2/ classifying life Flashcards
Linnean hierarchical system
taxonomy reflects phylogeny
ghost lineages
- represented with a dotted line
- we know they must have existed despite having no fossils due to relation with sister groups
revolution in classification - phylogenetic/cladistic analysis
- create a data matrix of character for the taxa under consideration
- use computer to analyse data and create a cladogram
- analyses presence or absence of particular traits (presence better)
analogous meaning
characters w similarity due to convergent evolution (homoplasy)
homologous meaning
characters w similarity due to common ancestry
synplesiomorphies meaning
shared ancestral characters
synapomorphies meaning
shared derived characteristics
autapomorphies
characters unique to a taxon
sister groups meaning
share a common ancestor
monophyletic group meaning
- contains latest common ancestor plus all and only all of its descendants
- ideal
paraphyletic group
- diagnosed by plesiomorphies and not including all descendants of a common ancestor
- remains after one or more parts of a monophyletic group have been removed
- bad
polyphyletic group
- most recent common ancestor is assigned to some other group and not the group itself
- defined on basis of convergence or non-homologous characters assumed to have been absent in the latest common ancestor
- v bad
5 kingdom domain system
- monera, protista, animalia, fungi, plantae
- 1st system
8 kingdom domain system
- monera - bacteria and archaea
- protista - archaeozoa, protista, chromista
- animalia, fungi, plantae same
3 domain system
- bacteria
- archaea
- eukarya (now inc protists)
parasexual meaning
- in prokaryotes
- bits of dna thrown out and mixed w other bacteria
2 types of prokaryote. which was at forefront of how life evolved?
- eubacteria/ bacteria
- archaebacteria/ archaea - less numerous and diverse, inhabit extreme environments, forefront of how life evolved
thermophiles/halophiles meaning
eubacteria that inhabit very hot/salty environments
how are bacteria and archaea related to each other?
- we don’t know - unrooted phylogenies
- may be 2 groups of archaea, we don’t know how they’re related
