Biology Notes Evolution Part 3 Pages 320 363

Biology Notes Evolution Part 3 Pages 320 -363

Standards 6. 7 Describe the scientific explanations of the ____ origin of life on Earth 6. 8 Explain the evidence supporting the ____ scientific theory of the origin of eukaryotic cells (endosymbiosis) 6. 14 ____ Identify basic trends in hominid evolution from early ancestors six million years ago to modern humans, including brain size, jaw size, language, and manufacture of tools

Essential Questions: 1. How does science help us explain how all life, including us, came to be? 2. How does the evidence used to support evolution help us connect past life forms to those living today?

I. Evidence of Evolution One of the oldest questions scientists have is how ____ life on Earth began. ____ provide the Fossils majority of evidence for the ______ of life on origin Earth. sedimentary • Remember, fossils are formed in ______ rock index fossils or • Scientists can use ___________ radioactive decay to date the fossils and gain old the Earth is as an estimate of exactly how ____ well as when certain _____ organisms existed

• index fossils = distinct fossils with a known compare to fossils date of existence used to _____ with an unknown date of existence

• radioactive decay = calculating the age of a radioactive sample based on the amount of ______ isotopes found within that sample fossils scientists • Through the discovery of _______, Geological time were able to construct a ______ scale which divides Earth’s history into major eras and ____ periods _____

II. The Origin of Life: Fact vs. Fiction A. Spontaneous Generation Hypothesis = the hypothesis that _______ matter could arrive from non -living matter • Generally this idea was accepted until _____ 1668 Redi performed his meat and when Francesco _____ fly experiment flies came from ____ maggots and v concluded that ____ were not spontaneously generated v summarizes his findings with theory that life can only come from other life ____

B. Organic Molecule Hypothesis • The Earth is believed to be ____ 4. 6 billion years cosmic old caused by a giant “collision” of _______ particles Big Bang Theory v elements within this cosmic debris settled density which formed the according to their _______ core parts of the Earth and its atmosphere v during this time, the Earth’s atmosphere was very unstable and contained very little _______ oxygen CO _____, CO 2 ___, N 2 ____, HS and Ø mostly there was ____, ______ water (vapor)

3. 8 billion years ago, scientists believe • ____ conditions occurred that allowed the Earth’s surface to cool large formations of ______ water to sedimentary rocks date appear (the earliest ______ back to this time) • water is crucial to life because it is needed to make life’s _____ essential organic molecules ** lipids, carbohydrates, nucleotides, proteins

Miller and Harold ______ Urey • In 1953, Stanley ______ tried to recreate Earth’s early atmosphere to see how the evolution of organic molecules could occur v Miller and Urey were successful in producing amino acids which showed that ____ organic _______ inorganic molecules can arise from _____

C. Meteorite Hypothesis Australia In 1969, a meteorite that fell in _____ amino acids, so perhaps organic contained ______ always existed molecules have _______

III. Milestones in the Formation of Life on Earth 3. 8 BYA = water formation; formation of many • ____ essential molecules of life’s _____ 3. 8 -2. 5 BYA = proteinoid microspheres • _______ DNA evolves from RNA (hypothetical) appear; _____ membranes are observed in these • the first ______ microspheres

3. 5 BYA = prokaryotic microfossils appear • ____ (fossil evidence) 2 BYA = Earth’s atmosphere becomes • ____ oxygenated (due to _______ photosynthesis ) ______ cellular respiration to occur • this allows for _______ 1. 5 BYA = prokaryotes develop internal • ___ eukaryotes membranes; rise of ______

Ø endosymbiotic theory = theory that states eukaryotic cells are formed from how ___________ prokaryotic organisms living together 1960’s • this is given critical support in the _______ chloroplast when Lynn Margulis compared ______ prokaryotes and mitochondria to free living ______

eukaryotic organisms appeared, • once _____ scientists believe the process of _______ sexual reproduction 254 MYA = Paleozoic ____ era shows first multi • ____ organisms followed by _____ Mesozoic cellular ______ Cenozoic era (see Geologic and finally the _____ time scale)

IV. Hominid Evolution History and fossil evidence indicates that the ____ hominid line of primates appeared 6 to __ 7 million years ago approximately __ • Primates are a class of organisms that have vision a well developed _____, brain binocular ______, relatively long _______ fingers and toes, as well as rotate arms that can ______ walk • Hominids are classified by their ability to _____ bipedal have an _____ opposable thumb, upright (_______), cerebrum and have developmentally larger _____

Major Hominid Milestones: v Genus Australopithecus 3. 8 -3. 6 mya: earliest known hominid divergence; walk bipodal; evidence _____ Lucy v Homo habilis 2. 5 mya: first use of tools _____ man (handy ____)

v. Homo erectus 1. 75 mya: largercerebrum ____; nostrils believed to have downward facing ____; originated in Africa and migrated to the Middle East v Homo neanderthalensis 500, 000 years ago: Germany evidence of living originating out of _____; groups in social _______ v Homo sapiens 100, 000 years ago: originating out of Middle East and Africa; body like that of humans modern ____

evolution has been strongly influenced Human _____ by culture. Instances include larger brains with smaller jaw lines which allowed capabilities of complex languages. The ability to walk more _____ upright and opposable thumbs led to tools increasingly sophisticated use of ______. Australopithecus afarensis Homo habilis Homo neanderthalensis Homo sapiens