Why Western Ghats are rich in biodiversity and endemism of species ?

upsc_cracker

Discussion thread for Western Ghats Biodiversity

Why Western Ghats are rich in biodiversity and endemism of species ?
How western ghat flora and fauna different from tropical rainforest (Amazonia )?

@Neyawn @Babur @wolverine8997

@all gyaani's plz pour in your valuable views

namantandon09

Western ghats receive orographic rainfall due to which rainfall is abundant with abundant rainfall species of different types can be found

upsc_cracker

@all

plz someone take a shot on "why Western Ghats are rich in endemism ?"

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@Babur

saar kahan se padhte ho yeh sab bata do mere jaise bacho ka bhala ho jayega :P
awesome answer

Wolverine8997

Reason for endemism

Endemism occurs due to speciation occurring in a specific geographical area. Speciation is the process by which new species are formed. There are two views regarding how speciation occurs.

Dispersalist view: According to this view speciation occurs as animals spread out from a centre of origin, crossing pre-existing barriers that they would not readily cross back, and hence they would be cut-off from the original group.

Vicariance view: According to this view, Species spread over an area become isolated due to emergence of a geographical barrier. The species in the isolated geographical area can’t cross the barrier and hence speciation occurs. These barriers emerge due to factors like continental drift or emergence of Himalayas.

The endemism of Western Ghats can be explained on the basis of Vicariance view. Once the Indian peninsula separated from the Gondwanaland approximately 100 million years ago, it had remained isolated for a considerable period of time till it collided with the Eurasian plate. This considerable isolation may have lead to emergence of lot of unique species limited to the peninsular region.

trying_tobawesm

@upsc_cracker @Wolverine8997

wolverine is on right track but i wonder if so much complexity is called for,,,

why would there be so many biological varieties and some varieties which are only found in western ghats:

- coz there are many habitats and niches available due to climatic features of topography, temperature and precipitation ,,,so many types of species evolved

And why otherwise u think when we talk of biodiversity we talk of ecosystem level biodiversity. Coz we understand that diverse ecosystems provide differentials conditions and habitats for proliferation and richness of biodiversity,,,

upsc_cracker

Reason for endemism

The endemism of Western Ghats can be explained on the basis of Vicariance view. Once the Indian peninsula separated from the Gondwanaland approximately 100 million years ago, it had remained isolated for a considerable period of time till it collided with the Eurasian plate. This considerable isolation may have lead to emergence of lot of unique species limited to the peninsular region.

I partially with the reasoning let me play the devil's advocate over here ( if u don't mind saar)

If Western Ghats Endemism is only due to separation from Gondwana land then why endemism is so localized. why it doesn't get spread in peninsular plateau ?
The separation from Gondwana can very well explain endemism in Indian Subcontinent in general but there could more specific reason for confinement of Endemism in Western Ghats

PS: I have shot an arrow in the dark for deliberating and debating to eventually identify the actual reason just like scientific researchers :P

sunNy1985

Adding to Wolverine. Also I suppose that western ghats themselves being hilly region with varying relief height, from Gujarat to Kanniyakumari, hinders' the mobility of animals and vegetative propagation and seed dispersal of plants which coupled with tropical nature of Plateau that is high rain and high temperatures, has contributed to isolated evolution of rich assemblage of endemic flora and fauna.