Complete the following vocabulary words on a
new sheet of notebook paper. This will be a
graded assignment.
Unit 10: Chapter 16-18
• Evolution
• Hardy-Weinberg
• Natural selection Principle
• Genetic
• Adaptation
equilibrium
• Speciation
• Phylogeny
• Gene pool
• Genetic drift
Unit 11: Chapter 19
• Population
• Community
• Ecosystem
• Climate
• Greenhouse
Effect
• Resource
• Biodiversity
Unit 10 Crash Course
Evolutionary Biology
History of Evolutionary Theory
• Early 1800s
• At the time, scientists believed that life evolved over time
• Darwin spent time in the Galapagos Islands and
developed a theory of evolution – which provided
evidence for how modern organisms evolved from
common ancestors
Natural Selection Video
• http://www.sciencechannel.com/tv-shows/greatestdiscoveries/videos/100-greatest-discoveries-shorts-natural-selection/
Evolutionary Theory
• Biological evolution analyzes
how inherited traits change in
frequency within a population
over time.
• Microevolution occurs in a small
amount of time and affects the
gene pool of a single population.
• Macroevolution occurs over long
periods of time and produces
notable changes within species.
Natural Selection Through History
Peppered Moths
Natural Selection
• A process through
which organisms with
variations that are most
suited to their
environment will
produce the most
offspring
• Natural selection is
survival of the fittest.
Continuity of Life Forms
• The continuity of lifeforms overtime is due to
the genetic processes
that all organisms share.
• All living things that have
ever existed on Earth
share at least two
structures: nucleic acids
and proteins.
How does reproduction affect variation?
• Sexual reproduction is an
important source of genetic
variation among individuals
within a population.
• Asexual reproduction may cause
a disadvantage in changing
conditions because genetically
identical offspring respond to
the environment in the same
way.
Diversity Increases Chances of Survival
• A species is a population or group of
populations whose members have the
potential to interbreed and produce
fertile offspring.
• The greater the diversity within a
population or species, the greater the
chances are for that population or
species to survive environmental
changes.
• If an environment changes, organisms
that well-suited phenotypes will
survive and reproduce at higher rates.
Hardy-Weinberg Principle
• There must be genetic variability for
biological evolution to occur.
• The Hardy-Weinberg states that in order
for a population to evolve, there must
be:
•
•
•
•
•
Small Population Size
Genetic drift
Migrations
Mutations
Natural selection.
• Genetic equilibrium is when there is no
change in the allele frequencies within a
species.
The Hardy-Weinberg Principle Explained
• Small populations
• Genetic drift = random changes in allele frequencies
• Migrations = seasonal movement of organisms from one environment to another
• Mutations = changes in genetic codes
• Natural selection = survival of the fittest
Hardy-Weinberg Equation
• p2 + 2pq + q2 = 1
•p+q=1
• p(% of “AA” allele); pq(% of “Aa” allele) q(% of “aa” allele)
• Suppose a population has an “A” frequency of 60% and an “a” frequency of
40%.
• If a population does not follow these percentages, EVOLUTION IS TAKING
PLACE!
Evidence to Biological Evolution
• Homologous, vestigial, and analogous structures provide evidence of evolutionary
relationships between organisms.
• Similarities exist between the embryos of organisms.
• The more similar the DNA and amino
acid sequences in proteins, the more
likely the organisms are to have common
ancestors.
• The fossil record shows similarities
between current and ancient species.
Phylogenetic Trees
• A phylogenetic tree is a scientific diagram used to represent the phylogeny of
organisms.
• Phylogenetic trees classify species in the order in which they descended.
• Branches of trees represent speciation.
Phylogenetic Tree Examples
• What characteristics do
Salamander, Turtle, and
Leopard ancestors all have
in common?
• What makes a leopard
different from all of the
other organisms?