Chapter one questions:
As is true for many issues in biology, scientists have proposed a number of competing definitions for adaptation (see Harvey and Pagel 1991, Lauder et al. 1993, Reeve and Sherman 1993). For some, the term must be reserved for a characteristic that provides “current utility to the organism and [has] been generated historically through the action of natural selection for its current biological role.” What do you think current utility means? If a trait originated for function X and later took on a different, but still adaptive, biological role Y, does that mean it is not an adaptation? Track down the evolutionary history of the flight feathers of modern birds (see Prum and Brush 2002). Where did these feathers come from, and what function did their predecessor feathers exhibit? If you go back far enough in time, will the ancestral form of any current trait have the same function that it does now?
Chapter Two Questions:
1. William Searcy and colleagues played recorded songs to captive female song sparrows (Melospiza melodia) that had been given hormone implants shortly after being taken to the laboratory from the wild (Searcy et al. 2002). The recorded songs came from male song sparrows that lived in the females’ population, as well as from males living various distances (18, 34, 68, 135, and 540 kilometers) from that population. Songs from males living 34 or more kilometers from the females’ population were not nearly as effective in eliciting the precopulatory display as songs from local males. However, songs from males living only 18 kilometers away were about as sexually stimulating as local songs. These data have relevance for more than one ultimate hypothesis on song learning by male sparrows. What are the hypotheses, and what importance do these findings have for them?
2. Parasites are often microscopic in size but have large negative effects on their hosts. If this is true for the parasites of songbirds, what predictions follow about their effects on male song performance, and how should females respond to the song of infected males as opposed to uninfected individuals (Garamszegi 2005)?
3. What features of language learning in humans are similar to song learning in birds? What do these similarities suggest about the genetic and developmental bases of human language learning? Do comparisons with birds also suggest some interesting hypotheses on the adaptive value of learned language for members of our species?
Chapter 3 Questions:
1. Why do queen honey bees (Apis mellifera) behave very differently from their workers even though a queen has essentially the same genome as her worker sisters and daughters? Develop at least one proximate hypothesis on why the two categories of bees behave so differently.
2. The nature–nurture controversy involves the belief that our nature (essentially our genes) dominates our behavioral development and another belief, held just as forcefully, that our nurture (especially our upbringing as children) is what shapes our personalities. Some have dismissed the controversy by saying that the two sides might as well be fighting about whether a rectangle’s area is primarily a matter of its height or mostly a function of its width. What’s the point of the rectangle analogy? Does the analogy have any weaknesses?
