Transcript Chapter 17: Classification

Grouping bags that carry your books
1.
2.
3.
4.
Determine a common name for all the bags that
carry your books
Divide your bags into 2 – 3 groups based on a
common characteristic for each group
Divide each group from #2 into 2-3 groups
depending on their common characteristics &
move them
Continue to do this 4 more times, getting more
specific each time.
5.
Once you get to an end point where you can no
longer divide them up, start giving them two part
names (Purpleus bistrapus)
Taxonomy
1.
2.
3.
4.
5.
Determine
Kingdom a common name for all the bags that
carry your books
Divide
your bags into 2 – 3 groups based on a
Phylum
common characteristic for each group
Class each group from #2 into 2-3 groups
Divide
depending on their common characteristics &
move them
Continue
to do this 4 more times, getting more
Order
specific
Family each time.
Once
you
get to annames
end point where you can no
Genus
& species
longer divide them up, start giving them two part
names (Purpleus bistrapus)
Chapter 17:
Classification
What does it mean to classify?
• Could you imagine your closet or your
drawers in your room not being organized?
• What if you just threw the kitchen utensils
into a drawer?
• Puts order into a system or group
• Give some examples from your life where
you have formed a classification system to
make your life easier
Taxonomy
• Field of biology that
names and groups
organisms according
to their
characteristics and
evolutionary history
Classification systems
• 1st system – Aristotle’s grouped plants
and animals by land, sea and air.
• Modern system - Carolus Linnaeus
(1707 – 1778)
• Modern system is based on morphological
similarities.
• Hierarchy of eight groups (Taxa)
–
–
–
–
–
–
–
–
Domain – New taxon. Eukarya
Kingdom – largest most inclusive grouping- Animalia
Phylum (Division in plants)- Chordata
Class - Mammalia
Order - Primate
Family - Hominidae
Genus - Homo
species – most exclusive, specific group. Members
of this grouping can mate and produce viable
offspring - sapiens
– varieties – same species but with slight differences
– subspecies – same species, different location
Some past systems
Linnaeus
1735
2
kingdoms
Haeckel
1866
3
kingdoms
Chatton
1937
2
Copeland
1956
4
empires
kingdoms
Whittaker Woese et al.
[8]
1969
1977
5
6
kingdoms
kingdoms
Woese et
al.
[9]
1990
3
domains
(not
treated)
Protista
Prokaryota
Plantae
Vegetabilia
Animalia
Monera
Eubacteria
Bacteria
Archaebacteria
Archaea
Protista
Protista
Eukarya
Fungi
Fungi
Plantae
Plantae
Plantae
Animalia
Animalia
Animalia
Protista
Plantae
Animalia
Monera
What’s in a name?
• Binomial nomenclature – each species
in given a two part name
• Genus name – Homo or Homo
• species name – species identifier –
usually descriptive - sapiens or
sapiens
• **Latin is the language of
classification – universal and does not
evolve (Dead language)
Today, we use Phylogeny (based on
evolutionary history) for classification
• Systematics – organizes living things in the
context of evolution
• Phylogenetic tree – family tree that shows
evolutionary relationships.
– Use morphology and ontogeny (embryological
development).
– Look at early development.
• Zygote (1 cell) to morula(solid ball of cells), to blastula
(hollow ball stage) with the blastopore (indentation of
gastrula) becoming the anterior end of the digestive tract
in most animals. In echinoderms (sea stars) and
chordates (that’s us), it is the posterior end. So we are
more closely related to the echinoderms than the
Arthropods (Insects and crustaceans)
Blastopore
Zygote
Morula
Blastula
Also used:
• Fossil record
• Macromolecules – comparison of DNA
and proteins. More proteins in
common, more recently two species
shared a common ancestor.
– “Molecular clock” model compares amino
acids in a protein sequence. Ie. Our
Hemoglobin and a gorilla’s is only 1 amino
acid off in a chain of 146 amino acids.
• Chromosomes – More similar the
karyotypes, the more similar the
organisms
Cladistics
• Named for branches of trees called clades
•
Uses certain features (derived characters)
to show evolutionary relationships
•
Derived characteristics – unique feature
to a group (feathers in birds)
•
Cladistics, ignores when and where a
branch occurs, using only derived characters
to define each branch point by a fundamental
character of evolutionary significance.
• Cladogram is a useful way of
organizing, in a visual way, the
relationships between creatures that
share and do not share derived
characters.
• Construction begins with data; a table
of traits or characteristics that have
evolved or been derived by the
evolutionary process.
Derived Characters
segmented jaws
hair placenta multicellular
li
m
bs
kangaroo
+
+
+
-
+
+
earthworm
amoeba
+
-
-
-
-
+
-
-
lizard
+
+
-
-
+
+
cat
+
+
+
+
+
+
sponge
salmon
+
+
-
-
+
+
-
Amoeba
Sponge
Earthworm Salmon
Lizard
Kangaroo Cat
Placenta
Hair
Limbs
Jaws
Segmented
Multicellular
Fish Amphibians Reptiles Birds
Monotreme
mammals
Marsupial
mammals
Warmblooded
Hair
Amniotic
egg
Lungs
Placental
mammals
Placenta
Early Internal
development
The New and Improved Six Kingdom System
Kingdom
Cell Type
# of Cells
Nutrition
Representative
organism
Archaebacteria
Prokaryotic
Unicellular
Autotrophic or
Heterotrophic
Blue-green bacteria,
Methanogens
Eubacteria
Protista
Fungi
Plantae
Animalia
Prokaryotic
Unicellular
Autotrophic or
Heterotrophic
E.coli,
Staphylococcus,
Streptococcus,
Spirochetes
Eukaryotic
Uni, multi or
colonial
Autotrophic or
Heterotrophic
Amoeba, Paramecium,
Euglena,
Plasmodium,
Diatoms
Heterotrophic
Yeast, Mushrooms,
Molds, smuts,
rusts
Eukaryotic
Eukaryotic
Eukaryotic
Uni or
Multicellular
Multicellular
Multicellular
Autotrophic
(some
heterotrophic)
Mosses, ferns,
Horsetails,
Conifers,
Flowering plants
Heterotrophic
Sponges, Coral, Sea
stars, EW,
Insects, Fish,
Amphibians,
Reptiles, Birds,
Mammals
Archaebacteria
• Many live in harsh
environments
(extremophiles)
• – Archae –
Ancient
• Asexually
reproduces by
binary fission
Eubacteria
• Eu – true
• Most of the bacteria belong here
• Asexually reproduces by binary fission
Protista
• Pro – first
• Plant-like, Animal-like and Fungus-like
characteristics.
• Least clear cut of all kingdoms.
• Asexually by binary fission &
segmentation
Fungi
• Absorptive heterotrophs.
• Cell walls made of chitin.
• Reproduces sexually and asexually
Plantae
•
•
•
•
Multicellular
photosynthetic organisms
a cell wall made of cellulose
Reproduces asexually and sexually
Animalia
• Multicellular
• ingestive heterotrophs.
• Reproduces asexually and sexually
Three - Domain System
•
Woese compared rRNA to show that
living things can be grouped into 3
groups/domains
•
The domains:
Bacteria (Eubacteria)
Archaea (Archaebacteria)
Eukarya (Everything else)
Human Classification:
•
•
•
•
•
•
•
•
Domain Kingdom –
Phylum –
Class –
Order –
Family –
Genus –
species –
Eukarya
Animalia
Chordata
Mammalia
Primate
Hominidae
Homo
sapiens
Dichotomous key
• Uses a branching system of two features to separate
steps. Helps in identification process
• 1A. With hair
Mammal
• B. Without hair
Go to 2
• 2A. Has scales
• B. Does not have scales
Go to 3
Go to 4
• 3A. Has a three chambered heart
• B. Has a two chambered heart
Reptiles
Fish
• 4A. Has feathers
• B. Does not have feathers
Birds
Amphibians
Dichotomous Key
Is a method for determining the identity of
something by going through a series of
choices that leads the user to the correct
name of the organism.
Dichotomous means "divided in two parts".
At each step of the process of using the key,
the user is given two choices; each
alternative leads to another question until
the item is identified
1a. Wings covered by an exoskeleton…..... Go to 2
b. Wings not covered by an exoskeleton …Go to 3
2a.
b.
Body has a round shape………….......Ladybug
Body has an elongated shape.......Grasshopper
3a.
b.
Wings fold against body......................Housefly
Wings point out from sides……..…….Dragonfly
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