BIOL 1108 Edition 1nd Lecture 3 Outline of Last Lecture I In the News Why have Liberian riot police and soldiers used scrap wood and barbed wire to seal off 50 000 people inside the West Point slum in the capital city of Monrovia II Scientific Theories A Jan Baptista van Helmont B Francesco Redi III The earliest living entities on Earth utilized a simpler type of biochemistry than do today s cells A Protocell B RNA molecule IV Last Universal Common Ancestor A Symbiosis living together B Bacterial Gene Exchange Transformation Transduction Conjugation V Evolution is random A Evolution is the product of two opposing forces Random These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Non random Outline of Current Lecture I In the News II Gene Duplication and Divergence A Genetics B Hemoglobin C Types Subfunctionalization Pseudogenes and Neofunctionalization III Do monotremes and marsupials have the genes for fetal hemoglobin IV Extinction A Causes B Mass Extinctions V Evolution A Macro vs Micro B Species C Types of Speciation Current Lecture I II In the News Why were authorities handing out bottled water in Toledo Ohio in early August of 2014 A An algea bloom of mircocystis aeruginosa spread in Lake Erie and contaminated Ohio s water supply The cyanobacteria is toxic and can cause multiple organ failure neurological deficits Gene Duplication and Divergence A Genetics If two copies of the same gene exist then one can be changed and mutated without affecting the function of the other There is overwhelming evidence of multiple genes parts of chromosomes even entire genomes having undergone duplication This allows one gene to undergo undirected mutation while the other functional copy remains unchanged B Hemoglobin The globin gene family has been studied extensively and shows the remarkable relationship between gene duplication divergence and the evolution of proteins with new functions Fetal hemoglobin has a higher affinity for oxygen than does maternal hemoglobin A necessary thing for placental mammals C Types of gene divergence Major source of gene variability Subfunctionalization partial loss of gene function Pseudogenes degeneration Neofunctionalization give rise to modified or new functions III IV V Do monotremes and marsupials have the genes for fetal hemoglobin The earliest placental mammals must have had a gene for a globin protein that was similar to the fetal sub unit globin Duplication of globin genes is widespread among the mammals and can be used to infer their evolutionary history This is known as a phylogenetic approach Extinction A Causes The primary cause of species extinction is An environment that changes too quickly with too little genetic diversity in a population to keep up with the change Extinction correlates with environmental change Gradual environmental change evolution Rapid environmental change extinction B Mass Extinctions The extinction of a large number of species within a relatively short period of geological time 1 End Ordovician 439 mya 2 Late Devonian 367 mya 3 End Permian 245 mya 4 End Triassic 208 mya 5 End Cretaceous 65 mya Must be 75 extinct to be considered Evolution A Macro vs Micro Macroevolution any evolutionary change at or above the level of species Microevolution any evolutionary change below the level of species Macroevolution is thought to be the combined effects of micro evolutionary processes Accumulated genetic changes can result in existing genes or structures becoming modified into new structures e g scales into feathers In this way new functions arise and can be selected for B Species is a taxonomic category just like genus and family to describe the biological cohesiveness and relatedness of the members of that group A group of populations whose members have the potential to interbreed with one another to produce fertile offspring C Types of Speciation Allopatric speciation A physical geographic barrier that prevents interbreeding and leads to genetic isolation Sympatric speciation Genetic isolation occurs within a population despite the lack of a physical barrier