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

Structure of the human vision apparatus, Q. What are the structures that co...

Q. What are the structures that compose the human vision apparatus? The organs of the human visual apparatus are the eyes the optical nerves and the visual areas of the brain l

Explain fundamental of the photosynthesis process, Q. Is it correct to cons...

Q. Is it correct to consider water decomposition by the action of light the fundamental of the photosynthesis process? In addition ADP photophosphorylation, photic energy is al

What is the functional unity of the kidneys, Q. What is the functional unit...

Q. What is the functional unity of the kidneys? The functional (filtering) unity of the kidneys is the nephron a nephron is made of efferent arteriole, afferent arteriole, glom

Floral induction, Floral Induction The transformation of vegetative ap...

Floral Induction The transformation of vegetative apex into a floral apex is a multifactor and multistep phenomenon. Despite researches on flowering carried out during the las

Define whey protein concentrates, Explain Whey protein concentrates Whe...

Explain Whey protein concentrates Whey protein concentrates (WPC) are  the products derived from whey from which the water, minerals and lactose have been removed.  WPC is a wh

Explain intubation and ventilation, Explain Intubation and Ventilation ? ...

Explain Intubation and Ventilation ? If supplemental oxygen therapy or non-invasive ventilation do not help, the next step would be to intubate and commence mec

Microbiology, 2. Vaccinations against various childhood diseases have contr...

2. Vaccinations against various childhood diseases have contributed to the entry of women, particularly mothers, into the fulltime workplace. a. Is this statement supported by data

Define ailing and failing, Define ailing and failing Clinically unhealt...

Define ailing and failing Clinically unhealthy implants are classified as "ailing" or "failing". It is necessary to distinguish between an ailing versus a failing implant to de

Define conjunctival xerosis - micronutrient deficiencies, Define Conjunctiv...

Define Conjunctival Xerosis - Micronutrient Deficiencies? Conjunctiva in nonnal children is bright white, smooth and glistening. Conjunctival xerosis is characterized by drynes

What is bioremediation, Q. What is bioremediation? The Bioremediation i...

Q. What is bioremediation? The Bioremediation is the use of microorganisms, like protists, bacteria and fungi to degrade noxious substances turning them into non toxic or less

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