Saturday, February 9, 2013

Darwin's Story





At the age of twenty-four, he was then invited to go to South America on the HMS Beagle. Argentina was where they made their first important stop. They found large fossils of mammals there.
It was the Galapagos that he made the most important discovery, there he found animals that existed nowhere else, like tortoises that way over 600lbs, or aquatic iguanas, and penguins that lived at the equator.  They rode on the giant tortoises when they were too tired to walk, they travel about 4 miles a day.
By looking at the shell of the tortoises they could tell what island they came from, some were different colors, somewhere different shapes. It wasn’t until later he noticed the significance of this.
         They studied the finches, and collected them. After 5 weeks on the islands he left with his bird collection.
When he was back at England, he realized that the birds he collected were 13variations of finches. They looked drastically different, which is why he didn’t realize until much later, that they were of the same species. The beaks like the finches were much like the shells of the tortoise. This is when he realized that species somehow change. There was one finch on the Galapagos, but depending on the foods available, the finches had different beaks.
         He also took notice of the large fossils he had found were actually giant sloths and armadillo like creatures, much like the smaller versions of the ones that were already there.  
         It became his job to convince people that species adapt to their surroundings. This lead him to study snake embryos.
         He noticed that the baby snakes had legs while inside the egg, meaning that snakes must have evolved from creatures with legs.  He also noticed that humans’ had slits in their Meaning humans must have evolved from fish.  
He learned that whales came from creatures with teeth, birds came from dinosaurs, and Darwin called this “Decent with modification.”   Darwin then created the idea, of the tree of life, some species may gain body part, some may loose them.
This lead him to study dogs. There are so many different variations of dogs. Through a process of selection, breeders would take different dog breeds, and combine their traits to create new dog breeds. Dog breeders mixed different traits, like size shape or ability, and the parents would then have offspring that have a combination of all of the traits that the parents had. For example, whippets, which are supposed to hunt rabbits, are a mix of greyhounds for speed and terriers, for small game hunting.  That’s when Darwin discovered natural selection, species were adapting by themselves, meaning, there was no human interference.  
Darwin realized that all creatures where just desperately trying to survive, he realized with the help of natural selection, more species were surviving. He noticed that all species were competing for survival, and it was just a race to see who could adapt to weather and predators better.   



Lewman, Lance, narr. What Darwin Never Knew. Dir. John Rubin, Rushmore DeNooyer, Serena Davies, and Sarah Holt. NOVA / WGBH , 2009. Web. 9 Feb. 2013. http://www.pbs.org/wgbh/nova/evolution/darwin-never-knew.html  


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