what is isolation? describe different types of reproductive isolation
Answers
Answer:
The field of biology describes "isolation" as a process by which two species that could otherwise produce hybrid offspring are prevented from doing so. There are five isolation processes that prevent two species from interbreeding: ecological, temporal, behavioral, mechanical/chemical and geographical.
Answer:
(1) Isolation means separation of the population of a particular species into smaller units. The orgarisms belonging to these suburits are prevented from interbreeding due to some barrier. These barriers are called isolating mechanisms.
(2) They prevent the genetie exchange and gene flOw.
(3) Due to isolating mechanisms in nature the divergence among organisms takes place gradually leading to speciation. The isolating mechanisis are of two types namely geographical isolation and reproductive isolation.
I) Geographical Isolation: The barrier in the form of physical distance or geographical barrier is called geographical isolation. The original population gets divided into two or more groups by geographical barriers such as river, ocean, mountain, glacier, etc. Organishms cannot crosse barners on their own and hence interbreeding is prevented between isolated groups. The separated groups experience different environmental factors and they acquire new traits by mutations. The separated populations develop distinct gene pool and they do not interbreed. Each subgroup then evolves differently which results into formation of new species. E.g Darwin's Finches, African elephant, Loxodonta and Indian elephant, Elephas.
ii) Reproductive Isolation : Two populaiions may be occupying the same area, they may not be separated by geographical barrier, Dut hen also they are reprodutively isolated. Such reprodutive isolation occurs due to change in genetic material, gene pool and structure of genital organs. Such differences prevent interbreeding between population. Such isolation later leads to speciation.
iii) Different types of reproductive isolations : Reproductive isolation is of two types, viz. pre-zygotic and post-zygotic isolating mechanisms.