Fossil Diversity Patterns - Middle School Life Science
Card 1 of 25
Which type of rock most commonly preserves fossils and is used to compare diversity across layers?
Which type of rock most commonly preserves fossils and is used to compare diversity across layers?
Tap to reveal answer
Sedimentary rock. Forms from layers of sediment that bury and preserve organisms.
Sedimentary rock. Forms from layers of sediment that bury and preserve organisms.
← Didn't Know|Knew It →
What two traits make a fossil most useful as an index fossil for correlating rock layers?
What two traits make a fossil most useful as an index fossil for correlating rock layers?
Tap to reveal answer
Wide geographic range and short time range. Must be widespread to correlate areas but exist briefly to mark specific time.
Wide geographic range and short time range. Must be widespread to correlate areas but exist briefly to mark specific time.
← Didn't Know|Knew It →
What is extinction as shown by fossil data across successive rock layers?
What is extinction as shown by fossil data across successive rock layers?
Tap to reveal answer
Permanent disappearance of a species from later layers. Species that go extinct never reappear in younger rocks.
Permanent disappearance of a species from later layers. Species that go extinct never reappear in younger rocks.
← Didn't Know|Knew It →
What is speciation as inferred from fossil data across successive rock layers?
What is speciation as inferred from fossil data across successive rock layers?
Tap to reveal answer
Appearance of a new species not found in older layers. New species evolve and first appear at specific time points.
Appearance of a new species not found in older layers. New species evolve and first appear at specific time points.
← Didn't Know|Knew It →
What pattern in fossils is the clearest evidence of a mass extinction event?
What pattern in fossils is the clearest evidence of a mass extinction event?
Tap to reveal answer
Many unrelated species disappear at the same layer boundary. Simultaneous extinctions indicate catastrophic environmental change.
Many unrelated species disappear at the same layer boundary. Simultaneous extinctions indicate catastrophic environmental change.
← Didn't Know|Knew It →
What does a rapid increase in the number of fossil species after a mass extinction most likely indicate?
What does a rapid increase in the number of fossil species after a mass extinction most likely indicate?
Tap to reveal answer
Adaptive radiation (rapid diversification into new niches). Survivors evolve rapidly to fill empty ecological roles.
Adaptive radiation (rapid diversification into new niches). Survivors evolve rapidly to fill empty ecological roles.
← Didn't Know|Knew It →
What is a fossil assemblage when analyzing diversity patterns in one rock layer?
What is a fossil assemblage when analyzing diversity patterns in one rock layer?
Tap to reveal answer
The group of different fossils found together in a layer. All species living together at one time get preserved together.
The group of different fossils found together in a layer. All species living together at one time get preserved together.
← Didn't Know|Knew It →
Which measure best represents diversity for a fossil layer: number of individuals or number of species?
Which measure best represents diversity for a fossil layer: number of individuals or number of species?
Tap to reveal answer
Number of species (species richness). Species count shows variety; individual count shows abundance.
Number of species (species richness). Species count shows variety; individual count shows abundance.
← Didn't Know|Knew It →
What principle states that, in undisturbed rock layers, lower layers are older than higher layers?
What principle states that, in undisturbed rock layers, lower layers are older than higher layers?
Tap to reveal answer
Law of superposition. Sediments deposit sequentially, making bottom layers oldest.
Law of superposition. Sediments deposit sequentially, making bottom layers oldest.
← Didn't Know|Knew It →
Identify the correct conclusion if a younger rock layer contains more fossil species than an older layer.
Identify the correct conclusion if a younger rock layer contains more fossil species than an older layer.
Tap to reveal answer
Diversity increased from the older time interval to the younger. More species types indicates higher biodiversity in recent times.
Diversity increased from the older time interval to the younger. More species types indicates higher biodiversity in recent times.
← Didn't Know|Knew It →
Identify the correct conclusion if a species appears in layers 3–7 but is absent above layer 7.
Identify the correct conclusion if a species appears in layers 3–7 but is absent above layer 7.
Tap to reveal answer
The species became extinct after layer 7 formed. Last appearance marks when the species died out completely.
The species became extinct after layer 7 formed. Last appearance marks when the species died out completely.
← Didn't Know|Knew It →
Identify the correct conclusion if the same index fossil is found in two distant rock layers.
Identify the correct conclusion if the same index fossil is found in two distant rock layers.
Tap to reveal answer
The two rock layers are the same relative age. Index fossils match layers formed during the same time period.
The two rock layers are the same relative age. Index fossils match layers formed during the same time period.
← Didn't Know|Knew It →
Identify the best interpretation if marine fossils are replaced by land plant fossils upward in a sequence.
Identify the best interpretation if marine fossils are replaced by land plant fossils upward in a sequence.
Tap to reveal answer
The environment changed from marine to terrestrial over time. Fossil types reflect the changing environment through time.
The environment changed from marine to terrestrial over time. Fossil types reflect the changing environment through time.
← Didn't Know|Knew It →
Which option best describes the most reliable way to compare diversity between two layers with different sample sizes?
Which option best describes the most reliable way to compare diversity between two layers with different sample sizes?
Tap to reveal answer
Standardize sampling effort (same area/volume or same method). Equal sampling prevents bias when comparing fossil counts.
Standardize sampling effort (same area/volume or same method). Equal sampling prevents bias when comparing fossil counts.
← Didn't Know|Knew It →
Identify the correct conclusion if many new species appear soon after a volcanic ash layer boundary.
Identify the correct conclusion if many new species appear soon after a volcanic ash layer boundary.
Tap to reveal answer
A disturbance was followed by diversification in later layers. Volcanic events often trigger extinction then rapid evolution.
A disturbance was followed by diversification in later layers. Volcanic events often trigger extinction then rapid evolution.
← Didn't Know|Knew It →
Which evidence best supports a change in environment affecting diversity: stable fossil types or a shift in fossil types?
Which evidence best supports a change in environment affecting diversity: stable fossil types or a shift in fossil types?
Tap to reveal answer
A shift in fossil types across layers. Different environments support different organism communities.
A shift in fossil types across layers. Different environments support different organism communities.
← Didn't Know|Knew It →
What is the most likely cause if a layer has very few fossils and low apparent diversity?
What is the most likely cause if a layer has very few fossils and low apparent diversity?
Tap to reveal answer
Poor preservation or limited deposition, not necessarily low life. Fossilization requires specific conditions often absent.
Poor preservation or limited deposition, not necessarily low life. Fossilization requires specific conditions often absent.
← Didn't Know|Knew It →
What is the correct way to compare diversity between two layers with different sample sizes?
What is the correct way to compare diversity between two layers with different sample sizes?
Tap to reveal answer
Standardize sampling effort before comparing species counts. Equal sampling prevents artificial diversity differences.
Standardize sampling effort before comparing species counts. Equal sampling prevents artificial diversity differences.
← Didn't Know|Knew It →
What is species evenness in a fossil assemblage from one rock layer?
What is species evenness in a fossil assemblage from one rock layer?
Tap to reveal answer
How evenly individuals are distributed among species. High evenness means no single species dominates the assemblage.
How evenly individuals are distributed among species. High evenness means no single species dominates the assemblage.
← Didn't Know|Knew It →
What is species richness when analyzing fossil data across rock layers?
What is species richness when analyzing fossil data across rock layers?
Tap to reveal answer
The number of different species present in a layer or interval. Counts unique species types, not individual organisms.
The number of different species present in a layer or interval. Counts unique species types, not individual organisms.
← Didn't Know|Knew It →
Which interpretation fits if the same few species persist across many layers with little change?
Which interpretation fits if the same few species persist across many layers with little change?
Tap to reveal answer
Long-term stability with low turnover in that environment. Stable conditions support consistent species composition.
Long-term stability with low turnover in that environment. Stable conditions support consistent species composition.
← Didn't Know|Knew It →
Identify the best conclusion if marine fossils are replaced by land-plant fossils upward in a sequence.
Identify the best conclusion if marine fossils are replaced by land-plant fossils upward in a sequence.
Tap to reveal answer
The area changed from marine to terrestrial conditions over time. Sea level drop exposed land, changing the ecosystem completely.
The area changed from marine to terrestrial conditions over time. Sea level drop exposed land, changing the ecosystem completely.
← Didn't Know|Knew It →
Identify the correct inference if a species is present in older layers but absent in all younger layers.
Identify the correct inference if a species is present in older layers but absent in all younger layers.
Tap to reveal answer
The species became extinct after the older layers formed. Absence in younger layers indicates the species died out.
The species became extinct after the older layers formed. Absence in younger layers indicates the species died out.
← Didn't Know|Knew It →
Which option best supports that two distant rock layers are the same age: similar rock color or same index fossil?
Which option best supports that two distant rock layers are the same age: similar rock color or same index fossil?
Tap to reveal answer
Same index fossil. Index fossils provide precise age correlation; rock color varies locally.
Same index fossil. Index fossils provide precise age correlation; rock color varies locally.
← Didn't Know|Knew It →
Identify the best conclusion if many new species appear soon after a boundary layer.
Identify the best conclusion if many new species appear soon after a boundary layer.
Tap to reveal answer
Adaptive radiation increased diversity after the event. Survivors rapidly evolve to fill empty ecological niches.
Adaptive radiation increased diversity after the event. Survivors rapidly evolve to fill empty ecological niches.
← Didn't Know|Knew It →