Introduction to Biological Oceanography

DiversityDefinition: The degree of variation of life on earthQ: how did diversity of life on earth happen?A: Evolution!

Evolution

• Definition: Change over time• Occurs to species, NOT to individuals• 6 Points:– Overproduction– Competition– Genetic variation– Adaptation– Natural selection– Speciation

Causes of Evolution

1) Mutation2) Gene flow3) Genetic drift4) Natural selection5) Non-random mating

Evidence of Evolution

1) Analogous structures2) Embryology3) Vestigial Organs4) Fossils5) Biochemical

Overproduction

• Too many individuals• Too many offspring• Too many gametes

Competition

• For food• For mates• For territory

Genetic Variation

• Genes• Traits• Individuals

Adaptation

• A trait with a current functional role in helping an animal better survive in its environment

• Three types:– Behavioral– Physiological– Structural

Natural Selection• Organisms better adapted to their

environment get to reproduce and pass their genes on to their offspring

SpeciesA species is a group of animals capable of producing

offspring with one another AND the offspring ALSO must be capable of reproducing too

Mules aren’t a species-they can’t have babies!

Speciation can happen through geographic isolation

Classification• Kingdom Phylum Class Order Family Genus Species• “King Phillip Came Over For Great Scallops”

• We name organisms using their most specific classifications: Genus and Species

• We use a Dichotomous Key to help identify organisms

• The proper way to write a scientific name is to write the Genus name with a capital, the Species name in lower case, and italicize or underline them both– Morone saxatilis or Morone saxatilis– Homo sapiens or Homo sapiens

How are organisms placed into Kingdoms?

• Cell type & complexity• Ability to make food• Number of cells in their body