Terms in this set (19)
the number of species in an area
the relative proportion of species in a
3 Ways Evolution Occurs
background extinction rate
The amount of animals per unit of time going extinct in the "background" naturally.
New species form as a result of the physical separation of populations over some geographic distance
This is why scientists think new species arise.
the disappearance of a species from the
Extinction most often occurs when
most often occurs when species do not have
the genetic make-up to adapt quickly enough to
4 random processes that lead to evolution
bottle neck effect
In smaller populations of the same species, there is a smaller amount of a species with that particular trait, so therefore there is a greater chance of it not finding a mate (being in lesser numbers.)
The population size decreases and genetic diversity decreases as well.
When a subset of a population colonizes a new area. Bringing their select traits.
An organism that uses the energy of the Sun to produce usable forms of energy.
An organism that is incapable of photosynthesis and must obtain its energy by consuming other organisms. Also known as heterotroph.
An organism that specializes in breaking down dead tissues and waste products into smaller particles.
Fungi and bacteria that convert organic matter into small elements and molecules that can be recycled back into the ecosystem
The total living mass of all living matter in a specific area.
The amount of biomass present in an ecosystem at a particular time
The proportion of consumed energy that can be passed from one trophic level to another.
A representation of the distribution of biomass, numbers, or energy among tropic levels.