Download Chapter One – Introduction to Primate Studies

Chapter Three – Primates Past to Present
Evolutionary History
Primate Diversity in the Past
Primate Origins
Biogeography and Barriers
Miocene Monkeys and Apes
ƒ Box 3.1 Mosaic Nature of Human Evolution
Pliocene Highlights
Pleistocene Glaciations
Holocene
Interpreting Diversity Today
Intraspecific Variation
Local Population Variability
The Status of Hybrids
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Box 3.2
Hybrid Baboons
The Status of “New Species”
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Box 3.3
Lucky Lemurs
Implications for Primate Behavioral Ecology
The material in this chapter is not covered in class, but you need to know it. Important
concepts in understanding primate evolution are introduced, such as adaptive radiation,
allopatric speciation, plate tectonics, and continental drift. The section on Primate
Diversity in the Past traces some of the major events in primate evolution from the
beginning of the Cenozoic Era (right after the end of the Mesozoic Age of Reptiles).
Seven geological epochs (Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene,
Holocene) are described in terms of major events in primate evolution and related world
climate. This material is summarize very briefly in Table 3.1. You should know each of
these epochs, when they started and ended, and for each one be able to identify key
events in world climate and primate evolution. Some other questions you should be able
to answer: What is the oldest new world primate and when did it live? How did new
world primates get to South America? When did the ancestral hominoids emerge? What
makes these ancestral hominoids distinguishable (from other anthropoids) in the fossil
record? What old world monkey (genus and popular name) ancestor was very large in
size and widespread throughout African grasslands during the Pliocene?
Table 3.2 is the Category for Threatened Taxa – don’t worry about this for Term Test
One – we will talk about it later when we cover Conservation, and this table will be
covered on the final exam.
Read carefully the section on Interpreting Diversity Today. What is a species? A
subspecies? What is the difference between “lumpers” and “splitters” with respect to
how they interpret intraspecific (within species) variation? The section on Local
Population Variability describes how local populations, if they become separated from
other local populations, begin to evolve separately (through both natural selection in their
respective environments, but also by other mechanisms of evolutionary change such as
genetic drift). Chimpanzees and bonobos are described as an example of how one
species became two due to geographic separation. Strier also stresses that debates over
whether two forms are different enough to have distinct subspecies, or even species level
designations is not at all trivial as it can have important consequences for the level of
protection afforded to them in legislation.
When individuals of two different species get together and produce a viable offspring,
these are known as hybrids. In the Status of Hybrids section hybrids are defined as
“genetically unique individuals that are the produce to fertile matings between two
different species”. Hybrids occur naturally whenever the geographic ranges of different
but closely relates species overlap. Obviously they must still recognize one another as
potential mates and be able to produce viable offspring. Box 3.2 describes Hybrid
Baboons in Ethiopia and the very interesting behavior patterns of the hybrid individuals.
Be familiar with the different behavior patterns of the two parent species and how
different crosses produce different offspring (both behavior and appearance).
The Status of New Species section describes a number of new primate species that have
been identified in recent years. Box 3.3 describes the discovery of a new species of
lemur in 1986. Why are these lemurs described as lucky?