Evolution__3rd_Edition

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Study and review questions
1 Review (a) the events leading to fossilization, and
(b) the divisions of geological time.
2 What is the age of a fossil that contains the following
ratios of 14 C to 14 N? Assume all 14 N has been formed by
the decay of 14 C.
(a) 1 : 1
(b) 2 : 1
(c) 1 : 2
CHAPTER 18 / The History of Life 555
plants. See Shear (1991) in general. Kenrick (2001) gives a brief overview of ideas about
the relation between roots, leaves, and carbon dioxide. Heckman et al. (2001) suggest,
from a molecular clock analysis, that fungi and perhaps plants colonized the land
earlier (maybe 700 million years ago for plants) than the fossil figures discussed in this
text. Willis & McElwain (2002) is an introductory text on plant evolution, particularly
on fossil evidence. Dilcher (2000) identifies the main themes in plant evolution. See
Kellogg (2000) on grasses.
On the mammal-like reptiles see Kemp (1999), Hotton et al. (1986), Bramble &
Jenkins (1989), Benton (2000a), and Carroll (1988, 1997). See Wellnhofer (1990) on
Archaeopteryx. Flynn & Wyss (2002) describe Mesozoic fossils from Madagascar that
help us understand the reptilian ancestry of mammals and dinosaurs. Novacek (1992)
reviews mammalian phylogeny.
On human evolution, Klein (1999) is an authoritative text, Lewin (2003) a more
introductory text, and Ehrlich (2000) a more personal book that nevertheless works as
an introduction and text. Science February 15, 2002, pp. 1214–25 has a news focus on
human evolution. Science April 23, 1999, pp. 572–3 has a newspiece on Australopithecus
garhi. Asfaw et al. (2002) provide evidence for the global use of the species name Homo
erectus.
Levinton (2001) discusses micro- and macroevolution, and refers to the literature.
The topic can also be followed, more from the microevolutionists’ perspectives,
through several papers in the special issue of Genetica (2001), vols 112–113, which was
also published as a separate book (Hendry & Kinnison 2001).
Many of Gould’s popular essays, anthologized in Gould (1977b, 1980, 1983, 1985,
1991, 1993, 1996, 1998, 2000, 2002a), are paleobiological.
14 C : 14 N Age
3 What features of RNA make it likely to have preceded
DNA as the hereditary molecule?
4 For a number of evolutionary events, including the
radiation of animals and the origin of angiosperms, dates
estimated from fossils seem to contradict dates from the
molecular clock. How can the difference between the two
estimates be reconciled?
5 What is the (possible) relation between the amount
of atmospheric carbon dioxide and the evolution of
terrestrial plants, roots, and leaves?
6 What features of the mammal-like reptile fossil record
suggest that the mammals evolved by an extended
period of microevolution?
7 What are the main changes (or classes of changes) in
human evolution?