Darwin and Evolution

Darwin and Evolution
Key: AWL to Study, Low-frequency Vocabulary
Who is Charles Darwin? What is evolution?
1831–1836: Voyage of Exploration
• Darwin traveled on the Beagle.
 knew the Earth was very old
 knew fossils represented extinct species
 knew living organisms were related in groups
Where did Darwin travel on his voyage of exploration?
Ambitious Naturalist
• Darwin knew that whoever solved the problem of how
new species originated would become famous.
Would you like to explore the natural world like Darwin?
Darwin’s Journal: 1838
• Natural selection is a process.
 Traits that enhance survival become progressively more
common in successive generations.
 These animals reproduce more.
 These traits become more pronounced.
How does natural selection work to form a new species?
• Process of natural selection explains the origin of
 When adaptations are
combined with
geographical separation,
this could explain the
origin of species.
How does natural selection explain the origin of
A Controversial Idea
• Darwin feared enormous
 did not publish for 20 years
 gathered additional evidence
Why was Darwin’s idea controversial?
• A letter from Wallace
 Wallace also had the idea of natural selection.
If you were Darwin, what would you have done after
receiving Wallace’s letter?
Darwin’s Reaction: Despair
• He thought the honorable course of action would be
to let Wallace publish alone.
• Prominent friends encouraged Darwin to arrange for a
joint publication.
• Darwin and Wallace
published back-to-back
papers in 1858.
What might have happened if Darwin hadn’t
published at this time?
Working Rapidly
• 1859: Darwin rushed to press with a book.
 assembling materials, summarizing evidence and making
 Darwin publishes The Origin of Species by Means of Natural
 The first print run of the
book sells out on the
first day.
Why do you think the book sold out?
A Sensation
• The most controversial implication:
 Humans descended from apes.
• The book also explained the astonishing diversity and
precise adaptation of living things.
Why do you think the book was thought to be so
Darwin’s Words
• To contemplate a tangled bank…
plants of many kinds
birds singing in the bushes
insects flitting about
worms crawling around
Do you like to contemplate nature? Why or why not?
Darwin Reflects
• Elaborately constructed forms, different from and
dependent upon each other in so complex a manner,
are produced by laws.
 Endless forms have been and are being evolved.
Explain how certain laws have created the diversity of