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15 - Teaching evolution and the nature of science
- from Part VI - Evolution and Society
- Edited by Aldo Poiani, Monash University, Victoria
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- Book:
- Pragmatic Evolution
- Published online:
- 05 April 2012
- Print publication:
- 10 November 2011, pp 281-296
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Summary
Evolutionary biologists are much given to quoting Dobzhansky's (1973) famous phrase, ‘Nothing in biology makes sense except in the light of evolution’, and to asserting that evolution is the most comprehensive unifying theme in biology. Indeed, evolution is surely one of the two most fundamental principles of biology (the other being that life phenomena are entirely a matter of physics and chemistry, not élan vital), and a good case can be made that it is biology's most important theory. Nevertheless, many of our fellow biologists seem to honour this acknowledgement more in the breach than the observance, for the chapters on functional biology in introductory biology textbooks usually lack any reference to evolution at all, and the universities that require undergraduate biology majors to take a course in evolution are almost surely in the minority.
Outside academia, the situation is much worse. ‘Scientific illiteracy’ is increasingly seen as a major problem in the US and elsewhere (Mooney and Kirshenbaum, 2009). Fewer than half of American adults can provide even a minimal description of DNA (Miller et al., 2006). Popular understanding of even the rudiments of evolution is worse, and is compounded by scepticism and hostility to a degree faced by no other claim in science. Over the past 20 years, only 40–45% of Americans say they accept evolution, almost the lowest proportion among developed nations (Figure 15.1). Creationism (in its several guises, including ‘intelligent design’) is increasing throughout many developed and developing countries. The situation in Australia is better: according to a Nielsen poll in 2009, ‘forty-two percent of [Australian] people believe in a wholly scientific explanation for the origins of life and thirty-two percent believe in an evolutionary process “guided by God”’; still, almost a quarter believe the biblical account of human origins (Jacqueline Maley, 2009). Despite its generally secular reputation, Australia was the birthplace of a group called ‘Answers in Genesis’ that spread widely; creationists successfully lobbied in 1980 for teaching creationism in Queensland; the Federal Education Minister in 2005 reportedly approved of teaching creationism along with evolution (Or, 2005).
Part I - Theory and Methods
- Edited by Michael P. Muehlenbein, Indiana University, Bloomington
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- Book:
- Human Evolutionary Biology
- Published online:
- 05 August 2012
- Print publication:
- 29 July 2010, pp 1-2
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Summary
“The natural phenomena of the evolutionary history of man claim an entirely peculiar place in the wide range of the scientific study of nature. There is surely no subject of scientific investigation touching man more closely, or in the knowledge of which he is more deeply concerned, than the human organism itself; and of all the various branches of the science of man, or anthropology, the history of his natural evolution should excite his highest interest.”
Ernst Haeckel (1834–1919), The Evolution of Man (1892)
1 - Evolutionary Theory
- Edited by Michael P. Muehlenbein, Indiana University, Bloomington
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- Book:
- Human Evolutionary Biology
- Published online:
- 05 August 2012
- Print publication:
- 29 July 2010, pp 3-16
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Summary
Our contemporary understanding of evolutionary processes builds on theory developed during the “Evolutionary Synthesis” of the 1930s and 1940s, when Darwin's ideas, especially on natural selection, were joined with Mendelian genetics. Since, then, of course, our understanding of evolution has been greatly advanced by the discoveries in molecular genetics, as well as by continuing elaboration of the “neo-Darwinian” theory that issued from the Evolutionary Synthesis (Futuyma, 1998, 2009).
A capsule summary of contemporary theory, to be followed by more detailed explication, is as follows. Elementary evolutionary change consists of changes in the genetic constitution of a population of organisms, or in an ensemble of populations of a species. These genetic changes may be reflected in change of the population mean or variance of phenotypic characteristics. Any change requires that genetic variation originate by mutation of DNA sequences, and/or by recombination. The minimal evolutionary process is an increase in the frequency of a mutation, or a set of mutations, within a population, and the corresponding decrease in frequency of previously common alleles. Such frequency changes are the consequence of random genetic drift (leading to occasional fixation of nearly neutral genetic variants) or of diverse forms of natural selection. Successive such changes in one or more characteristics cumulate over time, yielding potentially indefinite divergence of a lineage from the ancestral state. Different populations of a species retain similarity due to gene flow and perhaps uniform selection, but can diverge due to differences in mutation, drift, and/or selection.