Natural Selection
What is natural selection
Survival of the fittest
Organisms that have traits that are beneficial for the environment will pass those traits on to the next generation
A whale flipper, bat wing, cat leg, and human arm all contain similar bone structures.
Question:
Explain what this evidence suggests about these organisms.
The similar bone structures suggest the organisms share a common ancestor and evolved differently over time.
According to the Law of Superposition, which rock layer is the oldest?
A. Top layer
B. Middle layer
C. Bottom layer
D. All are the same age
C. Bottom layer
What is an index fossil?
Widespread
Abundant
Short-lived
What is a pandemic?
A disease outbreak that spreads across many countries or continents.
A species of rabbits lives in a snowy environment. Some rabbits are born with thicker white fur while others have thin brown fur. After many generations, most rabbits have thick white fur.
Question:
Explain why the population changed over time and identify the environmental factor responsible.
The snowy environment favored rabbits with thick white fur because they stayed warm and were better camouflaged. Those rabbits survived and reproduced more often, passing the traits to offspring.
What are vestigial structures?
Structures that no longer serve their original purpose.
What is the Law of Superposition?
In undisturbed rock layers, the oldest layers are on the bottom and the youngest are on top.
Which fossil would make the BEST index fossil?
A. A fossil found for millions of years
B. A fossil found in only one location
C. A fossil found worldwide but lived briefly
D. A fossil from a living species
C. A fossil found worldwide but lived briefly
Which energy resource is renewable?
A. Coal
B. Natural gas
C. Solar energy
D. Oil
C. Solar energy
A population of beetles contains both green and brown individuals. Birds can easily see the green beetles on tree bark.
Question:
Which prediction is MOST likely after many generations?
A. Green beetles become more common
B. Brown beetles become more common
C. Both colors disappear
D. Birds stop eating beetles
B. Brown beetles become more common
Bird wings and insect wings both allow flight, but their internal structures are very different.
Question:
Explain why these structures are considered analogous instead of homologous.
They perform similar functions but evolved independently and have different underlying structures, meaning they did not come from a common ancestor.
Layer A ---------------- Layer B ---------------- Layer C ---------------- Layer D
A fossil fern is found in Layer C. A fossil fish is found in Layer B.
Question:
Which statement is BEST supported by the evidence?
A. The fish fossil is older than the fern fossil
B. The fern fossil is older than the fish fossil
C. Both fossils are the same age
D. Layer D is the youngest layer
B. The fern fossil is older than the fish fossil
Marine fossils are found on top of a mountain.
Question:
Construct an explanation for how this may have occurred.
The area may have once been underwater and later uplifted by tectonic activity, raising marine rock layers to higher elevations.
A community relies heavily on coal-burning power plants.
Question:
Explain how this energy choice could affect both human health and Earth systems.
Coal burning releases pollutants and greenhouse gases that contribute to respiratory illness, air pollution, and climate change affecting the atmosphere and hydrosphere.
A population of insects becomes resistant to pesticides over time. What BEST explains this?
A. Insects chose to change
B. The pesticide caused all insects to mutate
C. Resistant insects survived and reproduced
D. Insects stopped reproducing
C. Resistant insects survived and reproduced
They perform similar functions but evolved independently and have different underlying structures, meaning they did not come from a common ancestor.
The claim is incorrect because dolphins have mammal-like bone structures and lungs, while sharks are fish with cartilage skeletons. Their fins evolved for similar functions but from different ancestors.
Layer A
----------------
Layer B
----------------
\ Fault
Layer C
----------------
|
Igneous Intrusion
|
Layer D
----------------Question:
Which sequence correctly orders the events from oldest to youngest?
A. Fault → Layer D → Intrusion → Layer B
B. Layer D → Intrusion → Fault → Layer A
C. Intrusion → Layer D → Fault → Layer A
D. Layer B → Fault → Intrusion → Layer D
B. Layer D → Intrusion → Fault → Layer A
If two distant rock layers contain the same index fossil, scientists can infer:
A. The rocks are the same color
B. The rocks are the same thickness
C. The rocks are made of identical minerals
D. The rocks formed at about the same time
D. The rocks formed at about the same time
Scientists observe a river slowly cutting through rock layers to form a canyon. They compare this process to the formation of the Grand Canyon.
Question:
Which statement BEST explains how the principle of uniformitarianism helps scientists understand the canyon’s formation?
A. Catastrophic events are the only forces that shape Earth’s surface.
B. Earth’s rock layers formed too quickly to study over time.
C. The same geologic processes occurring today also occurred in Earth’s past.
D. Rivers only affect surface rocks and cannot change landscapes over time.
C. The same geologic processes occurring today also occurred in Earth’s past.
A climate change event drastically alters an ecosystem. Scientists notice some species adapt and survive while others become extinct.
Question:
Construct an explanation for why natural selection does not guarantee survival for every species.
Natural selection depends on whether useful traits already exist within a population. Some species may lack traits needed for survival or may reproduce too slowly to adapt before environmental changes become too severe.
Compare homologous and analogous structures and explain how each relates to evolution.
Homologous structures show common ancestry because they have similar structures but different functions. Analogous structures have similar functions but different structures, showing organisms adapted similarly to environments.
A fault line cuts across several rock layers and an igneous intrusion.
Question:
Using relative dating principles, determine which feature is youngest and explain your reasoning.
The fault is youngest because it cuts across both the rock layers and the intrusion, meaning those features existed first.
The fault is youngest because it cuts across both the rock layers and the intrusion, meaning those features existed first.
Explain how index fossils and relative dating work together to help scientists understand Earth’s history.
Relative dating places rocks in order, while index fossils help match rock layers of similar age across locations, creating a timeline of Earth’s history.
List 3 ways in which water can be considered healthy
Answers can vary