copyright © 2009 pearson education, inc. © 2013 pearson education, inc. powerpoint lecture...
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Copyright © 2009 Pearson Education, Inc.
© 2013 Pearson Education, Inc.
PowerPoint Lecture prepared byJill Feinstein
Richland Community College
Fourth Edition
BIOLOGYScience for Life | with Physiology
Colleen Belk • Virginia Borden Maier
ChapterChapter 8 8
Where Did We Come From?The Evidence for Evolution
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1 What is Evolution? – The Process of Evolution
Biological populations Groups of individuals of the same species that are
subdivided from other populations by geography
Biological evolution Change in the characteristics of a population of
organisms that occurs of over the course of generations.
Evolutionary changes are inherited via genes.
Other changes may take place because of environmental changes and are not necessarily evolutionary.
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1 What is Evolution? – The Process of Evolution
Pesticide resistant lice are an example of biological evolution.
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1 What is Evolution? – The Process of Evolution
Natural selection – the differential survival and reproduction of individuals in a population
Process by which populations adapt to varying environments
Examples:
Pesticide resistance in crop-eating insects
Antibiotic resistance in infectious bacteria
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1 What is Evolution? – The Process of Evolution
Microevolution – changes that occur within a species and the characteristics of a population. Easily observed, relatively non-controversial.
Macroevolution – changes that occur, as a result of microevolution, over long periods of time and result in the origin of new species. Controversial among non-biologists.
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1 What is Evolution? – The Theory of Evolution
Ambiguity of the word “theory”
Everyday usage: theory = best guess, or tentative explanation
Scientific usage: theory = body of accepted general principles, supported by many lines of evidence.
Examples: atomic theory, gravity, germ theory.
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1 What is Evolution? – The Theory of Evolution
Theory of evolution
All species present on earth today are descendents of a single common ancestor, and all species represent the product of millions of years of accumulated evolutionary changes.
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1 What is Evolution? – The Theory of Evolution
Theory of common descent
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Animation: Principles of EvolutionClick “Go to Animation” / Click “Play”
BioFlix: Mechanisms of Evolution
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2 Charles Darwin and the Theory of Evolution
Theory of Evolution is sometimes called “Darwinism” because Charles Darwin is largely credited with introducing the concept to mainstream science.
Many philosophers of science before Darwin had notions of organisms changing over time.
Anaximander – Greek philosopher who suggested that humans evolved from fish that had moved onto land
Lamarck – published ideas about inheritance of acquired traits in 1809
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2 Charles Darwin and the Theory of Evolution - The Voyage of the Beagle
At age 22, Darwin set sail as ship’s naturalist aboard the HMS Beagle on a five year long trip.
Darwin’s job was to collect and observe “anything worthy to be noted for natural history.”
Darwin had a book by Lyell, Principles of Geology, which postulated earth was old and changes occurred over long periods of time.
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2 Charles Darwin and the Theory of Evolution - The Voyage of the Beagle
The following had influences on Darwin during the voyage: Rainforests of Brazil Fossils that he collected Birds and reptiles of the Galapagos Islands
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2 Charles Darwin and the Theory of Evolution - The Voyage of the Beagle
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2 Charles Darwin and the Theory of Evolution - Developing the Hypothesis of Common Descent
Darwin returned to England in 1836, but did not publish his ideas immediately.
Spent about 20 years refining his ideas
Learned about animal husbandry (selective breeding)
Finally published On the Origin of Species in 1858
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2 Alternative Ideas on the Origins and Relationship among Organisms
Theory of common descent is controversial. There are some possible alternative hypotheses that can be tested against available data.
Static model hypothesis
Transformation hypothesis
Separate types
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2 Alternative Ideas on the Origins and Relationship among Organisms
Graphical representations of theory of common descent and alternative hypotheses:
Figure 9.7
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3 Examining the Evidence for Common Descent
Several lines of biological evidence point to a common ancestor:
Biological classification
Anatomical similarities between organisms
Useless traits in modern species
Shared developmental pathways
DNA similarities
Distribution of organisms on earth (biogeography)
Fossil evidence
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3 Examining the Evidence for Common Descent
Biological classification implies common ancestry.
Linnaean Classification
Gives each species a two-part or binomial name in Latin
Carolus Linnaeus groups organisms in a hierarchy going from broadest to narrowest groupings
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3 Examining the Evidence for Common Descent
Anatomical homology
Mammalian forelimbs have the same set of bones. The underlying structure is similar despite the very different functions.
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3 Examining the Evidence for Common Descent
Useless traits in modern species
Vestigial traits are traits that function in one organism but are greatly reduced in others
For example:
Ostrich and penguins form wings but do not fly because the wings are non-functional
Humans have a tailbone by have no tail
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3 Examining the Evidence for Common Descent –Developmental Homologies
A consequence of shared developmental pathways is similarity among chordate embryos
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3 Examining the Evidence for Common Descent – Molecular Homology
DNA similarities
Birds in same genus have DNA that is more similar to one another, while distantly-classified birds have DNA that is less similar.
Molecular clock allows the use of DNA sequence differences between species to determine when they diverged from their common ancestor.
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3 Examining the Evidence for Common Descent – Biogeography
Biogeography is the distribution of species on earth.
Different species of mockingbird found on Galapagos all resemble another species found on the mainland.
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3 Examining the Evidence for Common Descent –The Fossil Record
Fossils are remains of living organisms left in soil or rock. Horse fossils provide a good sequence of
evolutionary change within a lineage.
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3 Examining the Evidence for Common Descent – The Fossil Record
Fossilization is the formation of fossils
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3 Examining the Evidence for Common Descent –Fossil Record
Bipedal humans have some unique anatomical traits, such as features of hips, knees, and skull.
Anatomical differences between humans and chimpanzees allow for identification of fossils
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3 Examining the Evidence for Common Descent –Radiometric Dating
Radiometric dating Used to determine age of rocks Relies on decay of radioactive isotopes into daughter
products The rate of decay is measured by the element’s
half-life
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3 Examining the Evidence for Common Descent –Radiometric Dating
Using radiometric dating, scientists have estimated the age of fossil hominims.
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3 Examining the Evidence for Common Descent – Radiometric Dating
Trends in human evolution
Larger brains, Flatter face, Reduced jaw size
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4 Are Alternatives to the Theory of Evolution Equally Valid?
The same lines of evidence that support common descent can be used to look for the closest relatives of humans.
Table 10.1 summarizes the evidence for common descent.
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4 Are Alternatives to the Theory of Evolution Equally Valid?
Weighing the alternatives
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4 Are Alternatives to the Theory of Evolution Equally Valid? – The Origin of Life
The origin of life
Evolution is the study of how life changes.
It doesn’t really address issue of how life began.
Experiment evidence does give some clues about beginnings of life.
Evidence for the theory of common descent demonstrates consilience.
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4 Are Alternatives to the Theory of Evolution Equally Valid?
Evolutionary theory informs all aspects of modern biology.
Evolutionary theory helps us understand the function of human genes.
Evolutionary theory is important to understanding species interactions.
Evolutionary theory is important for predicting the biological consequences of climate change.
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Which of the following is not an example of a scientific theory?
gravity
evolution
intelligent design
all of the above
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Which of the following is not an example of a scientific theory?
gravity
evolution
intelligent design
all of the above
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The head lice that have become resistant to the pesticide permethrin demonstrate microevolution.
True or False: The individual head lice have evolved.
True.
False.
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The head lice that have become resistant to the pesticide permethrin demonstrate microevolution.
True or False: The individual head lice have evolved.
True.
False.
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Giraffes stretched their necks by reaching for high leaves. They then passed this longer neck to their offspring. Who thought of this idea?
Darwin
Lyell
Lamarck
Wallace
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Giraffes stretched their necks by reaching for high leaves. They then passed this longer neck to their offspring. Who thought of this idea?
Darwin
Lyell
Lamarck
Wallace
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Which correctly lists the classification levels from broadest to narrowest groupings?
Order, Family, Genus, Species
Family, Genus, Order, Species
Species, Genus, Family, Order
Order, Species, Family, Genus
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Which correctly lists the classification levels from broadest to narrowest groupings?
Order, Family, Genus, Species
Family, Genus, Order, Species
Species, Genus, Family, Order
Order, Species, Family, Genus
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Which of the following do not belong in the order Primates.
monkeys
humans
apes
all of the above belong to the order Primates
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Which of the following do not belong in the order Primates.
monkeys
humans
apes
all of the above belong to the order Primates
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Which of the following is an example of a vestigial trait?
a human tailbone
a dolphin’s blowhole
a gorilla’s opposable thumb
a penguin’s flippers
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Which of the following is an example of a vestigial trait?
a human tailbone
a dolphin’s blowhole
a gorilla’s opposable thumb
a penguin’s flippers
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Where did humans evolve?
North America
Europe
Africa
Galapagos Islands
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Where did humans evolve?
North America
Europe
Africa
Galapagos Islands
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True or False: Differences in DNA sequences can help determine when two species diverged from their common ancestor.
True.
False.
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True or False: Differences in DNA sequences can help determine when two species diverged from their common ancestor.
True.
False.
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What proposed mechanism of evolution is shown in this figure?
static model
transformation
separate types
common descent
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What proposed mechanism of evolution is shown in this figure?
static model
transformation
separate types
common descent
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What is shown by the y-axis of this graph?
percentage of parent element remaining
time (in millions of years)
depth of burial
number of fossils found