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

Formation of notochord and somites, Formation of Notochord and Somites ...

Formation of Notochord and Somites The formation of notochord and somites from the transplanted dorsal lip was supposed; these are normally derived from cells of the dorsal li

List the tissues of pancreas, Q. List the tissues of pancreas? The panc...

Q. List the tissues of pancreas? The pancreas is made up of two types of tissue: The exocrine tissue secretes digestive enzymes. These enzymes are secreted into a network of

Size of ecosystem, Size of Ecosystem As you know an ecosystem may be as...

Size of Ecosystem As you know an ecosystem may be as small and as simple as a cow dung pad or as complex and large as an ocean or the biosphere itself, comprising a wide variet

Determine inharmonious intraspecific ecological interaction, Why is canniba...

Why is cannibalism an inharmonious intraspecific ecological interaction? In cannibalism an individual eats other of the same species (occurs in some insects and arachnids). Sin

Explain interaction of pyridoxine with carbohydrates, Explain Interaction o...

Explain Interaction of pyridoxine with Carbohydrates? Pyridoxine is involved in glyconeogenesis through its action in transaminase reactions. Low levels of pyridoxine impair gl

Explain digestion and of digestive system of platyhelminthes, Q What are th...

Q What are the kinds of digestion and of digestive system of platyhelminthes? Flatworms have incomplete digestive systems and they present intracellular and extracellular compl

Skeletal system - ribs, RIBS- Curved or stretched 'S' sha...

RIBS- Curved or stretched 'S' shaped bones. 12 pairs, form thoracic basket, attached by head part to vertebral column and by tail part to sternum. 7 pairs a

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