Transcript Darwin`s Evolution

Darwin’s Evolution
Charles Darwin
• 1809-1882
• Known as the founder of the modern
evolution theory
• Why did any theory of evolution develop?
to explain the fossils that were being
discovered
Voyage of the Beagle
• Left when he was only 21 years old. Hired as
the ship’s naturalist.
• His job was to collect, store and catalog all
unusual biological specimens along the way.
• The most important place he visited was the
Galapagos Islands.
• Here Darwin was able to isolate different species
and study their different character traits.
• Different Islands had species with similar looks
but different adaptations. i.e finches and
tortoises
Returned to England in 1836
• Journey lasted approximately 5 years
• Set up experiments with pigeons
• Began to formulate his theory of Evolution
by Natural Selection
On the Origin of Species by Means
of Natural Selection
• Published in 1859
• Original intent was to publish after he had
died but when Alfred Russell Wallace also
came up with a similar theory and was
about to publish it, he had to change his
plans.
• Darwin was very aware of the
consequences of writing a theory such as
this
What is evolution?
• Evolution is change over time
Descent with Modification
• Darwin believed that all species must have
descended through reproduction from a
preexisting species and that all species
must be able to change over time
• He was the first to argue, all life must have
come from one or just a few original forms
of life
Darwin’s Finches
• Descent with modification proof
• Darwin noticed 13 similar types of finches
on the different islands of the Galapagos
• Each bird was very similar except for its
beak which appeared to be adapted for
each specific type of food for the finches
• Darwin believed that these finches had a
common ancestor which had probably
flown there after the islands had formed.
The mechanism for descent with
Modification is natural selection
Natural selection is the process of nature selecting those individuals
with the traits that will enable them to survive in the environment.
1.
Overproduction- have more offspring than can possibly survive
2.
Genetic variation- individuals have different traits in a population
and hose traits may end up being selected for and sometimes
new traits appear through mutations
3.
Struggle to survive- individuals must compete in order to survive.
Some variations aid in survival others could hinder
4.
Differential reproduction- those offspring with the best adaptations
will survive to reproduce more offspring with that variation
Examples of Natural Selection