One important distinction that has emerged over the years is that fewer and fewer scientists have used "evolution" in rigorous usage to mean some particular process. Rather, the tendency has been to use "evolution" to indicate a particular class of phenomena. This class of phenomena are recognized by the diagnostic criteria of change in allele frequency or distribution in a population over time.
Another distinction is the recognition that evolutionary phenomena are phenomena of populations of organisms, not individuals. The typological stance seeks to find the "type", the ideal individual whose form a population varies from, where the populational view makes it clear that variation is the basic property of the population, and that no "type" is fixed for the population.
When dealing with evolutionary phenomena, one is dealing with those traits which are inherited. Traits which appear in individuals but are not passed on to descendants do not concern us as evolutionary biologists.
Given these considerations, we can construct a definition of biological evolution: Biological evolution is a class of phenomena characterized by changes in the distribution of heritable variation of populations. Some particular knowledge about how the genetics of organisms thus far studied works allows us to get more specific: Instances of biological evolution can be recognized by change in allele frequencies of a population, or by change in allele associations in a population. Defining evolutionary phenomena in this way has several advantages, among them the fact that the diagnostic criteria are both objective and quantifiable.
A major goal for evolutionary biology is to explain how adaptations
arise and become fixed in populations. Unfortunately, "adaptation" is often
used to indicate a process of accommodation in individuals, the acquisition
of beneficial characteristics in a population, and also to refer to the
beneficial characteristics themselves.
See the Notebook On Evolution page.
This is the beginning of a collaborative project to bring together concise
information concerning the evidence and theories of evolutionary change.
Not everyone is willing to let the field of evolutionary biology to the biologists. There are people who oppose the teaching of evolutionary biology, typically for reasons concerning their theological stance. Some are willing to say that their theology conflicts with evolutionary biology, and others are not. Whatever the motivation, it is also typically the case that they will attempt to critique evolutionary biology as if that elevated their own stances to the status of science. Uniformly, these arguments are made in ignorance of the biological data. Let me put that another way: in over a decade of active participation in online discussion of evolution, I have never been presented with a criticism of evoutionary theories from a theistic anti-evolutionist source that withstood scrutiny. Every single one has been rebutted. Now, sometimes a theistic anti-evolutionist will quote a valid critique of some theory or another from a biologist, but usually the anti-evolutionist is hampered in exploiting these concepts because of unfamiliarity with the field.
About the Zoologists
