Geography Reference
In-Depth Information
Figure 8.1
Geological area cladogram presented by Sanmartín and Ronquist
(2004) that represents the relationships between the southern continents based on
paleogeographic evidence. A, North Atlantic (180-160 mya); B, southern South At-
lantic (135 mya); C, Somali Basin (121 mya); D, northern South Atlantic (110 mya);
E, Mascarene Basin (84 mya); F, Tasman Sea (80 mya); G, New Caledonian Basin
(30 mya); H, South Tasman Sea (52-35 mya); I, Coral Sea Basin (30 mya).
There is still much discussion about some aspects of tectonics. Theories
postulating a lost Pacifica continent (Kamp 1980; Nur and Ben-Avraham
1980) or an expanding Earth (McCarthy 2003, 2007; Shields 1979, 1991,
1996) have been proposed to explain certain “anomalies” in Wegener's the-
ory, but they have not gained support by geophysicists (Humphries and
Ebach 2004).
Any of these theories implies a major role for vicariance in isolating pop-
ulations of plant and animal species (Cox and Moore 1998). Continents
split, and their fragments carry away their cargo of living organisms (“Noah's
arks”) and buried fossils (“Viking funeral ships”) (McKenna 1973). Hallam
(1974) characterized two main historical phenomena caused by plate tec-
tonics: convergence and divergence. Biogeographic convergence indicates
intermixing of biotas through continental shifting: Two continents approach
each other, and their biotas merge. Biogeographic divergence occurs when
two continents move apart or two landmasses are isolated by a seaway.
Briggs, J. C. 1987.
Biogeography and plate tectonics.
Amsterdam: Elsevier.
Cecca, F. 2002.
Palaeobiogeography of marine fossil invertebrates: Concepts
and methods.
London: Taylor and Francis.
Lieberman, B. S. 2000.
Paleobiogeography: Using fossils to study global
change, plate tectonics and evolution
. New York: Kluwer.
1. What is the relevance of a geobiotic scenario for the integration of biogeo-
graphy with other disciplines?
2. Carefully read the following article:
