HS-LS4-4: Natural Selection and Adaptation
Also called NGSS HS-LS4-4 · Topic: Natural Selection and Evolution · Life Science
The Official Wording
Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
Clarification statement: Emphasis is on using data to provide evidence for how specific biotic and abiotic differences in ecosystems (such as ranges of seasonal temperature, long-term climate change, acidity, light, geographic barriers, or evolution of other organisms) contribute to a change in gene frequency over time, leading to adaptation of populations.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What HS-LS4-4 Means in Plain English
Students use data to explain how natural selection makes a population better suited to where it lives. Differences between places, like temperature, acidity, light, toxic soil or a predator, favor certain inherited traits, so the genes behind them grow more common over generations.
Adaptation here means a change in a whole population across generations, not an individual adjusting during its life. It builds on HS-LS4-2 and HS-LS4-3 and leads to HS-LS4-5, where changing environments cause species to spread, split or vanish.
HS-LS4-4 I Can Statements
- I can explain how natural selection produces adaptation over generations.
- I can use data to link an environmental factor to trait changes.
- I can tell individual acclimation apart from population adaptation.
HS-LS4-4 Worked Example
A bead model of one grass population spreading onto the soil of an old copper mine and onto a nearby meadow.
How does copper-rich mine soil change the share of copper-tolerant plants in a grass population?
Set It Up: Two cups of 50 beads each (25 blue for tolerant seeds, 25 white for non-tolerant), one labeled mine and one meadow, a coin and a data table.
- In the mine cup, draw 20 seeds. Blue seeds always survive, and a white seed survives only if two coin tosses both land heads.Draw: 10 blue, 10 white. Survivors: 10 blue, 3 white
- Refill the cup to 50 beads in the survivors' proportions to make the next generation.Mine generation 2: 77% tolerant
- In the meadow cup, tolerant plants grow slowly and get crowded out: a blue seed survives only on heads, and white seeds always survive.Meadow generation 2: 38% tolerant
- Run four generations in each cup and graph percent tolerant.Mine climbs past 95%. Meadow falls below 10%
The same starting population became mostly copper-tolerant on mine soil and mostly non-tolerant in the meadow, so the two groups adapted in opposite directions.
Why it works: Copper kills plants without the tolerance trait, while in clean soil tolerance carries a growth cost, so each environment favors different inherited traits and shifts the gene mix over generations.
Common Mistakes with HS-LS4-4
Individuals adapting on purpose
“The grass learned to handle copper”
Try this: Plants already tolerant survived and made seeds. Tolerance spread through reproduction, not because any single plant changed itself.
Confusing acclimation with adaptation
“My dog grew a thick coat, so it adapted to winter”
Try this: Changes in one body during its lifetime are acclimation. Adaptation is an inherited change in a population across many generations.
Thinking a trait is good everywhere
“Tolerant grass is just better grass”
Try this: A trait's value depends on the environment. Copper tolerance helps on mine soil but costs growth in an ordinary meadow.
Where HS-LS4-4 Fits
Practice HS-LS4-4
Quick Check
- Why did the mine and meadow populations change in opposite directions?
- Is a person getting a suntan an adaptation?
- Why does adaptation need variation already present in the population?