Forces evolution
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Chapter4slides.pptxChapter 4
Forces of Evolution
Andrea J. Alveshere, Ph.D.
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Describe the history and contributions of the Modern Synthesis
Define populations, population genetics, and methods used to study them
Specify the forces of evolution: mutation, genetic drift, gene flow, natural selection
Explain how allele frequencies can be used to study evolution as it happens
Contrast micro- and macroevolution
Learning Objectives
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Origins of life
Phylogenies
Phylogenetic tree of life
Universal ancestor
Origin of Life
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Lamarckian inheritance
The Modern Synthesis
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Pangenesis
Weismann’s mouse-tail experiment
Gregor Mendel
Mutationists
Biometricians
The Modern Synthesis
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Continuous Range of Variation
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Mutations
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Fisher and Sanderson Haldane tested mathematical models for evolutionary change
Wright and Dobzhansky revealed the existence of chromosomes
Ford confirmed Fisher’s mathematical predictions
Polymorphisms: describe alternative phenotypes or multiple forms of a trait
Tying it all Together
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Populations
Species
Viable offspring
Fertile offspring
Subspecies
Sterile hybrids
Horse + Donkey = Mule
Population Genetics
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Populations smaller units: genes
Populations: gene pools
Gene variants: alleles
Inherited alleles: genotype
Observable traits of genotype: phenotype
Two of the same alleles: homozygous
Two different alleles: heterozygous
Population Genetics: Key Terms
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Evolution requires:
A population of breeding individuals
Some kind of a genetic change
Simple definition of evolution: change in the allele frequencies in a population over time
Allele frequencies
Genotype frequencies
Defining Evolution
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Mutations
deleterious, beneficial, spontaneous
Point mutations
Synonymous mutations
Non-synonymous mutations
Missense mutation
Nonsense mutations
Splice site mutation
Frameshift mutations
The Forces of Evolution: Mutations
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Random changes (“drift”) in allele frequencies
Example
Smooth and ruffled cells
The Forces of Evolution: Genetic Drift
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The Forces of Evolution: Population Bottlenecks
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Inbreeding
Lancaster County Amish population
Ellis-van Creveld syndrome
The Forces of Evolution: Founder Effects
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Gene flow in humans: admixture
Gene flow in non-human populations: hybridization
Harlequin ladybeetle
The Forces of Evolution: Gene Flow
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Peppered moth
Africanized honey bees
The Forces of Evolution: Natural Selection
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Directional selection
Balancing selection
Disruptive selection
The Forces of Evolution: Selection
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Peahen and peacock
Non-random mating (assortative mating)
Positive assortative mating
Negative assortative mating
The Forces of Evolution: Sexual selection
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Microevolution: changes in allele frequencies within breeding populations; single species
Macroevolution: changes that result in new species, similarities and differences between species and their phylogenetic relationships with other taxa
Speciation
Allopatric
Sympatric
Micro- to Macroevolution
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Micro- to Macroevolution
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Adaptive Radiation
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Attributions
| Slide # | Figure # | Attribution |
| 3 | 4.1 | Tree of life SVG by Ivica Letunic: Iletunic, retraced by Mariana Ruiz Villarreal: LadyofHats, has been designated to the public domain (CC0). This item has been modified (made grayscale, rotated, labels added). |
| 4 | 4.2 | Modern Synthesis original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 5 | 4.3 | Weismann’s mouse-tail experiment original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 6 | 4.4 | Weismann’s mouse-tail experiment original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 7 | 4.5 | Castle’s Hooded Rat Experiment original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 9 | 2.9 a, b x | Horse (pferd-tier-säugetier-reiten-153500) by openclipart-vectors-30363 has been designated to the public domain (CC0). Figure 2.9B Donkey by papapishu has been designated to the public domain (CC0). Figue x Mule (Simple black and white illustration of donkey) by public domain vectors has been designated to the public domain (CC0). |
| 15 | 13.15 4.12 | Bottleneck effect by Tsaneda is used under a CC BY 3.0 License. Figure 4.12 The Cretaceous–Paleogene extinction event original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
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Attributions
| Slide # | Figure # | Attribution |
| 16 | 4.13 | 6 Finger by Wilhelmy is under a CC BY-SA 4.0 License. |
| 17 | 4.14 | Ladybug Gene Flow original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 18 | 4.15 | Peppered moths c2 by Khaydock is under a CC BY-SA 3.0 License. |
| 19 | 4.16 | Biology (ID: [email protected]) by CNX OpenStax is used under a CC BY 4.0 License. |
| 20 | 4.18 | Peacock tail advantage and disadvantages soriginal to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 22 | 4.19 | Isolation Leading to Speciation original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
| 23 | 4.20 | Darwin’s finches original to Explorations: An Open Invitation to Biological Anthropology by Mary Nelson is under a CC BY-NC 4.0 License. |
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This presentation was developed by the editors of Explorations: An Open Invitation to Biological Anthropology.
Unless otherwise specified, all content is made available under a Creative Commons license: CC BY-NC
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