so what does evolution mean? well, the book says:
Post on 02-Jan-2016
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Charles DarwinCharles Darwin Took a trip on the S.S. Beagle to the Took a trip on the S.S. Beagle to the
Galapagos Islands to work as a naturalist.Galapagos Islands to work as a naturalist. Hypothesized that Hypothesized that Natural SelectionNatural Selection drove drove
evolution in his book, evolution in his book, On the Origin of On the Origin of SpeciesSpecies..
He invented the concept- He invented the concept- Survival of the Survival of the fittestfittest- - which actually means survival of the which actually means survival of the slightly better suited to a particular slightly better suited to a particular environment at a particular timeenvironment at a particular time
Darwin’s Theory : Darwin’s Theory : Natural Natural SelectionSelection
Environment limits Environment limits growth of populationsgrowth of populations Due to Due to variationsvariations
among individuals in a among individuals in a species, some species, some members of a members of a population population competecompete better for limited better for limited resources, so they resources, so they survive survive and and reproducereproduce, while , while others do not.others do not.
VARIATIONS• Differences in a species• Raw material for evolution• Caused by: 1) Crossing over
2)Chance Assortment3)Mutation
ADAPTATIONS: Variations that improvechances for survival!
Notice The Variation In These Individuals Of A Notice The Variation In These Individuals Of A House Finch PopulationHouse Finch Population
AdaptationsAdaptations
A variation that continues to exist A variation that continues to exist generation after generation and generation after generation and increases the organisms chance to increases the organisms chance to survive and reproduce (pass on its survive and reproduce (pass on its genes)genes)
Artificial SelectionArtificial Selection
Selecting and Breeding the organisms with Selecting and Breeding the organisms with the most desirible traits. the most desirible traits.
Can you think how humans do this?Can you think how humans do this?
Natural SelectionNatural Selection
Darwin thought that there must be a force Darwin thought that there must be a force in nature that worked like artificial in nature that worked like artificial selection.selection.
That force came to be known as Natural That force came to be known as Natural Selection, the basis for evolution.Selection, the basis for evolution.
Individuals struggle to surviveIndividuals struggle to survive
Competition for food (plants)Competition for food (plants)Escaping from predatorsEscaping from predatorsFinding MatesFinding MatesLocating ShelterLocating Shelter
Direct Evidence for EvolutionDirect Evidence for Evolution
Mimicry – Structural Adaptation evolved in Mimicry – Structural Adaptation evolved in some species where one species some species where one species resembles another. resembles another.
Camouflage – Structural adaptation that Camouflage – Structural adaptation that enables a species to blend with their enables a species to blend with their surroundingssurroundings
Bacterial resistanceBacterial resistance
Evidence Of EvolutionEvidence Of Evolution
FossilsFossils Homologous Homologous
StructuresStructures Analogous StructuresAnalogous Structures Vestigial StructuresVestigial Structures Embryological Embryological
SimilaritiesSimilarities Macromolecule (DNA, Macromolecule (DNA,
RNA, Proteins) RNA, Proteins) SimilaritiesSimilarities
Homologous StructuresHomologous Structures
Structures with Structures with common evolutionary common evolutionary origins. Can be origins. Can be similar in similar in arrangement, arrangement, function, or both.function, or both.
Analogous StructuresAnalogous Structures
Show that the Show that the environment selects environment selects for certain abilities.for certain abilities.
Structures that do not Structures that do not have a common have a common evolutionary origin but evolutionary origin but are similar in functionare similar in function
Vestigial StructuresVestigial Structures
Body structure that Body structure that has no function in a has no function in a present day organism present day organism but was probably but was probably useful to an ancestor.useful to an ancestor.
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