Evolution

Speciation

A process that allows new species to be generated

Allopatric Speciation

subspecies forms after a population is physically separated

How does speciation occur?

A population must be isolated for a generations

Phylogenetic tree

Treelike diagram that shows the history of the divergence of species or other taxonomic groups of organisms

What do phylogenetic trees show?

The history of life’s divergence

What are the Hawaiian Islands some time referred to as?

The natural laboratory of evolution

Who was the mind behind the phylogenetic tree?

Carl Linnaeus

Fossil

An imprint in stone of a dead organism

Paleontologists

Scientists who study the history of Earth’s life

Fossil record

The collection of fossils worldwide

Extinction

When a species no longer exists on earth

How long do species tend to spend on earth?

1-10 million years

Exponential growth

When there is an increase of population by a fixed percentage each year

What do other organisms provide us?

Food, fiber, medicine, and important ecosystem services

How does extinction occur?

When an organism cannot keep up with it’s changing environment

Winners

Organisms who are more able to adapt to changing environments and are more wide spread. There also tends to be more of them.

Losers

Organisms who aren’t able to adapt as well to their changing environment and are smaller in population size.

Endemic

When a species is only found in one area and found no where else on earth

Invasive species

Species who are not native to an area they are in.

How do we obtain a population’s rate of natural increases?

(birth rate)-(death rate)= rate of natural increases

How do we calculate population growth rate?

(birth rate- death rate) + (immigration rate - emigration rate)= )______

population growth rate x 100%

Population growth rate

How we obtain the rate of change within a population’s size per unit time

Limiting factor

A physical, chemical, or biological characteristic of the environment that restrains population growth

Biodiversity

The variety of life across all levels of biological organization, including species, genes, populations, communities, and ecosystems.

Species

A distinct type of organism

Species diversity

The variety of species found in one particular region

Species Richness

The number of species inhabiting an area

Evenness or Relative abundance

The amount of variety within a species. High Evenness means low diversity or variety

Subspecies

A population of a species that differs slightly from the original species it came from

Genetic diverstity

Different DNA composition within a species

Ecosystem diversity

The number and variety of ecosystems

Intraspecific competition

Takes place between members of the same species

Interspecific competition

Takes place between members of different species

When does competition become more intense?

When the population is more dense

Competitive exlusion

When one species is stronger compared to other species it may exclude other species from resources

Species coexitence

When there is no single competitor that excludes other species, they all live side by side

niche

A species role within an ecosystem

Community

An assemblage of populations of organisms that live in the same area at the same time

Community ecologists

The study of which species coexist, how they interact, how communities change over time, and why these patterns occur

Predation

The process by which individuals of one species captures, kills, or consumes individuals of pray

Herbivory

Animals that feed on plants

Trophic level

Species within a community are given a specific rank within their feeing hierarchy

Producers

Organisms that use photosynthesis or chemosynthesis to form their own food

Primary consumers

They consume the producers (plants)

Tertiary consumers

Feed on secondary consumers

Detritivores

Scavenge for waste and dead bodies

Deconposers

Breaks down nonliving matter into smaller molecules that cycle back into the soil

Food webs

Are more complex versions of food chains which shows the entire trophic levels of the entire community

Food chains

Shows the flow of energy and the feeding relationships from lower to higher trophic levels

Keystone species

A species that has a great and important impact on the environment it’s in

Examples of keystone species

Decomposers, ecosystem engineers, and top predators(controls populations of lower trophic level consumers)

Trophic cascade

When key stone species are no longer in an environment causing the alteration of the entire ecosystem

Disturbance

An event that caused rapid and drastic effects on a community ecosystem

Resistance

The ability for a community to resist change and remains stanble

Resilience

The ability for a community to bounce back after a disturbance

Succession

Caused by severe disturbance which may eliminate all or most of the species within a community

Pioneer species

Beginning forms of succession

Examples of pioneer species

grass and forbs

Primary succession

Happens when a disturbance removes all plants or soil life

Secondary ssuccession

Happens by a disturbance but leaves soil life intact

Invasive species

When an introduced species takes over native species and causes havoc within a ecosystem