9/9/14 Chapter 3: Biological Evolution ● Evolution: any continuous, unidirectional change. ○ organic evolution: life is descended from preexisting life ● 1859: Charles Darwin: Origin of Species ○ revelating date in intellectual history ● Before 1859: all species created thousands of years ago, unchanged ● After 1859: species are dynamic entities, adapting to changing environments through geologic time, all life forms are related; humans belong to the animal kingdom ● What is species? ○ latin: a kind of thing ○ generic nouns (grass, worm, snake) apply to categories of plants and animals ○ human language use words words to represent individual species that are edible, dangerous, useful, or conspicuous ○ allo > foreign ○ sym > together ○ patric > country ○ 16501730: Debate on Mutable vs. Fixed Nature of Species ■ mutability > changability ● Species real? ○ is the nature of a species fixed? ● Linnaeus 1758 ○ By 1730, debate was settled ■ species are real, fixed, numerous ○ Treated species as unitary, real, distinct ○ established modern zoological classification ■ hierarchical arrangement of species into groups ○ Founder of Taxonomy ■ Science of classification ■ description, illustration, identification, naming ■ studies evolutionary relationships of a group of organisms ● Species ○ “A species is a group of naturally occurring, interbreeding populations, which is reproductively isolated from other such populations.” ○ Real, not manmade concept ■ exist in nature ■ population not individuals ○ every species is genetically unique and distinct ○ species is a basic working unit ○ Species > genus > family > order > class > phylum > kingdom > domain ○ Phylogeny ■ phylum > branch ■ geny > origin ■ theory about evolutionary descent ○ a classification is revised whenever something new is discovered ○ genus ■ group of closely related species ○ species are real but classification is subjective ● Kingdoms? ○ Kingdom Animalia ■ ingestive multicellular eucaryotes ○ Kingdom Plantae ■ photosynthetic multicellular eucaryotes ○ Kingdom Protista ■ unicellular eucaryotes ○ Kingdom Fungi ■ absorptive, syncytial eucaryotes ○ Kindgom Monera ■ Procaryotes (bacteria) ● Prokaryote ○ small cells ○ DNA throughout cell ○ no nucleus ○ no mitosis, meiosis ○ no sexual reproduction ● Eukaryote: ○ large cell ○ DNA in chromosome in nucleus ○ mitochondria ○ mitosis, meiosis ○ sexual reproduction ● Domain archaea (archaebacteria) ○ prokaryotes, small, primitive anaerobic bacteria ○ live in extreme environment and deep within Earth ● Domain Eubacteria (monera) ○ prokaryotes, sophisticated, diverse bacteria ○ live in broad range of surface environments ● Domain Eukaryota ○ Kingdom Protista ○ Kingdom Plantae ○ Kingdom Animalia ○ Kingdom Fungi ● Georges, Comte de Buffon ○ first to define species ○ preset forms of life evolved from fewer forms ● Erasmus Darwin ○ Grandfather of Charles Darwin ○ Ontogeny ● Lamarck 1809 ○ greatest French Naturalist ○ first classification for invertebrate animals ○ progressionism: comprehensive philosophy of universe ○ proposed term, biology ● Inheritience of acquired characteristics ○ wrong but accepted ● August Weissmann 1900 ○ showed why the acquired characteristics was not possible ● Weissmann’s Law: changes to parental body do not affect inheritance ● Lamarck ○ first complete evolutionary theory ○ new species emerge by spontaneous generation ○ no organisms ever become extinct ■ fossil record shows the continuity of life ● Georges Cuvier opposed Lamarck’s ideas ○ founder of Catastrophism ○ dissected mummies of cats and ibis from Egyptian tombs ○ insisted on abrupt changes in world faunas ● Charles Darwin ○ Cambridge ○ opportunity to study continents and be the first geologist/biologist ○ observe, collect, make interpretations ○ fantastic diversity in rain forrest ○ european forest two species ○ stable population ○ species are not evenly distributed ■