Taxonomy: is the placing of organisms into a hierarchical system.

Nomenclature: is the naming aspect of the Science;

It is the foundation of Biology (Classification); & the cornerstone of Ecology (the studying of animals and plants in their environment).

The basic building block is referred to as the species.

The species: Is something in the minds of man. It is a biological entity.

When 2 creatures share a large number of similar qualities, look the same, with few or no major differences we say they are the same species. Works well for mammals; but definition is too simple. Difficulties: different morphs: Caterpillar - butterfly;

male - female, birds (eg. robin), fish (cuckoo wrasse).

A number of organisms (eg. some insects and crustaceans) can reproduce asexually; for example by parthenogenesis (eg. greenfly = aphids, bees, cladocerans = water fleas)

Aristotle: 384 - 322 BC. Developed a very simple classification which lasted for 2000 years. Too simple.

John Ray: 1627-1705. Father of classification: ‘Ray Society’ founded in his memory. All scientists began to travel around world.

Carl von Linné : 1707 - 1778. Swedish botanist. Knew about John Ray’s writings. Developed the hierarchical system we have today. Based on observed similarities between organisms. He used homologous characters. Described his system as ‘the natural system of classification’. Developed the ‘Binomial System’ of naming (2 names). 2 Scientific names in Latin.

Man wise

Genus always begins with a capital letter ; species always begins with a small letter.

Write the whole name in italics eg. Homo sapiens

If you can’t write italics singly underline the whole name eg. Homo sapiens

Often the name of the person who first gave the organism that name is written afterwards in brackets; eg. Arenicola marina (Linnaeus) the Lugworm.

Patella vulgata (Linnaeus) the common Limpet

Linnaeus named so many organisms that his name often gets shortened to (L).

If a name is mentioned more than once, the Genus may be shortened; eg.

Patella vulgata (L); P. vulgata (L);

Patella aspera (Lamarck) P. aspera (Lamarck)

Patella intermedia (Jeffreys) P. intermedia (Jeffreys)

Sometimes more than one name exists and the old name will be shown in brackets eg.

P. aspera (Lamarck) (= P. athletica)

P. intermedia (Jeffreys) (= P. depressa)

Where the Genus is known, but the species is not, it may be written: Patella sp.

Species (plural) is written: spp. ; eg. Patella spp. ; i.e. this could include all the above species.

Phylum : Class : Order : Genus : species.

Changed his own name to "Carlus linné us"; for the crack !

Linné an society founded in his memory.

His two works:

(1) (1753) Species Plantaeium 7000 species of plants. This was the start of botanical nomenclature.

(2) (1756) 10th edition of Systema Natureae. This was the start of zoological nomenclature.

They both came up with the same idea - This idea was that all species on the earth are interrelated having evolved from a common ancestor- published in 1858.

Charles Darwin was famous for his book ‘The Origin of Species’ which was published in 1859. Society was ready to accept new ideas at this time.

Wallace divided the world into biogeographic zones. Different continents have their own distinctive flora and fauna. The phenetic system of classification , which differentiates between the different species. The phylogenetic system classified species which were similar.

Classical Evolutionary Systematics: from fossil evidence.

The fossil record is only a tiny bit of evidence, of life that existed , because the fossils that survived were those which had shells.

Most important - Morphological - comparing the form; but also from:

* Fossil evidence

* Embryonic evidence

* Behavioural evidence

* Ecological evidence (habitat, feeding habits)

* Biochemical evidence.

Biochemical evidence:

(a) Looking at protein molecules, sequence of amino-acids. The more similar the sequence the closer related organisms are.

(b) Biochemical pathways

(c) Enzyme similarities.

So far there are 1.5 million animals described by scientists. By the time scientists have discovered all the types of existing animals on earth , there will be about 3-4 million kinds. Many groups evolved first in the sea.

All animals are :

* metazoans and multicellular;

* obligate heterotrophs (i.e. obliged to feed on some other organisms);

* eukaryotes (with a membrane bound nucleus);

* have two gametes (large egg and small sperm: all capable of sexual reproduction);

Types of asexual reproduction:

- budding,

- fragmentation,

- parthenogenesis (one of the cells begins to divide and grow into a new animal)

* motile during some stage of their life cycle;

* bilaterally symmetrical (are exceptions to the rule, i.e. radially symmetrical, or not symmetrical at all)

Starting from the very beginning all animals have evolved from a Protistan ancestor.

Sponges (Porifera) -------- dead end

Protista Coelenterates (Cnidaria; and Ctenophora = comb jellies) ---- evolutionary dead end

Flatworms (Platyhelminthes) ---------------- gave rise to all other animals.

Major Animal Phyla

Phyletic tree of the 5 Kingdom Classification

Metamerism and Types of Body Cavity

Cleavage: showing germ layers (ectoderm,endoderm, and tissues derived from the embryonic germ layers); blastocoel, blastopore, archenteron.

Development of the Coelom: the true body cavity, lined by mesodermal tissue.

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