Theory of evolution Evolution- process to explain change over time Theory-Well supported testable explanation

Many ideas were out there to explain how species change over time but the first published was  Charles Darwin in the H.M.S. Beagle traveled the world for 5 years to collect living plants and animals. During that time he made observations of both living and fossilized plants and animals Started to notice relationships among species  Most significant stop- the Galapagos Found many unique species similar but different then those of the mainland. Found differences between islands (future thought of relationship to common ancestor) Not until he returned to England and was cataloging his collection when he started to put his observations with facts together example birds and tortoises CAN SPECIES CHANGE OVER TIME? Patterns of diversity different animals on similar habitat fossils

Thinking of the times  The earth and all forms of life were created at one time and have remained so (no change over time)

Now that an idea was formed DARWIN had to collect evidence  For two decades Darwin worked and experimented and read and borrowed from Thomas Malthus. Hutton and Lyell provided evidence that the earth was still changing Lamarcks Evolution hypothesis Malthus idea was that human population grows faster than food supply  Darwin idea was that individuals struggle to compete in changing environmental conditions. Which individuals survive?

Orgion of species  Returned to England in 1836 published in 1859 why so long? Wallace also conceived of the theory of evolution forced Darwin to publish or lose notice for his life's work  Main idea species can be modified! Looked at artificial selection(wife's king Charles spaniel)Nature provides variation humans select

Natural selection  Survival of the fittest (easier to adapt to a new niche than compete) Mechanism for change in populations.  In Nature organisms produce more offspring than can survive  Due to independent assortment in any population individuals have variations  Individual with useful variations will survive  Over time offspring with certain variations make up most of the population and may look nothing like their ancestors Key words Fitness’-ability to survive and reproduce (sex and the single guppy) Adaptation-inherited characteristic that helps survival

Descent with modification  Over long periods specias no longer look similar  Implies (more important) all living organisms are related to one another.

Interpreting evidence after Darwin  Much data has been gathered but as Humans have only been here a short time and what happened before us is subject to interpretation.

Evidence for Evolution  Fossil record  Geographic distribution of living species  Structural adaptations Homologous structure Analogous structure Vestigial structure Embryology BIOTECNOLOGY

Homologous structure  Homologous structures, are characteristics which are shared by related species because they have been inherited in some way from a common ancestor.

 Analogous structures are features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature Analogous structurespecies

Similarities in Embryology

Vestigial organs