Transcript Taxonomy.domenico

Taxonomy
Branch of Biology that names and
groups organisms according to their
characteristics and evolutionary
history.
Adapted from
www.dellpassovoy.com/Taxonomy%5D.ppt
History
• Aristotle- Greek philosoper named
animals in three groups
– Air dwellers, land dwellers, water dwellers
– Not adaquate
• Ducks live on land and water, and fly in the air
• Carolus Linnaeus- Swedish Naturalist devised current
system
– Used morphology (Greek meaning srtucture or form)
– Seven Hierarchical categories
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Kindom
Phylum
Class
Order
Family
Genus
Species
Subspecies
Prokaryotic Cell
Eukaryotic Cell
 Autotrophs
capture the light energy from
sunlight and convert it to chemical energy
they use for food.
 Heterotrophs must get energy by eating
autotrophs or other heterotrophs.
 Decomposers, aka saprobes, are heterotrophs
that recycle dead organisms by breaking them
down.
• Taxonomy is the science of grouping
and naming organisms.
• Classification the grouping of
information or objects based on
similarities.
•We only know about a fraction of the
organisms that exist or have existed on Earth.
•Taxonomists give a unique scientific name to
each species they know about whether it’s alive
today or extinct.
• The scientific name comes from one of two
“dead” languages – Latin or ancient Greek.
Why use a dead language?
Devil Cat
Ghost Cat
Mountain Lion
Screaming Cat
Puma
Florida Panther
Cougar
•There are at least 50 common names for
the animal shown on the previous 7 slides.
•Common names vary according to region.
•Soooo……why use a scientific name?
Solution:
• Use Latin (and Greek) as the universal
language
– Latin is not changing today- not used by
many so not modified
– It’s descriptive
• Flower color- aurum= gold color, cerum= pink
Binomial Nomenclature
•a two name system for writing scientific names.
•The genus name is written first (always Capitalized).
•The species name is written second (never capitalized).
•Both words are
italicized if typed or underlined if hand written.
Example: Felis concolor or F. concolor
Which is the genus? The species?
"Formal" scientific names should have a third
part, the authority.
The authority is not italicized or underlined.
The authority is written as an abbreviation of
the last name of the person responsible for
naming the organism. Since Carolus Linnaeus
was the first person to name many plants, the L.
for Linnaeus is very common in plant scientific
names.
An example is Quercus alba L.
Phylogeny, the evolutionary history of an
organism, is the cornerstone of a branch of
biology called systematic taxonomy.
Systematics, as systematic taxonomy is
commonly called, is the study of the
evolution of biological diversity.
A phylogenetic tree is a family tree
that shows a hypothesis about the
evolutionary relationships thought to
exist among groups of organisms. It
does not show the actual evolutionary
history of organisms.
Why a hypothesis?
Phylogenetic trees are usually based on a
combination of these lines of evidence:
Fossil record
Morphology
Embryological patterns of
development
Chromosomes and DNA
Fossil
Morphology
Homologous
Structures
modifies
homologous
structures
Adaptive Radiation Modifies homologous structures
Convergent Evolution
These animals have evolved similar adaptations
for obtaining food because they occupy similar
niches. What can you infer about their
phylogeny from their geographic locations?
Convergent evolution leads to……….
Analogous Structures •Traits that are morphologically and
functionally similar even though there
is no common ancestor.
Embryology
Cladistics - is a relatively new
system of phylogenetics
classification that uses shared
derived characters to establish
evolutionary relationships. A
derived character is a feature
that apparently evolved only
within the group under
consideration.
DNA
There are three basic assumptions
in cladistics:
1.Organisms within a group are
descended from a common
ancestor.
2.There is a bifurcating pattern of
cladogenesis.
3.Change in characteristics
occurs in lineages over time.
A phylogenetic tree based on a
cladistic analysis is called a
cladogram.
What derived character is shared by
all the animals on the cladogram on
the next slide?
The acacia and its
ants are an example
of coevolution. Each
influences the others
evolution.
Can you think of any
other examples of
coevolution?
Punctuated Equilibrium
“instead of a slow, continuous movement,
evolution tends to be characterized by long
periods of virtual standstill ("equilibrium"),
"punctuated" by episodes of very fast
development of new forms”
The "punctuated equilibrium" theory of Niles
Eldredge and Stephen Jay Gould was proposed
as a criticism of the traditional Darwinian
theory of evolution…what is it called?
The Dichotomous Key
• A key is a device for easily and quickly
identifying
an unknown organism.
• The dichotomous key is the most widely used
type in biological sciences.
• The user is presented with a sequence of
choices between two statements, couplets,
based on characteristics of the organism. By
always making the correct choice, the name of
the organism will be revealed.
A. one pair of wings
1.
B. Two pairs of wings
Kingdom Classifications
Your book has 6 Kingdoms
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Animalia
Plantae
Fungi
Protista
Eubacteria (Eu- means true)
Archeabacteria (Archae- Greek for
ancient)
• Domain Archaea
– Includes newly discovered cell types
The Three
Domains
– Contains
1 kingdom – the Archaebacteria
•Domain Bacteria
– Includes other members of old kingdom Monera
– Has 1 kingdom – the Eubacteria
•Domain Eukarya
– Includes all kingdoms composed of organisms made
up of eukaryotic cells
– Protista
– Fungi
– Animalia
– Plantae
The major classification levels,
from most general to most specific
(several of these have subdivisions)
A group at any level is a taxon.
Categories within Kingdoms
Kingdoms are divided into groups called phyla
Phyla are subdivided into classes
Classes are subdivided into orders
Orders are subdivided into families
Families are divided into genera
Genera contain closely related species
Species is unique
Review Terms:
•Classification
•Taxonomy
•Aristotle
•Linnaeus
•Kingdom
•Phylum
•Class
•Order
•Family
•Genus
•Species
•Common name
•Scientific
name
•Binomial
nomenclature
•Phylogeny
•Systematics
Hypothesis
•Cladistics
•Derived
character
•Cladogram
•Dichotomous
Key