Biological evolution, Biology

Assignment Help:

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.


Related Discussions:- Biological evolution

Explain the completed test - most probable number test, Explain the Complet...

Explain the Completed Test - Most Probable Number Test? Coliform colonies on EMB or Endo agar are further examined by completed test by inoculating lactose broth and nutrient a

Why isnt the cooking of vitamin c-containing foods, Why isn't the cooking o...

Why isn't the cooking of vitamin C-containing foods appropriate for vitamin C supply? To obtain vitamin C, for example, from an orange dessert, the vitamin-containing food cann

Explain the types of modified gellan gum, Explain the types of modified gel...

Explain the types of modified gellan gum There are 3 types of modified gellan gum.  (a) High acetyl gellan (partially deacetylated), which provides a thermo reversible gel,

Explain hemicellulose, Hemicellulose In plant cell walls, the most abun...

Hemicellulose In plant cell walls, the most abundant compound present is α-cellulose with long fibers embedded in a matrix of cementing compounds (matrix polysaccharides). Thes

Define use of soy protein concentrates in bakery products, Define Use of So...

Define Use of Soy Protein Concentrates in Bakery Products? Unlesss higher protein fortification levels are necessary, there is no special reason for using soy protein concentra

Lymph, LYMPH - Lymph is a mobile connective tissue comprising lymph pla...

LYMPH - Lymph is a mobile connective tissue comprising lymph plasma (fluid) and lymphcorpuscles (cells).   COMPOSITIO N - (i )      Lymph Plasma - It is simil

Quantitative changes, Quantitative changes The quantitative changes in...

Quantitative changes The quantitative changes in the availability of the active biomolecules occur in order to compensate for the loss of efficiency of the system caused by th

Explain the process of ige-mediated allergic response, Explain the Process ...

Explain the Process of IgE-Mediated Allergic Response? Basically, there are three steps involved with the IgE-mediated allergic response These include: Step 1: Sensitizat

What do you mean by blackcaps, Q. What do you mean by Blackcaps? Blackc...

Q. What do you mean by Blackcaps? Blackcaps are small songbirds found throughout Europe. A large population of blackcaps inhabits the forests of Germany. These blackcaps have t

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd