Introduction to Evolution and Natural Selection

Evolution

Change in species over time through adaptation.

Hardy-Weinberg Equilibrium

Principle predicting genetic variation in a population.

Violations of Hardy-Weinberg

Factors disrupting genetic equilibrium in populations.

Species

Groups of organisms capable of interbreeding.

Speciation

Process by which new species arise.

Taxonomy

Science of classifying organisms into categories.

Classification

Grouping organisms based on shared characteristics.

Cladistic Method

Classification based on common ancestry and evolutionary relationships.

History of Life

Chronological record of biological evolution.

Human Evolution

Study of the origins and development of humans.

Natural Selection

Mechanism of evolution favoring advantageous traits.

Fossil Record

Historical evidence of past life forms.

Homologous Similarity

Similar structures in different species indicating common ancestry.

Biogeographical Patterns

Distribution of species across geographical areas.

Embryology

Study of embryos revealing evolutionary relationships.

Comparative Anatomy

Study of morphological similarities among organisms.

Analogous Similarity

Similarity based on function, not structure.

Homologous Similarity

Similarity based on shared ancestry, not function.

Morphological Series

Gradual changes in traits over evolutionary time.

Darwin's Hypothesis

Species change over time, reflecting common ancestry.

Special Creation

Species created separately with unique characteristics.

Descent with Modification

Darwin's model explaining evolutionary changes.

Embryology

Study of embryonic development across species.

Haeckel's Biogenetic Law

Embryos exhibit ancestral characteristics during development.

Vestigial Characters

Reduced or non-functional traits from ancestors.

Atavistic Characters

Traits reappearing from distant ancestors.

Gill Arches

Ancestral structures evolving into jaws in vertebrates.

Pelvic Bones in Whales

Example of vestigial characters in modern species.

Vermiform Appendix

Reduced structure in humans with no essential function.

Agnathan

Jawless fish, e.g., hagfish.

Teleost

Modern bony fish, e.g., clown fish.

Placoderm

Early jawed fish, type of gnathostome.

Spiny Thicket

Deciduous shrub, Alluaudia ascendans from Madagascar.

Ocotillo

Desert plant, Fouquieria splendans, related to cacti.

Forelimb Bones

Humerus, radius, ulna, carpals, metacarpals, phalanges.

Embryonic Teeth

Temporary teeth in embryos, later resorbed.

Milk Teeth

First set of teeth in mammals, replaced later.

Common Ancestry

The shared lineage of different species.

Functional Necessity

Requirement for a trait to serve a purpose.

Morphological Patterns

Structural features shared among different organisms.

Evolutionary Evidence

Data supporting the theory of species evolution.

Cecum

Large pouch in herbivores for cellulose breakdown.

Appendix

Small, wormlike structure in humans, vestigial.

Atavistic Characters

Reappearance of ancestral traits in species.

Darwinian Evolution

Theory that species evolve over time.

Special Creation

Belief that species were created independently.

Vestigial Characters

Non-functional traits inherited from ancestors.

Biogeographic Realms

Distinct regions with unique species assemblages.

Neotropics

Region with diverse species, especially hummingbirds.

Hummingbirds

Over 300 species, sexually dimorphic, found in Americas.

Sunbirds

Old World equivalent to hummingbirds, distinct species.

Convergent Evolution

Different species evolve similar traits independently.

Toucans

Fruit-eating birds in Neotropics, important foraging role.

Hornbills

Old World equivalent to toucans, found in Africa.

Marsupials

Mammals with pouch, primarily in Australia.

Placental Mammals

Dominant mammal group outside of Australia.

Geographical Barriers

Natural obstacles preventing species dispersal.

Geographical Corridors

Routes allowing species movement between areas.

Fossil Record

Historical evidence of species evolution over time.

Comparative Anatomy

Study of similarities and differences in organisms' structures.

Embryology

Study of embryos, revealing evolutionary relationships.

Plate Tectonics

Movement of Earth's plates affecting species distribution.

Natural Selection

Mechanism driving adaptive changes in species.

Sexual Dimorphism

Differences in appearance between male and female.

Adaptive Change

Changes in species traits enhancing survival.

Evidence-based Conclusion

Findings supporting Darwin's evolution hypothesis.

Developmental Errors

Mistakes in development leading to trait reappearance.

Distinct Assemblages

Unique groups of species in specific regions.

Evolutionary Hypotheses

Theories explaining species changes over time.