Quick Notes Bio2

Quick Notes Bio2 - Lecture 6 Systematics o The study of the...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 6 Systematics o The study of the diversity of organisms o Goals Identification and classification Nomenclature Phylogeny Categories > level or rank in a classification Taxa > group of organisms sufficiently distinct from other groups to warrant a name Homology > similarity due to common ancestry Homoplasy > similarity due to convergence or reversal Homologous characters > shared ancestral and shared derived character state (sympleisiomorphy and synapomorphy) Two types of homology > symplesiomorphy and synapomorphy Synapomorphies > tells us about the modification of characters and do allow us to distinguish one group that has the modification from another group that does not > scales in lizards, snakes/dinosaurs/(birds) Sympleisomorpheis > tell us about character state before modification, do not allow us to separate descendant taxa into distinct groups Autapomorphy > unique derived character state Cladograms > hypothesis of the origin of derived character states Passer is a genus of Old World sparrows. Monophyletic > the set of all known descendants form a single common ancestor > birds, beetles, and flowering plants Polyphyletic > includes unrelated lineages that are more closely related to species that are placed in other taxa > fish and whale Paraphyletic > group that is monophyletic except that some descendants of the common ancestor have been placed in other taxa Pongidae > Great Apes > orangutans, gorillas, and chimpanzees Family Hominidae includes gorilla, chimps, and humans. Subfamily homininae includes African apes and humans, and the tribe Homini designates a clade consisting of homo sapiens and their realtives
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Evidence of evolution > hierarchial organization of life, homology, embryological similarities, vestigal characters, convergence, suboptimal design, geographic distributions, intermediate forms Homologous characters > which have been inherited from an equivalent organ in the common ancestor > The wings of birds, bats, and pterodactyls are modified forelimbs > middle ear bones of mammals evolved form jaw ones of reptiles Hind limbs > adapted for swimming and flying Nectar feeding birds > homoplasious features > long, thin beak (can reach nectar) > mimicry Humans > primitive (five digits on hand and feet, teeth in lower jaw) > advanced (single lower jaw bone) Adaptive radiation > most common pattern of long-term evolution > Darwin’s finches > fruit flies and silverswords in Hawaiian islands > cichlid fishes in Africa Wing patterns of butterflies > convergent change Lecture 7 Important characteristics for data in phylogenetics o Large number of characters with easily recognized character states o Consistent rules for character state changes o Distinct classes of characters with different rates of change Nucleotide substituitions o Transition and transversions o For protein coding genes, rates depend on codon position (synonymous and non synonymous substituions o Rates of substitution in different parts of genes and in pseudo genes
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 10

Quick Notes Bio2 - Lecture 6 Systematics o The study of the...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online