Evolution

A brief treatise on How Science Works, and the state of science education in America in 2010, with references.

Can we talk?

How Science Works

I'm a science guy. I have a degree in science, I've worked in science labs, and I teach science, and I know a little bit about how it works. Most people know a little bit about how it works, but in the event that you need a refresher... here's how it works:

Science works more or less along the same lines as the step-by-step process that you probably learned about in your junior high earth science class: Someone observes something curious. They come up with a hypothesis, an informed reasoning that explains the event he or she observed. Some sort of experiment is devised to help test that hypothesis, the results of which either support or refute the original hypothesis. The hypothesis is modified, taking into account information from previous experiments, and ultimately, over time, a theory may be proposed, which is NOT just a guess, but a well-developed, well-tested, and generally-agreed-upon-by-experts understanding of some aspect of the natural world.

Some things you should know:

  • Science cannot be used to "prove" things.
    Scientists don't generally go around "proving" things--proof is a term that is more appropriate to use when talking about mathematical developments. No, what scientists do is, through research and experimentation, try to find evidence that either supports or refutes a hypothesis. Although an individual scientist often finds him- or herself favoring one particular hypothesis over another, in the end, the scientific community supports the hypothesis that seems to offer the best explanation, given current understanding.

    Which brings us to another thing you should know:
  • Science doesn't always get it right the first time
    Although some laypeople view this as a weakness of science, most scientists I know view this as one of its greatest strengths. In any field of study, as new evidence comes to light, scientists are bound examine that evidence, and use it to improve their understanding of how things work, even when that means that they have to change their minds about what they thought before. It can be difficult for an individual scientist to let go of an old idea, but he or she is bound to do so in the face of new information. (One convenient example of this is how our understanding of the atom has changed over the years.
  • Scientific progress happens in lots of different ways.
    The idealized description of the Scientific Method—Observation, Hypothesis, Experiment, and (after extensive testing) Theory—is a simplified model that doesn't adequately explain the many different ways that we come to understand things. Whether it's a fortuitous incident that inspires some new insight (Newton's proverbial apple), the accumulation of years and years of observational data (Kepler's analysis of Brahe's astronomical notes), or an impromptu series of simple experiments (Feynman trying to discover what factors affect how a strand of uncooked spaghetti breaks), there are lots of different ways of trying to understand how the world works.
  • Doing Science is a social process.
    Visions of a lone, rogue, mad scientist are best left to the movies. While any single discovery may be made by an individual, for a scientific theory or model to become validated, it has to be accepted by the scientific community at large. This process can sometimes become quite messy, but publishing the methods and results of one's work so that others can collect additional evidence to either support or refute a hypothesis is fundamental to scientific advancement.

    And finally:
  • Science can't solve everything.
    The process of scientific investigation is eminently suited to pursuing certain types of information, mostly related to furthering our understanding of how the world and universe we live in works.

    Science cannot, for example, tell us what the freeway speed limit should be, who was the best Renaissance painter, whether or not we should expand our use of nuclear power as a source of energy, or whether or not God exists. An individual scientist may have an opinion about any of these things, but science itself is not a tool that one can employ to answer these sorts of questions.

For more on How Science Works:

The Evolution of Evolution

Evolution refers to the fact that a population of organisms undergoes genetic change over a period of time. Observations regarding change in organisms over time, and discussion of what those changes might mean, go back to the 1700s. Proposals for the underlyinig mechanisms of that change came a bit later on, most famously by Charles Darwin in 1838, resulting in the publication of On the Origin of Species in 1859.

While the concept of evolution was first proposed on the basis of biological morphology changing over time (subtle changes in body shapes of populations, evident in the fossil record), it has since been refined and confirmed in the modern evolutionary synthesis, which uses natural selection and Mendel's work in genetics to explain the gradual evolution of a population over time.

Some common questions:

  • Isn't evolution just a theory?
    "Evolution," used to refer to the change of a population over time, is a scientific fact that has been observed and well-documented. Farmers use this change of species to develop drought- and pest-resistant crops, or to grow better tasting tomatoes and more beautiful orchids. So that aspect of evolution isn't questioned—it's considered a scientific fact.

    The mechanism of evolution is what most people are referring to when they ask about the theory, and confusion arises here because of the different ways that scientists and civilians use the word "theory." A non-scientist, in attempting to explain why dogs like to chase cars, might say "Oh, I have a theory about that...", using the word "theory" to mean "a guess." A scientific theory, however, isn't a guess at all—as discussed above, it's an idea or an explanation that has undergone rigorous testing and been vigorously discussed by experts in the field. Newton's Theory of Universal Gravitation and Einstein's Theory of General Relativity are both well-established: and understanding of Newton's analysis of gravity allows us to launch and place Global Position System (GPS) satellites into orbit around the earth, and Einstein's insights into relativity are required for the communications from those GPS satellites to work correctly. Without either one of those Theories, GPS wouldn't work.

    That being said, as good scientists we can acknowledge that there may be further discussion to be had about the finer points of these theories. And the Theory of Evolution will doubtless undergo some refinement as we come to better understand the biochemical processes involved.

For more on The Evolution of Evolution:

  • Introduction to Evolution - A good general introduction to the subject, from Wikipedia, with references.

  • Evolution - A more technical exploration, from Wikipedia, with references.

Science Education in America

Coming soon!

The Future

Coming soon!