Order out of Chaos classification and naming in biology. Part 1 Sandy Knapp Department of Life Sciences The Natural History Museum London

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CLASSES - Numbers of males (stamens) – Monandria to Polyandria Public marriages (flowers visible) In one bed (male and female together) Equal rank (males all the same size) ORDERS - Numbers of females (pistils) – Monadelphia to Polydelphia Monoecia (husbands and wives in the same house, but different beds); Dioecia (husbands and wives in different houses); Polygamia (husbands live with wives and concubines) In two beds (male and female in separate flowers)

Solanum sinuatirecurvum – “Pentandria Monogynia”

Paeonia officinalis – “Polyandria Digynia”

Thomas Pennant to Joseph Banks (1767) “I have no very high opinion of Linnaeus’s zoological merits…… he is too superficial to be thought of…” “My vanity will not suffer me to rank Mankind with Apes, Monkies, Maucaucos and Bats.”

Biological Classification Hierarchical Nested sets of smaller and smaller groups (Kingdom (Order (Family (Genus (species))))) Eukaryota (Animalia (Hominidae (Pan (trogolodytes)+ (Homo (sapiens))))

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Darwin (1859) - Species “From these remarks it will be seen that I look at the term species, as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms.” On the origin of species Chapter II: 52

Pierre Belon (1555) L'Histoire de la nature des oyseaux

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Homology and analogy - Owen Homology – “same organ in different animals under every variety of form and function” Analogy – “part or organ in one animal which has the same function as another part or organ in another animal”

Richard Owen (1849) On the Nature of Limbs

Homology after Darwin Homology - similarity in structure due to descent from a common ancestor; homologous structures are derived from a structure in a shared common ancestor of two organisms Unique homologies define groups

Characters Apomorphy – derived character Synapomorphy – shared, derived character Autoapomorphy – derived character unique to a particular taxon Plesiomorphy – “primitive” character

FLYFLY BATBAT COWCOW COWCOW BATBAT FLYFLY BATBAT FLYFLY COWCOW Let’s take three organisms: Fly Bat Cow

Kinds of groups - cladistics Monophyletic = ALL and ONLY descendents of a common ancestor

Kinds of groups - cladistics Paraphyletic = some descendents of a common ancestor, but not all