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Processes of Evolution & Genetics. Part 1. Learning Objectives: Part 1. Demonstrate an understanding of the historical context in which the theory of evolution was originally formed.
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Learning Objectives: Part 1 • Demonstrate an understanding of the historical context in which the theory of evolution was originally formed. • Demonstrate an understanding of the theory of evolution and the mechanisms of evolution (especially natural selection) • Illustrate this understanding through accurate examples • Demonstrate an understanding of the mechanisms that underpin inheritance • Describe the link between meiosis and Mendelian genetics • Explain how Mendelian inheritance patterns can be modified by linkage & sex chromosomes
What is Evolution? • Evolution • __________________ • More specifically: • _________________________________ • What does this definition imply? • Populations ___________, not _____________ • It is __________ • What does this mean?
What is Evolution? • Evidence that supports the theory of evolution • ___________ • ________________ ____________ ___________
History of Evolutionary Thought Pre-Darwinian Views • ___________ • _____________________ • Earth is ___________ • _________________(4th century) • _________________of organisms from _________ • _____________________ – closer to ________, greater excellence
History of Evolutionary Thought • Precursors to the Theory of Evolution • 5 scholars & their contributions
History of Evolutionary Thought Charles Lyell (1797-1875) • __________________ • ___________________ • Natural processes _________________________ ________________________________________ • Processes are _________________ • Used to reconstruct ____________________
History of Evolutionary Thought Georges Cuvier • _______________ • How does this idea compare to the concept of stasis? • __________________ • ___________event(s) explain • ____________________ • ____________________ • 1796 paper: Mammoth Remains
History of Evolutionary Thought Carolus Linnaeus (1707-1778) • Developed __________________ • Species, genus, class, order, kingdom • Binomial Nomenclature • Genus, species • Example: ___________
History of Evolutionary Thought Thomas Malthus (1776-1834) • “An Essay on the Principles of Population” • _____________________________ • Inspired Darwin • ____________________________ ______________________________
History of Evolutionary Thought Jean-Baptiste Lamarck (1744-1829) • Inheritance of __________________ • ______________________________ • Central idea: When life forms reproduce, _____ ______________________________________ • Changed in form over time for _________________ • Now know: Mechanism is _____________ • Offspring _________________________
Development of Natural Selection Charles Darwin • Using Mathus’ essay and Lyell’s uniformitarian view, combined with his own observations on biological variation and sexual reproduction, _______________ • _________________ • _________________ • _________________ • _________________
Development of Natural Selection Charles Darwin • _______________________ • Natural selection explains _________________ • Shifts in traits in response to ___________________ • Descent ___________________ • Similar traits indicate _________________ • ______________________ • ________________________ • Affects individual’s _____________________________ • Transmitted ___________________________________
Development of Natural Selection Key Points to Natural Selection • _________________________ • Traits are ___________________to the next generation • Over ______________, successful ______________ • Later generations ____________________________ • All species can ____________________________
Development of Natural Selection Key Points to Natural Selection • Competition for ___________ (___________) • Individuals with ________________________ ______________________________________ • _________________________________ • Determines whether a _____________________ • ________________________
Development of Natural Selection ____________________acts on __________ ________, but it is the _____________that they are a part of that actually ___________.
Describing Traits • Aptation • Adaptation • Exaptation
Natural Selection in Action Panda’s thumb • Lamarckian explanation • ____________________ • Darwinian explanation • _____________________ • _____________________________ • Ability to ________________________________ • “The panda's "thumb" is not, __________________. It is constructed from a bone called the radial sesamoid, normally a small component of the wrist,” (Gould, 1980)
Early Thoughts on Heredity • Ancient Greek Influence • Predominant belief characteristic of offspring resulted from the blending of parental traits • _______________________________ • How hereditary information was transmitted was unknown until the late 19th and early 20th century
Mendel’s Experiments Mendelian Trait: _______________________
Dominance and Recessiveness • Dominant Trait: governed by an ____________ _____________________ • Dominant alleles can _____________________ • Recessive Trait: a trait ___________________ • What’s an allele? • _________________________________________
Dominance and Recessiveness • How to recognize? • Uppercase letters refer to dominant alleles (i.e. T) • Lowercase letters refer to recessive alleles (i.e. t) • These symbols are used to represent the genotype • Genotype: __________________________ • Phenotype: ____________________________
Mendel’s Experiments What happened when Mendel crossed the parent generations? • Parent (TT) (tall) x Parent (tt) (short) • Resulting F1 generation • __________ • Genotype: ________ • Phenotype: _______
Mendel’s Experiments What happened when Mendel crossed F1 hybrids? • Expression that was absent from F1 reappeared • Resulting F2 generation: • Genotype: ____________ • Phenotype: ___________
Terms to Know • Homozygous: ______________________________ • Example: Parent Generation • All tall plants were homozygous for the dominant allele (tall) = TT • All short plants were homozygous for the recessive allele (short) = tt
Terms to Know • Heterozygous: _______________________________ • Example: F1 Generation • Offspring of F1 generation were Tt had inherited one allele from each parent plant • Possessing two different alleles at the same locus
Mendel’s Principles of Inheritance 1. Principle of Segregation • Genes ___________ (i.e. RR, or Rr, or rr) • During _____________________________ • During fertilization, the genes are reunited and the ______________________________ • Thus, ____________________________
Mendel’s Principles of Inheritance 2. Principle of Independent Assortment • Distribution of _________________________ ___________________________________ • ______________________________________
Mendelian Inheritance in Humans • Mendelian traits (or discrete/simple traits) • Describes a characteristic influenced only at one locus • Examples: • 1. • 2. • 3. • 4. • 5.