Brandon Schlautman Speciation of the American Cranberry (Vacciniummacrocarpon)
What is a species? • Domain- Eukarya • Kingdom- Plantae • Phylum- Magnoliophyta • Class- Magnoliopsida • Order- Ericales • Family- EricaceaeIs a member of the heath family. • Genus- VacciniumIs a member of the blueberry genus. • Species- VacciniummacrocarponAit.
Cranberry Morphology/Adaptations • Small vining shrub, forms dense mats in bog areas
Cranberry Morphology/Adaptations • Extensive rhizomes, asexual reproduction • Self-incompatible • Flowers look like a crane’s head and neck
Cranberry Morphology/Adaptations • Yellow/red false berries • Fruits contain locules • Fruits are very hardy
Vaccinium Phylogeny • Phylogenetic tree- a branching diagram revealing the evolutionaryrelationships among various biological speciesbased upon similarities and differences in their physical and/or genetic characteristics.
Vaccinium genus: some members V. vitis-idaea Lignonberry V. angustifolium Lowbush Blueberry V. corymbosum Highbush Blueberry V. myrtillus Bilberry V. ovatum Huckleberry V. darrowii
Subgenus: Oxycoccos • Sect. Oxycoccus • Vacciniummacrocarpon – American Cranberry • Vacciniummicrocarpum – Small Cranberry • Vacciniumoxycoccos – Common Cranberry • Sect. Oxycoccoides • Vacciniumerythrocarpus – Southern Mountain • Cranberry V. oxycoccos V. macrocarpon V. microcarpum V. erythrocarpus
How does evolution fit in this picture? • Basic definition of evolution: A genetic change in a population over time. • Main objective: What evolutionary forces and/or types of selection were acting upon Vacciniumsubgenus oxycoccos which caused it to split (i.e. speciate) into three or more distinct species? • Further objective: Are there really three species, and should the oxycoccos subgenus exist?
Speciation- a lineage-splitting event that produces two or more separate species • Allopatric Speciation- Speciation occurring in an alternate location • Geographic barriers to reproduction • Sympatric Speciation- Speciation occurring in same location • Barriers to reproduction in same geographic area • Ex) chromosome duplication/polyploidy
Selection’s Role in Speciation • Natural Selection- gradual random process which causes biological traits to become more or less common in a population • Survival of the fittest • Artificial Selection- Human mediated selection, agriculture
Oxycoccus Geographic Distribution V. macrocarpon V. oxycoccus 4N V. oxycoccus 2N V. microcarpum V. erythrocarpus
Following Speciation: Genetic Fingerprints • Microsatellites (SSRs)- Short Sequence Repeats • Ex) 5’-AGAGAGAGAGAGAGAGAGAGAGAGAGAGAG-3’ vs. 5’-AGAGAGAGAGAGAGAGAGAGAGAGAG-3’ • By tracking changes in genetic sequences (SSRs), we can follow the genetic change in populations overtime (i.e. Evolution!)
Chloroplast Data Example Why Chloroplast DNA Maternally inherited –only one copy per plant (i.e. every plant is a homozygote) Small size-110,000 bp vs. 550,000,000bp nuclear genome Minimal variation
Gentic Theory and Distribution V.erythrocarpus- Likely Allopatric Speciation- isolated in Appalacian Mountains V. Oxycoccus 4N- Sympatric Speciation- Reproductive barrier due to polyploidy V. Oxycoccus 2N- Allopatric Speciaion – geographic isolation V. Macrocarpon 2N- Allopatric Speciation – geographic isolation