Download Evolution

Evolution
The Tree of Life
A Summary of the Development of the Theory of
Evolution over Time
Pre Darwin
320 B.C.
1770
1795
1798
1809
1812
1830
1858
Aristotle-Metaphysical Classification System.
Linnaeus-Morphological Taxonomic System.
Hutton-Gradualism.
Malthus-4 Horsemen of the Apocalypse.
Lamarck-Adaptation.
Cuvier-Catastrophism.
Lyell-Uniformitarianism.
Wallace-Natural Selection.
Darwin
HMS Beagle 1831-1836
On the Origin of Species 1859
Big Ideas: Natural Selection or “Survival of the
Fittest” & Descent with Modification.
Variation + Overproduction = Natural Selection
Evolution.
Evidence: Fossil Record, Artificial Selection,
Geographic Distribution, Embryology, Homology
& Vestigial Structures.
Neo-Darwinism 1895-1950’s
Microevolution: Evolution of Populations.
1900 Mendelian Genetics rediscovered.
1908 Hardy-Weinberg allele frequencies & equilibrium.
1915 Wegener Biogeography-Pangaea, Continental Drift &
Plate Tectonics.
Big Ideas: Genetic Drift, Gene Flow, Founder Effect,
Bottleneck Effect & Heterozygous Advantage.
Types of Selection: Directional, Disruptive, Stabilizing &
Sexual.
Modernism 1950’s-1990’s
Speciation: Darwin’s “Mystery of Mysteries”.
“The bridge between Microevolution and
Macroevolution.”
What is a species? New definitions had to be
developed.
Reproductive Isolation & Hybrid zones.
Prezygotic & Postzygotic Barriers.
Allopatric Barriers-Geographic.
Modernism 1950’s-1990’s (continued)
Sympatric Barriers-Behavioral, Temporal & Polyploidy
(Plants).
Speciation Rates, Mass Extinctions & Punctuated
Equilibrium.
1978-1980’s Biotechnology, Genetic Engineering,
DNA analysis, HOX genes & Phylogenetic
Trees.
1990-2003 Human Genome Project & Gene Mapping.
Post Modernism Evolutionary Development
or “Evo-Devo” 1980’s-Today
Type of DNA
Amount
Research
Type of Evolution
Homeobox (HOX)
Found on every chromosome
Somewhat Understood
Macroevolution
Regulatory Sequences
At least 5% of DNA
Poorly Understood
Both
Genes
Only 1.5% of DNA
Very Well Understood
Microevolution
Function
Basic body plan design. Where
and when body parts develop.
Activate Regulatory Sequences.
Series of specific directions
(switches) on how, when and
how much genes are expressed.
Code for proteins.
Humans have about 23,000
genes. Same as most animals.
Significance
Mostly the same for Families of
organisms. Small mutations
cause major changes in structure.
Can cause rapid and extreme
evolution such as loss of legs.
Very complex specific steps on
how to assemble body
structure. Mutations cause
structural changes and complex
diseases.
Building blocks of bodies
(structural). Control chemical
reactions (enzymes). Immune
system (antibodies).
Examples
Head goes here, nervous system
Same within a species. Ex. All
develops first, eye goes there, etc. the steps and materials to make
an eye. Epigenetics: cancer,
MS, diabetes etc.
Small variations among
individuals. Ex. Eye color. Cause
genetic diseases. Ex. Sickle Cell
Anemia.