Mrs. Rago Bio Evolution

Charles Darwin English scientist who developed theory of evolution Studied species on the Galapagos Islands Observed the species to compare features from each

Natural Selection Mechanism for change in populations Occurs when an organism with certain variations (characteristics) survive, reproduce, & pass on their variations to the next generation These variations make the organism more likely to survive and reproduce

Reproduction in Natural Selection Favorable traits make individual more likely to survive & reproduce Individuals with the best traits pass them on to their offspring

Convergent Evolution Process 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 other’s influence

Artificial Selection Breeding organisms to produce offspring with identical traits Example: breeding pure bred dogs

On the Origins of Species Book by Charles Darwin First book on evolution

Structural Adaptations Changes that have developed in an organism’s form over time Example: thorns on some plants Take a long time to occur Millions of years

Mimicry Structural adaptation that allows one species to resemble another species Useful for a harmless species to resemble a harmful species, so that predators avoid the harmless species

Coral snake- venomous & deadly King snake-non venomous

Camouflage An adaptation that allows a species to blend into their surroundings and avoid predators

Physiological adaptations Occur much faster Changes in an organisms metabolic processes Example: resistance to penicillin, insects & weeds resistant to specific pesticides

Evidence for Evolution Fossil record Shows evidence of evolution but it is incomplete

Anatomy Homologous structures Similar structures that come from a common ancestor

Analogous Structures Similar structures that are similar because they are used for the same purpose

Vestigial Structures A body structure that has no function in a present-day organism but was probably useful to an ancestor Example: wings of an ostrich

Embryology Embryo is the earliest stage of growth & development of both plants & animals

Biochemistry Evidence for evolution, shows similarities in DNA or RNA

Atmosphere of Early Earth Large meteor impacted earth More comets hit earth and brought ice with them which along with gases from volcanoes produces the water we now find on earth

Atmosphere of Early Earth Very little free oxygen Water vapor Carbon Nitrogen

Evolution of photosynthesis Archaebacteria Do not require oxygen First group to develop Cyanobacteria Produce oxygen from their chemical reactions This changed earth’s atmosphere

Early Earth Very hot Lots of volcanoes meteorites Lots of gases Humans would never have survived early earth