Early OriginsEarth : 4.5 billion years old. bombarded by intense
ultraviolet radiation.Around 39 billion years ago, heavy rains and
violent storms basic inorganic chemical simple organic molecules
complex until amino acids and nucleic acids formed (organic soup)
protobionts (self replicating structures)Protobionts are said to be
1st RNA DNA unicellular organism multicellular organism
Charles Robert DarwinWrote The Original of Species Proposed
theory of evolution by natural selection Opposite of Hardy Weinberg
Theory
Other Important PeopleJean-Baptiste de Lamark suggested that
organisms pass on acquired traits in an attempt to reach a more
perfect form.Idea of use and disuseMalthus: idea that there would
soon be insufficient food and living space for the growing
population.Hutton and Lyell said Earth to be many millions of years
old, older than anyone believed (two people).
Evolutionary EvidenceThe Fossil RecordBiogeographyComparative
AnatomyEmbryology of OntogenyTaxonomyMolecular Biology
Rates of EvolutionPunctuated Equilibrium: change in organism
happen relatively quickly and are maintained over long periods of
timeMolecular Clock Hypothesis: genetic mutations occur in a genome
at a linear rateGradualism: slow evolutionary process
Modes of SelectionStabilizing selection: type of variation in
which extremes at both ends of phenotype are eliminated, resulting
in less genetic variationDirectional selection: type of variation
in which one extreme is selected against but not the other, so that
the average in the population moves in one directionDisruptive
(diversifying) selection: type of variation which favors both
extremes but selects against the averageSexual selection: force
exhibited by a member of the same species of the opposite
sexNatural selection: differential survival and reproduction of
individuals based on variation in genetically controlled traits
SpeciationPre-zygotic barriers: isolation of species due to
ecological, temporal, behavioral, or mechanical factors, or
physiological incompatibility of gametesAllopatric speciation: when
one population is separated into 2 distinct populations by some
geographic barrier such as the movement of a tectonic plate or the
elevation of a mountain rangeParapatric speciation: occurs when 2
populations are able to interbreed along a border, but the exchange
of alles is negligible compared to the amount of genetic exchange
occurring within each populationSympatric speciation: occurs when
individuals within a population acquire distinctively different
traits while in the same geographic areaPost-zygotic barriers:
ultimate inviability or sterility of hybrid organisms from the
interbreeding of 2 species
Hardy - WeinbergLarge populationIsolated population from
immigration and emigration (no gene flow)No mutationsNo selective
breeding & random mating No genetic drift
