The Origin and Evolution of Life on Earth

Inorganic Selection

Reactivity of molecules affects their abundance.

Early Atmosphere

Hydrogen-rich, toxic to modern life.

Stanley Miller Experiment

Simulated early Earth conditions to create amino acids.

Amino Acids

Building blocks of proteins formed in ancient oceans.

Photosynthesis

Process converting sunlight into chemical energy.

Oxygen Holocaust

Mass extinction due to rising oxygen levels.

Red Beds

Sediments indicating oxidized iron presence.

Procaryotes

Simple bacteria-like earliest life forms.

Eucaryote Cells

Complex cells with organelles and nuclei.

Endosymbiosis

Theory of organelles evolving from independent cells.

Gametes

Reproductive cells merging to increase genetic diversity.

Panspermia

Theory suggesting life originated from outer space.

Precambrian Era

Oldest geological time period, before 570 million years.

Cambrian Period

Marked by rapid diversification of life forms.

Ordovician Period

Era of marine life flourishing.

Silurian Period

First vascular plants appeared.

Devonian Period

Age of fishes and early land plants.

Mesozoic Era

Known as the age of reptiles.

Cenozoic Era

Current geological era, post-dinosaurs.

Stromatolites

Layered structures formed by microbial mats.

Vascular Plants

Plants with tubules for nutrient transport.

Psilophytes

Earliest vascular plants with stem-like leaves.

Archaeopteris

Early fern-like plant from the Devonian.

Seed Ferns

Early plants that produced seeds.

Lycopsids

Ancient vascular plants, some tree-sized.

Cordaites

Earliest gymnosperms and conifers.

Ginkos

Ancient trees with fan-shaped leaves.

Cycads

Palm-like plants from the Mesozoic era.

Gondwana Flora

Flora from the ancient supercontinent Gondwana.

Glossopteris

Fossil plant with strap-like leaves.

Cycadeoids

Extinct group of seed plants resembling cycads.

Angiosperms

First flowering plants appearing in the Jurassic.

Ediacaran

Period before the Cambrian, featuring early life forms.

Cambrian Explosion

Rapid diversification of life with hard parts.

Burgess Shale

Fossil site with diverse Cambrian organisms.

Eurypterids

Ancient marine arthropods, also known as sea scorpions.

Acanthodian Fish

Early jawed fish appearing in the Devonian.

Placoderms

Armored fish from the Devonian period.

Amphibians

First vertebrates to adapt to land.

Crinoids

Echinoderms resembling flowers, common in the Mississippian.

Synapsids

Mammal-like reptiles, ancestors of mammals.

Plesiosaurs

Marine reptiles with long necks from the Jurassic.

Teleosts

Modern bony fish appearing in the Jurassic.

Biogeography

Study of species distribution across geographical areas.

Founder Effect

Genetic differences due to small founding populations.

Background Extinction Rate

Normal rate of species extinction over time.

Mass Extinctions

Rapid loss of species in a short period.

Ordovician-Silurian Extinction

First major extinction event, 450-440 Ma.

Permian-Triassic Extinction

Largest extinction event, 252 Ma, affecting marine life.

Punctuated Equilibrium

Theory suggesting evolution occurs in rapid bursts.

Primates

Arboreal mammals with five fingers and binocular vision.

Prosimians

Early primates including lemurs and indrids.

Homo habilis

First known species to use tools.

Homo erectus

First species to migrate from Africa.

Homo neanderthalensis

Coexisted with Homo sapiens, later extinct.

Homo sapiens

Modern humans evolved in Africa, migrated globally.

Exaptation

Using traits for different functions than evolved.

Inherited Behavior

Genetically coded actions performed at development stages.

Learning

Change in behavior based on past experiences.

Memory

Ability to retain and recall past experiences.

Motivation

Drives behavior to meet survival needs.

Operant Behavior

Behavior modified by consequences and reinforcements.

Reinforcement

Outcome that increases or decreases behavior likelihood.

Primary Reinforcer

Stimulus directly related to survival needs.

Secondary Reinforcer

Neutral stimulus associated with primary reinforcers.

Survival

Meeting environmental demands to pass on genes.

Natural Selective Pressure

Environmental factors influencing survival and reproduction.

Behavioral Modification

Changes in behavior due to learning experiences.

Cognition

Mental processes influencing behavior in organisms.

Genetic Precondition

Innate ability to learn specific behaviors.

Hybridization

Interbreeding between different species, e.g., Neanderthals and humans.

Bering Land Bridge

Land connection allowing migration to the Americas.

Behavioral Reflex

Automatic response to specific stimuli.

Social Animals

Species that live and interact in groups.

Environmental Adaptation

Adjustments made by organisms to survive in environments.

Fitness

Ability to survive and reproduce in a given environment.

Culture

Learned behaviors not genetically encoded.

r-Type species

Small organisms with rapid reproduction rates.

K-Type species

Larger organisms with slower maturation and reproduction.

Generation rate

Speed at which a species reproduces.

Exclusive Fitness

Individual benefits from traits passed to offspring.

Inclusive Fitness

Fitness considering relatives' survival and reproduction.

Kin Selection

Helping relatives to propagate shared genes.

Altruism

Selfless behavior that benefits others at a cost.

Group Selection

Species evolve through collective natural selection.

Herding Behavior

Survival advantage from group living.

Social Behavior

Structured roles and altruism in species groups.

Reciprocal Altruism

Helping others with expectation of future help.

Cheater

Individual who benefits without reciprocating altruism.

Intelligent Design

Belief in a designer based on complexity.

Scientific Creationism

Religious view demanding equal teaching time with evolution.

Evolution vs. Creationism Debate

Conflict between scientific and religious explanations of origins.

Pesticides impact

Selective pressure leading to resistant genetic variants.

Human Kin Selection

Altruism in closely related small groups.

Lifespan

Average duration of an organism's life.

Predation Risk

Increased danger for isolated individuals.

Ecological Niche

Role of a species in its environment.

Evolutionary Advantage

Trait that enhances survival and reproduction.

Altruism in Humans

Higher altruism towards close relatives.

Learning in Evolution

Adaptation through acquired behaviors.