biological classifications alessandro minelli university of padova
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Biological classifications
Alessandro MinelliUniversity of Padova
Classification
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
The taxonomic hierarchy
phylum
class
order
family
genus
species
subspecies
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
P. Belon
1555
Characters: how many? which ones?
Homologue the same organ underevery variety of form and function Owen, 1843
Analogy
The origin of species (1859)
Charles Darwin
Ernst Haeckel
Willi HennigPhylogenetic systematics (1966)
Synapomorphy =
shared derived
character state
fin limb
‘cladistic’ methods of Renaissance scholars
Angelo Poliziano 1454-1494
monophyletic group
paraphyletic group
polyphyletic group
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
Invertebrates
Vertebrates
Protostomes
Deuterostomes
Birds
Reptiles
Testudinates
Archosaurs
Lepidosaurs
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
absolute ranks ?Equus
Conus
genus
MammalsGastropods
class
Biological classifications
Species, the units of classification
Groups within groups
– characters: problems of homology
– taxa: arbitrary vs. natural units
– ranks, abolute or relative?
Taxon names
Biological classifications
(the dark side)
Bad taxonomy can kill
Bad taxonomy can kill species
Bad taxonomy can kill thought
how many species are there?
Biological classifications