Population

A group of individuals of the same species living in the same geographic area

Population Genetics

Study of genetic makeup of populations and how they change over time

Gene Pool

All alleles present in a population

Allele Frequency

Proportion of a specific allele in a population

Evolution

Change in allele frequencies in a population over time

Natural Selection

Process where individuals with favorable traits survive and reproduce more

Fitness

Ability of an organism to survive and reproduce

Adaptation

A trait that increases survival and reproduction

Mutation

A change in DNA that introduces new alleles

Types of Mutations

Neutral, beneficial, or harmful

Nonadaptive Evolution

Random changes in allele frequency that do not affect fitness

Genetic Drift

Random change in allele frequencies, especially in small populations

Founder Effect

A small group starts a new population with reduced genetic diversity

Bottleneck Effect

population drastically reduced, decreasing genetic diversity

Gene Flow

Movement of alleles between populations

inbreeding

Mating between closely related individuals

Inbreeding Depression

Increased expression of harmful recessive traits

Genetic Diversity

Total genetic variation in a population

Why is Genetic Diversity Important?

Higher diversity increases survival in changing environments

Hardy-Weinberg Equilibrium

A state where allele frequencies do not change (no evolution)

Hardy-Weinberg Equation

p² + 2pq + q² = 1

p²

Homozygous dominant frequency

2pq

Heterozygous frequency

q²

Homozygous recessive frequency

Hardy-Weinberg Conditions

No mutations, no natural selection, large population, no gene flow, random mating

What happens if conditions are violated? (Hardy-Weinburg Equil)

The population evolves

Species

Group of organisms that can interbreed and produce fertile offspring

Speciation

Formation of new species

Reproductive Isolation

When species cannot interbreed successfully

Geographic Isolation

Separated by physical distance

Temporal Isolation

Different mating times

Behavioral Isolation

Different mating behaviors

Mechanical Isolation

Physical incompatibility

Gametic Isolation

Gametes cannot fuse

Hybrid Inviability/Infertility

Offspring cannot reproduce

Fossils

Preserved remains or impressions of organisms

How Fossils Form

Trapped, frozen, or buried

Radiometric Dating

Determines age using radioactive decay

Half-life

Time for half of a radioactive isotope to decay

Relative Dating

Determines age based on rock layers

Homology

Similarity due to common ancestry

Vestigial Structures

Structures with no current function but ancestral origin

Descent with Modification

Species change over time from common ancestors

Darwin's Theory

Natural selection drives evolution

Darwin's Influences

Geology (old Earth), Malthus (population limits)

Directional Selection

Favors one extreme phenotype

Stabilizing Selection

Favors average phenotype

Diversifying Selection

Favors extreme phenotypes

Antibiotics

Chemicals that kill or slow bacteria

Antibiotic Resistance

Bacteria evolve to survive antibiotics

Biogeography

Study of species distribution

Convergent Evolution

Unrelated species evolve similar traits

Taxonomy

Classification of organisms

Order of Classification

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Phylogeny

Evolutionary relationships among organisms

Human Evolution Origin

Africa

Genetic Similarity of Humans

99.9% identical DNA

Melanin

Pigment that determines skin color

melanocytes

cell that makes the melanin pigment

Skin Color Adaptation

Dark = protects from UV, Light = helps vitamin D production

Mitochondrial DNA (mtDNA)

Inherited only from mother

Why mtDNA is useful

Mutates faster, used to trace ancestry

Panspermia

the hypothesis that Life came from space

Chemical Evolution

Life formed from organic molecules

Mass Extinction

Large-scale extinction events

Adaptive Radiation

Rapid diversification after extinction

Punctuated Equilibrium

Rapid evolution after long stability

Prokaryotes

Unicellular organisms without nucleus

Bacteria Shapes

Bacillus (rod), Coccus (sphere), Spirillum (spiral)

Capsule

Protective outer layer of bacteria

Pili

bacterial appendages Used for attachment

flagella

bacterial tail used for movement

Archaea

Prokaryotes that live in extreme environments

Extremophiles

Organisms that live in extreme conditions (heat, cold, salt)

Methanogens

anaerobic bacteria that produce methane as a byproduct of energy metabolism

Hydrothermal Vents

Extreme environments where early life may have formed

Serpentinization

Chemical process producing hydrogen gas

Eukaryotes

Cells with nucleus and organelles

Plants

Photosynthetic eukaryotes with cell walls

Bryophytes

earliest form of plants, Nonvascular

ferns

earliest form of land plant after bryophytes, no seed uses spores to reproduce

Gymnosperms

plants with exposed seeds (spruce, fir, redwood, etc)

Angiosperms

flowering plants, seeds contained in fruit

Animals

Multicellular organisms that ingest food

Symmetry Types

Asymmetrical, radial, bilateral

Asymmetry

(no symmetry or organ/tissues)

Invertebrates

Animals without backbone (95%)

radial symmetry

circular (like a pizza :3)

bilateral symmetry

left and right sections of body are mirrored, 95% of animals

Arthropods

Exoskeleton, jointed limbs, segmented body, (insects, crabs, lobsters)

Vertebrates Groups

Fish, amphibians, reptiles, birds, mammals

endosymbiosis

theory that some organelles derived from bacteria AKA prokaryotes

mitochondria came from..

aerobic bacteria

chloroplasts came from..

photosynthetic bacteria

hyphae

long threadlike attributes of fungi that absorb nutrients

mycelium

multiple/colony of hyphae

protists

all eukaryotes other than plants, animals, fungi / generally unicellular / some are autotrophs, heterotrophs, and decomposers some traits overlap and mix

fungi

unicellular or multicellular eukaryotes that obtain nutrients by secreting digestive enzymes and absorbing digestive material