Chapter 15Chapter 15

Theory of EvolutionTheory of Evolution

ObjectivesObjectives

CLE 3210.5.3 CLE 3210.5.3 Explain how genetic Explain how genetic variation in a population and changing variation in a population and changing environmental conditions are environmental conditions are associated with adaptation and the associated with adaptation and the emergence of new species.emergence of new species. SPI 3210.5.3 SPI 3210.5.3 Recognize the relationships Recognize the relationships

among environmental change, genetic among environmental change, genetic variation, natural selection, and the variation, natural selection, and the emergence of a new species.emergence of a new species. 3210.5.2 3210.5.2 Explain how natural selection operates in Explain how natural selection operates in the development of a new speciesthe development of a new species

ObjectivesObjectives

CLE 3210.5.4 CLE 3210.5.4 Summarize the Summarize the supporting evidence for the theory of supporting evidence for the theory of evolution. evolution. SPI 3210.5.5 SPI 3210.5.5 Apply evidence from the Apply evidence from the

fossil record, comparative anatomy, amino fossil record, comparative anatomy, amino acid sequences, and DNA structure that acid sequences, and DNA structure that support modern classification systems.support modern classification systems.

3210.5.3 3210.5.3 Associate fossil data with Associate fossil data with biological and geological changes in the biological and geological changes in the environment. environment.

ObjectivesObjectives

Check210.Inq.1 Trace the historical Check210.Inq.1 Trace the historical development of a scientific principle development of a scientific principle or theory, such as cell theory, or theory, such as cell theory, evolution, or DNA structureevolution, or DNA structure

EvolutionEvolution

The process of The process of changechange in the in the inherited characteristics within inherited characteristics within populations populations over generationsover generations such such that new types of organisms that new types of organisms develop from preexisting types.develop from preexisting types.

The The processesprocesses that have that have transformed life on earth from it’s transformed life on earth from it’s earliest formsearliest forms to the vast to the vast diversitydiversity that characterizes it that characterizes it today.today.

A A changechange in the in the genes!!!!!!!!genes!!!!!!!!

The inheritance of acquired The inheritance of acquired characteristicscharacteristics

Proposed byProposed by Jean Jean Baptiste LamarckBaptiste Lamarck (early (early 1800’s)1800’s) by using or not using its by using or not using its

body parts, an individual body parts, an individual tends totends to developdevelop certaincertain characteristicscharacteristics, which it, which it passespasses on to itson to its offspringoffspring..

http://kentsimmons.uwinnipeg.ca/16cm05/1116/lamark.jpg

The inheritance of acquired The inheritance of acquired characteristicscharacteristics

CatastrophismCatastrophism

George CuvierGeorge Cuvier GeologistGeologist

Noted that fossilized Noted that fossilized organisms differed organisms differed greatly than currentgreatly than current

Sudden catastrophes Sudden catastrophes had caused the had caused the extinction of groupsextinction of groups

diogenesii.wordpress.com/ tag/geology/

UniformitarianismUniformitarianism

Charles LyellCharles Lyell natural forces natural forces

gradually change gradually change Earth’s surface and Earth’s surface and that the forces of the that the forces of the past are still operating past are still operating in modern timesin modern times

Influenced Darwin’s Influenced Darwin’s ideasideas

Darwin’s VoyageDarwin’s Voyage

Charles DarwinCharles Darwin

Darwin set sail on the Darwin set sail on the H.M.S. BeagleH.M.S. Beagle (1831- (1831-1836) to survey the south seas 1836) to survey the south seas (mainly South (mainly South America and the Galapagos Islands)America and the Galapagos Islands) to to collect plants and animals.collect plants and animals.

On the On the Galapagos IslandsGalapagos Islands, , Darwin observed Darwin observed species that lived no where else in the world.species that lived no where else in the world.

These observations led Darwin to write a book. These observations led Darwin to write a book.

On the Origin of Species On the Origin of Species by means of Natural by means of Natural

SelectionSelection Published 1859Published 1859 Two main points:Two main points:

1.1. Species were not created in Species were not created in their present their present form, but evolved form, but evolved from ancestral species.from ancestral species.

2.2. Proposed a mechanism for Proposed a mechanism for evolution:evolution: NATURAL NATURAL SELECTIONSELECTION

Natural SelectionNatural Selection IndividualsIndividuals with with favorablefavorable traitstraits

are more likely to leave more are more likely to leave more offspring better suited for their offspring better suited for their environmentenvironment..

Also known as Also known as “Differential “Differential Reproduction”Reproduction”

Example:Example:English peppered mothEnglish peppered moth ( (BistonBiston betulariabetularia))

- light and dark phases- light and dark phases

Natural SelectionNatural Selection

Organisms in a population Organisms in a population adapt adapt to their environmentto their environment as the as the proportion ofproportion of individuals with individuals with genes for favorable traits genes for favorable traits increases.increases. Those individuals that pass on Those individuals that pass on

more genes are considered to have more genes are considered to have greater greater fitnessfitness..

Natural SelectionNatural Selection

Artificial SelectionArtificial Selection

The The selective breedingselective breeding of of domesticated plants and animals by domesticated plants and animals by man.man.

http://toolbox-4-websites.com/2011/which-breed-of-humans-are-you/

Artificial SelectionArtificial Selection

http://alyannas-bioblog.blogspot.com/2010/04/artificial-selection-is-it-good-or-bad.html

Evidence of EvolutionEvidence of Evolution

1. Biogeography:1. Biogeography:

Geographical distribution of Geographical distribution of species.species. the study of the locations of organisms the study of the locations of organisms

around the world, provides evidence of around the world, provides evidence of descent with modificationdescent with modification.. http://

faculty.scf.edu/odaffej/WasDarwinWrong.3/biogeography.jpg

Evidence of EvolutionEvidence of Evolution

2. 2. Fossil Record:Fossil Record:Fossils and the order in which Fossils and the order in which

they appear they appear in layers of in layers of sedimentary rocksedimentary rock (strongest (strongest evidence).evidence).

The fossil record shows that the The fossil record shows that the types types and distribution of organisms and distribution of organisms on Earth on Earth have changed over time.have changed over time.

Fossils of Fossils of transitional speciestransitional species show show evidence of descent with evidence of descent with modification.modification.

Fossil RecordFossil Record

http://faculty.weber.edu/bdattilo/images/campsognathus.jpg

http://www.fossilmuseum.net/fossilpictures-wpd/Archaeopteryx/Archaeopteryx.htm

Fossil RecordFossil Record

Transitional SpeciesTransitional Species Fossils of Fossils of transitional speciestransitional species show show

evidence of descent with modification.evidence of descent with modification.

Evidence of EvolutionEvidence of Evolution3. Homologous 3. Homologous

structures:structures:Structures that Structures that

are similar because are similar because of of common common ancestry ancestry (comparative (comparative anatomy)anatomy)

Evidence of EvolutionEvidence of Evolution

4. 4. Comparative Comparative embryologyembryology

Study of Study of structures structures that appear that appear during during embryonic embryonic developmentdevelopment..

http://bealbio.wikispaces.com/file/view/compembryology_pic.jpg/89605487/compembryology_pic.jpg

Evidence of EvolutionEvidence of Evolution

5. Vestigial structures5. Vestigial structures Structures that are not used in current Structures that are not used in current

formform

http://www.kirksville.k12.mo.us/khs/teacher_web/alternative/whale-vestigial-structure.jpg

Evidence of EvolutionEvidence of Evolution

6. 6. Molecular biologyMolecular biology

DNA and proteins (amino acids)DNA and proteins (amino acids)

- the subunit sequences of biological - the subunit sequences of biological molecules such as RNA, DNA, and molecules such as RNA, DNA, and proteins indicates a common proteins indicates a common evolutionary history.evolutionary history.

Molecular biology: Molecular biology: HemoglobinHemoglobin

Case Study: Caribbean Case Study: Caribbean Anole LizardsAnole Lizards

Ongoing examples of evolution Ongoing examples of evolution among living organisms can be among living organisms can be observed, recorded, and tested.observed, recorded, and tested.

In In convergent evolutionconvergent evolution,, organisms organisms that are not closely related resemble that are not closely related resemble each other because they have each other because they have responded to similar environments.responded to similar environments.

Case Study: Caribbean Case Study: Caribbean Anole LizardsAnole Lizards

Divergence and RadiationDivergence and Radiation In In divergent evolutiondivergent evolution,, related related

populations become less similar as they populations become less similar as they respond to different environments.respond to different environments.

Adaptive radiationAdaptive radiation is the divergent is the divergent evolution of a single group of organisms evolution of a single group of organisms in a new environment.in a new environment.

Natural Selection of Anole Lizard Species

Convergent EvolutionConvergent Evolution

SpeciesSpecies from different from different evolutionary branchesevolutionary branches may come to resemble one another if they live in may come to resemble one another if they live in very similar environments.very similar environments.

Example:Example:

1.1. Ostrich (Africa) and Emu (Australia).Ostrich (Africa) and Emu (Australia).

2.2. Sidewinder (Mojave Desert) andSidewinder (Mojave Desert) and

Horned Viper (Middle East Desert)Horned Viper (Middle East Desert)

CoevolutionCoevolution Evolutionary changeEvolutionary change, in which one species act , in which one species act

as a as a selective forceselective force on a on a secondsecond species, species, inducing adaptations that in turn act as selective inducing adaptations that in turn act as selective force on the force on the firstfirst species.species.

Example:Example:

1.1. Acacia ants and acacia treesAcacia ants and acacia trees

2.2. Humming birds and plants with flowers Humming birds and plants with flowers with long tubeswith long tubes

3. 3. Antibiotic resistance among bacteria Antibiotic resistance among bacteria