NGSS – Progressions

student doing a labProgressions are included in the Next Generation Science Standards to illustrate how students are intended to progress throughout their school careers.

“First, it is built on the notion of learning as a developmental progression. It is designed to help children continually build on and revise their knowledge and abilities, starting from their curiosity about what they see around them and their initial conceptions about how the world works. The goal is to guide their knowledge toward a more scientifically based and coherent view of the natural sciences and engineering, as well as of the ways in which they are pursued and their results can be used.”

The progressions table is a good place to start if you are just looking for a broad overview of the themes that NGSS considers to be important. The progressions are divided into three large tables: Earth Space Science Progression, Life Science Progression, and Physical science Progression. Each table then has a description of what they term “endpoints” for each disciplinary core idea. The idea of endpoint is familiar to me, I’ve seen it in other incarnations as goals, outcomes, or standards. The endpoints described on the table are grouped into K-2, 3-5, 6-8, and 9-12, giving some flexibility to when particular ideas are addressed.

Reviewing Life Science Progressions  Draft

LS1 (A-D) focuses on structure and function of biological organisms. By the end of high school, students should understand cellular processes, such as mitosis. Students should also understand the molecular make-up of organisms, hydrocarbons, amino acids and other elements. Cellular respiration and energy flow is mentioned specifically.

LS1.D is titled “Information Processing” and proposes that students should know the integrated functioning of each distinct region and circuit of the brain, each primarily serving a dedicated function…. This last progression seems oddly out of place in the sequence. Why NGSS focuses on the brain as part of information processing makes little sense, and makes the odd assumption that all organisms have a brain and that is how they process information. It almost seems like this one was tacked on by someone who was not a biologist.

LS2 (A-D) looks at ecosystems, cycles of matter and energy transfer, and social interactions. By high school students should understand the interdependent relationships between biotic and abiotic factors. Photosynthesis and cellular respiration are stated to be key components of the global carbon cycle. Food webs are included with this section, including mention of how matter and energy are conserved. The last statement on LS2.C is vague and confusing

If a biological or physical disturbance to an ecosystem occurs, including one induced by human activity, the ecosystem may return to its more or less original state or become a very different ecosystem, depending on the complex set of interactions within the ecosystem.

I have no idea what that means or what the expectation is for biology teachers. I can only guess that maybe this is covered in the ecology unit when we address primary and secondary succession.

The social interaction section skirts around the issue of evolution but does not mention it directly, only stating that group and social interactions can improve chances of survival.

LS3 focuses on inheritance and DNA and includes specifics about how traits in a population can vary due to mutations and chromosome swapping.   (This seems like an odd way to mention variation, as if the only reason organisms have variation is due to mutation)

LS4 is the section on evolution, though the titles do not say evolution specifically.   Students should understand evidence of common ancestry, natural selection, adaptation, and biodiversity.   I find it odd that the authors chose not to use the word “evolution” in the section and speculate that it’s a way to appease states that currently discredit evolution or allow for teaching creationism.   Biologists should not have to apologize or obfuscate evolution and for this reason, the section bothers me.

I’m also puzzled by a word choice in the section on biodiversity.  “Sustaining biodiversity is essential to supporting life on Earth.”   I question the veracity of this claim and sounds more like an opinion or a call to action.          Is biodiversity essential?  We have seen ecosystems collapse when keystone species are removed, but it’s a rather broad statement to say that biodiversity is essential to supporting life on the entire planet.   I would rather see this statement just address the fact that biodiversity varies and loss of biodiversity can have an impact on ecosystems.

Overall Thoughts on Life Science Progression Draft

Thematically, the progressions are fairly closely aligned to what you see in AP biology and in most biology textbooks.  The wording in a few of the sections seems a bit wrong, vague, or outright confusing, but maybe those will be addressed in the final version.

I did not look very closely at the physical and earth science progressions since that is not my area of expertise.  The progressions are very broad, but its a good way to get an overview of what the NGSS is aiming for.   In later documents, each standard is expanded upon to include the specifics of what should be covered.