Chapter 4 - Evolution

Organizing fossils by age. Shows gradual change in organisms.

Different organisms have similarities in body structures, DNA sequences, and development.

Similar but unique organisms exist in similar environments around the world.

The theory that related organisms evolved from a shared ancestor.

Diagram that used shared characteristics to show how organisms are related.

Organisms possessing certain genotypic characteristics that make them better adjusted to an environment tend to survive, reproduce, increase in number or frequency, and therefore, are able to transmit and perpetuate their essential genotypic qualities to succeeding generations

The breeding of plants and animals to produce desirable traits.

Slight differences within the same species. E.g. Moth - Dark/Light wings.

One version of the trait must provide a greater chance of survival.

Cactus - Sharp Spines - Improves survivability by providing protection against being eaten. Cheetah - Fast - Improves survivability by increasing successful hunting. Birds - Elaborate/Colourful Plumage in Males - Increases desirability to be a mating partner.

Limited Sources - Food Supply, Clean Water, Living Space, Suitable Mates - In an environment where food is scarce throughout winter and animal may develop the adaptation of hibernation. Environmental Threats - Predators, Human Activity, Disease - In an environment where predators hunt by sight, a species may develop the adaptation of camouflage.

When a new species evolves from an existing species. E.g. Galapagos Finches.