Early Ideas About Evolution What ideas did Darwin use to develop his theory of evolution?

What is evolution? Process of biological change where descendants look different than their ancestors Darwin considered the “father of evolution” Theories existed 100’s of years before Darwin

Early Scientists Linnaeus – developed a classification system and observed that some organisms are hybrids Buffon – proposed that species share ancestors Erasmus Darwin – proposed more complex forms arose from less complex forms

Early Scientists Lamarck – proposed that changes in an environment caused resulting physical changes – inheritance of acquired traits (NOT ACCEPTED TODAY) Example – giraffe neck

Theories of Geologic Change Age of the Earth Fossils in lower layers of Earth are older than fossils higher up Changes in Earth’s landforms take place over a long period of time

Evidence of Evolution Anatomy Homologous Structures – features similar in structure but in different organisms with different functions

Evidence of Evolution Anatomy Analogous Structures – structures that perform a similar function but have different structures

Evidence of Evolution Anatomy Vestigial Structures – remnants of organs or structures that had a function in ancestors

Evidence of Evolution Fossil sequences show changes in organisms over time Geography – correlation between mainland species and island species

Evidence of Evolution Embryology – similarities between young in early stages of life