Group of related organisms that share distinctive characteristics

All members of the same species that occupy the same geographical location

Individuals with heritable traits that are best adapted to the environment are more likely to survive and reproduce

all the alleles for every gene in a population

Changes in allele and genotype frequencies from one generation to the next

likelihood of contributing fertile offspring to the next generation

Individuals with a trait on one side of the mean reproduce more than those on the other

Favors individuals with intermediate phenotype, and selects against individuals with extreme phenotypes

Favors two or more different phenotypes in different environments

Two or more alleles are maintained in a population. Also known as the heterozygote advantage

Changes in allele frequency due to random chance

A population is reduced in size dramatically due to a natural event

A small group of individuals move to a new area and start a new population

Gene flow occurs when individuals migrate between populations with different allele frequencies

Evolutionary changes that produce a new species or groups of species.

Group of related organisms that share distinctive characteristics.

Geographically distinct groups of the same species that have traits that are different, but not enough to warrant placement in a different species.

one species split into 2 distinct species

members of a different species don’t come into contact.

species reproduce at different times of the day or year

members of different species have different mating behavior

morphological (structural) features prevent interbreeding

fertilization fails between gametes.

fertilized egg cannot develop past embryonic stage.

a hybrid is viable, but sterile.

interspecies hybrids are viable and fertile, but subsequent generations have poor health and low fitness.

the study of interactions among organisms and their environment

biological factors, i.e., interactions among living organisms

physical factors, i.e., the non-living environment

the long-term average weather pattern in a region

gradual elevation of the Earth’s temperature

a group of interbreeding individuals of the same species in the same geographic location

studies factors affecting population size and distribution

Resources are unlimited, characteristic J-shaped curve

Characteristic S-shaped curve

small size, Fast-paced life, early sexual development, short lifespan, large numbers of offspring but limited parental care, high mortality of offspring, poor competitive ability

Large size, Slow-paced life, late sexual development, long lifespan, Few offspring but good parental care, Low mortality of offspring, Strong competitive ability

amount of genetic variation that occurs within and between population.

More likely when population sizes become small

Random change in allele frequencies due to chance

the number and relative abundance of species in a community.

diversity of structure and function within an ecosystem.