 |
|
|
|
![[info]](http://l-stat.livejournal.com/img/userinfo.gif) vexen | |
|
|
|
|
|
|
|
I've added a list of serious genetic diseases to my page on evolution, including Cystic fibrosis, Down's syndrome, Hemophilia, Huntingdon's disease, Muscular dystrophy, Sickle-cell anemia, Tay-Sachs disease and Thalassemia, to complement the list of inheritable personality disorders.
I also added a bit about dyslexia, which is closely linked with three genes. The genes involved include DCDC2, active in reading centres in the brain; and Robo1, which develops the corpus callosum connecting the two halves of the brain during foetal development.
The total picture is of a species that copes with multiple inherited dysfunctions. Many of our psychological ills result from the fact that our underlying psychological processes are leftovers from previous eras when life was much more simplistic and machiavellian. Prof Dietrich from the Philosophy Department at Binghamton University bemoans this history, stating that "it is a sad fact that much of our basic human psychology is built by evolution. These innate psychological capacities of ours are principally responsible for many of humanity's darkest ills. But in short, we abuse, discriminate, and rape because we are human"17. Genetic diseases are inherited or are made present from the moment of conception and do not result from any choice of lifestyle. Such random suffering is hardly the hallmark of a well-designed genetic system. Genetic diseases and undesirable personality traits afflict us because evolution is imperfect in its mechanism and blindly progresses down roads that can later turn out to be harmful.
Full page: "Evolution and the Unintelligent Design of Life: Inherited Traits, Genetic Dysfunction and Artificial Life" by Vexen Crabtree (2007) Tags: evolution
Current Location: Salisbury, UK
Listening To: "Little Suicide" by The Love Crave
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
From: vexen |
Date: May 16th, 2009 03:44 pm (UTC) |
| (Link) |
|
Well some diseases won't get wiped out, because they are side-effects of other things. Take what they call "heterozygote advantage", which is where having one allele is an advantage (e.g. against malaria), but having two causes a disease (i.e., blindness). This will create evolutionary pressure for the gene to be copied, but when two people with it have a child there is a 50% chance that the child will have two copies of the gene, causing a disease. This means that there will always be balances between certain diseases and certain advantages; i.e., evolution won't eradicate some diseases even given lots of time.
Other diseases, especially the ones to do with old age, and those that only come into affect after reproductive / childreading ages, simply do not have any evolutionary pressure on them. They arise as side-effects but because they don't hinder the passing on of genes during reproductive and child-reading ages, there is no selection operating againt them. Well none, that is, until we can properly diagnose such problems in advance and maybe fixing them manually through gene therapy.
Evolution just can't solve all genetic problems.
|
|
|
|
|
|
|
|
| |
|
|
|
Previous
