History of Life and Population Ecology Lecture Notes

Comprehensive vocabulary flashcards covering Earth's historical timeline, global biomes, precipitation controls, and population ecology concepts based on lecture notes.

Anaerobes

The first life forms on Earth that did not require oxygen ($O_2$) and predominated until photosynthesizing microorganisms emerged.

Prokaryotes

Primitive bacteria that emerged on Earth approximately $3.5\text{ billion years ago}$.

Eukaryotes

Organisms characterized by nucleated cells that developed on Earth approximately $2\text{ billion years ago}$.

Present-Day Atmospheric Composition

The current Earth atmosphere, which contains approximately $20_2$ oxygen ($O_2$).

Photosynthetic Proportions

The global breakdown of oxygen production, where $50\%$ of photosynthesis occurs in marine environments and $50\%$ occurs in terrestrial environments.

Earth Surface Composition

The geographical composition of the planet, consisting of $70\%$ water and $30\%$ land.

Axial Tilt

The slant on which Earth operates, determining seasons as well as sunrise and sunset patterns to create temporal change.

Tundra

A freeze/thaw ecosystem located from $70^\circ\text{N}$ to $90^\circ\text{N}$ that experiences no water shortage and contains extreme biodiversity.

Boreal Forest / Taiga

An ecosystem located at $60^\circ\text{N}$ comprising much of the land area in the Northern Hemisphere; characterized by constant rain, freeze/thaw cycles, a longer growing period than the tundra, and functioning as a huge producer of oxygen ($O_2$).

Temperate Forest

An ecosystem located at $45^\circ\text{N}$ that is generally rainy but susceptible to drought, is not typical of the entire planet, and is progressively getting hotter.

Desert

A hot, arid latitudinal biome at $30^\circ\text{N/S}$ characterized by no rain and severe water scarcity.

Tropical Rainforest

A biome located at the equator that serves as a huge producer of oxygen ($O_2$).

Rain Shadow Deserts

Deserts formed by a combination of altitude, latitude, and precipitation direction where topographical features block moisture, resulting in a rainy slope on the windward side and a dry rain shadow on the leeward side.

Marine Currents

Oceanic flows whose proximity significantly alters local precipitation and climate patterns.

Habitation Range

An area defined by two main aspects: geographical distribution decaying over time and ecological distribution.

Elevational Rule of Thumb

A model rule stating that every $1000\,ft$ change in elevation mirrors climate and ecological changes observed across latitudinal gradients.

Dispersion

The specific spatial ways organisms spread across an environment, influenced by latitudinal gradients.

Patterns of Dispersion

The three primary spatial arrangements of a population across an area: clumped, uniform, and random.

Abundance

A core goal in population ecology defined as determining how many individuals are present in a population.

Age Structure Analysis

The evaluation of a population's demographic breakdown used to address why only a specific subset of the population actively reproduces.

Intrinsic Growth Rate ($r$)

A measure of how fast a population grows when no limiting factors are holding it back, also characterized as exponential growth.

Exponential Growth Model

A growth model characterizing unrestricted, linear-rate population expansion over time when plotted on logarithmic scales.

Carrying Capacity ($K$)

The maximum population size that a specific environment can sustainably handle.

Logistic Growth Model

A growth model depicting population expansion that levels off as it approaches the carrying capacity ($K$).

Limiting Factors

Environmental attributes that directly influence or determine carrying capacity ($K$), including water, space, food, predators & predation, disease & pathogens, and competition.