Transcript Evolutionary Classification 2008

What is Evolutionary
Classification?
What criteria do
biologists use to classify
organisms?
LEQ
What criteria do
biologists use to
classify organisms?
(to group, categorize,
arrange, sort or cluster)
According to evolutionary
classification which is more closely
related a chimpanzee and a human
or a koala and a panda?
What evidence would you
expect to have to support your
claim?
Taxa (or “Groups”)
o Organisms are classified by
the number of characteristics
they have in common.
o The more characteristics
organisms have in common
the more taxa they have in
common.
Traditional Scientific
Classification
Panda
Koala
Kingdom:
Animalia
Kingdom:
Animalia
Phylum:
Chordata
Phylum:
Chordata
Class:
Mammalia
Class:
Mammalia
Order:
Carnivora
Infraclass:
Marsupialia
Family:
Ursidae
Order:
Diprotodontia
Genus:
Ailuropoda
Family:
Phascolarctidae
Species:
A. melanoleuca
Genus:
Phascolarctos
Species:
P. cinereus
Scientific Classification
Human
Kingdom: Animalia
Phylum: Chordata
Class:
Mammalia
Order:
Primates
Family:
Hominidae
Genus:
Homo
Species: H. sapiens
Chimp
Kingdom:
Phylum:
Class:
Order:
Family:
Genus:
Animalia
Chordata
Mammalia
Primates
Hominidae
Pan
Species:
Pan paniscus
Cladistics
Takes into consideration a
number of derived characters,
like…
1. Morphology
2. DNA or amino acid
sequence
KEY TERMS
Phylogeny (phyl- meaning “race or distinct type of organism”
or group + -gen meaning “producing” i.e. reproducing)
Tribe in which one is born
Cladistics (clade = family group)
System of organizing groups by # of shared
traits & their order of appearance (or
disappearance)
PHYLOGENY
o The idea that all organisms are
thought to have descended from
an ancient common ancestor.
o Hypothesized evolutionary paths
taken by organisms over long
periods of time is depicted by a
tree.
P
H
Y
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N
I
C
T
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CLADISTICS
o Grouping organisms into a “clade”
(group) that includes an ancestor
and all descendants
o It’s a hypothesis depicting one
possible path of speciation (based on
the inheritance of derived traits)
CLADOGRAM
Characteristics of a Cladogram
o Shows order of derived traits (lower branches
showed up earlier)
o Shows which groups share the same traits
o All taxa that are "upstream” from the point where
one line becomes two (traced directly to one node)
are said to be members of a group
o Any two branch tips sharing the same immediate
node are most closely related
CLADOGRAM
1. Which of these
is most unlike
the others?
2. And which trait
separates this
organism from
the others?
CLADOGRAM
Derived Characters (+ symbol means the organism does have that feature)
segmented
jaws hair
placenta
multicellular
limbs
kangaroo
+
+
+
-
+
+
earthworm
+
-
-
-
+
-
amoeba
+
+
+
+
+
+
+
-
+
-
+
+
+
+
+
+
-
lizard
cat
sponge
salmon
CLADOGRAM
CLADOGRAM
Derived Characters (+ symbol means the organism does have that feature)
segmented
jaws hair
placenta
multicellular
limbs
kangaroo
+
+
+
-
+
+
earthworm
+
-
-
-
+
-
amoeba
+
+
+
+
+
+
+
-
+
-
+
+
+
+
+
+
-
lizard
cat
sponge
salmon
CLADOGRAM
CLADOGRAM
Derived Characters (+ symbol means the organism does have that feature)
segmented
jaws hair
placenta
multicellular
limbs
kangaroo
+
+
+
-
+
+
earthworm
+
-
-
-
+
-
amoeba
+
+
+
+
+
+
+
-
+
-
+
+
+
+
+
+
-
lizard
cat
sponge
salmon
CLADOGRAM
CLADOGRAM
Derived Characters (+ symbol means the organism does have that feature)
segmented
jaws hair
placenta
multicellular
limbs
kangaroo
+
+
+
-
+
+
earthworm
+
-
-
-
+
-
amoeba
+
+
+
+
+
+
+
-
+
-
+
+
+
+
+
+
-
lizard
cat
sponge
salmon
CLADOGRAM
CLADOGRAM
Derived Characters (+ symbol means the organism does have that feature)
segmented
jaws hair
placenta
multicellular
limbs
kangaroo
+
+
+
-
+
+
earthworm
+
-
-
-
+
-
amoeba
+
+
+
+
+
+
+
-
+
-
+
+
+
+
+
+
-
lizard
cat
sponge
salmon
CLADOGRAM
CLADOGRAM
Derived Characters (+ symbol means the organism does have that feature)
segmented
jaws hair
placenta
multicellular
limbs
kangaroo
+
+
+
-
+
+
earthworm
+
-
-
-
+
-
amoeba
+
+
+
+
+
+
+
-
+
-
+
+
+
+
+
+
-
lizard
cat
sponge
salmon
CLADOGRAM
CLADOGRAM
What are the relationships
between A, B, C, D, and E?
Build A Cladogram
SOLUTION