Chapter 1: Biology and the Tree of Life
- Biological sciences are based on
1) cell theory (the theory that all cells come from pre-existing cells and all organisms are made of cells)
2) the theory of evolution by natural selection, that heritable traits eventually affect populations because some of them produce more offspring with more success
because all cells are made from pre-existing cells, we are all related from a common ancestor
- phylogenetic tree is a graphical representation of the evolutionary species among species and each tip of the phylogenetic tree is a species and each little triangle thing is a monophyletic group (aka a cale or a lineage) these relationships are dissected by looking at similarities and differences between traits and species in these cales. closely related species are placed closer together on the tree
scientists look at rRNA of different species to decide how similar/closely related they are to each other.
- biologists ask questions and generate hypotheses and such to try to explain then. pattern/process (see a pattern in nature, process explains the pattern)