HS-LS4-2 | Mechanisms of Natural Selection

Construct an explanation based on evidence that the process of evolution primarily results from four factors: (1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

Clarification statement: Emphasis is on using evidence to explain the influence each of the four factors has on number of organisms, behaviors, morphology, or physiology in terms of ability to compete for limited resources and subsequent survival of individuals and adaptation of species. Examples of evidence could include mathematical models such as simple distribution graphs and proportional reasoning.

Assessment boundary: Assessment does not include other mechanisms of evolution, such as genetic drift, gene flow through migration, and co-evolution.

Assessment

What assessment of HS-LS4-2 might look like on a NY state exam.

Exam	Cluster	Question
August 2026	Star of the Tide Pool	Question 1
June 2026	A Seasonal Strategy for Survival	Question 5
	Green and Black Frogs	Question 11
	Buzzy Bees	Question 29
	Australian Adaptations	Question 44
January 2026	Honeybee Behavior and Threats	Question 31
	Baboon Evolution	Question 34
	Zebra Coat Patterns	Question 43
August 2025	Strategies for Survival in Different Animal Species	Question 6
	Strategies for Survival in Different Animal Species	Question 9
	Keratin – A Very Versatile Protein	Question 28
	Evolutionary Relationships	Question 34
June 2025	Drinking Water Is Just The Beginning!	Question 7
	Heads or Tails?	Question 12
	Limb Evolution	Question 30
	Limb Evolution	Question 32
Sample clusters (Spring 2024)	Dinosaurs-Evolution	Question 1

Performance Level Descriptions

PLDs communicate the knowledge and skills expected of students to demonstrate proficiency in each Learning Standard. NYS assessments classify student performance into one of five levels.

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Level 1: Identify the evidence, from those provided, that supports the explanation that evolution is the result of a genetic and/or an environmental factor.

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Level 2: Identify the explanation based on evidence that evolution is the result of genetic and/or environmental factor(s) or justify why the given explanation is correct or incorrect.

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Level 3: Construct an explanation based on evidence that the process of evolution can involve: (1) the potential of species to increase in number, and/or (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, and/or (3) competition for limited resources, and/or (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

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Level 4: Construct an explanation based on evidence that the process of evolution primarily results from four factors: (1) the potential of species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

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Level 5: Construct an explanation based on evidence obtained from a variety of reliable sources that natural selection is a process leading to biological evolution of a species, primarily caused by four factors: (1) the potential of species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the proliferation of those organisms that are better able to survive and reproduce in the environment.

Resources

Examples and discussion of resources for the learning, teaching, and assessment of HS-LS4-2.

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NGSS Dimensions

Performance expectation HS-LS4-2 was developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Constructing Explanations and Designing Solutions
- Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

Disciplinary Core Ideas

LS4.B: Natural Selection
- Natural selection occurs only if there is both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information – that is, trait variation – that leads to differences in performance among individuals.
LS4.C: Adaptation
- Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment.

Crosscutting Concepts

Cause and Effect
- Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.

Page contributors: Conrad Richman, Caroline Leonard

Biology | HS. Natural Selection and Evolution