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!
An interesting observation made by an American biologist H.C. Bumpus (1899) provides a good explanation for normalising selection. Bumpus collected some 136 injured house sparrows after a severe snow and sleet storm with high winds at Woods hole. Of these birds 64 died, resulting in two groups of sparrows, those that were killed by the storm and the ones that survived. Bumpus, made measurements of a number of randomly chosen traits such as wing length, wing span, tarsus length etc and found that those that were killed by the storm had measurements which fell at the ends of the bell shaped curve. In other words, birds which had either mean or close to the rnean measurements were the ones to survive. Normalising selection generally eliminates during a catastrophe or a stressful situation individuals whose traits vary markedly from the mean values. By way of interpreting Bumpus's observations, it could be said that the birds which were blown down easily by the winds had either their wings too long for their body weight and therefore presented a larger surface area or they had too short wings for their body size and therefore could not fly against strong winds. Prjor to the catastrophe the range of individual measurements was larger as compared to the range of measurements that survived the catastroihe. Every catastrophe may narrow down the variability of the population thereby weeding out suboptimal genotypes.
What is genesis of coronary artery diseases ? Like any other disease conditions, origin of CAD depends on an interplay between the heredity and environment so called 'nature' a
Define Intentional Adulteration - Types of Adulteration? In intentional adulteration, the substance is added, removed or substitute knowingly by the adulterator for the purpose
Q. List the counselling skills? Slowly start winding up the contact with the client and the family by providing them support, motivating the client to take care of oneself with
Triple Fusion The fusion process between the other male gamete and the secondary nucleus follows the same pattern as syngamy. In most plants, the polar nuclei are only partial
Explain Hair changes - clinical signs of kwashiorkor? In kwashiorkor, the hair loses its healthy sheen and becomes silkier and thinner. It takes coppery red colour (referred to
Explain the Compartments of Body Water? Within the body, water is found in two major compartments. These are: - The intracellular compartment (inside the cell) - The extr
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
What are cytokinins? Where are they made? Cytokinins are phytohormones active in the promotion of cellular division; they slow down the aging of tissues and act together with a
Exudate gums Most exudates gums come from compounds produced when the plant is wounded and these substances seal the wound. Most widely used exudate gum is 'gum Arabic' exuded
Q. Class Reptilia identity card. How are they characterized according to examples of representing beings, basic morphology, skin, respiration, circulation, nitrogen waste, thermal
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd