Ethological isolation, Biology

Assignment Help:

Members belonging to different species refrain from mating because of the behavioural differences between them. Such behavioural differences usually centre around specific courtship patterns which the species have evolved. The behaviour patterns are more conspicuous in animals rather than in plants. And among animals, once again, the courtship behaviour is more pronounced among terrestrial and fresh water organisms than in marine forms. Mayr points out that in those forms where there is an elaborate courtship behaviour the interspecific hybrids are rare. Closely related species that do not have pair-binding courtship rituals do commonly give rise to hybrids. Mayr is of the opinion that in species where there is a courtship behaviour pattern, the "engagement" may be broken if the pairs do not belong to the same species, A detailed study of the courtship behaviour of six species of Drosophila showed that courtship and mating could be divided into six phases. If there is incompatibility at any one of these six phases, the potential mates break off and the courtship is discontinued. Under laboratory conditions, the interspecific crosses have not been successful and the courtship was terminated even in the first stage. What is more interesting here is that even to a trained observer differences in courtship behaviour exhibited by different species may appear to be trivial and insignificant. But the species recbgnise the specific signals and respond suitably. In certain other forms differences in courtship behaviour between species could be very pronounced, The courtship dances of the different species of Uca (shore crab) could be recognised from a distance. This is also true of mating dances of salamanders, turtles and birds.


Related Discussions:- Ethological isolation

Names and uses of the various laboratory tools, What are the names and uses...

What are the names and uses of the various laboratory tools? Tools are beakers, microscopes, tweezers, hot plates, lasers, test tubes, voltmeters, Erlenmeyer flasks, thermomete

Explain the function of cell walls, What is plant cell walls made of? ...

What is plant cell walls made of? Explain the function of cell walls? Plant cell walls are made of cellulose embedded in carbohydrates and proteins. Cell walls help su

Skin, SKIN - Largest organ of body. It is covered by hair...

SKIN - Largest organ of body. It is covered by hairs or pelage i.e. pillifera. Study of skin is dermatology. Outermost covering of body. Skin is elastic and

Agro industrial-complication during gestation, Complication during gestatio...

Complication during gestation Many complications like uterine torsion, vaginal prolapse, mummification, foetal maceration, hydra allantois, hydro amnios and teratological abno

Explain the history of animal taxonomy, Explain the History of Animal Taxon...

Explain the History of Animal Taxonomy? The beginning of animal taxonomy was made by Aristotle (384-322 B.C.). He extensively studied about anatomy, embryology, habit and ecolo

Define information required for management of emergencies, Define Informati...

Define Information Required for Management of Emergencies? Management or intervention needs accurate information about the actual situation and includes many non-nutritional co

Define micronutrient needs of a lactating mother, Define Micronutrient need...

Define Micronutrient needs of a lactating mother? Vitamin and mineral deficiencies can have profound influence on the composition of milk. Calcium is a nutrient of special conc

Preparation of dilutions - standard or total plate counts, Define Preparati...

Define Preparation of Dilutions - Standard or Total Plate Counts? 1. Serial dilution of homogenized sample in an appropriate diluent. Preparation of dilutions - Decimal dilu

Entropy, ENTROP Y - Transfer of energy takes place from high energy...

ENTROP Y - Transfer of energy takes place from high energy level to low energy level. Rudol f clausius gave this term. During it there is collision of particles, r

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