Evolution and Taxonomy Goals 3.05 and 4.01

Where did life come from? Abiogenesis –Life came from non-living material Biogenesis –Living things come other living things

The Beginning of Life Early Earth: – No oxygen –Primordial soup Abiogenesis had to happen once – Oparin Believed that at high temperatures and with electrical charge the early gases could form simple organic compounds Oxygen

Miller & Urey

First cells Organic compounds came together to form prokaryotic cells that were anaerobic –Did not use oxygen – Why? –There was no oxygen on primitive Earth –Plants had not yet evolved

First Prokaryotic Cells in the Primordial Soup Prokaryotic cells were undergoing Natural Selection –They were eating each other –Survival of the Fittest One way to be more fit if you are small is to live in larger prokaryotic cells –Endo (In) –symbiotic (both benefit)

Endosymbiosis One prokaryotic cell engulfs another Example Mitochondria in a cell –Mitochondria get protection from larger cell –Larger cell gets energy from mitochondria Evidence: Mitochondria and chloroplast –Have own DNA –Can divide on own

Evidence for Evolution Biochemical similarities Use differences in DNA to show relationships –Few differences = Groups split more recently in time –More differences = groups split farther back in time Fossils Show evolutionary history – Oldest fossils on bottom – Youngest fossils on top

Embryology The study of the embryonic states of different organisms –Look for the similarities –Shows that they have a common ancestor

Homologous and Analogous Structures Homologous structures are similar in structure but different in function –Example – Human are and bat wing Analogous structures are similar in function but different in structure –Example – Bat wing and insect wing

Charles Darwin Natural Selection –The most fit organisms survive Environment selects adaptations –Environment changes and puts pressure on the organism to change as well or die –The most fit to the change survive

Speciation – Making new species Geographic isolation –A physical barrier slits a population into 2 –Each population has it’s own adaptations –Over time they become so different they can no longer interbreed –Now have 2 distinct species

Antibacterial Resistance A mutation occurs, it happens to be resistant to the antibacterial soap Original population

The best fit survive and breed– Antibacterial resistant

Classification Organisms are classified into groups based on: – Phylogeny – How closely related organisms are – DNA – How similar the DNA is – Embryology – Embryotic similarities – Morphology – Structural similarities

Classification Least Specific Kingdom= King Phylum= Phillip Class= Came Order= Over Family= For Genus= Great Species = Spaghetti Most Specific Binomial nomenclature = Two names Genus species G enus is capitalized s pecies lowercase In italics or underlined Homo sapians

Phylogenetic Tree A tree showing the evolutionary relationships between species that have a common ancestor. Uses evidences for evolution

Dichotomous Keys A tool for identification of plants and animals. It is written as a sequence of paired questions (2) The questions are followed a name or identification is reached