darwinism

                                            Darwinism 

Charles Robert Darwin was born Inshewsbury,England(1809-1882).

Robert grant taught him zoology and Henslow taught him botany.

Darwin use to spent most of  time with henslow, so people call him man who walks with henslow.

H.m.s. beagle

Henslow arrange a trip for him in ship "h.m.s. beagle" as an unpaid naturalist(her majesty's ship)

The journey was intially planed for two years between lasted for 5 years.

Ship started from playmouth(england) in december, 1831 and returened back in october 1836.

During his journey, darwin explored the flora and fauna of many countries  and island eucador ,chili,peru,argentina and galapagous island.

Galapagos island 

These are volcanic islands located nearly 960km away from the west coast of south america in pacific ocean.

These are guano island.

Darwin reached here in 1835 and spent more than a month here.

Darwin   called galapagus island as "living laboratory of evolution"

Darwin absored many unusual animals here,like

1.giant tortoises

2.giant lguanas(lizard) marine as well as terrestrial 

3.finches

Finches

Darwin was very much impressed by the variety of finches(14 species).

13 species found in galapagus island.

1 species on cocos island.

There were insectivorous tree finches,insectivorous ground finches,vegetarian tree finches, seed eating finches,cactus eating finches.

      

Finches originally belong to same ancestral stock which migrate from south america main island to Galapagus  island.

From original seed eating variety, finches with altered from of beak evolved(like insectivorous tree finches,vegetarian tree finches  etc).

Finches provide an e.g. for adaptive radiation or divergent evolution.

In galapagus islands,finches got abundant food for feeding,space and partners for mating and competition free environment.

Finches provide an evidence for origin of species by mean of geographical isolation.