Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
Cellular respiration is the transfer of energy from various molecules to produce ATP; takes place in the mitochondria of the eukaryotes, the cytoplasm of prokaryotes. In the proce
What is the etiological agent and the main manifestations of cholera? Cholera is a bacterial disease caused by the Vibrio cholerae. The disease is transmitted by fecal-oral rou
Fourth Week to Eight Week - Embryonic Development The common changes in body shape and plan of the embryo from fourth week to eighth week are displayed in Figure. The fourth
Q. What is the antagonism between the sympathetic and the parasympathetic neural actions? In general the action of the parasympathetic and the sympathetic are antagonistic that
Define Regulation of Water Balance? The input of water, as well as, its loss can be highly variable due to individual habits and environmental factors; in spite of this, the to
Match dehydration reaction and hydrolysis reaction to molecule synthesis and molecule break-down.
Explain Saquinavir Saquinavir (SQV, Fortovase, Invirase) - When administered as a single protease inhibitor, a soft-gel preparation (Fortovase) with improved bioavailability an
Name the t major groups of cells required in attaining specific immunity. Name the end products of aerobic and anaerobic glycolysis List two ways by which molecules of ATP are
Explain the Clinical Features of PS and VSD ? Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Weight Measurement of New Born Check weight on an infant weighing machine. Weight of the neonate is 2.8-3.5 kg with an average weight of 2.5 kg. When taking weight take
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd