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32 Cards in this Set
- Front
- Back
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Endemism
Gigantism Dwarfism Flightlessness |
Island Patterns:
End: native to only one place Gigantism: Species much bigger than elsewhere Dwarfism: Species much smaller than elsewhere Flightlessness: Organisms that could fly, can't fly! |
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Linnaeus
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Systema naturae
Catalog of species |
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Lamarck
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1836-First suggestion that species might evolve from other species
Inheritance of Acquired Traits |
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Darwin
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HMS Beagle, barnacles
1844 - first Natural Selection 1858 - Alfred Russel Wallace sends letter 1859 - publishes letter |
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Theory of Natural Selection
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1. There is variation among individuals in a population
2. Some of this variation is heritable 3. More offspring are produced than can survive 4. Those variants that best meet environmental challenges will survive and reproduce |
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Gregor Mendel
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• Became a monk in Belgium where he started working with peas
• Presented results in 1865 and published in an obscure journal in 1866 • Nobody read it though…until 1900 |
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Sex Chromosomes vs. Autosomes
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Chromosomes which are matched in one sex and unpaired or absent in the opposite sex
Matched chromosomes in both sexes |
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Gene
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Determinant of a trait of an organism (codes for protein or functional piece of RNA)
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Locus
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Locus: Position on chromosome where gene is found
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Allele
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Allele: Variants of a gene. (brown allele for the eye color gene)
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Diploid vs haploid
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Diploid: having two copies of every gene
Haploid: single copy of every gene (unpaired chromosomes) |
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Genotype
Phenotype |
Genotype: Genetic constitution of an organism
Phenotype: Expression of genotype (structural or functional) (brown hair, blue eyes, sweating profusely) You can see it… |
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Mitosis
Meiosis |
Mitosis – somatic cells
Meiosis – germ cells |
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Principle of Segregation
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Two genes are split from each parent. Each allele is equally likely in offspring
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Principle of Independent Assortment
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For genes on different chromosomes, genes assort independently in meiosis
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Thomas Hunt Morgan
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Looked at Fruitflies
Looked at fruitflies! One day, a MUTANT Showed up in his research…he had white eyes, and could breathe fire He decided to cross wild type (red-eyed female) with mutant male. (sex linked traits) |
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Turner Syndrome
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When someone only has 45 chromosomes, with one missing allele from the sex gene (never develops)
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Klinefelter
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Klinefelter
Someone has 47 chromosomes, 2 XX’s from the mom, one Y from the dad. (transvestite |
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Non-disjunction
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Non-disjunction: doubled x chromosome from one parent maybe or lack of chromosome from one parent
like Turner Syndrome or Klinefelter |
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Incomplete Dominance
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incomplete dominance (sometimes called partial dominance) is a heterozygous genotype that creates an intermediate phenotype. In this case, only one allele (usually the wild type) at the single locus is expressed, creating an intermediate phenotype
Red, pink, white |
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Codominance
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Neither phenotype is completely dominant. Heterzygotes express both phenotypes
blood types |
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Penetrance
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% of population with phenotype coded for by a particular genotype
(epistatic effects, suppressor genes) |
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Expressivity
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Expressivity: degree to which a phenotype is expressed
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Phenotypic Plasticity!!!
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Interaction of genes and environment
• Regulatory genes Talking Trees Allelochemicals – herbivore deterrants Expensive to make, degrade quickly They would remove 7% of the leaf, and within 52 hours, allelochemical concentration went up! Then! They put two plants next to each other, and ripped off 7% of the leaves from one plant. The other plant started manufacturing allelochemicals as well! Airborne chemicals… Snails: It’s better to have soft shells when there’s no predators, better reproduction, growth, hard shells when there are crabs Snails are put into water where Cancer crab used to be, it gets harder shell |
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Modern Evolution
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Modern Evolution: any change in allele frequencies
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Agents of evolutionary change
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1. Selection
2. Mutation 3. Gene flow (migration) • two populations in different places exchange genetic material 4. Genetic Drift (sampling error) |
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Hardy-Weinberg
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In an infinitely large, randomly mating population, where selection, gene flow, mutation, and genetic drift do not occur, then:
1. Allele frequencies do not change over time 2. Genotype frequencies will be p2 + 2pq + q2 = 1 |
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Non-random mating
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Violation of Hardy-weinberg
Assortative Mating – like mates with like Height, social class, body type, religion, race, interests, geography Disassortative mating – unlike individuals mate • Tan striped females – good at finding food • White striped males – good defenders, poor foraging |
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p=q=.5
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p = q = .5
inbreeding depression, loss of vigor by elimination of heterozygotes |
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mutation
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Only evolutionary mechanism that increases allelic diversity
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Life Plant Life Cycle
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1. Gemetophye (1N haploid)
2. Eggs or sperm 3. Sporophyte (2N = diploid) 4. Spores (1N) |
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Cambrian Explosion
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All modern phyla of animals appeared suddenly (600 mya)
Unprecedented rate of speciation WHY? O2 became available Speculations: no way to test any belief |
