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

Phylum arthropoda, PHYLUM ARTHROPODA Definition and Introduction ...

PHYLUM ARTHROPODA Definition and Introduction Bilateral  and protostomial eucoelomate  eumetazoa with metamerically  segmented  and each  segment bearing a pair  of  join

Nature and structure of community, Nature and Structure of Community E...

Nature and Structure of Community Every place on earth -grasslands, forests, and ponds, edge of the river or sea is shared by many coexisting organisms. Plants, animals and mi

Evolution of the cell, EVOLUTION OF THE CELL All the living organisms a...

EVOLUTION OF THE CELL All the living organisms are made up of cells. A living cell may be defined as a compartment enclosed by a membrane that consists of several chemical cons

Chitin, CHITIN It is polymer of N-acetyl-D-glucosamine. It is a s...

CHITIN It is polymer of N-acetyl-D-glucosamine. It is a structural homopolysaccharide found in the fungal walls as fungus cellulose and as chitin in the exoskeleton of

What do you understand by abdomen, In organisms that have undergone tagmosi...

In organisms that have undergone tagmosisthe trunk often develops into two tagma, oneinvolved in locomotion and one that is notlocomotory. The tagma not involved in locomotionis re

Explain the transcription and the replication processes, What are similarit...

What are similarities and differences among the transcription process and the replication processes? A DNA polynucleotide chain serves as a template in replication (DNA duplica

Assignment of botany, habitat, habit, cell wall chemistry, reason why cell ...

habitat, habit, cell wall chemistry, reason why cell wall like this of Archaebacteria , eubacteria,fungi,algae,bryophytes ,pteridophyes, gymnosperms , angiosperms..

Explain brachial or radial approach, Q. Explain Brachial or Radial Approach...

Q. Explain Brachial or Radial Approach ? This technique involves performing the coronary angiogram through the right brachial artery in the right ante-cubital fossa. Usually a

Why the diluent is distilled water, A drug has a molec. weight of 200. How ...

A drug has a molec. weight of 200. How many grams would you use to make 100 ml of a solution that is isotonic (for man)? Assume that the diluent is distilled water and that the dru

Explain about simple proteins, Explain about Simple proteins Simple pro...

Explain about Simple proteins Simple proteins are those which are made of amino acid units only joined by peptide bond.  Upon hydrolysis they yield a mixture of amino acids and

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