• Proposed by Charles Darwin

• To "descent with modification"

• Plants and animals originate from earlier forms, with differences between ancestors & descendants leading to  generational changes

• first creatures were disembodied organs

• all matter was composed of four elements: fire, air, water, and earth

• species were fixed & unchanging

• all living things have a natural tendency to develop and grow towards a final, perfect state - telos

• species undergo changes

• all animals might have evolved from a single breeding pair

• the strongest and most active animal should propagate the species, which should hence become improved

• “survival of the fittest”

• grandfather of Charles Darwin

• change results from the needs

• evolutionary change occurs depending on the needs of the specie

• Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success

1. High reproductive potential

2. Inherited variations exist

3. Constant struggle for limited resources, many individuals die

4. Adaptive traits become more common in subsequent generations.

• Occurs when a heritable change in phenotype increases an animal's chances of successful reproduction

• Arises as result of chance mutations

• Perpetuated by natural selection

STRATIGRAPHY

• Estimating time relationships between events based on the position of one event in a rock stratum (layer) relative to surrounding strata

• Does not assign absolute dates to events, but geologists use it to correlate strata around the world

• Radiometric and molecular dating techniques

• Can be used to assign dates to rock strata and events that occurred in the past

• Would have hurled debris into the atmosphere, creating an “impact winter"

• Global cooling, death of photosynthetic organisms, acid rain

• Would have likely resulted in deadly sulfurous and CO2

emissions that spread across the globe

MICRO AND MACREVOLUTION

• Study of geographic distribution of plants and animals

• Life-forms in different parts of the world have distinctive evolutionary histories

• Explains distribution pattern

• Study of fossil record

• Direct evidence of sequences of appearance and disappearance of organisms

FOSSILS

• Evidence of plants and animals that existed in the past and have become incorporated into the earth's crust

• Resemblance that occurs because of common ancestry

  • similarity of the structure, physiology, or development of different species of organisms based upon their descent from a common evolutionary ancestor

HOMOLOGY-COMPARATIVE ANATOMY

• Study of the structure of living and fossilized animals and homologies that indicate evolutionarily close relationships

CONVERGENT EVOLUTION

• Evolution of superficially similar structures in unrelated organisms

• Show lines of descent

BRANCHES

• Evolutionary connections

NODES

• Branch points

• Genes, populations, species where change occurs