Download Classification - Herscher CUSD #2

Unit 3 – Chapter 18
 The
science of describing, naming, and
classifying organisms
 Classify – to arrange objects into groups
based on their similarities
 Carolus Linnaeus, father of modern
taxonomy
• Binomial nomenclature
A
system of naming organisms based on a
unique two-part scientific name
• Capitalize Genus name
• Lower case specific epithet “species” name
• Italicize or underline font
 Example: Zea mays
 Which
is the genus?
 Which is the species?
 How else can this be written?
 It
is a dead language!
• Therefore it does not change!
 To
be precise and avoid confusion when
describing a particular organism
 Scientific names are the same regardless of
the language of the speaker or writer
 Domain
 Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 Species
 One
or more populations whose members
can interbreed to produce fertile offspring
 Reproductively isolated from other
organisms
 Share common evolutionary ancestry
 Smallest unit of classification
 Geographically
distinct populations
 Within a species
 Display characteristics that distinguish
them from other populations of the same
species
 Can interbreed
Gilia latiflora
Gilia tenuiflora
subsp. excellens
subsp. davyi
subsp. latiflora
Figure 18-4
Same genus, different
species.
Fig. 18-4, p. 355
A
series of two contrasting statements
 Useful in identification of unknown plants
 Open
to page 357
b, a, a, b, b
Fig. 18-6a, p. 357
b, a, b, b
Fig. 18-6b, p. 357
 The
scientific study of the diversity of
organisms and their natural (evolutionary)
relationships
 Phylogeny = “evolutionary history”
 Monophyletic = a group of organisms that
share “one common ancestor”
 Classification
of organisms based on
recency of common ancestry rather than
degree of structural similarity
 Focus on when evolutionary lineages (lines
of descent) divide into two branches
 Form a cladogram
• A diagram that illustrates evolutionary
relationships & braking points