Evolution

Theory Well supported testable explanation of phenomena that have occurred in the natural world

Biosphere Part of earth in which life exists EX: Land, water, air

Evolution A change over time Most often used to refer to a change in a species over time EX: Dinosaurs change into birds

Charles Darwin One of the first scientist to publish his ideas about evolution in The Origin of Species He developed his theory of evolution from observations he had made during his world travels

Charles Darwin (cont.) Darwin traveled around the world on a ship called the HMS Beagle He observed a wide variety of organisms, and noted characteristics that occur in similar species of plants and animals

Galapagos Island In five years of traveling on the HMS Beagle, the Galapagos Islands proved to be the most influential on Darwin’s ideas about evolution

Galapagos Finches Although the islands were close together, each island had its own distinct animal and plant populations EX: Galapagos Finches – They had different beaks suited to the different foods they consumed

Natural Selection States that organisms with favorable traits are more likely to survive, reproduce, and pass those traits onto their offspring

Survival of the Fittest Also known as Natural Selection

Fitness An organism’s reproductive success Organisms with greater fitness reproduce and pass on their traits to their offspring

Adaptation The process by which a population becomes better suited to its environment which increases chances of survival EX: Peppered moth AND giraffes with long necks More examples: White rabbit in snow, duck web feet for swimming, skunk with smell, porcupine, chameleon to change color

Mutation A change in DNA. This is the only way of introducing a new trait to a species

Recombination Genes are rearranged during meiosis to create unique offspring and the species is more likely to survive a catastrophe, such as a disease EX: Crossing over

Evidence of Evolution

Fossil Record Older remains or fossils always lie beneath the newer remains or fossils This allows us to determine the age of a fossil in relation to the other fossils

Homologous Structure Similar structure BUT different function Evolve from a common ancestor EX: Whale fins and human arms

Analogous Structure Different structures BUT same function Share a similar environment EX: Butterfly wing and bird wing

Vestigial Structure Structures in species that serve no function EX: Leg and hip bones in whales AND appendix in humans

Embryology Study of similarities between organisms during early stages of development EX: Humans and fish both have gills in early development

Artificial Selection Selection by humans for breeding of useful traits EX: Pure breed dogs AND artificial crops