H Biology Unit 10: Evolution

Natural Selection and the Theory of Evolution

  • Charles Drawin proposed the idea that living things change slowly over time because of competition for resources and pass those changes onto their offspring. AKA Theory of Evolution

  • We now know that natural selection is caused by mutations, errors in DNA replication from DNA Polymerase lll.

  • Three types of Natural Selection

    1. Directional: Favors a population with a certain trait, against opposite trait.


    2. Stabilizing: Favors MIDDLE GROUND, against extreme traits


    3. Disruptive: Favors extreme traits, but not middle ground



Speciation

  • The idea that as populations evolve, species will become reproductively isolated from each other. This can happen for multiple reasons:

    1. Behavioral Isolation: Differences in mating behaviors

    2. Geographical Isolation: When populations are separated due to barriers

    3. Temporal Isolation: When populations breed at different times of the year

  • Example: Speciation of Galapagos Finches

    • Speciation occurred by founding of a new population, geographic isolation, changes in, new population's gene pool, reproductive isolation, ecological competition


Evidence for Evolution šŸ˜„

  • Fossils! ā†’ Law of Superposition, transitional species, holes, etc

  • Anatomical ā†’ Analogous, homologous, vestigial structures

  • Embryological ā†’ Differences in development (eg. all vertebrate embryos have something that represent pharnygeal gills)

  • Chemical ā†’ DNA analysis (comparing proteins)

  • Biogeography ā†’ Distribution of species around the world

  • HOX genes ā†’ wtf is thisā€¦similar genes between unrelated organisms?? or maybe distantly related

  • Resistance ā†’ human interference think antibiotics

Mechanisms and Patterns of Evolution

  • Artificial vs Natural Selection

  • Allele frequencies: the number of times an allele occurs in a gene pool compared to the total number of alleles in that pool for the same gene. This can be used to determine if a population is evolving

  • Equilibrium

    • types of genes stay constant in a population from one generation to the next, which is IMPOSSIBLE

    • To reach equilibrium, you must have Large Population, No Mutations, No Migration, Random Mating, No Natural Selection

    • WIth any of these changes, evolution occurs

  • Things that cause evolution: Mutations, gene flow, genetic drift, NON RANDOM MATING, natural selection

Misc

  • Three main types of adaptations: Anatomical, physiological, and behavioral

  • Definition of species: A group of organisms capable of interbreeding

  • Patterns of Evolution

    • Convergent evolution: aLSO OBVIOUS

    • Divergent evolution: oBVIOUS

    • Coevolution: evolve tg

    • Adaptive radiation: common ancestor, branch out

  • Antibodies, antigens, agglutination

    • Active immunity involves the production of antibodies by the body itself and the subsequent development of memory cells

    • Passive immunity results from the acquisition of antibodies from another source and hence memory cells are not developed


Endosymbiosis


Vocab

  • Macroevolution: When enough time and accumulated change creates an entirely new species through natural selection.

  • Microevolution: When species change in small ways, such as a populationā€™s change in color or size over the course of generations.

  • Biological Fitness: An organism's ability to live and reproduce in a certain environment

  • Transitional species: OBvious

  • Comparative embryology: the study of embryos to identify similarities and differences between species during development.

  • Population: A group of individuals of the same species that mate and produce offspring

  • Sexual selection: Females select males



Since stuff is all over the placeā€¦evolution summarized: