Common Ancestry - AP Biology
- What is the founder effect?
- When a new colony is started by a few members. Small founding population creates genetic drift in new location.
- What is an analogous structure?
- Structures with similar function but different origins. Result of convergent evolution, not common ancestry.
- How do vestigial structures support common ancestry?
- Remnants of structures from common ancestors. These useless structures indicate inheritance from functional ancestral forms.
- Which type of molecule is used to infer evolutionary relationships?
- DNA or protein sequences. Molecular sequences reveal evolutionary distances and relationships.
- Which term describes a trait inherited from a common ancestor?
- Homologous trait. Shows direct inheritance from a shared ancestor.
- Which term describes the evolutionary history of a species?
- Phylogeny. The complete evolutionary history and relationships of a lineage.
- What evidence supports the idea of a universal common ancestor?
- Universal genetic code. Same code in all life suggests all organisms share one ancestor.
- Which molecular evidence supports common ancestry?
- DNA and protein sequence similarities. These molecules show evolutionary relationships through sequence conservation.
- What is the bottleneck effect?
- Reduction in genetic diversity due to population reduction. Severe population decline randomly eliminates genetic variants.
- Define co-evolution.
- Reciprocal evolutionary changes in interacting species. Species evolve together, each influencing the other's evolution.
- Which molecule's universality supports common ancestry?
- DNA. All life uses the same genetic code, indicating common origin.
- What is the significance of the Galapagos finches in evolution?
- Example of adaptive radiation. Darwin's finches show how one species diversified into many.
- What is adaptive radiation?
- Diversification of a species into various forms. Shows rapid evolution from a common ancestor into new niches.
- Which is an example of a transitional fossil?
- Tiktaalik. Shows transition between fish and tetrapods with intermediate features.
- Identify a vestigial structure in humans.
- The appendix. A reduced organ that once served a function in ancestors.
- What is the definition of common ancestry?
- Organisms share a common ancestor if they descend from a shared species. This defines the fundamental concept of shared evolutionary origin.
- What is convergent evolution?
- Different species evolve similar traits independently. Creates analogous structures through similar environmental pressures.
- Define monophyletic group.
- A group that includes a common ancestor and all its descendants. Represents a complete evolutionary unit with no missing lineages.
- What is horizontal gene transfer?
- Transfer of genes between organisms in a manner other than reproduction. Allows rapid spread of advantageous genes between species.
- What is a homologous structure?
- Structures in different species with a common origin. Despite different functions, they share the same evolutionary blueprint.
- What is a synapomorphy?
- A shared derived trait in a clade. A defining characteristic that unites a group of related species.
- What is the significance of gene duplication in evolution?
- Provides material for evolutionary innovation. Extra gene copies can evolve new functions without losing originals.
- What is the principle of parsimony in phylogenetics?
- Simplest explanation with fewest evolutionary changes. Minimizes assumptions by choosing the most economical evolutionary pathway.
- What is a cladogram?
- Diagram showing evolutionary relationships. Uses branching patterns to show evolutionary relationships.
- Which evidence from biogeography supports common ancestry?
- Species distribution correlates with geological history. Geographic patterns match evolutionary divergence from common ancestors.
- What is the significance of fossil records in common ancestry?
- They show transitional forms and evolutionary history. Fossils provide direct evidence of evolutionary changes over time.
- Identify the term for a branching point in a phylogenetic tree.
- Node. Each branching point shows where lineages split from ancestors.
- Identify the common ancestor in a simple phylogenetic tree.
- The root of the tree. The base of the tree represents the original common ancestor.
- What does a sister group in phylogenetics represent?
- Two lineages that are each other's closest relatives. Shows the closest evolutionary relationship possible between lineages.
- What is the role of genetic drift in evolution?
- Random changes in allele frequencies. Causes random evolutionary changes independent of natural selection.
- Identify a molecular clock's role in phylogenetics.
- Estimating divergence times based on mutation rates. Uses constant mutation rates to calculate when species diverged.
- Identify a type of evidence for common ancestry from embryology.
- Similar embryonic development stages. Early developmental similarities reveal shared evolutionary history.
- Which type of DNA is often used to study maternal lineage?
- Mitochondrial DNA. Inherited maternally, useful for tracing female ancestry lines.
- Which process results in gene flow between populations?
- Migration. Movement of individuals transfers alleles between populations.
- Which structure indicates common ancestry: homologous or analogous?
- Homologous. Homologous structures share ancestry; analogous structures do not.
- Which type of selection favors intermediate traits?
- Stabilizing selection. Reduces extreme variations by favoring average characteristics.
- What does a polyphyletic group lack?
- A common ancestor. Polyphyletic groups incorrectly combine unrelated lineages.
- Which theory explains the origin of mitochondria?
- Endosymbiotic theory. Explains how bacteria became organelles through symbiosis.
- Which type of evolution results in similar traits across unrelated species?
- Convergent evolution. Independent evolution produces similar solutions to environmental challenges.
- What does a phylogenetic tree represent?
- Evolutionary relationships among species. Shows how species diverged from common ancestors over time.