transcript
TAXONOMY
SBI3U
A Good Classification 1. It groups together all
things that are
similar. 2. It excludes all things that are
dissimilar. 3. It serves a function.
TAXONOMY IS… the science of
discovering naming describing classifying
organisms
DISCOVERING
Danionella dracula Discovered in Burma Documented 2009 © Ralf Britz
| Natural History Museum, London
The discovery of new organisms is the first step of taxonomy. Every
year, new discoveries are made throughout the world, as taxonomists
explore new areas, or new tools become avail- able for analyzing
specimens.
TA X
O N
O M
Y IS
Electrolux addisoni (Compagno & Heemstra, 2007)
Not your average vacuum cleaner!
What’s in a name? A scientific name is the passport by which all
organisms are known.
NAMING TA
X O
N O
M Y
Photo: Phil Heemstra | Wikimedia Commons
DESCRIBING Part of this process involves the comparison to related
organisms to confirm if the species is new.
TA X
O N
O M
Y IS
CLASSIFYING
X O
N O
M Y
IS
LINNAEUS
"If you do not know the names of things, the knowledge of them is
useless"
Critica Botanica 1737
Carl von Linné (or Linnaeus), the “father of taxonomy”, laid the
foundations for the modern scheme of nomenclature - the discipline
of naming species.
N A
M ES
M A
TT ER
Linnaeus gave classification the consistency and precision we need
when we describe bio- diversity, trade commodities, buy seeds for
farming, manage pests, or deal with any other of the many areas in
which humans need taxonomic knowledge.
Carl von Linné, 1707-1778 Drawing: AMNH Library
Carolus Linnaeus
• Described organisms with two word
names • Developed binomial nomenclature
• First word = genus name •
Second word = species name
Modern classification is based on the 18th century work of Carolus
Linneaus
• Organisms are assigned to groups called “taxa” (sing.
“taxon”)
• Taxa are hierarchically arranged
• Each subsequent taxon contains fewer species than the preceding
taxon
• Only members of “species”, the smallest taxon, are able to
produce fertile offspring
Why binomial nomenclature?
• Much easier than a 10+ word
name under old “polynomial system”
• Same name no maFer where you
go • Less confusion • Binomial =
SCIENTIFIC NAME
What is a species anyway?
• Biological species concept –A group
of actually or potenLally breeding
natural groups that are
reproducLvely isolated from other
groups.
» Ernst Mayr, 1924
ScienLfic Names You May be familiar
with
• Homo sapiens • Canis lupus • Felis
domes0cus
All organisms classified in a
hierarchy
• Kingdom (broadest) • Phylum • Class •
Order • Family • Genus • Species (most
specific)
↓KINGDOM ↓
PHYLUM ↓
CLASS ↓
ORDER ↓
FAMILY ↓
GENUS ↓
SPECIES
↓ ANIMALIA ↓
CHORDATA ↓
MAMMALIA ↓
CARNIVORA ↓
ODOBENIDAE ↓
ODOBENUS ↓
Dichotomous Key…
ØBiological key ØA series of branching two-part statements used
to
identify organisms (or objects) ØEach step offers two mutually
exclusive options
designed to divide one group of organisms into two smaller
groups
ØCan be used to identify organisms using visual
information alone
Characteristics – organized either: A)Spider Key à similar to a
tree diagram
List Structure