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Biological Anthropology:Evolution

Anthropology

• Anthropology: the holistic study of humanity.

• In the US, Anthropology is broken up into four main sub-fields.

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Cultural Anthropology

Biological Anthropology

Archaeology

Linguistic Anthropology

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Biological Anthropology

• Biological Anthropology is the study of the human species from a biological perspective.

• Biological anthropologists rely on a scientific framework to make their claims about humans.

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Scientific Framework

• If something cannot be observed with the senses it can not be studied scientifically.

• Similarly, things that cannot be observed cannot be used for scientific explanations.

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Evolution

Evolution: Fact or Theory?

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What is a fact?

A fact is something that has been repeatedly observed and verified.

Hypothesis

• A hypothesis is an educated guess as to why something observed happens.

• Hypotheses are tested to determine their accuracy.

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What is a theory?

A theory is an well-supported explanation for why something observed (facts) occurs.

Theories are derived from hypotheses that have continually provided accurate explanations.

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Evolution

Evolution is defined as change (in gene frequencies) within populations over time.

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Evolution is Fact

• Changes in gene frequencies within populations have been observed many times.

MRSA: Methicillin-Resistant Staphylococcus aureus

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Archaeopteryx Fossil

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Theories of Evolution

Numerous scientists have attempted to explain the fact of evolution. This is what is meant by evolutionary theory.

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Theory of Natural Selection

Charles Darwin published The Origin of Species, in 1859. This book outlined his theory (or explanation) of evolution.

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Darwin’s First Point

• Within any population there is variation.

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Darwin’s Second Point

• Darwin suggested some of these characteristics were transmitted from parents to offspring.

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Darwin’s Third Point

• More organisms are born than can be supported by the environment. Limited resources result in some level of competition between organisms.

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Darwin’s Observations

• Darwin suggested that some traits provided an advantage to organisms within a given environment.

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Darwin’s conclusion

Natural Selection: Organisms possessing traits that make them well-adapted to their environment have a greater chance of surviving and passing on their traits to their offspring than those less well-adapted,

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The Peppered Moth

Moths on Birch Tree

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Evolution is NOT…

• Evolution is not necessarily about becoming more “advanced” or “complex.”

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Evolution

• Evolution relies on random mutations…just because a trait would be desirable in a given situation does NOT mean it will necessarily emerge.

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Jean-Baptiste Lamark (1744-1829)

• Jean-Baptiste Lamark was a naturalist that provided an interpretation of evolutionary change that has since been disproven.

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Lamark’s View

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