2: Evolution
- Page ID
- 158716
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- 2.1: The Science of Who We Are and Where We Come From
- In the 1700s, scholars began trying to reconstruct the history of the earth...naturalistically. Thomas Burnet speculated that perhaps a comet smashed into the earth, which set off the Great Flood related in the Bible. At about the same time, the anatomist Edward Tyson published the first anatomical study of a chimpanzee, noting similarities to humans. This chapter looks at the history of evolutionary thought that spans hundreds of years of speculation and scientific discovery.
- 2.2: Darwinian Theory
- The publication of The Origin of Species by Charles Darwin in 1859 became an intellectual flash point in European intellectual life (Darwin 1859). It was focused on a significantly narrow point: Where do new species, adapted to their surroundings, come from? By that time, the suggestion that species came from other species was not all that radical. By the 1850s biologists were confident that cells were fundamental units of life and the only way you could get new cells was from old cells.
- 2.3: Molecular Revolution
- The Evolutionary Synthesis successfully reduced evolution to genetics, but until the 1980s it was not possible to study the DNA sequence of the genes directly. Various surrogate measures had been employed for decades. We now appreciate that anatomical variation tracks adaptive divergence of the species, while genetic variation more closely tracks the time since the species diverged from one another.
- 2.4: The Biopolitics of Heredity
- Perhaps the hardest lesson about human evolution to learn is that it is intensely political. In some cases, people see unbiblical things in evolution, although most Christian theologians are easily able to reconcile science to the Bible. In other cases, people see immoral things in evolution, although there is morality and its opposite everywhere. Is the politics in evolution an aberration or is it somehow embedded in the science, even if we don’t see it?
- 2.5: Adaptation and Adaptationism
- Our own bodies are full of evident adaptations: eyes for seeing, ears for hearing, and feet for walking on. But what about hands? Feet are adapted to be primarily weight-bearing structures that is what we primarily use them for. But we use our hands in many ways... greeting, pointing, writing...which of these uses express what hands are “for,” when all of them express what hands do?
- 2.6: Misconceptions about Human Evolution
- At root, human evolutionary theory consists of two propositions: (1) that the human species is descended from other similar species and (2) that natural selection has been the primary agency of biological adaptation. Pretty much everything else is subject to some degree of contestation. To conclude this chapter, let us call attention to some of the major corrections we would like to apply to popular misunderstandings of human micro- and macroevolution.
- 2.7: End of Chapter of Review
- Discussion questions and key term definitions.