Charles Darwin 1809-1882
Charles Darwin
Son of a physician
Studied medicine – not his thing!
Became a minister
Real interest in nature and collecting
specimen.
Earned a position on the HMS Beagle as a
Gentleman Naturalist to travel around
South America and chart the coastline
Darwin on the Voyage of the HMS Beagle
At 22 years old, Darwin set out on what was expected to
be two years and ended up being five.
Darwin on the Voyage of the HMS Beagle
He collected large numbers of specimen and began to
recognize patterns in what features the organisms
presented based on the environments they lived in.
Darwin on the Voyage of the HMS Beagle
On the voyage, Darwin was reading about
Lyell who was a renowned geologist.
Lyell said that Earth was billions of years
old, has changed dramatically since its
creation and is still changing.
Darwin embraced Lyell’s Earth theories and
was influenced enough to start thinking
that living things perhaps changed slowly
too.
Development of ideas
When looking through his finch specimen, he noticed
that the 14 different species of finches each had
“unique beaks tailored to it’s specific diets.”
Warbler Finch has a sharp,
pointy beak to eat insects
in trees
Large ground finch has a
large, stout beak that allows
it to eat seeds and nuts
which are too big for other
species.
Development of ideas
He also could identify the island origin of
giant tortoises based on the patterns on
their shells.
He concluded that organisms
with favorable variations
would be better able to
survive and reproduce than
organisms with unfavorable
variations.
The Origin of Species
Through collaboration with other
researchers including Charles Lyell,
Richard Owen, and Alfred Wallace, he
eventually conclude that favorable
adaptations lead of the formation of new
species.
He felt that this explained the process of
EVOLUTION.
The Origin of Species
In 1859 Darwin published the Origin of
Species with the following main points.
1. Over production
Most species have more offspring than are
needed. If all lived, any
one species would cover
the earth, yet populations
are more or less constant.
The Origin of Species
2. Struggle for existence
Space and food are limited.
Offspring must compete
among themselves and
with other species.
Only a small fraction
survive long enough to
reproduce.
The Origin of Species
3. Variation
Individuals are not alike
Differences are variations
and some are important
The Origin of Species
4. Survival of the fittest
Because of variations, some individuals will
be better equipped to survive and
reproduce.
Those who are better adapted have a greater
chance
The Origin of Species
5. Natural Selection
Desirable traits are usually passed on.
The Origin of Species
6. Evolution of new Species
Over generations, favourable
characteristics accumulate and unfavourable
ones disappear.
This lead to the development of
a new species.
The Origin of Species
Weaknesses to Darwin’s work
1. Does not explain the origin and
transmission of variations
2. Does not differentiate between heredity
and environment.