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.
Determine the Modification of native starch Modification of native starch can be either physical or chemical. Chemical modification includes reaction of starch with acid or al
Ooplasmic Determinants and Somatic Cell Determination Eggs of tunicates go through typically mosaic development in which the various blastomeres become determined to follow th
Contagious ecthyma The contagious ecthyma virus is immunologically distinct from vaccinia, but similar to the causative agent of pseudo-cow-pox. It belongs to the genus Parapoxvi
Explain Theory or Principle of Gram Staining of Bacterial Cultures? Foods are rich in various nutrients and can support the growth and survival of microorganisms. The microbial
what is the fertilization?
Explain the factors that led to the decline of Science in Europe during iron age
Products of Cleavage (Morula and blastula) In several cases, the blastomeres in early cleaving stages tend to presume spherical shape like that of the egg earlier than cleava
Haustorial variations
It is important to explain to the patient about importance of taking treatment regularly. In case he misses the dose or takes medicine or insulin irregularly, explain the side effe
Q. What is the role of the ozone layer for living beings? The Ozone, O3, is a gas of the atmosphere that filters ultraviolet radiation from the sun disallowing most of that rad
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