SCIENTISTS OF EVOLUTIONAND 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 name2. 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:1. Bacteria2. Archaea3. Eukarya

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:1. Protista2. Fungi3. Plantae4. Animalia

•No peptidoglycan in cells•DNA with histone proteins