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.
Explain Stress and Psychosocial Tension in lifestyle risk factors? Stress and psychosocial tension are other lifestyle factors in initiating coronary artery disease and precipi
Peri operative Myocardial Infarction : Peri operative Myocardial Infarction is diagnosed by the appearance of fresh Q waves. Non-Q, myocardial infarction is suspected when there
Explain Theory of enzyme action L. Michaelis and k L. Menten developed a general theory of enzyme action and kinetics in 1913. According to this theory, we learnt that
Express the term ctene. This unique locomotory structure is found in Ctenophora and is made up of fused cilia arranged into flattened plates. Ctenes are then organized into eig
sir i''m not understanding cell division rightly. in case of meiosis both paternal and maternal chromosome goes in two cell separately while in case of mitosis they go alongwit
Strawberries are quick frozen at a rate of 6500 kg/h. The fruit enters the freezer at a temperature of 15°C and is frozen to a final temperature of -20°C. Calculate the rate of hea
What is the difference between monosaccharides and disaccharides? What are some examples of disaccharides and of monosaccharides that form them? Monosaccharides are simple mole
Floristic Composition - Qualitative Characters One of the important qualitative characteristics of a community is its floristic composition. This broadly refers to the kind o
Q. Properties of foods? various properties of foods, under which the quality attributes of foods were introduced to you in terms of food quality and its categories as appearanc
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
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