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

How do schistosomes differentiate regarding sex separation, Q. How do schis...

Q. How do schistosomes differentiate regarding sex separation? The Schistosomes are dioecious that is the species has separated sexes, female and male individuals.

What are cotyledons, What are cotyledons? Cotyledons, or seed leaves, a...

What are cotyledons? Cotyledons, or seed leaves, are structures formed by the embryo of angiosperms to absorb nutrients from the endosperm and to keep and transfer these nutrie

Cloning protocol, Sally Subcloner wants to clone a fragment into pUC19 (Map...

Sally Subcloner wants to clone a fragment into pUC19 (Map above - From New England Biolabs). Her fragment was a protein coding gene of 2.7 kb, and had Xho I sites on either end (a

Plant water, Plant Water Role of Water in Plants You know that water i...

Plant Water Role of Water in Plants You know that water is the main constituent of plant cells. It performs the following major functions Water as a Solvent Water is a v

What is the gross primary production of an ecosystem, What is the gross pri...

What is the gross primary production of an ecosystem? How does GPP relate to photosynthesis? Gross primary production of an ecosystem, or GPP, is the amount of organic material

What is behavioural neurology, What is Behavioural neurology Behavioura...

What is Behavioural neurology Behavioural neurology contains the study of disorders of mood, personality, intelligence, perception and arousal and is concerned with the structu

Etiological factor of malabsorption syndrome, Q. Etiological factor of mala...

Q. Etiological factor of malabsorption syndrome? The causes cited for malabsorption can be associated with a number of diseases. Many of these diseases you may not know presen

Effects of long term malnutrition on adults, Effects of long term malnutrit...

Effects of long term malnutrition on adults In adults, once the stored carbohydrates and fats are used up, the body starts using proteins to generate energy. These protei

What is biomaterial, What is Biomaterial Biomaterial is defined, in the...

What is Biomaterial Biomaterial is defined, in the broader sense, as any pharmacologically inert material that is capable of interacting with a living organism without causing

Protozoa phylum, what is the main quality of this phylum

what is the main quality of this phylum

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