Download Activity 1: Evolve or Die – Theory of Evolution

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SBI3U: Biology, Grade 11, University Preparation
Unit 3: Evolution
Activity 1: Evolve or Die – Theory of Evolution
Overview | Expectations | Content | Assignment
Overview
This activity will introduce you to the Theory of Evolution. You will learn about the contributions of
scientists preceding Darwin and how these scientists helped set the stage for the theory of evolution.
You will learn of Darwin’s voyage of discovery to South America and how he came to realize that
species evolve over time. You will learn of the theory he formulated in his paper called the “Origin of
Species”. You will continue to add to your portfolio notes and create a timeline of major events
leading to the Theory of Evolution. You will write a mock dialogue between yourself and a scientist
who was a major contributor to evolutionary thought.
SBI3U: Biology, Grade 11, University Preparation
Unit 3: Evolution
Activity 1: Evolve or Die – Theory of Evolution
Overview | Expectations | Content | Assignment
Content
In the 18th and 19th centuries, scientists began questioning beliefs on the formation of the Earth and
began formulating new theories about the Earth’s origins and how the Earth changed and continues
to change. Scientists such as James Hutton and Sir Charles Lyell revolutionized ideas about the
Earth. Notably, they challenged the notion that Earth was stagnant. This idea was significant to
biologists particularly with respect to the fossil record. Biologists such as George Buffon speculated
100 years before Darwin that species change over time.
Contributors to Evolutionary Theory
Others such as Carl Linnaeus and Erasmus Darwin (Charles Darwin’s
grandfather) also supported the idea that species can change and even may
have come from a common ancestry. Jean Baptiste Lamarck proposed that
the environment can enable species to adapt to changing conditions and
become more complex. He proposed that organisms can acquire traits by
interacting with the environment, establishing a need to change, and passing
that change on to the next generation.
Did you know?
Lamarck proposed that organisms can change depending on the needs of
the environment. For example if it was advantageous for a bird to have a
longer beak to acquire food, then it would grow one. His theory was
significant because it introduced the role of the environment in evolutionary
change.
Portfolio:
Notes help prepare you for tests. Keep all of your notes in your portfolio. Be prepared to submit your
portfolio notes and organizers to your teacher for assessment at various times during the course.
Use your portfolio to make more detailed notes on Lyell, Buffon, Linnaeus, Erasmus Darwin, and
Lamarck.
Find out more on the history of evolution.
Understanding Evolution
History of Evolution
A mathematician named Thomas
Malthus (1766-1834) writing in his
Essay on the Principal of Population,
proposed that populations will grow at
an unchecked rate unless limited by
subsistence or the environment.
Malthus said that human populations
are limited by their struggle for
existence. Alfred Wallace (1823-1913)
read the work of Malthus and proposed
the Theory of Natural Selection. This
theory states that favourable traits that
help organisms survive become more
common in successive generations.
Did you know?
Both Alfred Wallace and Charles Darwin read the work of Thomas Malthus
and came up with the Theory of Natural Selection independently.
Next
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Overview | Expectations | Content | Assignment
SBI3U: Biology, Grade 11, University Preparation
Unit 3: Evolution
Activity 1: Evolve or Die – Theory of Evolution
Overview | Expectations | Content | Assignment
Content
Darwin’s Theory
Darwin is known for his Theory of Evolution. Evolution is the study of how inherited traits of a
population change over time. Darwin proposed that species change over time through a process
called natural selection.
Darwin’s theory of evolution is more complex than stated above and
is explained in detail in his paper, “On The Origin of Species”.
While on his voyage, Darwin observed that many species have
similarities to other species. For example, the picture below shows
four different species of finches, all slightly different, but with
obvious similarities.
From his many observations Darwin came up with several
conclusions:


organisms evolve over time;
all organisms come from a common ancestry;

change occurs gradually;


species multiply and evolve into new species;
surviving organisms have traits adaptive to their environment
and pass those characteristics on to the next generation.
Find out more on Darwin’s Theory
Darwinism
Evidence for Evolutionary Theory
Analogous
Structures:
This diagram shows
different structures of
wings that may have
evolved through
separate pathways.
They have a common
function.
Embryology:
Homologous Structures:
This diagram shows various
organisms in their embryonic state.
This implies that embryonic
development may have come from
common ancestry.
This is a picture of the forearms of
various organisms such as an
orang-utan, rind, and tapir. They
have similar skeletal structures
thought to have evolved from a
common ancestor.
Find out more on Evidences: Fossil Record and Dating, Vestigial Structures,
and Biochemistry
Carbon Dating
Fossil Record
Vestigial Structures
Portfolio:
Notes help prepare you for tests. Keep all of your notes in your portfolio. Be prepared to submit your
portfolio notes and organizers to your teacher for assessment at various times during the course.
Use your portfolio to make more detailed notes on evidence for evolution: The Fossil Record,
Carbon Dating, Vestigial Structures, and Biochemistry.