insulating blubber, and gained mutated legs that are great for swimming and terrible for walking. If the penguin was not in the environment it is so well suited for, it would be very vulnerable and helpless. The mutations that have helped it survive in Antarctica would quickly become useless in a place like the grasslands or mountains. In an environment without water nearby, mutated wings and legs suited for swimming are useless.
The naked mole rat is an unusual mammal that has very little hair and is blind. It lives in underground tunnels in East Africa. Deep underground, being ‘naked’ and blind make no difference to this small rodent. If it is taken out of its subterranean home, though, it becomes helpless. The rat’s mutations are a huge liability in an environment other than the one it is accustomed to.
These animals show that their mutations which were beneficial can easily become harmful if it is placed in a different environment. They are only a few examples from a world where mutations abound and environments govern life.

Human Mutations

Blue Skin (Diaphorase deficiency)

Physical Description: People with a blue skin trait have, obviously, blue, plum- colored, indigo, or almost purple skin. The blood of the person accumulates a blue molecule that shows more than the normal pink pigments, so a blue color results. This is caused by a deficiency of the enzyme diaphorase.
Inheritance: A recessive allele. The population in Kentucky of affected individuals was started by Martin Fugate and passed down from generation to generation(Trost).

Werewolf Syndrome, or CGH(Congenital generalized hypertrichosis)

Physical Description: Affected people have excessive hair growth on their face and upper body. The name Werewolf Syndrome came about because people with the disorder resembled werewolves.
Inheritance: X-linked dominant allele. A family in Mexico had several members with the trait, showing it could be inherited (Henahan).

Bibliography

Attenborough, David. The Life of Birds. Princeton University Press, Princeton, 1998.

Chromosome X. Human Transcript Map. Http://www.ncbi.nlm.nih.gov/SCIENCE96(online).

Gould, Stephen Jay. The Panda’s Thumb. W.W. Norton, New York, 1980.

Henahan, Sean. Atavistic werewolf Gene Localized. Access Excellence, 1995. http://www.accessexcellence.org/WW/SUAO5/wolfman.html(online).

Naked Mole Rat. Fantasticards(106). Educational Insights, 1993.

Trost, Cathy. The Blue People of Troublesome Creek. Science82, November, 1982. http://www.people.virginia.edu/~rjh9u/blkysc82.html(online).