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

Symmetry system characterized in echinoderms, Q. How are the nervous and th...

Q. How are the nervous and the symmetry system characterized in echinoderms? Adult echinoderms, along with cnidarians, are the animals that present radial symmetry that is thei

How to dna fragments for comparison with other dna samples, DNA fingerprint...

DNA fingerprinting produces a unique banding pattern of DNA fragments for comparison with other DNA samples.

Assessment of ventricular septal defect, Assessment   On assessment a c...

Assessment   On assessment a child with ventricular septal defect will show clinical manifestations depending upon the size of  the defect. The small defects are usually asympt

Mollusca, family ,genus, class order , species of mollusca

family ,genus, class order , species of mollusca

Biota of pelagic zone, Biota of Pelagic Zone Pelagic region constitute...

Biota of Pelagic Zone Pelagic region constitutes 90 per cent of the total ocean surface and is less rich in species and numbers of organisms than the two regions discussed bef

Management for poisoning and overdose, Management  for Poisoning  and Ove...

Management  for Poisoning  and Overdose: The following data should be obtained at the time of initial contact.  Phone Number:  getting the caller's telephone number  is n

What are hormones, What are hormones? Hormones are chemicals secreted b...

What are hormones? Hormones are chemicals secreted by the body to create changes in physical appearance, reproductive behavior, and emotions. Hormones are organic chemical m

What is asexual reproduction, What is Asexual Reproduction? Asexual re...

What is Asexual Reproduction? Asexual reproduction occurs in prokaryotes through the process of binary fission. Primitive eukaryotes and plants also reproduce by various t

Regulation of pyruvate kinase, Regulation of pyruvate kinase, pyruvate carb...

Regulation of pyruvate kinase, pyruvate carboxylase and PEP carboxykinase A) In liver,  pyruvate  kinase  is inhibited  by high levels  of ATP and alanine  so which  glycolysis

Describe a method of diagnosing diabetes mellitus, Q. In ancient Greece the...

Q. In ancient Greece the father of Medicine, Hypocrates, described a method of diagnosing diabetes mellitus by tasting the patient's urine. What is the physiological explanation fo

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