Biological evolution, Biology

Natural selection is a process which directs all biological evolution. It is a process that directs genetic changes which when proved to be adapted to the environment are retained in the genome. In other words, man like any other organism may have to passively adapt lo changing ecological circumstances through a slow, generation by generation change in gene complexes. The question is, does natural selection act in the same way in man as it is acting on other organisms. The major difference between man and other organisin is that man is capable of steering his own evolution whereas the other organisms cannot. Teilhard de Chardin, an eminent human paleontologist and anthropologist says "the evoluton of life on earth, far from having come to a stop, is on the contrary now entering a new phase. The Darwinian era of survival by natural selection is thus succeeded by a Lamarkian era of super life brought about by calculated invention". Such a statement gives credence to the hypothesis that man can monitor his own evolution in future.

There is evidence to suggest that man through the technological revolution has modified the role of natural selection. As an example one may mention the cancer of the eye, the retinoblastolna caused by a dominant mutation. The disease develops as a tumor in one of the eyes of the affected child, spreads to the other eye and then extends to the brain causing the death before the individual reaches the adulthood. Today, if the condition is detected sufficiently early, it is possible to remove the tumor surgically despite the loss of one eye. The child can grow into a near normal adult, marry and give birth to children. But there is a 50% chance for his children to be born with retinoblastoma. And inturn they have to be treated for the disease. Here is an instance where, through a surgical treatment a lethal gene is permitted to be preserved and passed on to the subsequent generations. Natural selection in normal course would have aimed to eliminate the gene from the population. But if the lethal condition were to be completely cured in every patient the frequency of the gene would increase slowly in the population.

Posted Date: 4/5/2013 2:55:43 AM | Location : United States







Related Discussions:- Biological evolution, Assignment Help, Ask Question on Biological evolution, Get Answer, Expert's Help, Biological evolution Discussions

Write discussion on Biological evolution
Your posts are moderated
Related Questions
Define Aerobic Exercise or Aerobic Energy System? To produce necessary energy, the body uses an aerobic pathway and an anaerobic pathway. Exercise that relies heavily on oxygen

What are the differences between blood retinal barrier and blood aqueous barrier? Blood Retinal Barrier: Blood retinal barrier is present in retina. In retina there are t

E r y s i p e l a s A sudden onset of infection with the bacterium E rysipelothrix insidiosa ( E . rhusiopathiae ) is seen in turkeys and increasingly in free-rang

Alluvial Materials of this catego~ya re deposited by running water in the form offroodplains, river terraces, deltas and alluvial fans. These deposits have two outstanding char

Surgical preparation of the bone - drill technique It is essential not to allow the bone to be heated above 47°C during preparation of the site as this will cause bone cell dea

LIGHT All of us know that the sun is the ultimate source of energy for all activities in our biosphere. The electromagnetic radiations from the sun supply energy which warms up t

Q What are instances of human diseases caused by bacteria? Some human diseases caused by bacteria are tuberculosis, pertussis, diphtheria, gonorrhea, bacterial meningitis, bubo

What is an example of a situation in which the neuron cell body is located in a part of the body and its axonal terminal portion is in another distant part of the body? Why does th

Define Nutrition, Diet and Cancer? In this, we will discuss the common forms of cancer, how they develop, relevant etiological factors, pathological/metabolic changes and other

Some people have disbeliefs regarding insulin injection. You have to find out if there are any disbeliefs and try to explain the importance of insulin injection. Do not force the p