Evolution & Natural Selection Vocabulary Gradual change in the genetics of a species/population over time; how descendants differ from their ancestors.

Types of Selection Artificial Selection Selection by humans for breeding of useful traits from the natural variation among different organisms, Ex. Dog Breeding

Types of Selection Natural Selection Process by which individuals that are better suited to their environment survive and reproduce successfully

How to Survive Struggle for Existence Competition among members of a species for food, living space, and the other necessities of life Fitness Ability of an organism to survive and reproduce in its environment Adaptation Inherited characteristic that increases an organism’s chance of survival

Do you think that there is a struggle for existence between humans? Question: Do you think that there is a struggle for existence between humans?

Example of natural selection, adaptations, fitness and the struggle for existence. Peppered Moth Peppered Moth Evolution

Ancestry / Evidence of Evolution Common Descent Principle that all living things have a common ancestor Descent with Modification Principle that each living species has descended, with changes, from other species over time Fossil Record Evidence that organisms from the past are not the same as those found today; fossils show a progression of evolution. Evolution - "Stated Clearly"

Ancestry Homologous Structures Structures that have different mature forms in different organisms but develop from the same embryonic tissues; common ancestor Vestigial Organs A structure or organ that is useless today but an ancestor used Guess the Embryo

Variation Gene Pool Combined genetic information of all the members of a particular population Relative Frequency Number of times an allele occurs in a gene pool compared with the number of times other alleles occur

Who is represented in the gene pool? Question: Who is represented in the gene pool?

Selection Genetic Drift Random change in allele frequencies that occurs in small populations Founder Effect Loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population Genetic Equilibrium Situation in which allele frequencies remain constant TED Ed - Five Fingers of Evolution

How do we get separate species? Speciation Formation of new species Reproductive Isolation Separation of a species or populations so that they cannot interbreed and produce fertile offspring Behavioral Isolation Form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding. Ex. Albatross, Birds of Paradise, Flamingos

How do we get separate species? Geographic Isolation Form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water Temporal Isolation Form of reproductive isolation in which two populations reproduce at different times. Ex: Flowering plants / Seasonal breeding Speciation Mechanisms

CC - Big History "Evolution" What Darwin Never Knew - Part 1