Chapter 1: Ecology, Evolution, and the Scientific Method

Vocabulary flashcards covering key ecological and evolutionary terms from Chapter 1 notes.

Ecology

The scientific study of the abundance and distribution of organisms in relation to other organisms and environmental conditions; from Greek oikos (house) and logia (study of).

Oikos

Greek for 'house'; root of the word ecology.

Individual

A single organism with its own internal processes, bounded by a membrane; it acquires nutrients and energy and produces waste.

Population

All members of a species in a given area at a given time; the unit of evolution through natural selection; varies in number and demographic composition.

Community

Association of interacting populations defined by their interactions or the place they live; boundaries are not rigid.

Ecosystem

Assemblage of communities plus the abiotic physical and chemical environment; involves energy flow and nutrient cycling and element pools (C, O, H, N, P).

Biosphere

Integrated system of all environments and organisms on Earth; teleconnection links distant ecosystems through wind, water, and movement of organisms.

Teleconnection

Distant ecosystems linked together by exchanges of wind and water and by the movement of organisms.

Habitat

The place where an organism lives, defined by resources and environmental conditions; supports shelter, food, water, and reproduction.

Niche

The range of abiotic and biotic conditions an organism can tolerate; its functional role in the environment; no two species share the same niche.

Prokaryote

Single-celled organisms lacking membrane-bound organelles (bacteria and archaea).

Eukaryote

Organisms with membrane-bound organelles; evolved from prokaryotes via endosymbiosis.

Endosymbiosis

Mutualistic relationship where one organism lives inside another; mitochondria originated from engulfed bacteria, enhancing fitness.

Endosymbiotic theory

Origin of eukaryotes through engulfment of bacteria/archaea; organelles arose from symbiotic relationships that increased fitness.

Photosynthesis

Process by which organisms convert light energy into chemical energy (cyanobacteria can perform

Conservation of matter

Matter cannot be created or destroyed in ecological processes; it can change form.

Conservation of energy

Energy cannot be created or destroyed; it can only be transformed (First Law of Thermodynamics).

Dynamic steady state

A state in which gains and losses in an ecological system are balanced over time.

Evolution

A change in the genetic composition of a population over time.

Natural selection

Change in gene frequencies due to differential survival and reproduction of individuals with certain phenotypes.

Artificial selection

Human-directed selection for specific traits.

Genetic drift

Random fluctuations in allele frequencies due to chance events.

Genotype

The genetic makeup of an organism.

Phenotype

The outward expression of environmental effects on an organism’s genotype; includes morphology, development, and behavior.

Mutation

Random changes in genetic material that create variation.

Recombination

Exchange or rearrangement of genetic material during reproduction, creating new allele combinations.

Fitness

Reproductive success; individuals with advantageous traits leave more offspring, increasing those traits in the population.

Variation

Differences among individuals in traits; can be heritable or non-heritable.

Heritable variation

Variation that can be passed to offspring and thus fuels evolution via natural selection.

Adaptation

A trait that increases an organism’s fitness in a given environment; results from natural selection.

Bacteria, Archaea, and Eukarya.

The Three Domains of Life:

Bacteria

One of the three domains; prokaryotic organisms lacking membrane-bound organelles.

Archaea

One of the three domains; prokaryotic organisms often adapted to extreme environments.

Eukarya

One of the three domains; includes all organisms with eukaryotic cells (plants, animals, fungi, protists).

Density dependence

Population growth rate depends on population density.

Density independence

Population changes that are not influenced by population density.

Habitat destruction

Loss or modification of habitat due to human activity, leading to species declines.

Pollution

Contamination of the environment that harms living organisms and ecosystems.

Climate change

Long-term changes in climate patterns affecting ecosystems around the world.

Overharvesting

Excessive removal of resources from ecosystems, reducing populations.

Energy flow

Movement of energy through organisms and the ecosystem, from producers to consumers.

Element pools

Pools of essential elements (carbon, oxygen, hydrogen, nitrogen, phosphorus) in ecosystems.

Biodiversity

Variety of life in an area or on Earth; encompasses genetic, species, and ecosystem diversity.