24 April 2015 § Leave a Comment
The standards for high school biological sciences curricula in New York State are described in The Living Environment Core Curriculum. (“LE Standard,” hereafter) The Living Environment curriculum is Standard 4 in a set of 7 describing the science curriculum in New York State. “Key Idea 3″ in the LE Standard describes the central point instructors in Living Environment courses are supposed to make about evolution.
Individual organisms and species change over time.
There are many ways in which this statement and the associated Performance Indicators fail to describe, even in broad outline, what we know about evolution. For one thing, they almost all concern natural selection. For instance, there is no mention of random drift or historical contingency, or the use of evolution in explaining taxonomy and biodiversity. While this deserves further comment, what I would like to call attention to here are two points at which the LE Standard qualifies support for teaching evolution.
Use of “theory”
Key Idea 3 is further elaborated in the LE Standard as follows.
Evolution is the change of species over time. This theory is the central unifying theme of biology.
The problem here is “theory,” which is widely misunderstood, and which does not appear anywhere else in the LE Standard. Teaching evolution is often attacked on the grounds that scientific knowledge about evolution is “just a theory.” This is not how scientists use “theory,” which, in proper scientific parley, indicates a well-confirmed statement or set of statements of general or universal application, such as Newton’s theory of gravitation, or Einstein’s theory of relativity. Although both of these have been modified with time, no one attributes either to Newton or Einstein as conjectures or guesses. They are understood as describing facts about physical objects derived from initial claims made by Newton and Einstein. Glenn Branch, in a recent blog post, explains the cognitive status of evolutionary biology in depth, and provides some useful links.
The LE Standard ought to state that “The central, unifying theme of biological science is that all living things have relationships of descent with one another.”
Belief vs. acceptance
Key Idea 3 is also explained with:
According to many scientists, biological evolution occurs through natural selection.
This is the only point in the LE Standard at which the level of support among scientists for a scientific claim is mentioned. Indeed, it would be absurd to preface “Organisms from all kingdoms possess a set of instructions (genes) that determines their characteristics,” the explanation of Key Idea 2, about heredity, with “According to many scientists.” Any scientist that denies this would not be deemed worth of the name. The aim of the LE Standard should be to state what the best scientific evidence provides rational warrant for, which is that evolution has occurred and will continue to do so. Formulating the standard in terms of how many scientists would affirm that evolution occurs by natural selection suggests that there is a parallel between religious belief and acceptance of evolution. This is not the case, as explained in a National Academy of Sciences FAQ.