Biology, Seventh Edition
Solomon • Berg • Martin
Chapter 17
Introduction to
Darwinian Evolution
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Terminology
• Evolution
–Accumulation of inherited changes within
populations over time
• Population
–Group of individuals of one species that live in
the same geographic area at the same time
• Species
–Group of organisms with similar structure,
function, and behavior capable of
interbreeding
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Pre-Darwinian ideas
• Aristotle (384–322 B.C.E.)
–Saw evidence of natural affinities
• Leonardo da Vinci (1452–1519)
–Correctly interpreted fossil rocks
• Jean Baptiste de Lamarck (1744–1829)
–First to propose that organisms undergo
change as a result of natural phenomenon
–Lamarck ideas discredited when Mendel’s
theories rediscovered around 1900
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Darwin
and evolution
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Voyage of the H.M.S. Beagle
• 1831
• Basis for Darwin’s theory of evolution
• Darwin observed similarities between
animals and plants
–Arid Galapagos Islands
–Humid South American mainland
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Voyage of the H.M.S. Beagle
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Influences on Darwin
• Principles of Geology by Lyell
• Artificial selection
–Breeders developing many varieties of
domesticated animals in a few generations
–Plant varieties, such as kale and broccoli,
developed from wild cabbage
• Ideas of Thomas Malthus
–Population growth not always desirable
–Population increases geometrically; food
supply increases arithmetically
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Artificial
selection in
chickens:
“Big Bird”
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Artificial
selection in
Brassica
oleracea
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Evolution occurs by natural selection
• Adaptation
–Inherited variations favorable to survival
persevere
–Unfavorable variations are eliminated
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Genetic variation in emerald tree boas
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Theory of evolution by natural
selection
• Proposed by both Darwin and Wallace
• Based on four observations
–Genetic variation exists among individuals
–Reproductive ability of species causes its
populations to geometrically increase
–Organisms compete for resources
–Offspring with most favorable
characteristics is most likely to survive
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Synthetic theory of evolution
• Began in 1930s and 1940s
• Combines principles of Mendelian
inheritance and natural selection
–Mutation provides genetic variability on
which natural selection acts
–Incorporates expanding knowledge in
genetic, systematics, and other scientific
fields
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Wing size in female fruit flies
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Evidence for evolution from fossil
records
• Direct evidence of evolution comes from
fossils
• Evidence shows progression from
earliest unicellular organisms to
organisms of today
• Shows life has evolved through time
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Exposed layers
of
sedimentary
rock
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Fossils develop
in different
ways
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Fossil
intermediates
in whale evolution
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Determining
the age
of fossils:
radioisotope
decay
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Evidence for evolution from comparative
anatomy
• Homologous features
–Derive from same structure in common
ancestor
• Homoplastic features
–Similar functions in distantly related organisms
demonstrates convergent evolution
• Vestigial structures
–Remnants of structures indicating adaptation
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Homology in animals
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Homology in plants
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Homoplasy
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Convergent evolution: mammals who eat ants and
termites
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Vestigial structures
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Biogeography
• Study of past and present geographic
distribution of organisms
• Continental drift has played a major role in
evolution
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Continental drift
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Evidence for evolution from
developmental biology
• Proteins and DNA contain record of
evolutionary change
• Phylogeny
–Evolutionary history of group of related species
• Phylogenetic trees
–Diagrams showing lines of descent based on
molecular data
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Phylogenetic
tree of
whales and
their closest
living relatives
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
• Evolutionary hypotheses tested
experimentally
• Reznick and Endler
• Differences in predation correlated with
differences in guppies
–Male coloration and behavior
–Life history traits
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 17 Introduction to Darwinian Evolution
Experimental
evidence
of
natural
selection
in guppies
Copyright © 2005 Brooks/Cole — Thomson Learning