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Polar Bear Ursus maritimus
Why Does A Polar Bear:
a) Have White Fur?
b) Have Black Skin?
c) Have a Large Body?
White Fur?
To blend with habitat
Black Skin?
Better heat absorption from the sun
Large Body?
Why is this
important?
To eat large prey (seals)
IT IS EVOLUTION!!!
EVOLUTION UNIT
What does the word
E
volution mean to you?
Some Definitions
Term
Species
Organisms in a population
that produce fertile offspring
Adaptation
Genetic trait that
increases chances of survival
Variation
Niche
Differences between
individuals of a
population
The function a species
plays in its habitat
Definition
Which of the following is a closely-related modern descendent of
the T-rex?
Alligators evolved from the T. rex, but the closest living relatives of the
dinosaur, according to biochemistry, are ostriches and chickens.
MISCONCEPTION: Scientific theories are more like
hypotheses and are supported like
scientific laws.
Hypothesis: Is a suggested explanation of observations, which can be
tested by further research or experiments.
Theory: Is a set of statements that explains a group of facts or
phenomena. The statements have been tested repeatedly and
are supported by evidence.
Introductory Activity (LMC-4)
Charles Darwin developed a theory to
explain the diversity of life.
A theory is a set of statements that explains a group of facts or phenomena. These statements
have been tested repeatedly and are supported by evidence.
Darwin’s theory of evolution suggests that all of today’s species are descendents of ancient
species.
Theories have developed with contributions from many scientists; and changed as a result of
new technologies.
Before Darwin, there were two prominent beliefs about the diversity of life on Earth.
All species were the same as they had always been.
Earth, and its species, were less than 10 000 years old, and were relatively unchanged.
The theory of evolution helps us understand
the diversity of life: Steps Leading Up to
Charles Darwin’s Theory
Charles Darwin’s ideas have upset many people
since he first proposed them.
Scientists Contributions to the Theory of Evolution
How Was This
Theory Formed?
?
Darwin's
Voyage
The HMS Beagle, travelled to South America in 1831
Darwin collected samples and specimens, and wrote extensively in his journals.
He noticed three patterns on his journey:
GLOBALLY
1) Species varied
, but there were similarities between
some species such as emus, ostriches, and rheas.
2) Species varied
, especially on islands, as similar
species in different habitatsLOCALLY
had different features, such as
the finches of the Galapagos Islands.
3) Species varied
, which Darwin noted while
studying fossils on his journey.
OVER TIME
Galapagos finches appeared to be descendents of a
common ancestor, but each species had unique
beaks for their niche.
Darwin Movie Questions
http://www.youtube.com/watch?v=vmphlbRhLu8
1. Who was Charles Darwin? (3 points)
2. What islands helped Darwin make his theory?
Give 1 reason describing what they did to help him?
3. What is the central idea to Evolutionary Theory?
(1 point)
4. Why did Darwin take so long to publish his theory? (2 reasons)
5. What is Darwin's central 'mechanism' that describes Evolutionary Theory?
Tree of Life Video
Timeline Graph
Basic Timeline of Life
What does Evolution tell us?
Evolution tells
us how life forms
have changed
over time
What did Charles Darwin
conclude?
Nature Selects
the most fit
organisms
to survive
Quick Write Questions?
1. What does 'evolution' mean for biological life?
2. Why doe Charles Darwin believe life has a
single, common ancestor?