Classification of biodiversity Topic 5.3

Why are grocery stores organized like this?

Classification =All living things arranged into groups according to their similarities

NOS: Cooperation and collaboration between groups of scientists: Scientists use the binomial system to identify a species rather than the many different local names. – Why do we need a system? – Carl Linnaeus, 1700’s came up with binomial system for naming species – Used a style of naming that was used in many languages before: specific name attached to group name

Carolus (Carl) Linnaeus

Linnaea borealis – named after Carl Linnaeus, Swedish biologist – National flower of Sweden – aka Twinflower

U: The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses. Plants & fungi congress – International Botanical Congress (IBC) – 1892 IBC held in Genoa proposed that 1753 be start date for binomial system for naming plants,fungi (year Linnaeus published Species Plantarum, which named all species then known) – 19th IBC will be in Shenzhen China 2017 Animals congress – International Zoological Congress first held in Paris in 1889 – 1758 chosen as start date for naming animals (year Linnaeus published Systema Natura, which named all species then known) – current International Code for Zoological Nomenclature is 4 th edition

Can you read French? – The International Botanical Congress of Vienna in 1905 accepted by 150 votes to 19 the rule that "La nomenclature botanique commence avec Linné, Species Plantarum (ann. 1753), pour les groupes de plantes vasculaires."

U:When species are discovered they are given scientific names using the binomial system Binomial Nomenclature – 2 words – Genus species – G. species (after used once in text) – Latin or Greek – Earliest published names for species, from 1753 onwards for plants or 1758 for animals, is the correct one Examples – Linnaea borealis (L. borealis) – Homo sapiens (H. sapiens) – Escherichia coli (E. coli) – Bacillus cereus (B. cereus)  my fave! – Cedecea davisae (discovered at the CDC) – C. lupus – F. domesticus – U. horribilis

U: Taxonomists classify species using a hierarchy of taxa Taxon – Greek – “a group of something” – Taxa (plural) – Species are grouped into taxa – Each taxon includes taxa from level below Example

U: All organisms are classified into 3 domains – Old system - 2 categories: eukaryotes & prokaryotes – Current system – 3 domains:  Eukaryota (“eukaryotes”)  Eubacteria (“bacteria”)  Archaea (“archaeans”)  Includes extremophiles (e.g. methanogens); range of habitats (ocean surface, deep ocean, oil deposits)  Virus are non-living

How the 3 domains are linked based on rRNA sequences

U: The principal taxa for classifying eukaryotes are K, P, C, O, F, G, S Eukaryote Taxa – Kingdom – Phylum (Phyla, pl) – “Division” in plants – Class – Order – Family – Genus (Genera, pl) – Species 4 eukaryotic kingdoms 1. Animalia (animals) 2. Plantae (plants) 3. Fungi (fungi) 4. Protoctista (protists)

App: Classification of one plant and one animal species from domain to species level

DBQ p262: Classifying cartilaginous fish

U: In a natural classification, genus & accompanying higher taxa consist of all species that have evolved from 1 common ancestral species Natural classification = all members of a genus or higher taxon should have a common ancestor – Members of group share many characteristics – Not always clear – Convergent evolution – make distantly related organisms appear similar – Adaptive radiation - make closely related organisms appear different – Based on visible & molecular characteristics Unnatural (artificial) classification – do not share common ancestor – E.g. grouping birds, bats & insects together because they all fly – E.g. Plants & fungi in same group because they have cell walls & don’t move

U: Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species Ways to reclassify – If not related: Group split up into 2 or more taxa – If related: 2 of more taxa are combined, or species moved from one taxa to another Primates have been reclassified

U: N atural classifications help in identification of species & allow prediction of characteristics shared by species w/in group Advantages of nat class 1. ID of species is easier – dichotomous keys help – Start with Kingdom, then phylum etc 2. Prediction of characteristics of species within a group e.g. if new species of bat found, then predictions: hair, mammary glands, placenta, 4-chambered heart, etc = a key that consists of a series of choices that lead you to the correct name of a given item (dichotomy = division into 2) Dichotomous Key

SKILL: Construction of dichotomous keys for use in identifying specimens

Construct a dichotomous key

App: 4 major PLANT PHYLA: External recognition features of bryophytes, filicinophytes, coniferophytes, angiospermophytes

App: 6 out of 30 ANIMAL PHYLA: Recognition features of porifera, cnidarian, platyhelminthes, annelida, mollusca, arthropoda, chordata

App: 5 largest CLASSES of CHORDATES : bony ray-finned fish, amphibians, reptiles, birds, mammals