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.
Find the initial osmotic pressure at room temperature of a cell if the only ions present are CaCl2 on either side of the membrane. Assume the concentrastions for K+ and Cl- from Ta
What is Indications for Operation Single Ventricle Physiology ? The operation is indicated in patients with single ventricle physiology. Fontan operation is also indicated in p
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Explain about enzymes All enzymes are proteins. Many enzyme proteins lack catalytic activity in the absence of a non-protein component, called a 'co-factor'. In this case, the
What is Crystal twinning Crystal twinning happens when two separate crystals share some of the similar crystal lattice points in a symmetrical manner. The result is an intergro
Necrobacillosis of liver It is a disease of cattle and lambs. The causative organism is Fusobacterium necrophorum. The condition does not usually cause any clinical symptoms i
Q. Explain Surlyn film? Surlyn films: Surlyn (SU) is a versatile film which is sometimes favoured over polyethylene due to some unique properties such as excellent moisture b
wdomestic effluent hat is
What evidence is there that makes it seem humans have more than a material existence?
I nclusion body hepatitis (IBH) A disease of chickens characterized by acute mortality, often with severe anemia, is caused by an adenovirus. A number of different serotypes h
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