SCIENTISTS OF EVOLUTION AND TAXONOMY

Carl von Linne (Linnaeus, 1707-1778) Swedish botanist Invented system for naming, ranking and classifying organisms 1st to group similar organisms and assign them Latin names Two word name known as Binomial nomenclature “Father of Taxonomy”

Thomas Malthus (1766-1834) British economist Studied how populations of organisms grow geometrically until reaching inevitable limit Limiting resources: Food Living space Mates

Charles Lyell (1797-1875) Proposed theory of Uniformitarianism Geological processes work at uniform rates building and wearing down Earth’s crust Proposed that the Earth was millions of years old instead of a few thousand

Gregor Mendel (1822-1884) Austrian monk Experimented on pea plants to develop a theory of genetics Explained how hereditary traits are transferred from parent to offspring

Jean-Baptiste de Lamarck (1744-1829) French scientist who published his own theory of evolution Believed more complex organisms evolved from simpler ones Theory of “use and disuse” – more used body parts develop while unused parts grow weak Inheritance of Acquired Traits – traits acquired during an organisms lifetime would be passed on to offspring

Charles Darwin (1809-1882) British naturalist Developed modern concept of evolution Process of natural selection – explain species descend from common ancestor “Survival of the Fittest”

Alfred Russel Wallace (1823-1913) British biologist Co-developer of the theory of evolution Expert on geographical distribution of animal species Idea of “warning coloration” – bright or unusual coloring protects species by warning predators

Darwin vs. Lamarck Lamarck: Theory of Inheritance of Acquired Characteristics – change in organism during lifetime will be passed on to offspring Change in organism determined by what they want or need Darwin: Helpful traits passed on from parent to offspring aid in survival Organisms better suited for a specific environment tend to survive and reproduce Agreed: Life changed gradually over time and was still developing Living things change to better adapt to their environment Life evolved from less complex organisms

Classifying Organisms Taxonomy – system used for classifying organisms, developed by Linnaeus Species assigned a name consisting of two parts: 1. Species name 2. Genus name EX. Homo (genus) sapien (species) Broader classification from more general to specific: Domain -> Kingdom-> Phylum-> Class-> Order-> Family-> Genus-> Species

Three Domain System Based on differences in DNA structure or evolutionary relationships (phylogeny) Systematics: study of taxonomy focusing on evolutionary outcomes and tracing the ancestors of organisms The three domains are: Bacteria Archaea Eukarya

Domain Bacteria All single-celled prokaryotes Cell walls of most are thick and rigid; made of peptidoglycan Able to grow and reproduce very rapidly Many are disease causing Play important role in the decomposition of dead organic matter

Domain Archaea All are single-celled prokaryotes Cell walls made of polysaccharides DNA with histone proteins Considered “extremophiles” – live in extreme environments such as geysers, hot springs, salt lakes

Domain Eukarya All are eukaryotes and includes kingdoms: Protista Fungi Plantae Animalia No peptidoglycan in cells DNA with histone proteins