Look at the drawings carefully then answer the following questions…
1) What is the main difference you notice about the Galápagos finches?
2) Why do you think this difference exists?
• change over time: the process by which modern organisms have descended from ancient organisms.
• Theory = A well-supported, testable explanation of phenomena that have occurred in the natural world.
• What is the “support” in science?
– EVIDENCE!!!
• Charles Darwin was first to propose the theory of evolution in 1800’s
DEFINITION OF EVOLUTION:
• Born 1809 (England)
• Completed college after studying to become a doctor but could not stand sight of blood …
• Set sail on 5 year voyage on H.M.S., Beagle in 1831 as the natural historian for expedition.
The Life of Charles Darwin
• Made extensive drawings and notes on the trip but also collected many species of plants and animals.
• Began to OBSERVE that animals were well adapted to their environments, but…• why were different animals found in areas that appeared
to be similar in climate? And some survived others did not?
• Argentina• Australia • Europe
The Life of Charles Darwin
All had grasslands but very different animals
• He collected fossils. – noticed some looked like living organisms– others looked like nothing he had ever seen
before
• Were these related to the living (present day) organisms?
• Why did some organisms disappear altogether?
The Life of Charles Darwin
The Life of Charles DarwinGalapagos Islands
Organisms Darwin Observed on the Galapagos• Land Tortoise = different shaped carapace (shell) depending
what island they inhabited.• Finches = different shaped beaks depending on environment in
which they lived.
• Through his observations and talking to other islanders…– he realized that characteristics of many animals and plants
varied noticeably among the different islands of the Galapagos.
• On the journey home he began to pose the question…– Could animals on the different islands
once have been members of the same species?
Those Who Influenced DarwinBe sure to read pages 374-377
Hutton (Geologist) – Geologic processes operate extremely slowly
– millions of years– therefore, the earth is very old
Lyell (Geologist) – Scientists must explain past events in terms of
processes that they can actually observe• since processes that shaped the Earth millions of
years ago continue to shape present day Earth• This explained how geological features can be
built or torn down over long periods of time.
Darwin wondered…
• If the earth could change over time, could life change as well?
• Also: it must have taken many, many years for life to change the way Darwin had in mind– This would only be possible if the
earth was very old…
Those Who Influenced DarwinBe sure to read pages 374-377
Malthus (Economist) • proposed that war, famine,
disease, limits the growth of human populations
• if populations continue to grow unchecked, they will run out of resources (food/shelter)
•LAMARK’s explanation on evolution
ASSUMPTION #1
CRITICISM OF THIS
ASSUMPTION
Law of Use and Disuse: an organism can change certain body parts during its lifetime and pass these changes on.
Implies that an organism can sense its needs and change to meet them.
LAMARK continued…
ASSUMPTION #2
CRITICISM OF THIS
ASSUMPTION
Inheritance of Acquired Characteristics: acquired traits can be passed on to offspring population changes.
Suggests that changes in body cells (like building bigger muscle mass) can be inherited.
New York Times Article
You are a reporter for The New York Times newspaper. It is 1836. You have been assigned to cover a story about the young Charles Darwin, who has just returned from his travels to the Galápagos Islands. You are to interview him and talk about the observations he made on his journey. How did his observations lead to ideas about his theory of evolution? What has he learned from others in the scientific community that may influence his theory (Hutton, Lyell, Lamarck, and Malthus)? Don’t forget to give your article an eye-catching headline and BE CREATIVE!
USE YOUR OWN WORDS WHEN DESCRIBING HIS IDEAS!
GRADING—this MUST BE TYPED!!! POINTS possible
1. Includes information about the observations 6 made on his trip to the Galápagos Islands (Tortoises, birds…what was he thinking/ learning?) 2. Includes information that Darwin learned from: 8* Hutton* Lyell * Lamarck* Malthus
3. Answers the question: How did his observations of all these animals 6 give rise to his ideas about the theory of evolution?
4. Article must have a catchy headline, be neat, 5 well written with few grammatical errors _______
Total points: 25