Chapter 18: Evolution and the origin of species

Evolution

The change in organisms throughout earths history

• “descent with modification”

How does evolution happen

Descent with modification

Who originally proposed decent with modification

Charles Darwin

How do organisms evolve from common ancestors

• Change in genetic makeup of organism leads to new trait potentially becoming prevalent

• Many organisms descend from this point and have this trait

• New variations continue to arise some adaptive and persist, leading to new traits

• With new traits, a new Claude is determined

What was the ancient philosophy in western thoughts

Ideas about nature and life from Greek and Roman times through the Middle Ages

What was the ancient philosophy in non-western cultures

Spiritual and philosophical traditions like Hinduism, Buddhism, Chinese philosophy, and Islamic thoughts contributed diverse understanding of life

What was the age of reason (1700-1800)

• Rise of scientific inquiry and the use of reason

• Emphasis on observation, experimentation, and challenging established doctrines

What did Aristotle contribute

• foxed ideal species

• Scala naturae “ladder of nature”

  • Ranking of complexity

What did Linnaeus do

• orderly, nested classification system

• Binomial naming

• Grouping based in similarity

What did James Hutton do

• slow continuous processes → geological features

• Gradualism

What did Charles Lyell do

• Uniformitarianism expanded Hutton’s ideas

  • Same geological processes in past as today, same rate as today

  • I spired Darwins theories

What did Lamarck do

linked evolution to adaptation

• extinct species replaced by descendants with new features

• These adaptations helped the, survive in environment

• Darwin agreed with these ideas

• Proposed inheritance of acquired characteristics but it’s wrong and Darwin rejected ideas

  • “Lamarckism”

What were Darwins two main ideas

• Descent with modification

• Natural selection

How did Darwin get his theory

• Traveled mostly to South American including the Galapagos

• Collected plants, wildlife, fossils

• Observed species’ geographic locales and adaptions

  • Beak shape of finches

Who was Wallace

Gave letter to Darwin with similar ideas to him and helped contribute ideas of natural selection

What is the definition of Darwins idea of descent with modification

All present life is related through “decent with modification” from a common ancestor in the past

• Extinction is common

What is the dentition of Darwin’s Henry of natural selection

• Natural selection is the mechanism for evolution

What did Darwin observe to help with his natural selection theory

• heritable variation exists in most species

  • Characteristics of offspring vary and these variation are variable

  • Farmers can enhance small heritable variation by artificial selection (breeding)

• More offspring are produced that can survive; there is competition for resources

What are the misconceptions of evolution

• Evolution is just a theory

• Individuals evolve

• Evolution explains the origin of life

• Organisms evolve on purpose

• Species are always evolving into “higher” or “better” beings

• Evolution creates new forms of life by dramatic mutations

• Evolution is a completely random process

What is the therapy of evolution by natural selection

• explains both diversity and unity of life

• accounts for much of form and function

• can predict outcome of environmental change

Can individuals evolve

No, populations evolve

Does evolution explain the origins of life

No, only