EVOLUTION UNIT: CHAPTERS 7 TO 9
UNIT TEST: ____________________________________________________________
Topics to Study
CHAPTER 7
• Terminology
o Extinct - of a species, family, or other group of animals or plants having no living
members; no longer in existence.
o Adaptation- Structure, behavior or physiological process. that helps an organism
survive and reproduce.
o Mimicry - One species changes over time to look like another, harmful species.
o Variation - Differences between individuals.
o Mutation - A change in a DNA sequence.
o Selective advantage - Mutation that increases the chances of survival.
o Natural selection - Characteristics of a population change over generations.
o Selective pressure - Environmental conditions that ‘select’ for certain characteristics
and against other characteristics.
o Fitness - contribution an organism makes to the gene pool of the next generation.
o Artificial selection - humans choose the traits they are selecting for.
o Biotechnology - Technology that uses biological systems, living organisms to create
different products.
o Monoculture - growth of a single organism on forest land.
• Adaptation and Variation
o What are adaptations and how is that related to variation within a species - Adaptations are
structure, behavior or physiological process that helps an organism survive and reproduce.
Adaptations develop when certain variations in a population of species help some members
survive better than others.
• Types and Examples of Adaptation
o Structural behavioral or physiological - Structural; feature of organism's body that helps it to
survive/reproduce (e.g., mimicry & camouflage), Behavioral; responses made by organism
that help it to survive/reproduce (e.g., Birds fly south in winter so they can find more food),
Physiological; body process that helps organism to survive/reproduce (e.g., temperature
regulation & release of toxins or poisons,).
• Mutations
o Positive, neutral, negative effects - Positive; beneficial by providing selective advantage,
neutral; no effect on organism’s fitness (ability to reproduce), negative; may cause genetic
disorders.
o how can mutations lead to genetic variation & selective advantages - Mutation is a change in
DNA of an individual which allows more genetic variation. More genetic variation in a
population allows a greater chance of selective advantage
o Antibiotic resistant bacteria - When bacteria develop the ability to defeat the drugs designed
to kill them (e.G., MRSA).
• Natural Selection vs. Artificial Selection
o Natural selection is when Characteristics of a population change over generations and
Artificial selection is when humans choose the traits they are selecting for. Artificial
selection only allows the selected traits to be passed through successive generations.
CHAPTER 8
• Terminology
o Paleontology - The study of ancient life through fossils.
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o Catastrophism – Catastrophes that killed many species and that these events corresponded to
the boundaries between the fossil strata.
o Uniformitarianism - Geological processes operated at the same rates in the past as they do
today.
o Inheritance of acquired traits - The idea that characteristics acquired during an organism’s
lifetime can be passed on to offspring.
o Theory of evolution by natural selection - Life has changed and continues to change, due to
natural pressures.
o Evolution - The process by which different kinds of living organisms are thought to have
developed from earlier forms during the history of the earth.
o Survival of the fittest - Organisms that are the “fittest” leave the most offspring, so those
organisms win the struggle for survival.
o Descent with modification - Natural selection does not show
o progress, but results from a species’ ability to survive local conditions at a specific time.
o Fossil record - The collection of fossils discovered so far and the information from them.
o Transition fossil - Fossils show an link between past and present groups of organisms.
o Vestigial structure - Reduced versions of what were once functional structures in an ancestral
species.
o Biogeography - Study of geographical distribution of species.
o Homologous structures - Structures that have similar structural elements and origins but
may have different functions.
o Analogous structures - Structures of organisms that do not have a common evolutionary
origin but perform similar functions.
o Embryology - The study of pre-birth stages of an organism’s development.
Hypothesis vs. Theory vs. Law
o Hypothesis; A testable and tentative statement that provides an answer to a question, or
explanation to an observation, Theory; A hypothesis that is supported by extensive testing
and accepted by the overall scientific community, Law; Statement about an observed
phenomenon or a unifying concept.
Contributions of Scientists to Evolution
o What each individual is known for & how it helped to shape the overall theory of evolution –
John Ray; Developed classification system for plants and animal, based on anatomy and
physiology.
Georges-Louis Leclerc; He challenged the idea that life forms are unchanging and speculated
that Earth was more than 6000 years.
Mary Anning; Worked as a fossil hunter and uncovered the first plesiosaur.
Georges Cuvier; Founder of the field of paleontology and suggested that catastrophes killed
many species (catastrophism).
Charles Lyell; Proposed the theory of uniformitarianism.
Jean-Baptiste Lamarck; Proposed a “line of descent” progression between current species
and fossil forms.
Charles Darwin; Used observations to create the “theory of natural selection”.
Darwin Vs. Lamarck
o Darwin's and Lamarck's theories of evolution and their similarities and differences Darwin’s theory is the theory of evolution by natural selection; life has changed and
continues to change, due to natural pressures
Lamarck's theory is the theory acquired characteristics; the idea that characteristics acquired
during an organism’s lifetime can be passed on to offspring.
Their similarities are that they both thought that organisms changed. They thought these
changes could be very useful and could help them survive. The changes could then get passed
down to the young.
Their theories are different because Lamarck thought that organisms changed out of need
and after a change in the environment and that organisms got helpful variation after a change
in the environment.
Darwin thought organisms changed by chance when they were born and before there was a
change in the environment and that organisms get helpful variation before changes in the
environment.
 Darwin's 5 observations
o 1. Flora and fauna of the different regions were distinct from those in Europe,
2. Fossils of extinct animals looked very similar to living animals,
3. Finches and other animals Darwin saw on the Galapagos Islands closely resembled animals
he had observed on the west coast of South America,
4. Galapagos species (tortoises and finches) looked identical at first, but varied slightly
between islands, each finch was adapted to eating different types of food, and had different
beak size and shape,
5. Through his experience with artificial selection (breeding pigeons and studying dogs and
flowers), he knew it was possible for traits to be passed down from parent to offspring.
• Evidence for Evolution
o Know how Fossil records, Biogeography, Anatomy (Homologous vs. Analogous Structures),
Embryology and DNA all contributed to proving the theory of evolution Fossil Records; Shows the large amounts of time in which simple organisms have evolved
into complex organisms.
Anatomy; Species may share similar physical features because the feature was present in a
common ancestor (homologous structures).
Embryology; Many embryos of developing vertebrates will look similar and develop similar
structures in its time in the womb.
Biogeography; The global distribution of organisms and the unique features of island species
reflect evolution and geological change.
DNA; DNA and the genetic code reflect the shared ancestry of life. DNA comparisons can
show how related species are.
• Transition species
o What are they, why are they important, who is archaeopteryx - Archaeopteryx is a genus of
bird-like dinosaurs. These features make archaeopteryx look like a transitional fossil
between non-avian dinosaurs and birds. Archaeopteryx plays an important role in the study
of the origin of birds and the study of dinosaurs.
CHAPTER 9
• Terminology:
o Gene flow - The net movement of alleles from one population to another due to the
migration of individuals.
o Non-random mating - Mating among individuals based on a particular phenotype or due to
inbreeding.
o Genetic drift - The frequency of certain alleles can be changed due to chance (in small
popl’n).
o Founder effect – Individuals from a population start a new population with a different allele
frequency than the original population.
o Bottleneck effect - An extreme example of genetic drift that happens when the size of a
population is severely reduced due to environmental events or human activities.
o Stabilizing selection - Favours intermediate phenotypes and acts against extreme variants of
the phenotype.
o Directional selection - Favours phenotypes at one extreme over the other.
o Disruptive selection - Favours the extremes of a range of phenotypes rather than
intermediate are favored.
o Sexual selection - Competition for mates between males through combat or through visual
displays.
o Speciation - The formation of a new species from an existing species.
o Post-zygotic mechanisms - Zygote cannot develop into a viable offspring.
o Pre-zygotic mechanisms - Impedes mating between species or prevent fertilization of the
eggs.
o Sympatric speciation - Populations in the same geographical area become reproductively
isolated.
o Allopatric speciation - Occurs when populations are separated by a geographical barrier and
diverge genetically.
o Ecological niche - The range of resources and conditions allowing the species to maintain a
viable population.
o Adaptive radiation - Diversification of a common ancestral species into a variety of
differently adapted species.
o Divergent evolution - Species that were similar to the ancestral species diverge and become
increasingly distinct.
o Convergent evolution - Similar traits arise because different species have independently
adapted to similar environmental conditions.
o Gradualism - Views evolutionary change as slow and steady, before and after a divergence.
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o Punctuated equilibrium - Views evolutionary history as long periods of stasis, or
equilibrium, that are interrupted by periods of divergence/
Evolution & population
o why do evolutionary processes deal with populations rather than individuals?
Individual organisms don't evolve. Populations evolve. Because individuals in a population vary,
some in the population are better able to survive and reproduce given a particular set of
environmental conditions.
o what is the gene pool, why do evolution & diversity depend on the gene pool.
The gene pool is a population that consists of all the alleles of all genes of each individual in that
population. evolution depends on the gene pool because the ability of a population to adapt to
changing environments and evolve is thought to be influenced in part by the size of its gene pool.
Mechanisms of Evolution on Populations (Five Factors-- Refer to completed
worksheet,should know each/examples/ diagrams would be an asset)
Sexual selection
o know the two types and be able to come up with pros and cons based on a situation.
Combat –
Visual display – Multiple males competing for female (Peacock)
Speciation
o Allopatric vs Sympatric
In allopatric speciation, groups from an ancestral population evolve into separate species due to a
period of geographical separation. In sympatric speciation, groups from the same ancestral
population evolve into separate species without any geographical separation.
o Convergent vs Divergent evolution
In divergent evolution two or more distinct species share a common ancestor from which they
diverged. In convergent evolution two or more distinct species share traits not due to a common
ancestor.
o Gradualism vs Punctuated equilibrium
Gradualism is changes in species that is slow and gradual, occurring in small periodic changes in
the gene pool, and for Punctuated Equilibrium, evolution occurs in spurts of relatively rapid
change with long periods of non-change.
Reproductive Isolating Mechanisms (Pre-zygotic and Post-zygotic)
o compare and contrast the 5 different pre-zygotic and 3 different post zygotic mechanisms
o use a flow chart to represent reproductive isolating mechanisms
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Adaptive Radiation
o what type of speciation is it? Why was it so important to helping Darwin on the Galapagos
islands
Adaptive radiation is a type of allopatric speciation.
Impact of Human beings
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Mass extinctions
SOME HELPFUL TEXTBOOK REVIEW QUESTIONS:
Pg. 379 #1-3, 5-8, 11, 14, 16, 18, 20, 21
Pg. 387 # 1-3, 5-10, 13, 14, 19, 22, 26, 27, 29, 37,
45, 46, 52