Class Notes
Evolution of Evolution
(Historic ideas about
Organism Change)
Questions/Main Idea:
Who is Aristotle
and how did he
describe the natural
world?
(384 - 322 B.C.)
Who is JeanBaptiste Lamarck
and what were his
ideas about nature?
(1744-1829)
Explain Lamarck’s
3 assumptions
(give examples)
Who was Charles
Darwin and what
were his early ideas
about nature?
(1809-1882)
Give 4 ideas
Darwin had about
organisms after his
travels and studies:
Name: _______________________________________
Period:_______________________________________
Date: _______________________________________
Notes:

“Ladder of life”
o Nature is ordered from lower to higher
o No vacant rungs
o No movement up or down the ladder
o Included living and non-living things

First scientist to propose a mechanism for how organisms change
(1809)
His idea: “Inheritance of Acquired Traits”
o Greater use of a body part would change it, and the change
would pass on to the organism’s offspring.

1. Organisms have a desire to change. (Ex: Birds tried to fly and
eventually grew wings because of their efforts.)
2. Organisms can change shape by using or not using their bodies. (Ex:
The wings of a bird that does not fly would get smaller from
generation to generation and the wings would eventually disappear.)
3. Organisms can pass on acquired traits to their offspring. (Ex: An
animal developed muscles from lifting weights during its lifetime, it
could pass those muscles on to its offspring.)
● English naturalist
● Traveled around the world on the Beagle (1831); famously stopped in
the Galapagos Islands
● Observed many species and fossils
● Particularly studied finches, tortoises, blue-footed boobies
1. Individuals differ, and some of this variation can be inherited.
2. Organisms produce more offspring than can survive; thus they have
to compete for resources, and only the most fit will survive and
reproduce.
3. The most fit organisms pass on their heritable traits to their offspring.
4. Species alive today are descended with modification (change) from
their ancestors.
What is “descent
with modification”?
…change in organisms over time (many generations)
What is “natural
selection”?
… “pressure” the environment puts on the specific traits that affects their
ability to survive
What is
“evolution”?
… change over time
Who was Thomas
Malthus and what
was his prediction?
How was Darwin
influenced by
Malthus?
Who were James
Hutton & Charles
Lyell?
(1766-1834) British clergyman and scholar
His prediction:
 the human population would grow faster than the space and food
supplies needed to sustain it.
 The only checks on the human population would be war, famine, and
disease.
Malthus’ theory of population growth was observed by Darwin in other
animal populations as well.
In nature, Darwin saw many organisms that produced many offspring.
Most died.
Darwin wondered, what determines which individuals survive and
reproduce?



Hutton is considered the “father of modern geology”
Based on layers found in rock structures, Lyell proposed that Earth is
millions of years old
Lyell proposed that geological features could be built up or torn down
over long periods of time
How was Darwin
influenced by
Hutton & Lyell?


After reading Lyell’s book, Darwin was convinced that Earth was old.
Darwin reasoned that if geological phenomena could change the
earth, then life on Earth could change as well.
How did farming
practices influence
Darwin?


Farmers recognize that within a population, there is natural variation.
Farmers improve their plants and animals through selective breeding.
What is artificial
selection?
Farmers bred the plants or animals with the most desired traits.
This process of humans allowing only the best organisms to reproduce is
called artificial selection.
Ex.
How are artificial
selection and
natural selection
similar and/or
different?
Summary: