Evolution__3rd_Edition

380 PART 4 / Evolution and Diversity
Study and review questions
1 Review the main arguments for and against the
phenetic, biological, and ecological species concepts.
2 In a pair of “sibling species,” how many species are
there in the: (i) phenetic, (ii) biological, and (iii) ecological
species concepts?
3 Review the kinds of prezygotic and postzygotic
isolating barriers that exist.
4 Calculate the statistic G ST , which describes the amount
of geographic differentiation within a species, for species
1–3 below.
Species H T H S G ST
1 0.5 0.5
2 0.5 0.25
3 0 0
What biological factors might cause G ST to be lower in
some species than in others?
5 Do asexual organisms form species like sexual
organisms, and what consequences does the answer
have for our concept of species?
6 Is population or typological thinking more appropriate
in classifying the following entities? (The answer is not
certain in all cases, and they are as much topics to think
about and discuss, as to provide final answers about.)
(i) Chemical elements (such as atoms of carbon,
hydrogen, gold, etc.); (ii) human cultures; (iii) biological
species; (iv) human emotions (such as fear, anger,
etc.); (v) mechanisms of transport (such as cars,
walking, airplanes, and so on); and (vi) scientific
theories (such as evolution, gravity, quantum
theory, etc.).
7 How can we test between the ecological and genetic
theories of postzygotic isolation?
8 In the (i) phenetic, (ii) biological, and (iii) ecological
species concepts, are (a) species, (b) subspecies/races,
and (c) higher taxonomic categories, real or nominal
entities in nature?
..