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

Define the estimation of haemoglobin in blood, Define the Estimation of Hae...

Define the Estimation of Haemoglobin in Blood? Several methods are used to determine haemoglobin. In these methods hemoglobin is measured as oxyhaemoglobin, carboxyhaemoglobin,

What are the cells that form the cartilaginous tissue, What are the cells t...

What are the cells that form the cartilaginous tissue? The main cells of the cartilages are the chondrocytes, originate from the chondroblasts that secrete the intersticial ma

Describe the electron transport system, a) Describe the electron transport ...

a) Describe the electron transport system. Where does it happen in a mitochondrion and what is the role of oxygen in it ? b) Explain the events that happen in the human heart du

Calculate the minimum dissolved oxygen tension, Given our knowledge so far ...

Given our knowledge so far we now need to evaluate if it is feasible to run the process in the designed vessel. We therefore need to compare the oxygen uptake rate and the oxygen t

What is class amphibia , What is Class Amphibia ? Class Amphibia take...

What is Class Amphibia ? Class Amphibia takes its name from the Greek words "amphi" and "bios." Amphi means "both sides," or "both types," and bios means "life." This name-bo

Define complete assessment for dietary management - surgery, Define Complet...

Define Complete Assessment for Dietary Management during Surgery? A complete assessment must include: Physical examination (anthropornetric measurements such as ideal/us

Describe the organization of the vascular plant body, Describe the Organiza...

Describe the Organization of the Vascular Plant Body? A typical plant body consists of two distinct systems: a root system and a shoot system. The root system is usually below

Antimicrobial barriers - proliferation of microorganisms, Q. Antimicrobial...

Q. Antimicrobial Barriers -  proliferation of microorganisms? The first barrier is the integument: a physical barrier to protect the food, e.g., the shell on eggs, the skin on

Define herbals - old books about plants, Define Herbals - Old books about P...

Define Herbals - Old books about Plants? During the Middle Ages, following the decline of the Greek and Roman civilisations, little significant botanical progress was made. The

Infectious and inflammatory conditions for lymphatic system, Q. Why in infe...

Q. Why in infectious and inflammatory conditions may clinical signs related to the lymphatic system occur? The lymph nodes or lymph glands have lymphoid tissue that produces ly

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