ECOL 485 Lecture Notes - Lecture 10: Shoulder Girdle, Laurasiatheria, Euarchontoglires
1 Oct 2018
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Document Summary
Convergent evolution: 2 not so similar mammals that share a common ancestor. Construction phylogenies; insights on how taxa should be grouped. Character states- heritable states that can be measured by the history of the organisms. Identify shared derived characteristics by only descendants of a particular clade= synapomorphies. Out groups- looking at a related group, but not closely related group. Evaluate hypothesis- map order character states evolved. George simpson- major influence on organization of classification of mammalian orders. Young hatch from eggs (most notable reptilian like feature) Lower body temperature (about 32 degrees c) Chain of at least 9 sex chromosomes- sex determination isn"t well understood. Lack teets- milk drains from mammary glands and milk comes out of pores. Occupied niches with little to no competition. Sensory perception, generation of motor commands, spatial reasoning, conscious thought, in humans- language. Usually not present, but it is not formed in the tympanic bone. Jugal and dentary do not articulate together.
