Observation of bumpus, Biology

Assignment Help:

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.


Related Discussions:- Observation of bumpus

Role of biotic factors inducing senescence, Role of Biotic Factors Inducing...

Role of Biotic Factors Inducing Senescence Besides environmental and endogenous factors, biotic factors also play a role in inducing senescence. For example, due to an attack

Explain about the adie''s pupil disease, Adie's  (Tonic) Pupil In Adie'...

Adie's  (Tonic) Pupil In Adie's syndrome there is no evident cause for the denervation. Most patients are women, aged 20-40 and have poor light reaction in one eye. When examin

Agro industrial-potassium, Potassium Potassium, the third most abundan...

Potassium Potassium, the third most abundant mineral in the body, is the major cation in intracellular fluid. Forages are excellent source of potassium, usually containing 1 t

Into which subphyla are the protochordates divided, Into which subphyla are...

Into which subphyla are the protochordates divided? What are some representatives of each protochordate subphylum? Urochordates (or tunicates) and cephalochordates are the two

Define relation between volatile substances and proteins, Interactions betw...

Interactions between Volatile Substances and Proteins               Flavour binding may involve adsorption at the surface of food or penetration to the food interiority by diffu

What is paediatric clinical literature, What is paediatric clinical literat...

What is paediatric clinical literature The paediatric clinical literature has expanded greatly in its coverage of the wide variety of medical circumstances that can negatively

Why immune response involves the activities of proteins, The immune respons...

The immune response involves the activities of proteins, cells, and the lymphatic system.

Organisms contain enzymes, Some organisms contain enzymes that condense a f...

Some organisms contain enzymes that condense a fatty alcohol and a fatty acid to generate wax esters. Draw decanol, plamitic acid (C16:0 fatty acid) and the resulting wax ester gen

Unit membrane model, structure explanation of unit membrane model

structure explanation of unit membrane model

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd