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

Sickle Cell, Sickling occurs in deoxyhemoglobin S, but not in oxyhemoglobin...

Sickling occurs in deoxyhemoglobin S, but not in oxyhemoglobin S. Oxyhemoglobin has a small hydrophobic \"pocket\" in a ß chain region located in the interior of the protein. In de

Explain the stages of alzheimer''s disease, Explain the Stages of alzheimer...

Explain the Stages of alzheimer's disease? Stage I - There is an increased forgetfulness, anxiety and depression. Associated nutrition related changes include difficulty in

What is the kind of digestion occurs in cnidarians, Q. What is the kind of ...

Q. What is the kind of digestion that occurs in cnidarians? These animals have a digestive cavity and they make intracellular and extracellular digestion. The extracellular dig

Define post-surgical nutrition support for chd patient, Define Post-surgica...

Define Post-surgical Nutrition Support for CHD Patient? Nutrition support should be started as soon as possible. If oral not possible, enteral nutrition support should be pr

Explain dna replication, Q. As a result of the DNA replication two DNA mole...

Q. As a result of the DNA replication two DNA molecules come into existence. Why is it not correct to assert that the two "new" DNA molecules are created? What is the name given to

Pathophysiology of bronchial asthma, Pathophysiology Asthma result fro...

Pathophysiology Asthma result from several physiological alterations, including altered immunologic response, increased airways resistance, increased lung-compliance, impaire

Concept of universality of the genetic code, Q. What is the concept of univ...

Q. What is the concept of universality of the genetic code? What are the exceptions to this universality? The genetic code is universal because the rules of protein codificatio

Define the cooper''s run (12 minute run) method, Define the Cooper's Run (1...

Define the Cooper's Run (12 minute run) Method? To undertake this test, a 400 metre running track is required-marked every 100 m and a stop watch. The test comprises of noticin

Define interaction of vitamin k with calcium, Define interaction of vitamin...

Define interaction of vitamin k with Calcium? Since vitamin D functions have an impact on calcium metabolism, an inter-relationship exists between vitamin IS-dependent proteins

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