Chapter 13: Evolution Flashcards
Definition of Natural Selection
Unequal Reproduction.
2 Observations of Natural Selection
Members of population often vary in inherited traits.
All species are capable of producing more offspring than the environment can support.
2 Inferences of Natural Selection
Those with stronger inherited traits (survival & reproduction) tend to produce more offspring.
The unequal reproduction will cause accumulation of favourable traits in population over generations.
3 Key Points of Natural Selection
Individuals do not evolve, but can adapt to environment.
Natural Selection can only amplify or diminish heritable traits.
Evolution is not goal directed, but is the response to environmental factors.
Adaptive Radiation
An event where a lineage rapidly diversifies.
Aristotle’s Belief
Species were fixed & unchanging.
Recognized continuous variation in nature, with hierarchy of life forms of increasing complexity.
Charles Darwin (1809 - 1882)
Partnered with Alfred Wallace.
Theory of descent of modification (natural selection).
Believes that all life forms are related.
Artificial Selection
Man- modified species by selecting repeatedly & breeding organisms with desired traits.
Fossils
Remnant of an organism that lived in the past.
Preservation of Fossils
Hard body parts preserve better (bones, teeth, shells).
Soft body parts require special circumstances to prevent decay (amber, ice, acid bogs).
Cast
Body part decays but leaves a mould in sediments, can be filled by minerals in water.
Trace Fossils
Remnants of ancient organism’s behaviour (footprints, burrows).
Fossil Record
Sequence in which fossils appear in layers of sedimentary rocks.
Hierarchy of Life (Largest to Smallest)
Kingdom > phylum > class > order > family > genus > species.
Mass Extinctions: Permian
AKA the great dying.
Largest ( 96% of marine life & 70% of terrestrial species).
Caused by massive increase in volcanic eruptions.
Occurred In Siberia.
Mass Extinctions: Cretaceous
The end of dinosaurs.
Caused by a meteor.
Occurred in Mexico.
Techtonic Plate Boundaries: Divergent
Plates moving away from each other.
Creates large crack/ rift.
Or seafloor spreading.
Techtonic Plate Boundaries: Convergent
Plates move towards one another.
Subduction zone.
Or both plates lift & form mountains (increase height 1-2 inches per year).
Fast movement of plates together cause friction (earthquakes).
Techtonic Plate Boundaries: Transform
Plates moving parallel in opposite directions.
Creates crack/ fault in earth’s crust.
Built up pressure causes earthquakes.
Subduction
2 earth plates come together, lighter pushed up, heavier sinks into hot mantle, rock melts & volcanoes form.
Ring of Fire
Frequent eruptions & earthquakes.
Seafloor Spreading
2 plates diverge, magma from mantle rises to fill gap & creates ridge.
Mechanical Layers of Earth (Outer to Inner)
Lithosphere > Asthenosphere > mesosphere > outer core > inner core.
Archaean Eon
4.6 bya - 2.5 bya.
Prokaryotes.
Proterozoic Eon
2.5 bya - 542 mya.
Prokaryotes, atmospheric 02, single- celled eukaryotes, multicellular eukaryotes.
Phanerozoic Eon
542 mya - present.
Prokaryotes, atmospheric 02, single- celled eukaryotes, multicellular eukaryotes, animals, colonization of land.
Stanley Miller Experiment- 1953 (Cell Replication): Objective
Simulation of organic compounds on earth.
Stanley Miller Experiment: Step 1
Organic molecules formed.
Amino acids, gases, N2, CO2.
Stanley Miller Experiment: Step 2
Polymer creations.
Stick monomers together using dehydrogenase enzymes (removes water).
Stanley Miller Experiment: Step 3
Protocells.
Lipids to water with clay vesicles naturally form.
Fatty membrane around, which can grow & divide.
Organic molecules more concentrated on surface of clay, which helps interact easier.
Stanley Miller Experiment: Step 4
Self- replicating RNA.
Monomers of RNA form short RNA polymers, assemble RNA chain.
When RNA added to solution of monomers can create complementary RNA.
Carolus Linnaeus (1707-1778)
Father of taxonomy.
Created binomial naming system (hierarchy of species).
Believed that the grouping did not imply evolution, but God’s plan.
Georges Cuvier (1769-1832)
Father of palaeontology.
First to document history of life on earth, recorded in layers of rock.
Oldest layer. deepest strata contained species very different from today.
Did not believe in evolution, but catastrophism.
James Hutton (1765)
Scottish geologist.
Proposed theory of gradualism.
Possible to explain variations in landforms by examining mechanisms currently operating in the world.
Changes in earth’s crust were overall product of slow, continuous processes.
Charles Lyell (1797-1875)
Wrote “Principles of Geology”.
Theory of uniformitarianism.
Processes that build up mountains must eventually be balanced by erosion of those mountains.
Jean Baptiste (1744-1829)
First theory of evolution.
Compared fossil species with living animals.
