Genbio Notes PDF

**Villasin, Jann Eurhee Genbio Notes** **Evolution** - the process by which different kinds of living organisms are thought to have developed and diversified. **Mechanisms of Change** **Artificial Selection -** A process where humans breed organisms for specific traits. \- Selective breeding in...

**Villasin, Jann Eurhee Genbio Notes** **Evolution** - the process by which different kinds of living organisms are thought to have developed and diversified. **Mechanisms of Change** **Artificial Selection -** A process where humans breed organisms for specific traits. \- Selective breeding in dogs or agricultural crops **Natural Selection -** where organisms with traits better suited to their surroundings are more likely to survive. -Peppered Moth changing into a more darker color to deceive predators. **Genetic Drift -** a random change in allele frequencies in a population. **Bottleneck Effect -** a natural disaster drastically reduces population size and diversity. **Founder Effect -** a small group of individuals starts a new population. **Mutation -** random changes in DNA that can create new traits. **Sickle Cell trait -** resistant to malaria, change in hemoglobin gene. **Recombination** - process where sexual reproduction where chromosomes exchange genetic material, leading to new combinations of genes. **Patterns of Descent with Modification** **Tree of life -** shows different life forms diverging over time. **Descent with Modification -** accumulation of small changes over many generations that produce variations among species. **Homologous Structures** - body parts have similar structure indicating a common ancestor. **Austria's Marsupials -** most mammals in Australia are marsupials, which carry their young in a pouch. **Speciation -** lineage-splitting event that produces two or more separate species. **Allopatric Speciation -** allo -"other place" isolated in an other place. **Peripatric Speciation -** peri - "near", small groups of individuals break off from a larger group. **Parapatric Speciation -** patric - "place", para - "beside" individuals are beside each other **Sympatric Speciation -** sym- "same" all individuals live in the same place **Reproductive Isolation** **Geographic isolation -** separated by geographc barriers. **Behavioral isolation -** separated by mating calls, physical traits, or mating dances **Temporal isolation -** separated by time, like nocturnal, diurnal, seasons, or months. **The Precambrian** **Precambrian -** Age of early life, covers 88% of Earth's history \- formation 4.54 billion years ago to the Cambrian, about 542 million years ago. **Hadean Eon -** 4.6 billion years ago \- Rocks that form from cooling lava were buried under new flows. **Archean Eon -** means "Ancient" or "Primitive", began about a billion years after Earth's formation. **Proterozoic Era -** Longest geologic eon \- The Great Oxygenation Event was one of the defining transformations of the Proterozoic. **Key Geological Events** **Hadean -** Formation of Earth and Moon \- Differentiation of Earth's layers **Archean -** Formation of first stable crust \- Formation of first oceans \- Emergence of life **Proterozoic -** The Great Oxygenation Event \- Formation of supercontinents \- Snowball Earth glaciations **Evolution of Life** **Hadean -** Possibility of early life, formation of prebiotic molecules **Archean -** Development of photosynthesis, Diversificiation of life **Proterozoic -** Increase in oxygen levels, development of multicellular life **Cambrian and Ordovician Periods** **- Cambrian Period a.k.a. Cambrian Explosion** **Key Geological Events during the Cambrian Period** **- Rising Sea Levels, Oxygenation events, Breakup of supercontinents** **Key Geological Events during the Ordovician Period** **- Continental drift, Sea Level Changes, Climate and Glaciation** **The Paleozoic Era : Silurian and Devonian Periods** **Precambrian, Paleozoic, Mesozoic, and Cenozoic - four main eras** **Key Geological Events** **-Supercontinent Formation** **- High Sea Levels** **- Orgenesis** **Supercontinent(s)** **Silurian Period - Gondwana(South)** **Devonian Period - Laurentia & Baltica = Euramerica** **-During this era, there were a variety of new fish species.** **Carboniferous and Permian Periods** **Carboniferous Period -** vast swamp forests "Carbon - bearing" **Key Geological Events** **Formation of Coal Swamps -** extensive tropical forests created significant coal deposits **Shallow Seas -** covered large land areas **Mountain building -** early phases of the Appalachian mountains formed due to continental collision. **Shift in Climate -** transition from warm, humid conditions to cooler, drier periods towards the end. **Mesozoic Era** **-Age of Reptiles** **-252.2 Million years ago and ended 66 million years ago** **Triassic Period -** marked the beginning of the age of dinosaurs and the recovery f life after the Permian-Triassic extinction event. **-Pangaea supercontinent was formed surrounded by the ocean Panthalassa.** **- Triassic-Jurassic extinction event, around 201 million years ago, resulted in the loss of many large amphibians and other species, allowing dinosaurs to dominate the Jurassic period.** **Cretaceous Period -** dominance of dinosaurs on land along with angiosperms(first flowering plants) -Tithonian-early Barrermian Cool interval(TBCI) began 150 MYA -**The Cretaceous period ended when a large asteroid impacting off the coast of mexico which altered the planet's climate** **Cenozoic Era** **-Age of Mammals** **-Intoduced by English Geologist Hong Phullips in 1840. (Kainozoic)** **-Quaternary period is the current geological era, began 2.58 MYA until the present day.** **-Neogene marked the diversification of mammals and birds.** **-Paleogene marked the evolution of mammals and birds.**