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

Illustrate the different types of drug receptor interactions, Problem 1: ...

Problem 1: Briefly describe the different types of parenteral routes of drug administration. Definition of parenteral routes of administration. Show different types of

Tuberculosis, T ub e rc u l o si s Tuberculosis in animal is ca...

T ub e rc u l o si s Tuberculosis in animal is caused by Mycobacterium bovis , M. tuberculosis and M. avium and among these the most important causal agent is M.

Phylum platyhelminthes, PHYLUM  PLATYHELMINTHES Definition and Introd...

PHYLUM  PLATYHELMINTHES Definition and Introduction Bilateral and protostominal  organ  grade eumetazoans  without  a body cavity ( acoelomates)  platyhelminthes means fl

Structure and content of halsted reitan battery, Structure and Content of ...

Structure and Content of Halsted Reitan battery Although there are several versions of the Halsted Reitan battery, the differences tend to be minor, and there appears to be a

Periods of the second meiotic division, Q. What are the periods of the seco...

Q. What are the periods of the second meiotic division? Meiosis II is divided into metaphase II, prophase II, anaphase II and telofase II.

Who did epa consult with outside of the agency, Who did EPA consult with ou...

Who did EPA consult with outside of the Agency in making this rule? EPA consulted with many agencies, organizations, and individuals in the process of finalizing the plant- inc

Respiration, comparitive chart on different types of respiration obserbed i...

comparitive chart on different types of respiration obserbed in different type of respiration organ of respiration , types of respiration,energy obtained , by product formed

Explain monosaccharides, Monosaccharides :- Sugars consisting of  a  sin...

Monosaccharides :- Sugars consisting of  a  single  polyhydroxy  aldehyde or ketone unit.

Define chromatography - basic separation technique, Define Chromatography -...

Define Chromatography - Basic Separation Technique? Chromatography is the most effective technique for the separation, purification and identification of one or more biological

Elaboration of yolk- reproduction, Normal 0 false false fal...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

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