biological classifications alessandro minelli university of padova

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