All flashcards
Flashcard 1: What is a homologous structure in the context of evolutionary relationships?
Answer: A body part with similar anatomy due to common ancestry. Same internal structure indicates inheritance from a shared ancestor.
Flashcard 2: What is an analogous structure in the context of evolutionary relationships?
Answer: A body part with similar function but different evolutionary origin. Similar use but different structure shows independent evolution.
Flashcard 3: What is a vestigial structure, and what does it suggest about evolution?
Answer: A reduced remnant; it suggests descent from ancestors with a function. Non-functional structures inherited from ancestors who used them.
Flashcard 4: Which type of anatomical similarity is stronger evidence of common ancestry: homologous or analogous?
Answer: Homologous. Same structure from shared ancestry is stronger than similar function.
Flashcard 5: What is meant by a common ancestor when comparing anatomical structures?
Answer: An earlier species from which multiple species evolved. The shared ancestor that gave rise to descendant species.
Flashcard 6: What is comparative anatomy, and why is it used in evolutionary biology?
Answer: The study of body structures to infer evolutionary relationships. Comparing structures reveals shared ancestry and divergence.
Flashcard 7: Which term describes evolution of similar traits in unrelated lineages due to similar environments?
Answer: Convergent evolution. Unrelated species develop similar traits in similar environments.
Flashcard 8: Which term describes divergence of related species into different forms as adaptations accumulate?
Answer: Divergent evolution. Related species evolve different traits over time.
Flashcard 9: Identify the best conclusion if two species share the same basic limb bone pattern but different functions.
Answer: They likely share a common ancestor (homologous structures). Same bones arranged similarly indicates shared ancestry.
Flashcard 10: Identify the best conclusion if two species have wings that serve flight but have different internal anatomy.
Answer: They likely evolved flight independently (analogous structures). Different internal structure shows separate evolutionary paths.
Flashcard 11: Which anatomical evidence best supports a close evolutionary relationship: similar bone arrangement or similar habitat?
Answer: Similar bone arrangement. Structural similarity shows ancestry; habitat is environmental.
Flashcard 12: What does it suggest when multiple species share a complex structure with the same underlying layout?
Answer: Shared ancestry is likely. Complex shared structures rarely evolve independently.
Flashcard 13: What does it suggest when a structure is present but reduced and nonfunctional in a species?
Answer: The species inherited it from ancestors in which it was functional. Vestigial structures are evolutionary leftovers.
Flashcard 14: Choose the word that completes the statement: Analogous structures usually result from evolution.
Answer: Convergent. Similar environments drive similar adaptations independently.
Flashcard 15: Choose the word that completes the statement: Homologous structures are evidence of ancestry.
Answer: Common. Same structures inherited from shared ancestors.
Flashcard 16: Identify the most likely relationship if two species share many homologous structures across the body.
Answer: They are closely related evolutionarily. Multiple shared structures indicate recent common ancestry.
Flashcard 17: Identify the best interpretation if two species share a trait that is adaptive in the same environment but not homologous.
Answer: The similarity is due to convergent evolution, not close ancestry. Environmental pressure creates similar traits independently.
Flashcard 18: What is the key difference between homologous and analogous structures?
Answer: Homologous: shared ancestry; analogous: shared function only. Origin differs: inheritance vs. independent evolution.
Flashcard 19: Which option best indicates a vestigial structure: fully functional, reduced remnant, or newly evolved feature?
Answer: Reduced remnant. Vestigial means reduced and no longer functional.
Flashcard 20: Which option is the best anatomical evidence for relatedness: shared embryonic structures or shared habitat?
Answer: Shared embryonic structures. Early development reveals evolutionary relationships most clearly.
Flashcard 21: What is the key evidence used to identify homologous structures: function or underlying anatomy?
Answer: Underlying anatomy (basic structure and arrangement). Bone patterns reveal evolutionary relationships, not current use.
Flashcard 22: What is the definition of a homologous structure in evolutionary biology?
Answer: Similar structure due to common ancestry, possibly different functions. Inherited from a shared ancestor but adapted for different uses.
Flashcard 23: Identify the evidence type: pelvic bones in whales that do not support hind legs.
Answer: Vestigial structures. Remnants from land-dwelling ancestors with functional hind limbs.
Flashcard 24: Which term describes divergence of related species into different forms as they adapt to different niches?
Answer: Divergent evolution. Related species evolve different traits in different environments.
Flashcard 25: Which type of anatomical similarity most strongly supports close evolutionary relatedness?
Answer: Homologous structures. Same underlying structure indicates shared ancestry.
Flashcard 26: What is the definition of common ancestry as used in evolution?
Answer: Two species share an ancestor in their evolutionary past. Species descended from the same ancestral population.
Flashcard 27: What is the definition of a vestigial structure?
Answer: Reduced or unused structure inherited from ancestors. Remnants of features that were functional in ancestral species.
Flashcard 28: What is the definition of an analogous structure in evolutionary biology?
Answer: Similar function due to similar selection, not common ancestry. Evolved independently in response to similar environmental pressures.
Flashcard 29: What is the definition of comparative anatomy as evidence for evolution?
Answer: Comparing body structures to infer evolutionary relationships. Anatomical similarities reveal shared evolutionary history.
Flashcard 30: What does it suggest when two species share complex homologous structures?
Answer: They likely share a common ancestor. Complex shared structures rarely evolve twice independently.