Evolution

Evolution: A change in the frequency a trait/gene in a population over many generations.

Misconceptions about evolution “I don’t believe in Evolution because it is only a theory” “If people evolved from apes then why are there still apes!” “Humans are more evolved (i.e. better)

Grandaddy? 40,000,000 years removed, maybe.

Misconceptions about evolution “Evolution happened a really, really, really long time ago.” “Evolution takes like millions of years” “If you believe in evolution then you must be an atheist!”

Misconceptions about evolution “Evolution must have an intelligent designer (i.e. a creator).” “Organisms adapt to their environment.” “Species evolve to better survive.”

Questions Evolution is a change in the (a)_______ of a (b)_____ over many (c)_______. Chimpanzees and humans are very similar because they share a (d)___ ____. What evolves? (e) __ or ___. Organisms reflect (f) ____to their environment. Bacteria evolve very quickly when they become (g) ____ ____. Belief in God depends on (h) ____ while understanding evolution depends on (i) ___.

Theory of Evolution: Define evolution- A change in the frequency of a gene/trait in a population over many generations (individuals cannot adapt or evolve!) Review: population = a group of organisms of the same species who appear similar and can interbreed

What is the theory? populations change traits! Changes reflect adaptation to the environment New species have evolved from pre-existing species (i.e. speciation) to create Earth’s biodiversity All living things are descendant from a universal common ancestor

An early theory on evolution (WRONG! Mostly?) Jean-Baptiste Lamarck: a. The Theory of Use and Disuse- “organisms develop traits needed to survive” “ traits not used disappear” b. The Inheritance of Acquired Characteristics- “ traits that parents acquire in their lives will be passed on to their offspring”

August Weismann Disproved Lamarck’s theory on The Inheritance of Acquired Characteristics Cut the tails of many mice and bred them for many generations All the offspring always had tails! Duh! Why?

Laetoli footprints

Horse evolution horse poster is it true?

Homologous Structures (same structure/different function)

Analagous Structures

Vestigial Structures (relic from past,no current function)

Comparative Embryology

Fossil Distribution

State 3 facts that scientists use to support the idea of evolution. A time-line of evolution and extinction is preserved and apparent in the _______ record. All organisms are chemically similar and the more similar they are the more recently they shared a _____ ______. All organisms are made from _____ which are basically all the same in structure and function.

State 3 facts that scientists use to support the idea of evolution. Comparative anatomy has unveiled that many organisms share ____ , ____, and ____ body parts that reflect descent with modification. Vertebrates share a common evolutionary history evident in our ____ slits, a postanal ___, and a ___ sac. Species distributed over a large _____ will show variation according to climate and environment.

The best evidence for Natural Selection is… Artificial Selection- when humans selectively breed animals and plants to create new and desired phenotypes.