Advertisements
Advertisements
प्रश्न
Define 'speciation'. Explain how speciation occurs.
उत्तर
The process by which new species develop from the existing ones is known as speciation. Speciation occurs when the population of the same species splits into two separate groups, which then get isolated from each other geographically by barriers such as mountain ranges, rivers or the sea. The geographical isolation of the two groups of population lead to their reproductive isolation due to which no genes are exchanged between them. However, breeding continues within the isolated populations producing more and more generations. Over the generations, the processes of genetic drift and natural selection operate in different ways in the two isolated groups of population and make them more and more different from each other. After thousands of years, the individuals of these isolated groups of population become so different that they will be incapable of reproducing with each other, even if they happen to meet again. In this way, two new species have been formed.
APPEARS IN
संबंधित प्रश्न
List three main factors responsible for the speciation and briefly describe each one of them
What factors could lead to the rise of a new species?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
Name one reptile in given case where higher incubation temperature leads to the development of :male progeny.
How does the creation of variation in a species ensure its survival
A plant has two varieties, one with red petals and the other with white petals. When these two varieties are cross-pollinated, all the offsprings have red petals?
(a) Which gene is dominant?
(b) Choose suitable letters to represent the two genes.
Name an animal having rudimentary eyes.
How are those species which are now 'extinct' studied?
Define speciation according to A.E. Emerson and explain its types giving suitable examples.