Species as units: Taxonomy - Millersville...
Transcript of Species as units: Taxonomy - Millersville...
![Page 1: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/1.jpg)
1
Species as units: Taxonomy
![Page 2: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/2.jpg)
2
Species as units: Phylogenetics
1 2 3 4
Barthlott 1997
Species as units: Biodiversity Studies & Conservation
![Page 3: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/3.jpg)
3
Speciation: A cladogram perspective
1 2 3 4
Speciation: A cladogram perspective
![Page 4: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/4.jpg)
4
Geographic barriers to gene flow: e.g., vicariance
Phylogeny of the 6 species of Geogenanthus
Allopatric Speciation: Deeper Evidence
![Page 5: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/5.jpg)
5
Non-Geographic barriers to gene flow: e.g., ethological (involving pollination)
Non-Geographic barriers to gene flow: e.g., polyploidy
Anemone
1.) Mistake during cell division in meristem (c-some duplication without mitosis or cytokinesis).
2n to 4n.
2.) 4n plants can mate with other 4n.Offspring are 4n and fertile.
3.) 4n plants can mate with 2n plants.But offspring are 3n. Irregular pairing of homologous c-somes during meiosis.Offspring sterile.
4.) 4n plants are isolated from 2n plants.
![Page 6: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/6.jpg)
6
Ecological Speciation: Evidence
Anthoxanthum odoratum
Ecology mediated geographic speciation: Evidence from empirical studies.Dodd (1989)
1.) dispersal across or emergence of a barrier.
2.) change via drift or drift + selection.
Over generations, change in enzyme production.
Mating selection to restrict gene-flow.
3.) Remix, groups don’t mix.
![Page 7: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/7.jpg)
7
1 2 3 4
Allopatric Speciation: Evidence from Cladograms
III. Species conceptsA. Species as category vs. Species as concept vs. species as entities
*-Vast and somewhat confusing literature.*
![Page 8: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/8.jpg)
8
*-Vast and somewhat confusing literature.*
III. Species conceptsA. Species as category vs. Species as concept vs. species as entities
*-Vast and somewhat confusing literature.*
III. Species conceptsA. Species as category vs. Species as concept vs. species as entities
![Page 9: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/9.jpg)
9
Platanus occidentalis (N. America) Platanus orientalis (Asia Minor to Iran)
Platanus occidentalis (N. America) Platanus orientalis (Asia Minor to Iran)
![Page 10: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/10.jpg)
10
Ophrys spp. (Europe; interfertile but isolated via pollinators)
Ophrys spp. (Europe; interfertile but isolated via pollinators)
![Page 11: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/11.jpg)
11
Ophrys spp. (Europe; interfertile but isolated via pollinators)
3) Phylogenetic Species ConceptHennig (1950; 1966)
![Page 12: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/12.jpg)
12
3) Phylogenetic Species Conceptscontributors to its practice
Cracraft (1983)
Nixon & Wheeler (1990)
![Page 13: Species as units: Taxonomy - Millersville Universityherbarium.Millersville.edu/class-web/325-topic08-species-powerpoint.pdf2.) 4n plants can mate with other 4n. Offspring are 4n and](https://reader035.fdocuments.in/reader035/viewer/2022062915/5ea9ecd908352a784206c9aa/html5/thumbnails/13.jpg)
13
4) Ecological species concept:Van Valen (1976)
Difficult species like Taraxacum officinale
more easily accommodated under this concept.