Mitochondrial dna mtdna distinct from dna in nuclei

This preview shows page 16 - 22 out of 22 pages.

Mitochondrial DNA (mtDNA) (Distinct from DNA in nuclei) Inherited only from mother Mutation rates used for constructing relationships 7. Modern Evolutionary Theory In past rival viewpoints emphasized either “mutation” or “natural selection” as prime mover of evolutionary change A “Modern synthesis” Mutation and natural selection both required Evolution two stages 1) Production and redistribution of variation 2) Natural selection acting on this variation B. Current Definition of Evolution Modern genetic perspective Evolution defined as A change in allele frequencies from one generation to the next Short-term effects called Microevolution Long-term called Macroevolution (species)
Image of page 16

Subscribe to view the full document.

8.Factors That Produce and Redistribute Variation 1) Mutation Mutation is the only way new variations produced First stage in evolutionary process. 2) Gene Flow Gene flow is the exchange of alleles between populations 3) Genetic Drift Chance (random) factor in evolution Tied to small population size Founder Effect A type of genetic drift Small migrant band colonizes new region 9. Natural Selection is Directional and Acts on Variation Natural Selection Populations adapt and evolve through natural selection
Image of page 17
Natural Selection provides directiona l change Sickle-cell Allele Geographic correlated with Malaria Heterozygous individuals with one Hbs allele Greater resistance to Malaria Levels of Organization in the Evolutionary Process Evolutionary Factors Mutation Recombination Natural Selection Drift and gene flow Levels 1) DNA 2) Chromosomes 3) Cell 4) Organism 5) Population
Image of page 18

Subscribe to view the full document.

1) DNA Level Mutation is the evolutionary factor 2) Chromosome Level Mutation is the evolutionary factor 3) Cell Level Recombination is the evolutionary factor (sex cells only) 4) Organism (Individual) Natural selection is the evolutionary factor 5) Population Drift and gene flow are the evolutionary factors Chapter 05 MACROEVOLUTION Processes of… Principles of Classification Classification Ordering organisms into categories Homologies Similarities based on descent from common ancestor Analogies Similarities based on common function (not descent)
Image of page 19
Classification and Evolutionary Relationships Evolutionary Systematics Ancestors and descendants traced in time Cladistics Based solely on analysis of certain homologous characters Ancestral Derived Characters modified from ancestral condition Diagnostic of particular lineages Phylogenetic Tree Chart showing evolutionary relationships Shows time Implies ancestor-descendant relationship Cladogram Chart showing evolutionary relationships Determined by cladistic analysis No time component Does not imply ancestor-descendant relationship Definition of Species
Image of page 20

Subscribe to view the full document.

Image of page 21
Image of page 22
You've reached the end of this preview.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern