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.