Science and Charles DarwinScience and Charles DarwinCh. 16 Evolution Targets:•State Charles Darwin’s contributions to science.

•Identify scientists influencing Darwin and his Theory of Natural Selection

•Explain the role of inherited variation in artificial selection.

•Explain natural selection using correct terms

•Describe what homologous structures and embryology suggest about the process of evolutionary change.

•Explain how molecular evidence can be used to trace the process of evolution.

Young Charles DarwinYoung Charles Darwin

• Born in 1809 Born in 1809

in Shrewbury, Englandin Shrewbury, England

• Studied medicine and Studied medicine and ministry in his twenties ministry in his twenties

• His true interest was His true interest was naturenature

• Encouraged by his Encouraged by his Cambridge professor Cambridge professor to take a job as a to take a job as a naturalistnaturalist

• Darwin traveled on Darwin traveled on the H.M.S. Beagle the H.M.S. Beagle working as a working as a naturalist for five naturalist for five years years

• He traveled along the He traveled along the east and west coasts east and west coasts of South Americaof South America

• He studied differences He studied differences within the land and within the land and collected fossilscollected fossils

Galapagos Islands Galapagos Islands about 600 miles west of South Americaabout 600 miles west of South America

• As a naturalist, As a naturalist, Darwin collected Darwin collected specimens with specimens with great care and great care and interestinterest

• As he traveled, Darwin noticed three distinctive As he traveled, Darwin noticed three distinctive patterns of biological diversity: patterns of biological diversity:

1.1.Species vary Species vary globallyglobally

2.2.species vary species vary locallylocally

3.3.species vary species vary over timeover time

Darwin’s FinchesDarwin’s Finches

• While on the While on the Galapagos Islands Galapagos Islands Darwin found 13 Darwin found 13 species of finchesspecies of finches

• This lead to his This lead to his idea of descent idea of descent from a common from a common ancestorancestor

– The process of change over time is called The process of change over time is called evolution.evolution.

– Darwin developed a scientific theory of Darwin developed a scientific theory of biological evolution that explains how modern biological evolution that explains how modern organisms evolved over long periods of time organisms evolved over long periods of time through descent from common ancestors.through descent from common ancestors.

Darwin’s Theory of Natural Darwin’s Theory of Natural SelectionSelection

• Tendency towards overproductionTendency towards overproduction• Not all offspring surviveNot all offspring survive• Variations exist in any populationVariations exist in any population• Variations are inheritedVariations are inherited• The best organism will live longer The best organism will live longer

and produce more offspringand produce more offspring• Populations change as it becomes Populations change as it becomes

better adapted to it’s environmentbetter adapted to it’s environment

Origin of Species by Natural Origin of Species by Natural SelectionSelection

• Written in 1844Written in 1844

• Published in 1859Published in 1859

• Darwin continued throughout most of Darwin continued throughout most of the rest of his life to publish his the rest of his life to publish his research and writings on biology. research and writings on biology.

• In his later years, Darwin was In his later years, Darwin was plagued by fatigue and intestinal plagued by fatigue and intestinal sickness, thought by some historians sickness, thought by some historians to have been caused by Chagas' to have been caused by Chagas' disease, contracted during his travels disease, contracted during his travels in South America. in South America.

Charles Darwin died on April Charles Darwin died on April 19, 1882, and lies buried in 19, 1882, and lies buried in Westminster Abbey. Westminster Abbey.

Isn’t evolution just a theory?Isn’t evolution just a theory?  In science, a theory is a rigorously tested statement of In science, a theory is a rigorously tested statement of

general principles that explains observable and general principles that explains observable and recorded aspects of the world. A scientific theory recorded aspects of the world. A scientific theory therefore describes a higher level of understanding therefore describes a higher level of understanding that ties "facts" together. A scientific theory stands that ties "facts" together. A scientific theory stands until proven wrong -- it is never proven correct. The until proven wrong -- it is never proven correct. The Darwinian theory of evolution has withstood the test Darwinian theory of evolution has withstood the test of time and thousands of scientific experiments; of time and thousands of scientific experiments; nothing has disproved it since Darwin first proposed nothing has disproved it since Darwin first proposed it more than 150 years ago. Indeed, many scientific it more than 150 years ago. Indeed, many scientific advances, in a range of scientific disciplines advances, in a range of scientific disciplines including physics, geology, chemistry, and including physics, geology, chemistry, and molecular biology, have supported, refined, and molecular biology, have supported, refined, and expanded evolutionary theory far beyond anything expanded evolutionary theory far beyond anything Darwin could have imagined.Darwin could have imagined.

http://www.pbs.org/wgbh/evolution/library/faq/cat01.html#Q01http://www.pbs.org/wgbh/evolution/library/faq/cat01.html#Q01

Influential ScientistsInfluential Scientists• Darwin’s Cambridge ProfessorDarwin’s Cambridge Professor

• Charles Lyell, a contemporary geologist Charles Lyell, a contemporary geologist

- wrote - wrote Principles of GeologyPrinciples of Geology

• Jean Lamarck, proposed theory of Jean Lamarck, proposed theory of evolution in 1801 evolution in 1801

• Alfred Wallace, made similar Alfred Wallace, made similar observations and conclusions about the observations and conclusions about the process behind evolution shortly before process behind evolution shortly before Darwin published his bookDarwin published his book

Why is the theory of evolution Why is the theory of evolution important to the study of important to the study of biology?biology?

How did Darwin influence other How did Darwin influence other scientists and does he still scientists and does he still influence scientists today?influence scientists today?