NVCC - Nesbitt
Key Terms for Bio 101 - Chapters 19 and 20
biological species (Mayr) – defined by sexual repro between population members
speciation modes – allopatric (physical separation); sympatric (no PS); parapatric
repro isolation: prezygotic by mechanical, temporal, behavioral, ecological
postzygotic by gamette mortality - ex. hybrid zygote dies or sterile (as mule)
plant polyploidy (autopolyploids and allopolyploids) – no problems as in animals
evolution models: gradual and punctuated (distinct spin-offs) evolutionary lines
extinction – 98 percent of all species now extinct even though over 2M species
Carl von Linne – father of taxonomy (organizing life by naming representatives)
Linne’s binomial system, specific epithet for each using Latin names
(kingdom, phylum, class, order, family, genus, species)
Animala, Chordata, Mammalia, Carnivora, Canidae, Canis familiaris
Animala, Chordata, Mammalia, Primates, Hominidae, Homo sapiens
Major Kingdoms: Bacteria, Archaea, Protista, Plantae, Fungi, Animalia
gymnosperms, angiosperms, dinosaurs, reptiles, etc. are the life forms
prokaryotic, eukaryotic, eubacteria, archaebacteria - defined by nucleus
endosymbiosis is thought to have resulted in the mitachondria and chloroplast
earliest atmosphere: H2, N2, CO, CO2, no H2O; no O2 until after photosynthesis
Some Milestones in Evolutionary History:
65 MYA – K/T dinosaurs go extinct; mammal begin adaptive radiation
250 MYA – 95 percent of all species lost in mass dieoff
900 MYA – all major lineages of life developed and diversity is underway
1.2 BYA – mitochondria deveop as do later chloroplasts, both symbionts
2.5 BYA – O2 release pathway develops that allows aerobic respiration
3.2 BYA – living cells begin to use cyclic path photosynthesis
3.8 BYA – first prokaryotes develop and use anaerobic pathways
4.6 BYA – start of a basis for life with cell precursor chemicals/compounds
12-15 BYA – the “big bang” that gave start to our universe