DARWIN vs WALLACE How Money Power and Connections can make all the Difference in the World
CHARLES DARWIN -lots of time to observe -careful note taker -young & energetic -well educated -well off HMS BEAGLE
-stopped at many places in South America -Darwin as gentleman companion and then as a naturalist -5 year trip around the world HMS Beagle.
Travelled down the east coast of South America Noted pattern of life changing as he went south found giant fossil species that resembled current species there What existing animal does this resemble?
GALAPAGOS ISLANDS -very few land animals present;all of which arrived recently -volcanic islands 1600 km from South America
Darwin visited each of the islands, and he found that each islands had mockingbirds with slightly different beaks and feeding habits
Darwin’s Finches: each had different bills & different diets.
The giant tortoises on each island had slightly different shells and ate slightly different plants.
Testing has suggested the giant creature was born around 1830, a few years before Darwin visited the Galapagos archipelago in She died in A zoo in Australia has held a 175th birthday party for Harriet the tortoise, one of the world's oldest known living creatures, a Giant Galapagos tortoise.
Darwin back in England -He was afraid of his own theories as they related to the church -Did more research on collected specimens for the next 20 years [ ] -Every Royal Navy vessel that landed on the Galapagos was required to collect finches & note where they were shot.
ground finches # tree finches # warbler finch woodpecker finch
Woodpecker finch chooses different cactus spine for each job a large cactus spine a small cactus spine
A small population of ground finches have found a new source of food….blood from large birds Ground finches with a booby These are called vampire finches
GALAPAGOS FINCHES -DARWIN thought that diet may have helped select or shape the beaks of the finches -mainland only has one finch -finches beaks match their diet -each island has unique finches
As Darwin thought, and experimented back in England, Alfred Russell Wallace was busy at work during the 1850’s in Brazil Unfortunately, all of his collected materials were destroyed when his boat sank in 1852 Others would have given up, Wallace just went off to Indonesia to start again
WALLACE -visited islands -careful observer -sold specimens he collected mostly “BIRDS OF PARADISE” -not well off
Bird of Paradise worth quite a bit as a preserved specimen
Wallace’s journey
Wallace’s Line Wallace’s Line Separates the Ecosystem of Asia and Australia (with an aptly named area called Wallacea in the middle) West of the Line are Asiatic species and East of the Line are a mixture of Asiatic and Australian species Even though Bali and Java share 97% of their bird species, Balia and Lombok only share 50% of their bird species
Wallace’s Line
Sailing 1000km from Java to Bali, saw only hornbills eating large fruit with big seeds After crossing 32km of ocean, at Lombok, saw only cockatoos eating large fruit with big seeds What Wallace observed
Remember, you can see Lombok from Bali Wallace wondered: “Why had God had created two such different birds to eat the same large fruit on two islands that were right beside each other?” Wallace concluded: The Environment had selected the best Asian bird [the Hornbill] and the best Australian bird [the Cockatoo] to match the same fruit
Darwin and Wallace in 1855
DARWIN / WALLACE Each concluded: -environment somehow shapes species -species vary due to natural selection
NATURAL SELECTION KEY IDEA – more births occur than can be supported so only the ‘fit’ survive Darwin & Wallace were both influenced by: Malthus – ESSAY ON POPULATIONS
WALLACE wrote to DARWIN -they shared similar theories -DARWIN was afraid WALLACE would scoop him -they agreed to publish a joint paper 1855
DARWIN published a book: 1859 “ On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life.”
The book was greeted with much criticism and ridicule, especially cartoons, although Darwin never mentioned humans at all in his book. Mr. Darwin, sir!
Reaction to “The Origin of Species”
Darwin fled to his country house and would see no visitors Thomas Huxley was a friend who agreed to speak for Darwin. He became known as “Darwin’s Bulldog” because he loved to argue about evolution [with anyone]
There was a famous evolution debate on June 30, 1860 between Huxley and Bishop Wilberforce. Huxley responded that “I would rather be descended from an ape than from a pompous ass like you!”. Bishop Wilberforce was winning the debate until he strayed into Human Evolution. At some point he challenged Huxley about his ancestry. And the audience ended the debate with applause for Huxley. Evolution had won its first trial. It would face many more
Now back to the giraffes….how would Darwin explain the longer necks?