Aim: How do scientists explain how organisms have changed from simple to more complex orgainisms? Evolution 1

First organism on Earth simple unicellular organisms Anaerobic heterotrophs The first organisms on earth were _______________________. prokaryote cells

How do scientists explain this change from simple to more complex organisms? Theory of Evolution The process by which species ________ over time (simple to complex). Present day species are ______ to ancient species. change related

What is a theory? Theory of Evolution Is an explanation, supported by __________ and/or____________ , that can be used to explain related occurrences. observations experiments

What is the evidence that supports the Theory of Evolution? ______________ collection of fossils that provides _______ to the history of Earth’s organisms. The fossil record spans much of _____________ (billions of years of Earth’s history). Comparitive ______________ Comparative Embryology(_____________) 4)Comparative Biochemistry (_________________) Fossil Record- clues geologic time Structure similar embyos DNA & Proteins

Embryology Anatomy

Amino Acid Sequence DNA Sequence

How do we know that we have evolved from ancestors distinctly different from us? The fossil record (remains of dead organisms) have given scientists the ______ they needed to determine an organisms ________ by ___________ them to present day species. clues ancestry FOSSILS comparing

The fossil record shows… simple Life has evolved from _______ to more _____________ complex Newer Organisms: more complex Older Organisms: more simplistic

What do we learn from fossils? http://www.pbs.org/wgbh/evolution/educators/teachstuds/svideos.html How did ___________ evolve? How long did individuals _____? How do ________ evolve over time? behaviors live features http://www.ucmp.berkeley.edu/education/explorations/tours/stories/middle/C7a.html

Speciation Evolution has lead to the formation of _____ species from _________ ancient organisms new different Species- a group of organisms that share certain ______________ & can _____ with one another, producing __________ offspring. characteristics mate fertile

Similar to a family tree Descendents Descendents Common Ancestor

Evolutionary Tree Species living at ______ time (top) present Ancestral _________ species (bottom) common

100’s of Millions of year ago Our Common Ancestor Unicellular Common Ancestor 100’s of Millions of year ago

How closely related are they? Which organisms are closely related? Those who have a _______ common ancestor (a ______ point of intersection in a tree diagram) Which are distant relatives? Those who have a _________ common ancestor (a _____ point of intersection in a tree diagram) recent distant close far

Summary of early evolution Present day