Transcript Introduction and Chapter 1: Origins of Evolutionary Thought

Introduction and Chapter 1: Origins of
Evolutionary Thought
Key Terms
 Primate: member of the mammalian order Primates, including
prosimians, monkeys, apes, and humans, defined by a suite of
anatomical and behavioral traits.
 Evolution: a change in the frequency of a gene or trait in a
population over multiple generations.
 Biological/Physical Anthropology: the study of humans as
biological organisms, considered in an evolutionary framework.
 “Biologically anthropology is particularly concerned with the
evolutionary transformation that occurred over the past 6 million
years, as an ape-like primate began to walk on two legs and became
something different: a hominin – a member of the primate family
Hominadae, distinguished by bipedal posture and, in more recently
evolved species, a large brain.
Anthropology and the 4 fields
The Scope of Biological Anthropology
 Paleoanthropology: the study of the fossil record of
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ancestral humans and their primate kin.
Osteology: the study of the skeleton.
Paleopathology: the study of diseases in ancestral human
populations.
Bioarchaeology: the study of human remains in an
archeological context.
Forensic anthropology: the study of human remains
applied to a legal context.
Primatology: the study of the nonhuman primates and
their anatomy, genetics, behavior, and ecology.
Paleoanthropology
Osteology
Paleopathology
Bioarcheaology
Forensic Anthropology
Primatology
Human Biology
Chapter 1: Origins of Evolutionary
Thought
Religion?
Scientific Method
Importance of Deductive
Reasoning
• Science is always changing and correcting itself. We set up
experiments that are falsifiable.
• How many scientific laws are there?
Progression of Science
 Aristotle’s Great Chain of
Being.
Renaissance
Linnaeus and the Natural Scheme of
Life
 Carolus Linnaeus (1707-1778), an eminent Swedish
botanist and the author of Systema Naturae built on John Ray’s
writings to create the most comprehensive classification of
the plant world compiled at the time.
 Taxonomy: the science of biological classification.
 Binomial nomenclature: Linnaean naming system for all
organisms, consisting of a genus and species label.
The Road to Darwinian Evolution
 Comte de Buffon: observed that animals that migrate to
new climates often change in response to environments,
although like others of his day, he had no idea about the
mechanism of change.
 Georges Cuvier: sought to explain fossils with the theory
of catastrophism – theory that there have been multiple
creations interspersed by great natural disasters such as
Noah’s flood.
 Geoffroy Saint-Hiliaire: contemporary opponent to
Cuvier and proponent of his colleague Jean-Baptiste
Lamarck.
Lamarkian Evolution
 Theory of inheritance
of acquired traits:
discredited theory of
evolutionary change
proposing that changes that
occur during a lifetime of
an individual, through use
or disuse, can be passed on
to the next generation.
The Uniformitarians: Hutton and
Lyell
Uniformitarianism: theory that the same gradual geological
process we observe today was operating in the past.
Chuck D.
“Darwin’s finches”
 “Seeing this graduation and diversity of structure in one
small, intimately related group of birds, one might really
fancy that from on original paucity of birds in this
archipelago, one species have been taken and modified for
different ends” - Darwin 1839
 The good and the bad?
Key terms
 Biogeography: the distribution of animals and plants on
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the Earth.
Adaptive Radiation: the diversification of one founding
species into multiple species and niches.
Natural Selection: differential reproductive success over
multiple generations.
Vestigial Organs: body parts that seem to serve no modern
purpose and have, therefore, atrophied.
Fitness: reproductive success (and no, not what you do on
the weekends!)
Alfred Wallace pushes Darwin
Darwin’s three observations and two
deductions
 Observation 1: All organisms have the potential for explosive
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population growth that would outstrip their food supply.
Observation 2: But when we look at nature, we see populations
that are roughly stable.
Deduction 1: Therefore, there must be a struggle for existence.
(This Darwin labeled natural selection to parallel the term
artificial selection in use by animal breeders of the period).
Observation 3: Nature is full of variation. Even in one animal
group, every individual is slightly different from every other
individual.
Deduction 2: Therefore, some of these variation must be
favored, and other must be disfavored, in a process we call natural
selection.
For natural selection to work, three
preconditions must be met.
 The trait in question must be inherited.
 The trait in question must show variation between
individuals.
 The filter between organism and its genetic makeup is the
environment, which must exert some pressure in order for
natural selection to act.
More key terms
 Population: an interbreeding group of organisms.
 Mutation: an alteration in the DNA, which may or may not
alter the function of a cell. If it occurs in a gamete, it may be
passed from one generation to the next.
 Evolution happens at the level of the population while natural
selection occurs at the level of the individual organism.
Reaction to Darwin