BC: Simpson's Tree of Life :P
FC: Chapter 26: Phylogeny and the Tree of Life | By: Ricaely Ninobla Savanna Fastidio
1: Overview: Investigating the Tree of Life | How do biologists distinguish species on Earth? | Instead of focusing on evolutionary mechanisms, we will discuss its pattern (product) | Phylogeny: the evolutionary history of a species or group of species. | Systematics: a method of classifying organisms and determining their evolutionary relationships. (fossils, molecules, and genes are used to make the relationships in evolution; connect the dots so to say)
2: Phylogenies show evolutionary relationships | Taxonomy: the scientific discipline in which organisms are named and classified. | Taxon: a specific level of classification. | Binomial: a two part format of the scientific name; instituted in the 18th Century by Carolus Linnaeus.
3: Hierarchical Classification
4: PhyloCode: names groups that include a common ancestor and all of its descendants. | Phylogenetic Tree is an evolutionary history of a group of organisms. | Branch points represents two evolutionary lineages
5: Determining species and their relatives. Identifying genes. Tracing the source of bioterrorist attacks. | Uses of Phylogenetic Trees
6: Phylogenies Are Inferred From Morphological and Molecular Data. | Homologies: similarities due to shared ancestry. | Organisms that share similar morphologies (similar DNA sequences) are more closely related than organisms with similar phenotypes. | Analogy: similar phylogeny due to convergent evolution. | Homoplasies: analogous structures that arose independently. | Molecular systematics: process that uses DNA to determine evolutionary relationships.
7: Shared Characteristics are used to Construct Phylogenetic Trees | Scientists begin to classify an organism by separating analogous and homologous features. | They then decide which cladistics (sytematics strictly using common ancestry) they will use, which puts the species into clades. Clades is equivalent to a Monophyletic group. There are three group types: monophyletic, paraphyletic, polyphyletic | Shared characteristics are how clades are identified. There are two types: shared ancestral and shared derived.
8: Polyphyletic Group: Group containing descendants with similar traits but no recent common ancestor. | Monophyletic Group: Group containing an ancestor and all of its descendants. | Paraphyletic Group: Group containing an ancestor but not All of its descendants.
9: Shared ancestral character: a character that originated in an ancestor of the taxon/clade. | Shared derived character: an evolutionary novelty unique to a particular clade.
10: Comparing members of ingroups to outgroups helps determine which characters were derived at the various branch points of evolution. | Outgroup: species or group of species closely related to but not included within a taxon. | Ingroup: species being studied.
11: Applying maximum parsimony and maximum likelihood can narrow possibilities to make a more accurate phylogenetic tree. | Maximum parsimony: always investigate/use the simplest explanation that is consistent with the facts. | Maximum likelihood: always take into account the hypothesis that reflects the most likely sequence of evolutionary events. | Phylogenetic bracketing: predicting that two groups of organisms is present in their common ancestor and all of its descendants.
12: An Organism's Evolutionary History is Documented in its Genome. | Orthologous genes: homologous gene that is found in different species due to speciation | Paralogous genes: result from gene duplication, so they are found in more than one copy in the same genome.
13: Molecular Clocks Help Track Evolutionary Time | Researchers estimate the number of genetic differences with molecular clocks. | Molecular Clock: a yardstick for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates.