LS2: Interactions, Energy, and Dynamics Relationships in Ecosystems

Students who demonstrate understanding can: 

MS-LS2-1. Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem. [Clarification Statement: Emphasis is on cause and effect relationships between resources and growth of individual organisms and the numbers of organisms in ecosystems during periods of abundant and scarce resources.] 

MS-LS2-2. Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems. [Clarification Statement: Emphasis is on predicting consistent patterns of interactions in different ecosystems in terms of the relationships among and between organisms and abiotic components of ecosystems. Examples of types of interactions could include competitive, predatory, and mutually beneficial.] 

MS-LS2-3. Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem. [Clarification Statement: Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system.] [Assessment Boundary: Assessment does not include the use of chemical reactions to describe the processes.] 

MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations. [Clarification Statement: Emphasis is on recognizing patterns in data and making warranted inferences about changes in populations, and on evaluating empirical evidence supporting arguments about changes to ecosystems.] 

MS-LS2-5. Evaluate competing design solutions for maintaining biodiversity and ecosystem services.* [Clarification Statement: Examples of ecosystem services could include water purification, nutrient recycling, and prevention of soil erosion. Examples of design solution constraints could include scientific, economic, and social considerations.]

The performance expectations above were developed using the following elements from the NRC document A Framework for K-12 Science Education:

Science and Engineering Practices

Developing and Using Models

Modeling in 6–8 builds on K–5 experiences and

progresses to developing, using, and revising models to

describe, test, and predict more abstract phenomena and

design systems.

 Develop a model to describe phenomena. (MS-LS2-3)

Analyzing and Interpreting Data

Analyzing data in 6–8 builds on K–5 experiences and

progresses to extending quantitative analysis to

investigations, distinguishing between correlation and

causation, and basic statistical techniques of data and

error analysis.

 Analyze and interpret data to provide evidence for

phenomena. (MS-LS2-1)

Constructing Explanations and Designing

Solutions

Constructing explanations and designing solutions in 6–8

builds on K–5 experiences and progresses to include

constructing explanations and designing solutions

supported by multiple sources of evidence consistent

with scientific ideas, principles, and theories.

 Construct an explanation that includes qualitative or

quantitative relationships between variables that

predict phenomena. (MS-LS2-2)

Engaging in Argument from Evidence

Engaging in argument from evidence in 6–8 builds on K–

5 experiences and progresses to constructing a

convincing argument that supports or refutes claims for

either explanations or solutions about the natural and

designed world(s).

 Construct an oral and written argument supported by

empirical evidence and scientific reasoning to support

or refute an explanation or a model for a

phenomenon or a solution to a problem. (MS-LS2-4)

 Evaluate competing design solutions based on jointly

developed and agreed-upon design criteria. (MS-LS2-

5)

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Connections to Nature of Science

Scientific Knowledge is Based on Empirical

Evidence

 Science disciplines share common rules of obtaining

and evaluating empirical evidence. (MS-LS2-4)

Disciplinary Core Ideas

LS2.A: Interdependent Relationships in Ecosystems

 Organisms, and populations of organisms, are dependent on

their environmental interactions both with other living things and

with nonliving factors. (MS-LS2-1)

 In any ecosystem, organisms and populations with similar

requirements for food, water, oxygen, or other resources may

compete with each other for limited resources, access to which

consequently constrains their growth and reproduction. (MS-LS2-

1)

 Growth of organisms and population increases are limited by

access to resources. (MS-LS2-1)

 Similarly, predatory interactions may reduce the number of

organisms or eliminate whole populations of organisms. Mutually

beneficial interactions, in contrast, may become so

interdependent that each organism requires the other for

survival. Although the species involved in these competitive,

predatory, and mutually beneficial interactions vary across

ecosystems, the patterns of interactions of organisms with their

environments, both living and nonliving, are shared. (MS-LS2-2)

LS2.B: Cycle of Matter and Energy Transfer in Ecosystems

 Food webs are models that demonstrate how matter and energy

is transferred between producers, consumers, and decomposers

as the three groups interact within an ecosystem. Transfers of

matter into and out of the physical environment occur at every

level. Decomposers recycle nutrients from dead plant or animal

matter back to the soil in terrestrial environments or to the

water in aquatic environments. The atoms that make up the

organisms in an ecosystem are cycled repeatedly between the

living and nonliving parts of the ecosystem. (MS-LS2-3)

LS2.C: Ecosystem Dynamics, Functioning, and Resilience

 Ecosystems are dynamic in nature; their characteristics can vary

over time. Disruptions to any physical or biological component of

an ecosystem can lead to shifts in all its populations. (MS-LS2-4)

 Biodiversity describes the variety of species found in Earth’s

terrestrial and oceanic ecosystems. The completeness or

integrity of an ecosystem’s biodiversity is often used as a

measure of its health. (MS-LS2-5)

LS4.D: Biodiversity and Humans

 Changes in biodiversity can influence humans’ resources, such as

food, energy, and medicines, as well as ecosystem services that

humans rely on—for example, water purification and recycling.

(secondary to MS-LS2-5)

ETS1.B: Developing Possible Solutions

 There are systematic processes for evaluating solutions with

respect to how well they meet the criteria and constraints of a

problem. (secondary to MS-LS2-5)

Crosscutting Concepts

Patterns

 Patterns can be used to identify cause and

effect relationships. (MS-LS2-2)

Cause and Effect

 Cause and effect relationships may be used to

predict phenomena in natural or designed

systems. (MS-LS2-1)

Energy and Matter

 The transfer of energy can be tracked as

energy flows through a natural system. (MSLS2-3)

Stability and Change

 Small changes in one part of a system might

cause large changes in another part. (MSLS2-4),(MS-LS2-5)

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Connections to Engineering, Technology,

and Applications of Science

Influence of Science, Engineering, and

Technology on Society and the Natural

World

 The use of technologies and any limitations

on their use are driven by individual or

societal needs, desires, and values; by the

findings of scientific research; and by

differences in such factors as climate, natural

resources, and economic conditions. Thus

technology use varies from region to region

and over time. (MS-LS2-5)

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Connections to Nature of Science

Scientific Knowledge Assumes an Order and

Consistency in Natural Systems

 Science assumes that objects and events in

natural systems occur in consistent patterns

that are understandable through

measurement and observation. (MS-LS2-3)

Science Addresses Questions About the

Natural and Material World

 Science knowledge can describe

consequences of actions but does not make

the decisions that society takes. (MS-LS2-5)

Connections to other DCIs in this grade-band: MS.PS1.B (MS-LS2-3); MS.LS1.B (MS-LS2-2); MS.LS4.C (MS-LS2-4); MS.LS4.D (MS-LS2-4); MS.ESS2.A (MS-LS2-3),(MS-LS2-4);

MS.ESS3.A (MS-LS2-1),(MS-LS2-4); MS.ESS3.C (MS-LS2-1),(MS-LS2-4),(MS-LS2-5)

Articulation across grade-bands: 1.LS1.B (MS-LS2-2); 3.LS2.C (MS-LS2-1),(MS-LS2-4); 3.LS4.D (MS-LS2-1),(MS-LS2-4); 5.LS2.A (MS-LS2-1),(MS-LS2-3); 5.LS2.B (MS-LS2-3);

HS.PS3.B (MS-LS2-3); HS.LS1.C (MS-LS2-3); HS.LS2.A (MS-LS2-1),(MS-LS2-2),(MS-LS2-5); HS.LS2.B (MS-LS2-2),(MS-LS2-3); HS.LS2.C (MS-LS2-4),(MS-LS2-5); HS.LS2.D (MSLS2-2); HS.LS4.C (MS-LS2-1),(MS-LS2-4); HS.LS4.D (MS-LS2-1),(MS-LS2-4),(MS-LS2-5); HS.ESS2.A (MS-LS2-3); HS.ESS2.E (MS-LS2-4); HS.ESS3.A (MS-LS2-1),(MS-LS2-5);

HS.ESS3.B (MS-LS2-4); HS.ESS3.C (MS-LS2-4),(MS-LS2-5); HS.ESS3.D (MS-LS2-5)

Common Core State Standards Connections:

ELA/Literacy –

RST.6-8.1 Cite specific textual evidence to support analysis of science and technical texts. (MS-LS2-1),(MS-LS2-2),(MS-LS2-4)

RST.6-8.7 Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram,

model, graph, or table). (MS-LS2-1)

RST.6-8.8 Distinguish among facts, reasoned judgment based on research findings, and speculation in a text. (MS-LS2-5)

RI.8.8 Trace and evaluate the argument and specific claims in a text, assessing whether the reasoning is sound and the evidence is relevant and sufficient to support

the claims. (MS-LS-4),(MS-LS2-5)

WHST.6-8.1 Write arguments to support claims with clear reasons and relevant evidence. (MS-LS2-4)

WHST.6-8.2 Write informative/explanatory texts to examine a topic and convey ideas, concepts, and information through the selection, organization, and analysis of relevant

content. (MS-LS2-2)

WHST.6-8.9 Draw evidence from literary or informational texts to support analysis, reflection, and research. (MS-LS2-2),(MS-LS2-4)

SL.8.1 Engage effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grade 8 topics, texts, and issues,

building on others’ ideas and expressing their own clearly. (MS-LS2-2)

SL.8.4 Present claims and findings, emphasizing salient points in a focused, coherent manner with relevant evidence, sound valid reasoning, and well-chosen details;

use appropriate eye contact, adequate volume, and clear pronunciation. (MS-LS2-2)

SL.8.5 Include multimedia components and visual displays in presentations to clarify claims and findings and emphasize salient points. (MS-LS2-3)

Mathematics –

MP.4 Model with mathematics. (MS-LS2-5)

6.RP.A.3 Use ratio and rate reasoning to solve real-world and mathematical problems. (MS-LS2-5)

6.EE.C.9 Use variables to represent two quantities in a real-world problem that change in relationship to one another; write an equation to express one quantity, thought

of as the dependent variable, in terms of the other quantity, thought of as the independent variable. Analyze the relationship between the dependent and

independent variables using graphs and tables, and relate these to the equation. (MS-LS2-3)

6.SP.B.5 Summarize numerical data sets in relation to their context. (MS-LS2-2)