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

Allow the natural capital from one country to be utilized, In today's globa...

In today's global economy, goods flow from one country to another like never before, allowing the natural capital from one country to be utilized in many other countries. Some have

Theory or principle of determination of the quality of milk, Explain the Th...

Explain the Theory or Principle of Determination of the Quality of Milk Milk is an ideal medium for the survival and growth of microorganisms. It contain all the nutrients, i.e

What are the advantages of yoga, What are the advantages of Yoga Yoga h...

What are the advantages of Yoga Yoga has been derived from the Sanskrit word Yuj which means union. It is popular since ancient times. It is also one of the means to maintain f

Tropical deciduous forests, Rainfall is high, sometimes higher than tropica...

Rainfall is high, sometimes higher than tropical rain forests but seasonal. There are pronounced wet and dry periods, and so are winter and summer seasons. The soils are brown in c

Explain the difference among dna primase and dna polymerase, Which of the f...

Which of the following is not a difference among DNA primase and DNA polymerase? A. DNA primase can initiate replication of DNA de novo whereas DNA polymerase needs a short oli

Shivering - heat production, Shivering - Heat Production The mechanis...

Shivering - Heat Production The mechanism of thermogenesis with which we are more familiar is shivering and all adult birds and mammals seem to use these mechanism. Shivering

Define efficiency - terminologies used in chromatography, Define Efficiency...

Define Efficiency - terminologies used in chromatography? Efficiency in chromatography is expressed as number of theoretical plates.           H =   L/N Where, H is heigh

Define paediatric problems and nutritional management, Define Paediatric Pr...

Define Paediatric Problems and Nutritional Management? The process of accepting and digesting food in adequate amounts to meet nutrition needs is termed as feeding. Certain gro

Amnion adaptation to terrestrial life, Q. Why can the amnion also be consid...

Q. Why can the amnion also be considered an adaptation to terrestrial life? The amnion is as well an adaptation to dry land since one of its functions is to prevent desiccation

Dietary approach for pectic ulcer, Q. Dietary approach for pectic ulcer? ...

Q. Dietary approach for pectic ulcer? Let us now move on to understand the dietary approach. We shall begin with the nutrient requirements of the patients. However before we ta

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