Evolution Chapter 13. “ A change over time ”. http://www.youtube.com/watch?v=-FT3FU2XOgo http://www.hulu.com/watch/403434#details=expand. The Theory of Evolution. Evolution literally means to change over time.
EvolutionChapter 13 “A change over time”
http://www.youtube.com/watch?v=-FT3FU2XOgo • http://www.hulu.com/watch/403434#details=expand
The Theory of Evolution • Evolution literally means to change over time. • A theory is a well supported, testable explanation that observes observations from the natural world
Questions that evolution attempts to answer. • How do species adapt to changes in the environment? • How do new species develop?
Charles Darwin • 1809-1882 • Studied to be a doctor and a minister • 1831 sailed around the world as a naturalist on the HMS Beagle
James Hutton • Geologist • Proposed that the earth was millions of years old based on geologic evidence
Sir Charles Lyell • Geologist • Proposed that geologic changes occur slowly over long periods of time. • Darwin read his book, Principles of Geology, on the Beagle
Jean Baptiste Lamarck French Naturalist Published his ideas on evolution in 1809 in Philosophie zoologique
Lamarck’s Hypothesis Organisms Strive for Perfection – all individuals are trying to better themselves
Lamarck’s Hypothesis Use and Disuse – If an individual uses a trait it will be more useful If an individual does not use a trait it will decrease in usefulness
Lamarck’s Hypothesis Inheritance of Acquired characteristics
Analyzing Lamarck’s Hypothesis • There is no evidence to suggest that plants and animals are trying to improve themselves
Analyzing Lamarck’s Hypothesis • Use and disuse do not change all characteristics • Stretching will not make you taller • Reading will not make your eyesight better
Analyzing Lamarck’s Hypothesis • Acquired characteristics are not inherited • A mouse that loses its tail will still produce offspring with tails
Erasmus Darwin Charles Darwin’s Grandfather Physician and Scientist 'All vegetables and animals now living were originally derived from the smallest microscopic ones.'
Thomas Malthus – • Economist • Human Population would be limited • Starvation • War (Competition) • Disease
Alfred Wallace • Developed his own theory of Natural Selection • Contacted Darwin • This caused Darwin to finally publish his theory with Wallace
On Origins of Species • After publishing with Wallace, Darwin submitted all of his ideas in a book titled On Origin of Species, By Means of Natural Selection in 1858
Artificial Selection • Darwin was influenced to believe change was possible because of the humans selecting for traits in plants and animals.
Darwin’s Theory • Evolution “Change” is driven by natural selection
Variation • There are differences within a population • Mutation and Sexual Reproduction
Competition for resources • Not all offspring will survive • Starvation • Overcrowding • Predation
Fitness • Some of the variants will have an advantage over the others, they will survive and produce more offspring
Reproduction and Inheritance • These advantages will be passed on to the next generations
Descent with Modification • Species alive today are descended with modification from ancestral species
Tree of Life • All species are connected on a single tree of life
Modern Theory • Mendel’s discoveries in genetics explained a great deal in evolution
Evidence for Evolution • Fossil Record • Anatomy • Development • Molecular Evidence
Fossil Record • Since most of the “ancestor” species are extinct, fossils are the only evidence that can be examined. • Intermediate “missing link” fossils are very informative
Archaeopterix A fossil of a bird like creature Has feathers, teeth and claws in its wings
Whale Ancestors • http://www.youtube.com/watch?v=lx079oEgKKs
Anatomy Structures similarities in body structure indicates organisms are related
Homologous Structures Structures that have common function and design (ancestry)
Vestigial Organs Structures that have reduced size and or function http://www.youtube.com/watch?v=pbc7ee9u1JE
Developmental Evidence • Similarities in embryonic development are interpreted to mean closer relationships.