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

Effects on health - consequences of air pollution, Effects on Health - Cons...

Effects on Health - Consequences of Air Pollution Since the air pollutants are inhaled they attack various parts of the respiratory system on their route to air sacs. Once the

Surrogacy, what is surrogate motherhood

what is surrogate motherhood

How are antivenoms produced, Q. How are antivenoms produced? Why are antive...

Q. How are antivenoms produced? Why are antivenoms an example of passive immunization? Antivenoms are obtained by the following process: the venom (antigen) is inoculated into

Artificial respiration, Artificial respiration First - aid for drown...

Artificial respiration First - aid for drowning victims should aim to restore respiration as quickly as possible. First of all, nose, mouth and throat of the victim shoul

Experiments do not support the hypothesis, If experiments do not support th...

If experiments do not support the hypothesis, the hypothesis is always rejected or wrong. True or False?

How calcium prevents luxury consumption of potassium, How calcium prevents ...

How calcium prevents luxury consumption of potassium Increasing Ca:K ratio in soil solution depresses the uptake of potassium. Thus one of the harmful effects of over liming m

Diagnosis, The symptoms and signs of endocarditis are often constitutional ...

The symptoms and signs of endocarditis are often constitutional and, when localized, often result from a complication of IE rather than reflect the intracardiac infection itself. C

Define higher order structure, Which kind of weak interaction can define hi...

Which kind of weak interaction can define higher order structure and in the same time DNA.

State three main ways in which the body uses food, State three main ways in...

State three main ways in which the body uses food. The body uses food (i) for energy, (ii) for growth (making new cells), (iii) repairing or replacing tissues.

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