Download Evolution - Doral Academy Preparatory

Warm - Up
• Write short reflection on your thoughts about
genetic engineering.
• You will share this with the class.
Warm - Up
• Who was Darwin? Why is he such a big deal?
• Why is he credited with developing the Theory
of Evolution even though the idea of evolution
was already around.
Chapter 15
Evolution
Charles Darwin
• Charles Darwin
– British naturalist
– Developed the theory of evolution
– Galapagos Islands
Darwin’s Voyage
Galapagos Islands
Evolution
• Evolution – the development of new types of
organisms from preexisting types of organisms
over time.
• It is the process of change in the inherited
characteristics within populations over
generations such that new types of organisms
develop from preexisting types.
Evolution
• Evolution involves a change in a population
over time
• Populations evolve
• Individuals do not evolve
Darwin’s Finches
Ideas of Darwin’s Time
• Catastrophism (Cuvier)
• Uniformitarianism (Lyell)
• Inheritance of acquired characteristics
(Lamarck)
Classwork
• Read Page 373 – 377
• What ideas shaped Darwin’s thinking? (Write
a few notes).
• Who else had ideas that life on Earth has
changed over time?
• What was Lamarck’s idea? How do we know
that this is not the correct mechanism by
which evolution occurs?
Darwin’s Ideas
• Descent with modification
• Natural selection
Darwin’s Ideas
• Descent with Modification
– Darwin wrote On the Origin of Species, in which
he argued that descent with modification occurs,
that all species descended from common
ancestors, and that natural selection is the
mechanism for evolution.
Darwin’s Ideas
• Natural Selection
– Organisms in a population adapt to their
environment as the proportion of individuals with
genes for favorable traits increases.
• Adaptation – a trait that makes an individual successful
to survive in its environment.
– Those individuals that pass on more genes are
considered to have greater fitness
• Fitness – a measure of an individual’s hereditary
contribution to the next generation (how many
offspring are produced!)
Natural Selection
Natural Selection
1.
2.
3.
4.
Overproduction
Genetic Variation
Struggle to survive
Differential reproduction (fitness)
Evidence of Evolution
• Evidence of evolution can be found by
comparing several kinds of data:
– the fossil record
– biogeography
– anatomy and development
– biological molecules
The Fossil Record
• The Age of Fossils
– Geologic evidence supports
theories about the age and
development of Earth
• The Distribution of Fossils
– The fossil record shows that the
types and distribution of
organisms on Earth have changed
over time.
• Transitional Species
– Fossils of transitional species show
evidence of descent with
modification.
Evidence of Whale Evolution
Biogeography
• Biogeography, the study of the locations of
organisms around the world, provides
evidence of descent with modification.
Anatomy and Physiology
• Homologous structures have a
common evolutionary origin.
– Example: Human arm and bat
wing
• Analogous structures are
similar in function but have
different evolutionary origins.
– Example: Butterfly wing and bat
wing
Anatomy and Physiology
• A species with a vestigial structure probably
shares ancestry with a species that has a
functional form of the structure.
– Examples: human appendix, whale pelvic bone
• Related species show similarities in embryological
development.
Biological Molecules
• Similarity in the subunit sequences of
biological molecules such as RNA, DNA, and
proteins indicates a common evolutionary
history.
Hemoglobin Comparison
Developing the Theory of Evolution
• Modern scientists integrate Darwin’s theory
with other advances in biological knowledge.
• Theories and hypotheses about evolution
continue to be proposed and investigated.
Evolutionary Relationships Between
Whales and Hoofed Mammals
Evolution in Action : Types of Evolution
• Convergent evolution - organisms that are not
closely related resemble each other because
they have responded to similar environments.
– Converge = to come together
• Divergent evolution - related populations
become less similar as they respond to
different environments.
– Diverge = to come apart
Adaptive Radiation
• Adaptive radiation is the divergent evolution of a
single group of organisms in a new environment.
• Example – Galapagos finch beaks
Natural Selection of Anole Lizard
Species
Artificial Selection
• The great variety of dog breeds is an example
of artificial selection.
Coevolution
• Coevolution – two species evolving in
response to one another
– Example – population of poisonous lizards evolves
a stronger poison over time. Populations of birds
that prey on lizards evolve a stronger tolerance to
poison.
– Example – antibiotic resistance
Self Quiz
• What are three things that provide evidence
of evolution?
• What is the difference between convergent
and divergent evolution?
• What is the difference between homologous
and analogous structures?
• What is coevolution?