Transcript Charles Darwin and Adaptationx - Darwin and Evolution

Charles Darwin and his Theory of
Evolution
Part One: Charles Darwin, Adaptation
Objectives
 Be able to define evolution.
 Be able to identify a physical difference between two
given animals, and formulate a reason why these
adaptations are useful for their individual environments.
 Be able to list and give a short definition of 4 of the 5
evidences of evolution.
 https://www.youtube.com/watch?v=lX7veVXwRi8
Pre-Darwin Beliefs
 Neither the planet nor the species that inhabited it had
changed since the beginning of time.
Charles Darwin
Charles Darwin: (1809-1882)
Father of Evolution
Scientist credited with the Theory
of Evolution & Natural Selection
Charles Darwin
 When he was 22, Darwin was invited to join the HMS
Beagle.
 He spent 5 years travelling round the world as a naturalist.
 A naturalist makes observations about the natural world.
 Darwin kept a scientific journal of his findings.
Where did he go?
What did he observe?
 The finches on each island in the Galapagos had
different types of beaks.
 They differed in shape, length, strength, etc.
 Question: Why would different finches have different
types of beaks?
Finches
What did he observe?
 Darwin also observed that tortoises on each island in the
Galapagos had different sizes of shells, and some
tortoises had longer necks than others.
 Question: Any ideas about the reason tortoises from
different areas would have different shell and neck
characteristics?
Tortoises
Question of the day:
 Question: What does the world “adapt” mean?
Question of the day:
 Question: What does the world “adapt” mean?
 Answer: make something suitable for a new purpose;
modify, become adjusted to new conditions
 Biological definition: an alteration or adjustment in
structure or habits, often hereditary, by which a species
or individual improves its condition in relationship to its
environment
What did he hypothesize?
 Darwin hypothesized that organisms
had a common ancestor, but had
adapted to their particular
environments and changed over
time.
 Evolution: change in the inherited
characteristics of populations over
generations.
 Darwin published his research in 1859
in his book “Origin of Species”
Build a Beast Worksheet
Evidence for Evolution:
Common Ancestry
 Common Ancestry: If species evolved
from a common ancestor, then they
should share common anatomical traits
 Hawaiian Honeycreeper: family of birds
in Hawaii that have similar skeletons and
muscles, indicating they are closely
related.
 Over time, their common ancestor
evolved into several species, each with
a specialized bill for eating certain
foods. Just like Darwin’s finches on the
Galapagos!
Evidence for Evolution:
Homologous Structures
 If animals evolved from a
common ancestor, then they
should share common
structures – and they do!
 These are called homologous
structures
 Homologous structures are
parts of the body that are
similar in structure to other
species' comparative parts.
Evidence for Evolution:
Embryo Development
 What do you notice? List 2
observations.
 An embryo is an unborn (or
unhatched) animal or human
young in its earliest phases.
 This shows that the animals are
similar and that they develop
similarly, implying that they are
related, have common
ancestors and that they started
out the same, gradually evolving
different traits, but that the basic
plan for a creature's beginning
remains the same.
Evidence for Evolution:
Vestigial Organs
 Some organisms have
structures or organs that no
longer have a useful function.
 These structures or organs
may have been useful to the
ancestors of a species, but
over time have evolved into
what we term vestigial
organs.
 Kiwi (flightless bird), Whales
(hind leg bones), Humans
(tailbone, appendix)
Evidence for Evolution:
Fossils
 Fossils provide a look into the
past.
 Scientists can trace how a
species has evolved by
studying fossils.
Worksheet