apes unit 7 vocab

biodiversity

species richness

the count of the different types (species) of organisms in a specific area or ecosystem

species evenness

the proportion or relative abundance of individuals among species in a community

evolution

the process of living things changing gradually over millions of years

natural selection

the process where organisms better adapted to their environment tend to survive and produce more offspring

adaptation

a heritable trait—physical, behavioral, or physiological—that improves an organism's chances of surviving and reproducing in its specific environment

gene flow

the transfer of genetic material (alleles) from one population to another

genetic drift

a mechanism of evolution that causes random, unpredictable changes in the frequency of gene variants (alleles) within a population over time

bottleneck effect

a type of genetic drift that occurs when a population's size is drastically reduced for at least one generation, usually due to a natural disaster, disease, or human activity

extinction

the permanent loss of a species, occurring when the very last individual of that species dies

geographical isolation

the physical separation of populations of the same species by natural barriers

allopatric speciation

the formation of new species caused by geographic separation

reproductive isolation

occurs when different populations or species are unable to successfully interbreed and produce fertile offspring due to geographical, behavioral, or genetic barriers

sympatric speciation

the process where a single population splits into two distinct species while living in the same, shared geographical area

mass extinction

• a short geological period (thousands to millions of years) when a very high percentage of all life on Earth—often 75% or more—dies out

• a widespread, rapid, and severe drop in global biodiversity

background extinction rate

the natural, low-level rate at which species disappear over long periods of time

population

a group of individuals of the same species living in a particular area at the same time

community

all the populations of different species that live and interact together in a particular, defined area

population ecology

the study of how and why the population size, density, and structure of a specific species (like apes or humans) change over time in a particular area

inbreeding depression

the reduction in survival and fertility of offspring that occurs when closely related individuals mate

community ecology

the study of how different populations of species interact, coexist, and form complex networks within a specific habitat

symbiotic relationship

a close, long-term interaction between two different species

competition

an interaction where organisms (same or different species) vie for limited resources like food, water, light, or space

competitive exclusion principle

two species competing for the exact same, limited resources cannot coexist indefinitely in the same habitat

predation

an interaction between species where one organism (the predator) directly feeds on all or part of another living organism (the prey)

parasitism

a relationship where one organism (the parasite) lives on or inside an ape (the host), gaining nutrients and shelter while causing harm, weakening, or disease to the ape without immediately killing it

herbivory

the consumption of plants and plant-based materials as the primary source of nutrition

commensalism

a type of symbiosis (long-term interaction) where one species (the commensal) benefits, while the other (the host) is neither helped nor harmed

keystone species

an organism that holds an ecosystem together, having a massive impact on its environment despite relatively low population numbers

primary succession

the process of building an ecosystem from scratch on bare, inorganic surfaces (like rock, lava, or glacial deposits) that lack soil and previous life

secondary succession

the process of ecosystem recovery following a disturbance (e.g., fire, flood, farming) that clears vegetation but leaves the soil intact

pioneer species

the very first type of organism (usually plants, fungi, or bacteria) to grow in an area that has no life or has been destroyed by a disaster

theory of island biogeography

the biodiversity (number of species) on an island is determined by two main factors: island size and distance from the mainland