BioeeOctober18 - and migrate iii Parapatric Divisions of...

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Bioee October 18, 2007 I. Five Examples of How We Think of SModespecies a. Biologically isolated b. Evolutionary species concept- different tracts on evolutionary tree c. Numerical or phenetic taxonomy- taking characters into account, if X% different, new species d. Phylogenetic Systematics (cladism) similar to number two but not tied to evolution e. Species recognition concept- different sounds, looks, actions, species recognize each other II. The Great Problem: Universal Species Definition a. “Species” category is generally not helpful to speciation b. However, species are helpful to systematics and constructing phylogenies c. Because species definitions do not agree: i. Must look at each group or organisms in a special way ii. Species defined by systematisists agree in large part with species defined by natives III. Speciation a. Modes i. Allopatric: Species become different species from living apart; geographic isolation ii. Peripatric: Migration means; pregnant females take part of genome
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Unformatted text preview: and migrate iii. Parapatric: Divisions of population by mountains/rivers/ext coming up and separating species iv. Sympatric: Division of species in the same area v. Hybrid speciation: mostly in plants b. Reproductive isolation i. Reproductive isolation and phenotypic differentiation are not highly correlated ii. Speciation is hard to observe 1. Not clear when it is happening 2. Sometimes it takes a long time relative to the life of humans 3. One has to know everything about the groups 4. How can you do it? a. Watch microorganisms! b. Biodiversity in sugar water c. Within 5 days, bacteria had diversified into niches d. Bacterial resistance to antibiotics i. Best demonstration of natural selection c. With speciation, within a single genus, it may occur in one way between two species, and another way between two different ones...
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