Unit 7

Evolution Definition The process of changing the genetic makeup of an entire population over many generations.
Population Members of a single species living in one specific area.
Species Organisms that can interbreed in nature and produce fertile offspring.
Example of Different Species Lions and tigers are different species because ligers are sterile.
Scientific Theory A widely accepted explanation supported by large amounts of evidence.
Evolution Is Changes in allele frequencies in populations over generations.
Evolution Is NOT An individual changing during its lifetime.
Fitness How well an organism survives and reproduces in its environment.
Natural Selection Survival and reproduction of organisms best suited to their environment.
Survival of the Fittest Another phrase for natural selection.
V in VIDA Variation — differences in traits within a population.
Variation Example Some beetles are green and some are brown.
I in VIDA Inheritance — traits must be passed from parents to offspring.
D in VIDA Differential Survival/Reproduction — individuals with beneficial traits survive and reproduce more.
A in VIDA Adaptation — beneficial traits become more common over time.
Adaptation A beneficial trait that helps a population survive over generations.
Structural Adaptation Physical body features that help survival.
Structural Adaptation Example Camouflage or cactus waxy skin.
Behavioral Adaptation Changes in behavior that help survival.
Behavioral Adaptation Example Bird migration or pack hunting.
Functional/Physiological Adaptation Internal body process changes that help survival.
Functional Adaptation Example Venom production or hibernation.
Adaptive Evolution Evolution driven by natural selection that increases fitness.
Adaptive Evolution Example Parrots developing stronger beaks during droughts.
Non-Adaptive Evolution Evolution caused by random changes or events not directly tied to fitness.
Mutation A random change in genes.
Mutation Example A cat born with extra toes.
Artificial Selection Humans breeding organisms for desired traits.
Artificial Selection Example Dog breeding or GMO crops.
Natural Disaster Effect Random events that can reduce populations regardless of fitness.
Three Results of Evolution Population increase, speciation, or extinction.
Speciation The formation of new species.
Extinction The complete elimination of a species.
Fossil Record Preserved remains or impressions of ancient organisms.
Purpose of Fossils Show evidence of extinct organisms and evolutionary change.
Tiktaalik A transitional fossil between fish and tetrapods.
Archaeopteryx A transitional fossil between dinosaurs and birds.
Homology Similarity due to common ancestry.
Homologous Structures Similar structures inherited from a common ancestor with different functions.
Homologous Structure Example Human, bat, and whale forelimbs.
Vestigial Structures Reduced structures inherited from ancestors that no longer have major functions.
Vestigial Structure Example Appendix or whale pelvic bones.
Analogous Structures Structures with similar functions but different origins.
Analogous Structure Example Bird wings and insect wings.
Developmental Homology Similarities in embryos of different organisms.
Developmental Homology Example Vertebrate embryos with tails and pharyngeal pouches.
Molecular Homology Similarities in DNA and proteins.
Human and Chimp DNA Similarity Humans and chimps share about 97–99% of DNA.
Humans and Apes Clarification Humans did not evolve from modern apes but share a common ancestor.
Coevolution Two species evolving in response to each other.
Coevolution Example Flowers and pollinators evolving together.
Convergent Evolution Unrelated organisms independently evolving similar traits.
Big Bang Approximate Time 13.7 billion years ago.
Solar System Formation 4.6 billion years ago.
Earth Formation 4.5 billion years ago.
Primordial Soup Time 4.0 billion years ago.
Age of Dinosaurs 252 million to 66 million years ago.
Modern Humans Appeared About 300,000 years ago.
Relative Dating Determining age by rock layer position.
Relative Dating Rule Older rock layers are lower than younger layers.
Radiometric/Carbon Dating Measuring radioactive decay to determine absolute age.
C-14 Radioactive carbon isotope used in dating fossils.
Carbon Dating Rule Older fossils contain less C-14.
Primordial Soup Theory Life formed from simple molecules in Earth’s early atmosphere.
Primordial Soup Gases Hydrogen, methane, ammonia, and water vapor.
Four Biomolecules Carbohydrates, lipids, proteins, and nucleic acids.
Hydrothermal Vent Theory Life likely began near deep-sea vents with heat and minerals.
Adaptive Radiation Rapid evolution of many species from one ancestor.
Darwin’s Finches Example Different beak shapes evolved for different food sources.
Taxonomy The science of naming and classifying organisms.
Purpose of Taxonomy Organizes biodiversity based on relationships.
Taxonomic Hierarchy Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Mnemonic for Taxonomy Did King Philip Come Over For Good Soup?
Most Broad Taxonomic Group Domain.
Most Specific Taxonomic Group Species.
Prokaryotic Cells without a nucleus.
Eukaryotic Cells with a nucleus.
Unicellular Organism made of one cell.
Multicellular Organism made of many cells.
Autotroph Organism that makes its own food.
Heterotroph Organism that consumes other organisms for food.
Three Domains Bacteria, Archaea, and Eukarya.
Eubacteria Traits Prokaryotic, unicellular, autotrophic or heterotrophic.
Archaebacteria Traits Prokaryotic organisms living in extreme environments.
Protista Traits Eukaryotic, mostly unicellular, diverse.
Fungi Traits Eukaryotic, mostly multicellular, heterotrophic decomposers.
Plantae Traits Eukaryotic, multicellular autotrophs.
Animalia Traits Eukaryotic, multicellular heterotrophs.
Phylogeny The study of evolutionary relationships.
Cladogram A branching diagram showing evolutionary relationships.
Root of Cladogram Common ancestor of all organisms in the tree.
Node on Cladogram Point where branches split; represents a common ancestor.
Branch on Cladogram Represents a lineage’s evolutionary history.
Derived Trait A new trait passed to descendants after a split.
Cladogram Relationship Rule Species with more shared derived traits are more closely related.
Example of Closely Related Species on Cladogram Turtles and leopards because they share amniotic eggs and limbs.
Tuatara Placement on Cladogram Groups closest to turtles because it lacks hair but has amniotic eggs and limbs.
Cladogram Split Rule The more recent the split, the more closely related the species are.