Layers of living stromatolites

microfossils

Biosignatures

problems with biosignatures

isotope ratios as evidence for life

problems with using isotope ratios as evidence for life

Hadeon era

Archaean era

Paleoproterozoic

Neoproterozoic era

Possible energy sources for earliest life

earliest conditions for living things on earth

redox reactions involving available substrates during the Archaean era

Oxygenic Photosynthesis of Cyanobacteria

Evolutionary relationships

Possible phenotypic characteristics (not DNA) that were used to determine evolutionary relatedness

problems of using phenotypic similarities to determine evolutionary relatedness

Assumptions of using DNA as molecular clocks

what type of DNA can we look at?

Why is 16S rRNA a good choice of DNA to study evolutionary relatedness?

Methods of comparing two 16S rRNA sequences

correlation factor

endosymbiosis

evidence for endosymbiosis

discovery of three domains

evolutionary tree LUCAs

relationship between archaea and eukaryotes

Major groups of Archaea

Euryarchaeota

Crenarchaeota

Thaumoarchaeota

memorize key differences between domains!!!

When are evolutionary trees a good model of relationships?

Limitations of using phylogenetic trees