Evolution and Diversity of Life: Chapters 14-19

Molecular Evidence

Molecular Evidence

DNA and protein similarities indicating evolutionary relationships.

Analogous Structures

Similar traits in unrelated species due to environment.

Genetic Drift

Random changes in allele frequencies in populations.

Founder Effect

Genetic drift occurring when a small group starts a population.

Bottleneck Effect

Population reduction leading to loss of genetic diversity.

Migration

Movement of individuals introducing new alleles to populations.

Stabilizing Selection

Favors intermediate phenotypes, reducing variation.

Disruptive Selection

Favors extreme phenotypes, increasing variation.

Charles Darwin

English naturalist who proposed natural selection theory.

Natural Selection

Mechanism explaining evolution through survival of favorable traits.

On the Origin of Species

Darwin's 1859 book revolutionizing evolutionary biology.

HMS Beagle

Ship on which Darwin made key observations.

Galapagos Finches

Species with varied beak sizes adapted to food sources.

Thomas Malthus

Influential economist highlighting resource competition.

Alfred Russel Wallace

Co-developer of evolution theory, prompting Darwin's publication.

Fossil Record

Evidence showing progression of life forms over time.

Anatomical Record

Similarities in anatomy indicating common ancestry.

Homologous Structures

Similar structures in different species from common ancestor.

Mutations

DNA changes providing genetic variation for evolution.

Non-random Mating

Mate selection based on specific traits.

Directional Selection

Favors one extreme phenotype, shifting population average.

Speciation

Process of new species arising from existing ones.

Reproductive Isolation

Barriers preventing gene flow between species.

Prezygotic Mechanisms

Prevent zygote formation through various isolating factors.

Postzygotic Mechanisms

Prevent hybrid viability or fertility after zygote formation.

Miller-Urey Experiment

Simulated early Earth conditions forming organic molecules.

Bubble Model

Proposes organic molecules concentrated in ocean surface bubbles.

Microspheres

Spherical structures resembling early cell precursors.

Archaea

Domain of prokaryotes found in extreme environments.

Bacteria

Domain of prokaryotes with diverse shapes and functions.

Gram Staining

Method classifying bacteria based on cell wall structure.

Conjugation

Genetic exchange process in bacteria via plasmids.

Binary Fission

Asexual reproduction method in prokaryotes.

Prokaryotic Features

Small, single-celled organisms lacking membrane-bound organelles.

Circular Chromosome

Single chromosome located in cytoplasm of prokaryotes.

Methanogens

Archaea that produce methane in anaerobic environments.

Thermoacidophiles

Archaea thriving in hot, acidic habitats.

Viruses

Non-living entities that cannot reproduce independently.

Capsid

Protein coat enclosing viral genetic material.

Lytic Cycle

Viral reproduction cycle killing host cells.

Lysogenic Cycle

Viral DNA integrates into host genome, remains dormant.

Prophage

Integrated viral DNA within a host's genome.

Endosymbiotic Theory

Explains origin of mitochondria and chloroplasts.

Sexual Reproduction

Fusion of gametes from two parents, increasing diversity.

Asexual Reproduction

Offspring genetically identical to the parent.

Parthenogenesis

Development of unfertilized egg into an adult.

Zygotic Meiosis

Meiosis occurs immediately after zygote formation.

Gametic Meiosis

Diploid stage dominant; produces haploid gametes.

Sporic Meiosis

Alternation of generations between gametophyte and sporophyte.

Protists

Eukaryotes that are not fungi, plants, or animals.

Phototrophs

Organisms that obtain energy through photosynthesis.

Heterotrophs

Organisms that ingest or absorb nutrients.

Hyphae

Thread-like filaments that make up fungi.

Mycelium

Mass of hyphae forming the main body of fungus.

Spores

Light structures used by fungi for reproduction.

Mycoremediation

Use of fungi to clean up environmental pollutants.

Vascular Tissue

Xylem and phloem transport water and nutrients.

Nonvascular Plants

Plants lacking true vascular systems, e.g., mosses.

Gymnosperms

Seed plants producing naked seeds, e.g., conifers.

Angiosperms

Flowering plants producing seeds enclosed in fruit.