Ch 10 Principles of Evolution 10 1 Early

Ch 10 Principles of Evolution 10. 1 Early ideas about evolution • Scientists: – Carolus Linneaus: Swedish botanist, developed classification system (binomial nomenclature) for species – Georges Louis Leclerc de Buffon: French naturalist, suggested species shared ancestors, he and Charles Lyell suggested earth was much oder then 6000 yrs – Erasmus Darwin: Charles’ grandfather, English doctor/ poet, proposed living things from common ancestor

10. 1 cont’d – Jean-Baptiste Lamarck: French naturalist, proposed all organisms evolved towards perfection/ complexity b/c of change in enviro. • Leading up to Darwin’s theory – Georges Cuvier: French zoologist, fossils different in layers and catastrophism – James Hutton: Scottish geologist, proposed gradualism – Charles Lyell: English geologist, agreed and theory of uniformitarism

10. 2 Darwin’s observations • Island species differences – Variation was interspecific and intraspecific based on islands he visited – Galapagos Islands: tortoises (necks/ legs), finches (size beak) • Fossil/ geologic evidence – Giant armadillo fossils; suggested ancestor and earth older 6000 yrs – Marine fossils in mountains; volcanoes/ other activity changed land over time (gradualism)

10. 3 Theory of Natural Selection • Artificial selections- people make genetic diversity of plants/animals • Natural selection – Darwin- heredity; Malthus- struggle for survival/ competition • 4 principles of Natural Selection: – Variation: inherited/ mutations – Overproduction: many offspring= survival or compete – Adaptation: better suited for environment – Descent with modification: better trait passed on – “fitness”: ability to survive in environment/ adapt

10. 3 cont’d • Natural selection changes phenotypes not genotypes • Why evolve? – Changing environments: ex food/ finches – Not really ‘passed on’ over many generations, can be response to need in evnironment

10. 4 Evidence of Evolution • Evidence/ support – Fossils: age/ location/ environment when organism was alive; layers had oldest at bottom – Geography: Galapagos similar plants/ animals as S. America; distance from mainland, biogeography – Embryology: crab/ barnacles look alike as larva; embryos in verts. Look similar too – Anatomy: homologous structures (forelimbs)- look same but have different functions; analogous structures (wings)- do the same function, but look very different; vestigial structures (ostrich/snake)- organs or structures had function for earlier ancestors

10. 5 Evolutionary Biology Today • Paleontology- fossils/ extinct organisms; NEW and lacked transitional fossils • Fossil/ anatomical evidence – DNA sequence analysis: nucleotides show closely related – Pseudogenes: no longer function but still in DNA (like vestigial organs) – Homeobox genes: control development of specific structures- links us back to common ancestor – Protein comparisons: molecular fingerprinting to show common cells and make ancestor connections • Evolution is in all biology fields!