Evidence of Common Ancestry - Middle School Life Science
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What is a phylogenetic tree (cladogram) used to show?
What is a phylogenetic tree (cladogram) used to show?
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Hypothesized evolutionary relationships and common ancestors. Diagrams branching patterns of evolution from shared ancestors.
Hypothesized evolutionary relationships and common ancestors. Diagrams branching patterns of evolution from shared ancestors.
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What is the fossil record?
What is the fossil record?
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Preserved remains or traces showing life over time. Fossils document evolutionary changes through geological time.
Preserved remains or traces showing life over time. Fossils document evolutionary changes through geological time.
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Choose the correct inference: two species have very similar embryos early in development.
Choose the correct inference: two species have very similar embryos early in development.
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They likely share a common ancestor. Similar embryos indicate shared developmental programs.
They likely share a common ancestor. Similar embryos indicate shared developmental programs.
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Identify the correct conclusion: Species A and B have fewer DNA differences than A and C.
Identify the correct conclusion: Species A and B have fewer DNA differences than A and C.
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Species A and B are more closely related than A and C. Fewer differences mean more recent common ancestor.
Species A and B are more closely related than A and C. Fewer differences mean more recent common ancestor.
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Which observation most strongly indicates convergent evolution: homologous bones or analogous wings?
Which observation most strongly indicates convergent evolution: homologous bones or analogous wings?
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Analogous wings. Similar function without shared structure shows convergence.
Analogous wings. Similar function without shared structure shows convergence.
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Which type of evidence is being used when comparing amino acid sequences in proteins?
Which type of evidence is being used when comparing amino acid sequences in proteins?
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Molecular (biochemical) evidence. Proteins are molecular evidence like DNA sequences.
Molecular (biochemical) evidence. Proteins are molecular evidence like DNA sequences.
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What is a homologous structure, and what does it indicate about ancestry?
What is a homologous structure, and what does it indicate about ancestry?
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Similar structure from common ancestor; may have different functions. Same basic structure evolved once in shared ancestor.
Similar structure from common ancestor; may have different functions. Same basic structure evolved once in shared ancestor.
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On a cladogram, which organisms are most closely related: the two sharing the most recent node or the root?
On a cladogram, which organisms are most closely related: the two sharing the most recent node or the root?
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The two sharing the most recent node. Recent nodes show more recent divergence from common ancestor.
The two sharing the most recent node. Recent nodes show more recent divergence from common ancestor.
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What is common ancestry in evolutionary biology?
What is common ancestry in evolutionary biology?
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Shared descent from the same ancestral species. All organisms evolved from earlier life forms through branching lineages.
Shared descent from the same ancestral species. All organisms evolved from earlier life forms through branching lineages.
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Which part of a cladogram represents the most recent common ancestor of two species?
Which part of a cladogram represents the most recent common ancestor of two species?
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The node (branch point) where their lineages meet. Nodes show where one ancestral species split into two.
The node (branch point) where their lineages meet. Nodes show where one ancestral species split into two.
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What does it mean when two species are "sister taxa" on a cladogram?
What does it mean when two species are "sister taxa" on a cladogram?
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They share an immediate common ancestor not shared by others shown. Closest relatives that split from same recent ancestor.
They share an immediate common ancestor not shared by others shown. Closest relatives that split from same recent ancestor.
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Identify the stronger evidence for common ancestry: homologous structures or analogous structures?
Identify the stronger evidence for common ancestry: homologous structures or analogous structures?
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Homologous structures. Shared structure indicates common descent, not convergence.
Homologous structures. Shared structure indicates common descent, not convergence.
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Which evidence best supports common ancestry: same bone pattern in forelimbs or same habitat use?
Which evidence best supports common ancestry: same bone pattern in forelimbs or same habitat use?
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Same bone pattern in forelimbs (homologous structure). Structural similarity shows shared ancestry, not ecology.
Same bone pattern in forelimbs (homologous structure). Structural similarity shows shared ancestry, not ecology.
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What is an analogous structure, and what does it indicate about ancestry?
What is an analogous structure, and what does it indicate about ancestry?
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Similar function, different origin; indicates convergent evolution. Different ancestors evolved similar solutions independently.
Similar function, different origin; indicates convergent evolution. Different ancestors evolved similar solutions independently.
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What is a vestigial structure, and what does it suggest about evolution?
What is a vestigial structure, and what does it suggest about evolution?
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Reduced or unused trait; inherited from ancestors where it was useful. Evidence of evolutionary history when structures lose function.
Reduced or unused trait; inherited from ancestors where it was useful. Evidence of evolutionary history when structures lose function.
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What is comparative anatomy used for when inferring common ancestry?
What is comparative anatomy used for when inferring common ancestry?
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Comparing body structures to identify shared evolutionary origins. Reveals homologous structures that indicate common descent.
Comparing body structures to identify shared evolutionary origins. Reveals homologous structures that indicate common descent.
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What is comparative embryology evidence for in evolutionary biology?
What is comparative embryology evidence for in evolutionary biology?
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Similar early development patterns suggest common ancestry. Shared developmental stages reveal evolutionary relationships.
Similar early development patterns suggest common ancestry. Shared developmental stages reveal evolutionary relationships.
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What is molecular evidence for common ancestry?
What is molecular evidence for common ancestry?
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Similar DNA or protein sequences indicate relatedness. Genetic similarities reflect shared evolutionary history.
Similar DNA or protein sequences indicate relatedness. Genetic similarities reflect shared evolutionary history.
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What does it mean if two species share many DNA sequence similarities?
What does it mean if two species share many DNA sequence similarities?
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They likely share a more recent common ancestor. Less time since divergence means fewer genetic differences.
They likely share a more recent common ancestor. Less time since divergence means fewer genetic differences.
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What does a fossil record provide as evidence for common ancestry?
What does a fossil record provide as evidence for common ancestry?
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Shows changes over time and transitional forms linking groups. Preserves evidence of evolutionary transitions between groups.
Shows changes over time and transitional forms linking groups. Preserves evidence of evolutionary transitions between groups.
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What is a phylogenetic tree (cladogram) used to show?
What is a phylogenetic tree (cladogram) used to show?
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Hypothesized evolutionary relationships and common ancestors. Visual diagram mapping evolutionary relationships.
Hypothesized evolutionary relationships and common ancestors. Visual diagram mapping evolutionary relationships.
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What is molecular evidence of common ancestry based on?
What is molecular evidence of common ancestry based on?
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Similarities in DNA or amino acid sequences. Genetic code similarities reflect shared evolutionary history.
Similarities in DNA or amino acid sequences. Genetic code similarities reflect shared evolutionary history.
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What does comparative embryology study to infer relatedness?
What does comparative embryology study to infer relatedness?
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Similarities in early developmental stages. Related species show similar patterns during embryonic development.
Similarities in early developmental stages. Related species show similar patterns during embryonic development.
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Which type of structure is stronger evidence of common ancestry: homologous or analogous?
Which type of structure is stronger evidence of common ancestry: homologous or analogous?
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Homologous structures. Same structure from inheritance shows direct evolutionary connection.
Homologous structures. Same structure from inheritance shows direct evolutionary connection.
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Identify the best overall conclusion if fossils, DNA, and homologous structures all agree.
Identify the best overall conclusion if fossils, DNA, and homologous structures all agree.
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The organisms share a common ancestor. Multiple independent evidence types confirm evolutionary relationship.
The organisms share a common ancestor. Multiple independent evidence types confirm evolutionary relationship.
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