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Taxonomy: naming species
y Vernacular versus scientific names
Section 4
S
Professor Donald McFarlane
Lecture 4 Taxonomy and Systematics
“The Wind in the Willows” Kenneth Grahame, 1908
y Vernacular versus scientific names
Reindeer or caribou ?
North American “badger”
Carl von Linneaus – 1735 – Systema Naturae (10th Edition)
Binomial, hierarchical, scientific names
Red Deer or Elk?
Elk or Moose?
Meles meles
Taxidea taxus
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•Domain Eukarya
•Supergroup Opisthokonta
•Kingdom Animalia
•Phylum Chordata
•Class Mammalia
•Order Carnivora
•Family Mustelidae
•Genus Meles
•Species meles
Linnean taxonomy
y Taxa must be formally described in the open literature
y Names are latinized, binomial (generic and Order: Carnivora
specific names)
y Names sit at the bottom of a hierarchy of relationships.
family: Mustelidae
Genus: Meles
SYSTEMATICS: Cladistic Analysis
Genus: Taxidea
Family Canidae
Genus: Canis
Shared ancestral traits are not very useful:
•Cladistics produces evolutionary trees called Cladograms
•Cladograms reflect phylogeny, not superficial similarity
•Ancestral versus derived traits
•Any 2 traits derived from
common ancestor are HOMOLOGOUS
Common ancestor had fur, so presence of fur in these three mammals tells us nothing about their relationships!
Shared derived traits ARE useful:
HOMOPLASY
= Analagous structures mistaken for Homologies due to convergent evolution
fox
Naked mole rat
vole
Common ancestor did NOT have rodent‐like incisors, so they are a shared derived trait.
vole
naked mole rat
fox
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•Canis latrans
Cladograms: Importance of MONOPHYLETIC groups
Erroneous cladograms (1) – Paraphyletic groups
A monophyletic group includes the most recent common ancestor and ALL the descendent species
Leptocyon
(Late Miocene)
CA + some, but not ALL, descendent species
Canis latrans ‐ coyote
Canis lupus –
lupus Gray wolf
Canis rufus – Red wolf
Canis simensis – Ethiopian wolf Canis adustus – Side‐striped jackal
Canis aureus – Golden jackal
Canis mesomelas – Black‐backed jackal
Erroneous cladograms (2) – Polyphyletic groups
Common Ancestor
Simple vertebrate cladogram
Multiple most‐recent‐common ancestors!
= MCA
Reptile cladogram
The group “REPTILES” is PARAPHYLETIC!
Birds
Crocs
Lizards and snakes
Turtles
Mammals
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