Chapter 4 Evolution and Biodiversity. ORIGINS OF LIFE 1 billion years of chemical change to form...
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Transcript of Chapter 4 Evolution and Biodiversity. ORIGINS OF LIFE 1 billion years of chemical change to form...
ORIGINS OF LIFEORIGINS OF LIFE
1 billion years of chemical change to form the 1 billion years of chemical change to form the first cells, followed by about 3.7 billion years first cells, followed by about 3.7 billion years of biological change. of biological change.
Figure 4-2Figure 4-2
Biological Biological EvolutionEvolution
This has led to This has led to the variety of the variety of species we species we find on the find on the earth today.earth today.
Figure 4-2Figure 4-2
How Do We Know Which Organisms How Do We Know Which Organisms Lived in the Past?Lived in the Past?
FossilsFossils chemical analysischemical analysis cores drilled out of cores drilled out of
buried iceburied ice DNA analysis.DNA analysis.
Figure 4-4Figure 4-4
EVOLUTION, NATURAL EVOLUTION, NATURAL SELECTION, AND ADAPTATIONSELECTION, AND ADAPTATION
MacroevolutionMacroevolution Microevolution - brought about by mutation, Microevolution - brought about by mutation,
natural selection, gene flow, & genetic driftnatural selection, gene flow, & genetic drift Gene poolGene pool Differential reproductionDifferential reproduction Directional SelectionDirectional Selection Disruptional SelectionDisruptional Selection Stabilizing SelectionStabilizing Selection
Natural Selection and Adaptation: Natural Selection and Adaptation: Leaving More Offspring With Leaving More Offspring With
Beneficial TraitsBeneficial Traits Three conditions necessary for biological Three conditions necessary for biological
evolution:evolution: Genetic variability, traits must be heritable, trait Genetic variability, traits must be heritable, trait
must lead to must lead to differential reproductiondifferential reproduction. .
Coevolution: A Biological Arms RaceCoevolution: A Biological Arms Race
Predator and prey speciesPredator and prey species Batesian Mimicry (1 bad, 1 not)Batesian Mimicry (1 bad, 1 not) Mullerian Mimicry (many poisonous animals Mullerian Mimicry (many poisonous animals
are brightly colored)are brightly colored)
GEOLOGIC PROCESSES, CLIMATE GEOLOGIC PROCESSES, CLIMATE CHANGE, CATASTROPHES, AND CHANGE, CATASTROPHES, AND
EVOLUTIONEVOLUTION
The movement of solid (tectonic) plates The movement of solid (tectonic) plates making up the earth’s surface, volcanic making up the earth’s surface, volcanic eruptions, and earthquakes can wipe out eruptions, and earthquakes can wipe out existing species and help form new ones.existing species and help form new ones. The locations of continents and oceanic basins The locations of continents and oceanic basins
influence climate.influence climate. The movement of continents have allowed The movement of continents have allowed
species to move.species to move.
Climate Change and Natural Climate Change and Natural SelectionSelection
Changes in climate throughout the earth’s Changes in climate throughout the earth’s history have shifted where plants and history have shifted where plants and animals can live.animals can live.
Figure 4-6Figure 4-6
ECOLOGICAL NICHES AND ECOLOGICAL NICHES AND ADAPTATIONADAPTATION
Each species in an ecosystem has a specific Each species in an ecosystem has a specific role or way of life.role or way of life. Fundamental nicheFundamental niche: the full potential range of : the full potential range of
physical, chemical, and biological conditions and physical, chemical, and biological conditions and resources a species could theoretically use.resources a species could theoretically use.
Realized nicheRealized niche: to survive and avoid : to survive and avoid competition, a species usually occupies only part competition, a species usually occupies only part of its fundamental niche.of its fundamental niche.
Generalist and Specialist Species: Generalist and Specialist Species: Broad and Narrow NichesBroad and Narrow Niches
Generalist Generalist species tolerate species tolerate a wide range of a wide range of conditions.conditions.
Specialist Specialist species can species can only tolerate a only tolerate a narrow range of narrow range of conditions.conditions.
Figure 4-7Figure 4-7
SPOTLIGHTSPOTLIGHTCockroaches: Nature’s Ultimate Cockroaches: Nature’s Ultimate
SurvivorsSurvivors 350 million years old350 million years old 3,500 different species3,500 different species Ultimate generalistUltimate generalist
Can eat almost anything.Can eat almost anything. Can live and breed almost Can live and breed almost
anywhere.anywhere. Can withstand massive Can withstand massive
radiation.radiation.
Figure 4-AFigure 4-A
Specialized Feeding NichesSpecialized Feeding Niches
Resource partitioning reduces competition Resource partitioning reduces competition and allows sharing of limited resources.and allows sharing of limited resources.
Figure 4-8Figure 4-8
Evolutionary DivergenceEvolutionary Divergence
Each species has a Each species has a beak specialized to beak specialized to take advantage of take advantage of certain types of certain types of food resource.food resource.
Figure 4-9Figure 4-9
SPECIATION, EXTINCTION, AND SPECIATION, EXTINCTION, AND BIODIVERSITYBIODIVERSITY
Speciation: A new species can arise when Speciation: A new species can arise when member of a population become isolated for member of a population become isolated for a long period of time.a long period of time. Reproductive isolation:Reproductive isolation: Temporal isolationTemporal isolation Behavioral isolationBehavioral isolation Geographic isolationGeographic isolation
Geographic IsolationGeographic Isolation
……can lead to reproductive isolation, can lead to reproductive isolation, divergence of gene pools and speciation.divergence of gene pools and speciation.
Figure 4-10Figure 4-10
Extinction: Lights OutExtinction: Lights Out
Background Background extinctionextinction
Mass ExtinctionMass Extinction Adaptive Adaptive
radiationradiation GradualismGradualism Punctuated Punctuated
EquilibriumEquilibrium FitnessFitness
The golden toad of Costa Rica’s The golden toad of Costa Rica’s Monteverde cloud forest has Monteverde cloud forest has become extinct because of become extinct because of changes in climate.changes in climate.
Figure 4-11Figure 4-11
Fig. 4-12, p. 93
Tertiary
Bar width represents relative number of living speciesEra Period
Species and families experiencing
mass extinction
Millions ofyears ago
Ordovician: 50% of animal families, including many trilobites.
Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites.
500
345
Cambrian
Ordovician
Silurian
Devonian
Extinction
Extinction
Pal
eozo
icM
eso
zoic
Cen
ozo
ic
Triassic: 35% of animal families, including many reptiles and marine mollusks.
Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites.Carboniferous
Permian
Current extinction crisis causedby human activities. Many speciesare expected to become extinctwithin the next 50–100 years.Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including manyforaminiferans and mollusks.
Extinction
Extinction
Triassic
Jurassic
Cretaceous
250
180
65Extinction
ExtinctionQuaternary Today
GENETIC ENGINEERING AND THE GENETIC ENGINEERING AND THE FUTURE OF EVOLUTIONFUTURE OF EVOLUTION
We have used We have used artificial selectionartificial selection to change to change the genetic characteristics of populations with the genetic characteristics of populations with similar genes through similar genes through selective breedingselective breeding..
We have used We have used genetic engineeringgenetic engineering to transfer genes to transfer genes from one species to from one species to another.another.
Figure 4-15Figure 4-15