Glossary
Acclimation
A short-term, reversible physiological adjustment that an individual organism makes in response to changes in its environment.
Example:
When a person moves from sea level to a high altitude, their body undergoes acclimation by producing more red blood cells to cope with lower oxygen levels.
Adaptations
Heritable genetic variations that increase an organism's fitness in a specific environment, enhancing its chances of survival and reproduction.
Example:
The thick fur of a polar bear is a crucial adaptation that allows it to survive and thrive in extremely cold Arctic environments.
Anthropogenic impacts
Changes or effects on the environment that are caused or influenced by human activities.
Example:
Deforestation for agriculture is a significant anthropogenic impact that leads to habitat loss and increased carbon emissions.
Competition
An interaction between organisms or species in which the fitness of one is lowered by the presence of another due to limited resources.
Example:
Two male lions engaging in a fierce fight over territory demonstrate intense competition for resources and mates.
Ecosystem disruptions
Significant changes or disturbances to an ecosystem's structure and function, often leading to shifts in species populations and community dynamics.
Example:
A massive wildfire, while natural, can cause severe ecosystem disruptions by destroying habitats and altering nutrient cycles.
Extinction
The complete disappearance of a species from Earth, occurring when the last individual of that species dies.
Example:
The dodo bird's inability to adapt to introduced predators and habitat loss led to its extinction within a few centuries.
Fitness
An organism's ability to survive and reproduce in its environment, contributing its genes to the next generation.
Example:
A bird that successfully raises more offspring than its peers has higher fitness because it passes on more of its genetic material.
Interspecific competition
Competition that occurs between individuals of different species for shared limited resources.
Example:
When foxes and coyotes hunt the same small rodents in an area, they are engaged in interspecific competition for food.
Intraspecific competition
Competition that occurs between individuals of the same species for limited resources, such as food, mates, or territory.
Example:
A group of oak trees growing close together will experience intraspecific competition for sunlight and soil nutrients.
Invasive species
A non-native species introduced to an ecosystem that causes ecological or economic harm, often outcompeting native species due to a lack of natural predators or controls.
Example:
The introduction of the Burmese python into the Florida Everglades has made it a destructive invasive species, preying on native wildlife.
Mutations
Random changes in the DNA sequence that introduce new alleles into a population's gene pool, serving as the ultimate source of genetic variation.
Example:
A spontaneous mutation in a bacterial gene might confer resistance to an antibiotic, allowing that bacterium to survive treatment.
Natural disruptions
Environmental changes or disturbances that occur due to natural processes, such as geological events or weather phenomena.
Example:
A volcanic eruption is a powerful natural disruption that can reshape landscapes and alter atmospheric conditions.
Natural selection
The process by which individuals with advantageous heritable traits survive and reproduce more successfully than others, leading to an increase in the frequency of those traits in a population over generations.
Example:
In a population of finches, natural selection might favor birds with beaks better suited for cracking available seeds, leading to an increase in that beak type over time.
Population
A group of individuals of the same species living in the same geographic area at the same time, capable of interbreeding.
Example:
Ecologists study how the size and genetic makeup of a deer population change in response to hunting pressures and food availability.
Selective pressures
Environmental factors that favor the reproductive success of individuals with certain traits over others, driving natural selection.
Example:
The presence of a new predator creates strong selective pressures on prey populations, favoring individuals with better camouflage or faster escape mechanisms.