Evolution
Mrs. RagoBio
EvolutionCharles DarwinEnglish scientist who developed theory of evolutionStudied species on the Galapagos IslandsObserved the species to compare features from each
Natural SelectionMechanism for change in populationsOccurs when an organism with certain variations (characteristics) survive, reproduce, & pass on their variations to the next generationThese variations make the organism more likely to survive and reproduceReproduction in Natural SelectionFavorable traits make individual more likely to survive & reproduceIndividuals with the best traits pass them on to their offspringConvergent EvolutionProcess by which different species evolve similar traits Different ancestors but species with similar traits that have evolved to deal with the problem
Divergent evolution Descendants of a single ancestor diversify into species that each fit different parts of the environment
Coevolution When 2 or more species have evolved adaptations to each others influence
Artificial SelectionBreeding organisms to produce offspring with identical traitsExample: breeding pure bred dogs
On the Origins of SpeciesBook by Charles DarwinFirst book on evolution
Structural AdaptationsChanges that have developed in an organisms form over timeExample: thorns on some plantsTake a long time to occurMillions of years
MimicryStructural adaptation that allows one species to resemble another speciesUseful for a harmless species to resemble a harmful species, so that predators avoid the harmless species
Coral snake- venomous & deadlyKing snake-non venomous CamouflageAn adaptation that allows a species to blend into their surroundings and avoid predators
Physiological adaptationsOccur much fasterChanges in an organisms metabolic processesExample: resistance to penicillin, insects & weeds resistant to specific pesticidesEvidence for EvolutionFossil recordShows evidence of evolution but it is incomplete
AnatomyHomologous structuresSimilar structures that come from a common ancestor
Analogous StructuresSimilar structures that are similar because they are used for the same purpose
Vestigial StructuresA body structure that has no function in a present-day organism but was probably useful to an ancestorExample: wings of an ostrich
EmbryologyEmbryo is the earliest stage of growth & development of both plants & animals
BiochemistryEvidence for evolution, shows similarities in DNA or RNAAtmosphere of Early EarthLarge meteor impacted earthMore comets hit earth and brought ice with them which along with gases from volcanoes produces the water we now find on earthAtmosphere of Early EarthVery little free oxygenWater vaporCarbonNitrogen
Evolution of photosynthesisArchaebacteriaDo not require oxygen First group to developCyanobacteriaProduce oxygen from their chemical reactionsThis changed earths atmosphere
Early EarthVery hotLots of volcanoes meteoritesLots of gasesHumans would never have survived early earth