Download Charles Darwin

EVOLUTION
STANDARD
• SB5. Students will evaluate the role of natural
selection in the development of the theory
of evolution.
• A. Trace the history of the theory of evolution
ESSENTIAL QUESTION
• Unit:
• How is life organized at all levels from
cells to the biosphere?
• Today:
• Where does the theory of evolution
come from?
SOME IMPORTANT SCIENTISTS
• Francesco Redi (1626-1697)
• Proved Aristotle’s idea of
spontaneous generation incorrect
• This introduced the idea that living
things come from living things
• Carolus Linneaus (1707-1778)
• Wrote “Systema Naturae”
• Basis of the modern classification
system
• Came up with the way organisms
are named
• Binomial nomenclature
MORE SCIENTISTS
• Jean Baptiste Lemarck
(1744-1829)
• Known for his early ideas of
evolution
• Charles Darwin (18091882)
• Wrote “On the origin of the
species”
• Theory of evolution based on
natural selection
MORE SCIENTISTS
• Gregor Mendel (18221884)
• Father of genetics
• Introduced the idea that
traits were inherited
• Watson and Crick
• Pieced together the model
of DNA
• DNA can now be mapped
• It is used as strong
evidence for evolution
CHECKING FOR UNDERSTANDING #
3
•Directions: Label the top of your paper as ‘Checking for Understanding’. Put
today’s date as indicated below. Write the questions and the answer to the
following questions:
•8/26`/15
1. How did Carolus Linnaeus contribute to the theory of
evolution?
2. How did Watson and crick contribute to our understanding of
evolution?
3. What scientist is credited for the modern theory of evolution
•Keep this paper in your notes until the next ‘Check for Understanding’. This
is for a grade!
WHAT IS EVOLUTION?
• Evolution
• Change in
inherited
characteristics
over
successive
generations
• Theory explains
the history of life
• 2 types:
• Microevolution
• Macroevolution
MICROEVOLUTION
• The accumulation of small changes in the gene
pool over a short period of 2 or more generations
• Outcome: change in phenotype (visible traits) frequency
• Causes:
•
•
•
•
•
Genetic Mutations
Gene flow
Non Random Mating
Genetic Drift
Natural Selection
• Only natural selection results in adaptation to the environment
CAUSES OF MICROEVOLUTION
• Genetic Mutation
• Accidental changes in the DNA
• Creates variation in a population
• Gene Flow
• Movement of alleles between populations
by breeding individuals
• Makes organisms in different populations
similar.
• migration
• Genetic drift
• Changes in allele frequencies of a gene
pool due to chance
• reduces variation
CAUSES OF MICROEVOLUTION
• Genetic Drift continued
• Two types
• Founder Effect
• a small sample of a population settles in a location
separated from the rest of the population
• Genes that were uncommon in the original
population might be common in the new population
• Bottleneck
• a population declines to a very low number and then
grows
CAUSES OF MICROEVOLUTION
• Nonrandom Mating
• Certain traits selected for
• Ex: Pedigree of dogs
• Two Types:
• Assortative mating
• Mate with individuals with a certain similar trait
• Sexual selection
• Males compete for female
• Female chooses certain traits
CHECKING FOR UNDERSTANDING #
3
•Directions: Label the top of your paper as ‘Checking for
Understanding’. Put today’s date as indicated below. Write the
questions and the answer to the following questions:
•8/25/15
1. Explain gene flow. How does this relate to
microevolution
2. How does genetic drift contribute to microevolution?
3. Define Evolution.
•Keep this paper in your notes until the next ‘Check for
Understanding’. This is for a grade!
CAUSES OF MACROEVOLUTION
• Macroevolution
• Evolution above the level of
individual species and
populations
• Adaptive Radiation
• One species gives rise to 2 or
more species
• Response to an ecological
opportunity like new habitat
• Coevolution
• The relationship between two
species might be so close that
the evolution of one species
affects the evolution of the
other species
CAUSES OF MACROEVOLUTION
• Convergent Evolution
• Unrelated species
evolve similar traits due
to similar environments
even though they live in
different parts of the
world
• Extinction
• A lineage dies off
• Makes room for another
species to thrive
• Punctuated Equilibrium
• Some biologists argue
that species just appear
after a period of long
environmental change.
CAUSES OF MACROEVOLUTION
• Gradualism
• Small changes (i.e.
microevolution) build up over
time.
• Result of Macroevolution
• Speciation
• Formation of a new species
• Link between
microevolution and
macroevolution
• Species
• Group of closely related
organisms that can produce
fertile offspring
CHECKING FOR UNDERSTANDING #
4
•Directions: Label the top of your paper as ‘Checking for
Understanding’. Put today’s date as indicated below. Write the
questions and the answer to the following questions:
•8/25/15
1.
Connect Speciation to microevolution and
macroevolution
2.
Give an example of convergent evolution.
3.
Define Evolution.
•Keep this paper in your notes until the next ‘Check for
Understanding’. This is for a grade!