Deep Time, Evolutionary History, and The Anthropocene

These flashcards cover key concepts, definitions, and significant events related to deep time, evolutionary history, human impact on the environment, and biodiversity conservation.

Hadean Eon

4.6–4.0 BYA; time of Earth's formation with no life.

Archean Eon

4.0–2.5 BYA; first evidence of life with anaerobic prokaryotes.

Great Oxygenation Event

2.4 BYA; significant increase in Earth's atmospheric oxygen.

Endosymbiosis Theory

Explains the origin of eukaryotes; organelles derived from engulfed prokaryotes.

Cambrian Explosion

541 MYA; rapid diversification of animal phyla.

Stromatolites

Earliest fossil evidence of life formed by microbial mats.

Mass Extinction

A period where at least 75% of species are lost.

Permian Extinction

252 MYA; caused by volcanic eruptions, led to massive species loss.

Cretaceous Extinction

65 MYA; caused by an asteroid impact, leading to the extinction of non-avian dinosaurs.

Adaptive Radiation

Rapid evolution of diversely adapted species from a common ancestor.

Out-of-Africa Hypothesis

Homo sapiens migrated from Africa, replacing other hominins.

Savannah Hypothesis

Suggests bipedalism and tool use evolved due to changing environments.

Variability Selection Hypothesis

Rapid climate changes influenced the evolution of adaptability in humans.

Anthropocene

An unofficial epoch characterized by significant human impact on Earth.

Great Acceleration

Post-WWII increase in human activity metrics (population, consumption).

Ecosystem Engineers

Humans significantly modify habitats, affecting ecosystem balance.

Ecological Footprint

Land/water area needed to sustain a population's lifestyle.

Greenhouse Effect

Natural process where gases trap heat in the atmosphere.

Keeling Curve

Graph showing the rise of atmospheric CO₂ over time.

Ocean Acidification

Process by which ocean absorbs CO₂, lowering pH and affecting marine life.

Positive Feedback Loop

Warming that leads to more greenhouse gases released by thawing permafrost.

Negative Feedback Loop

Increased plant growth that absorbs CO₂ and stabilizes climate.

Eutrophication

Nutrient pollution leading to algae blooms and hypoxia in aquatic systems.

Dead Zone Process

Excess nutrients cause oxygen depletion in water, harming aquatic life.

H.I.P.P.O.

An acronym for threats to biodiversity: Habitat loss, Invasive species, Pollution, Overexploitation, Climate change.

Invasive Species

Non-native species that disrupt local ecosystems and outcompete natives.

Flagship Species

Charismatic species that raise awareness for conservation efforts.

Keystone Species

Species whose presence significantly affects the ecosystem's structure.

Amphibian Vulnerability

Sensitive to pollutants and pathogens due to their permeable skin.

Ecosystem Services

Benefits provided by ecosystems, such as clean water and pollination.

Monoculture Risk

Low genetic diversity in crops increases vulnerability to diseases.

Bipedalism

Evolved physical trait in hominins allowing upright walking.

Permian Extinction Cause

Major volcanic activity from Siberian Traps.

Cretaceous Extinction Cause

Asteroid impact at the Chicxulub crater.

Ecosystem Corridors

Habitat linkages that facilitate species migration and gene flow.

Carbon Cycle

Cycle describing carbon's movement through the environment.

Nitrogen Cycle

Cycle that describes how nitrogen moves through the atmosphere, soil, and living organisms.

Phosphorus Cycle

Cycle that illustrates how phosphorus moves through ecosystems.

Sustainable Practices

Actions that meet current needs without compromising future generations.

Incentives vs Regulations

Approaches to promote sustainable practices through financial benefits and rules.

Feedback Mechanisms

Processes that amplify or stabilize changes in environmental conditions.

Climate Change

Long-term alteration in temperature and typical weather patterns.

Hypoxia

Low oxygen conditions in water that can lead to marine dead zones.

Natural Selection

The process where organisms better adapted to their environment tend to survive.

Extinction Risk

The likelihood of a species becoming extinct.

Transitional Fossil

Fossils that exhibit traits common to both an ancestral group and its derived descendant group.

Tiktaalik

Transitional fossil linking fish to early tetrapods.