A lowering of effective power, vitality, or essential quality to an enfeebled and worsened kind or state; intellectual, moral, or artistic decline; progressive deterioration of physical characters from a level representing the norm of earlier generations or forms; deterioration of a tissue or an organ in which its function is diminished or its structure is impaired.
The domestic dog offers a unique opportunity to explore the genetic basis of disease, morphology and behaviour. We share many diseases with our canine companions, including cancer, diabetes and epilepsy, making the dog an ideal model organism for comparative disease genetics.
Elinor K. Karlsson, Kerstin Lindblad-Toh - Leader of the pack: gene mapping in dogs and other model organisms
In the same way that inbreeding among human populations can increase the frequency of normally rare genes that cause diseases, the selective breeding that created the hundreds of modern dog breeds has put purebred dogs at risk for a large number of health problems, affecting both body and behavior.
Cancer is among the leading causes of death worldwide.
As we unlock the secrets of the human genome (the complete set of human genes), we are learning that nearly all diseases have a genetic component. Some diseases are caused by mutations that are inherited from the parents and are present in an individual at birth, like sickle cell disease. Other diseases are caused by acquired mutations in a gene or group of genes that occur during a person's life. ... Most genetic disorders, however, are "multifactorial inheritance disorders," meaning they are caused by a combination of inherited mutations in multiple genes, often acting together with environmental factors.
How can the human genome even be maintained against the degrading effects of billions of new deleterious mutations, which enter the human population each generation?
Evolutionary biologists at the University of Toronto have found that individuals with low-quality genes may produce offspring with even more inferior chromosomes, possibly leading to the extinction of certain species over generations. A study published in Proceedings of the National Academy of Sciences (PNAS) predicts that organisms with such genetic deficiencies could experience an increased number of mutations in their DNA, relative to individuals with high-quality genes. The research was done on fruit flies whose simple system replicates aspects of biology in more complex systems, so the findings could have implications for humans.
Human beings are compelled to live within a lie, but they can be compelled to do so only because they are in fact capable of living in this way. Therefore not only does the system alienate humanity, but at the same time alienated humanity supports this system as its own involuntary masterplan, as a degenerate image of its own degeneration, as a record of people's own failure as individuals.
Believing as I do that man in the distant future will be a far more perfect creature than he now is, it is an intolerable thought that he and all other sentient beings are doomed to complete annihilation after such long-continued slow progress.