Transcript Unit 2 - Microbiology - KCI-SBI3U

Unit 1 – Diversity of
Living Things
The international year of Biodiversity 2010
http://www.youtube.com/watch?v=V1V
YmpTikgw
International day of Biodiversity - May
22 2014
The Axolotl
What is Biodiversity?
• Biodiversity= the number and the
variety of species on Earth
• Overall ~ 30-100 million species exist
but only 1.75 millions species
categorized so far
Edward O. Wilson
Coined the term Biodiversity in 1988
• Discover Life IDnature database
http://www.discoverlife.org/nh/id/
How is a “species” defined?
2 ways:
(i)Biological species concept
•Species= a group of organisms that
interbreed and produce fertile offspring
(ii)Morphological species concept
•Species defined on a set of shared physical
characteristics
Advantages and disadvantages to the
following definitions of a species:
A) Biological species concept
Advantages
Widely used by
scientists
Disadvantages
Not applicable to different
plants species that can
hybridize under natural
conditions or
If species reproduce
asexually
Advantages and disadvantages to the
following definitions of a species:
b) Morphological species concept
Advantages
Disadvantages
Simple to use
Incorporates
plants and
organisms that
reproduce
asexually
Almost all pop’n are
made up of non-identical
individuals doesn’t
mean that are not from
the same species
Why is studying biodiversity important?
•Nature's Services to Humans
–Clean water, clean air, soil for agriculture,
the pollinating effect of many insects etc.
•Economic Reasons
- Lumber, fishery catches, agriculture,
livestock, recreation
•Medicine
•Aesthetic and Intrinsic Value
Taxonomy
•Taxonomy is the
identification, classification,
and naming of species.
If you were a taxonomist in charge of creating a
universal system of classifying organisms. What are the
challenges in classifying Earth’s millions of species?
1. What language would you use?
2. What criteria does a modern taxonomist use for
characterizing organisms?
3. What are some problems with using common names,
such as “cat” or “starfish” or “flesh-eating shark” in
classifying organisms?”
Traditional Taxonomic
Systems
Carolus Linnaeus (Li-nay-us)(17071778), a Swedish naturalist
•created rules for classification based
on organism shared characteristics:
– Binomial nomenclature (Two-part name)
– Genus species
– 1st letter of the Genus name is capitalized;
species in lower case
– always italicized if typed, or underlined if
handwritten
The Binomial System
• Black bear Ursus Americanus
• Grizzly bear Ursus horribilis
• What can be said about 2 species
having the same genus?
• The same genus name indicates that
these two species are closely related in
anatomy, embryology and evolutionary
ancestry.
Levels of Classification
• There are 8 levels or taxa (singular:
taxon):
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
• Can you come up with a mnemonic device
for 7 taxa?
• King Phillip Comes Over For Great Soup
Taxonomic Classification of Grey
Wolf- an example
Becoming more specific
Three Domains and Six
Kingdoms Classification
System
All Living
Things
Domain
Bacteria
Kingdom
Bacteria
Domain
Archaea
Kingdom
Archaea
Domain
Eukarya
Kingdom
Protista
Kingdom
Fungi
Kingdom
Plantae
Kingdom
Animalia
HW- Create a dichotomous key to
classify 6 kingdoms
Dichotomous Key
• A step-by-step guide to help identify an
organism
• Follows a series of choices will lead you to the
organism’s name
2 types of dichotomous keys: same result
ibis
heron
spoonbill
cardinal
eagle
Dichotomous key: more
examples
Please do Practice Exercise now
Use a dichotomous key to identify
creatures on planet Pamishan
Practice creating a dichotomous key
Assign Latin-like binominal name for
each deer-like creature
Answer
Example:
• 1. body with large spots ......go to 2
Plain body ..... go to 4
• 2. Has 4 legs .....go to 3
Has 8 legs .......... Deerus octagis
• 3. Has a tail ........ Deerus pestis
Does not have a tail ..... Deerus magnus
4. Has a pointy hump ...... Deerus humpis
Does not have a pointy hump.....go to 5
5. Has ears .........Deerus purplinis
Does not have ears ......Deerus deafus
Many possible answers
As long as your key works
oval body
….. Deerus ovus
humpback body
….. Deerus humpis
1-loop tail
With tail
2-loop tail
body with
dark spots
body with
faint spots
….. Deerus darkus
4 legs …..Deerus tetragis
8 legs ….. Deerus
octagis
Without
tail
….. Deerus tailess
Announcement
Lab quiz “Classifying the
Kingdom of pasta”
Changed to Monday Sep
15 2014
in class, ~30 min
The importance of classification to
Technology, Society, and the Environment
• Environmental conservation of organisms
• tracing the transmission of diseases and the
development and testing of possible treatments
• Medical Products - helps narrow search to species
closely related to organisms already known to produce
valuable proteins or chemicals for medical purposes.
• increasing crop yields through disease and pest
resistance
Problems with traditional taxonomy
• Deciding and agreeing on what
criteria to use to define each taxon
• Internal anatomical and
physiological features are more
significant than external features
when creating dichotomous key.
However, they are difficult to
observe.
Modern taxonomy and Phylogeny
Going back in time
• Phylogeny = the study of the
evolutionary relatedness between and
among species
Family Tree
Common
ancestor
Phylogenetic tree
(also cladogram)
1.
2.
3.
Which organisms in the above cladogram have hard shelled
eggs?
Which organisms in the cladogram have a backbone?
Which shared a common ancestor most recently – a bird and a
crocodile or bird and a monkey?
Looking at clades in a cladogram
A clade includes a single ancestor species and all
its descendents (both living and extinct)
Looking at clades in a cladogram
A clade includes a single ancestor species and all
its descendents (both living and extinct)
HOW TO BUILD A CLADOGRAM
• http://ccl.northwestern.edu/simevolution/ob
onu/cladograms/Open-This-File.swf
Comparing traditional and modern
taxonomy
Based on shared
physical features
Based on recent shared
ancestor
Recent advancement: International
Barcode Of Life project
• Launched in 2010
• Use DNA to create DNA profile of every
species in the form of a barcode
• http://ibol.org/.
Paul Herbert, U of Guelph
http://www.uoguelph.ca/~phebert/
DNA Barcoding
International Barcode Of Life Project
• DNA sequence of Arctic warbler
(Phylloscopus borealis) looks like:
• CCTATACCTAATCTTCGGAGCAT
GAGCGGGCATGGTAGGC....
And its image looks like this:
Benefits of iBol project:
•reveals wide spread false labelling of fish products sold in
Canada and US
•Allows low cost sampling and monitoring diversity of entire
ecosystem
Review
1. Which group is more specific, order or
class?
• Order
2. What is meant by binomial nomenclature?
• A two name system (Genus species)
3. List the 6 kingdoms in order from primitive
to advanced
• Bacteria, Archaea, protista, fungi, plants,
and animals
Review
4. Which of the following pairs is MOST
closely related?
• Acer rubrum & Acer saccharum
• Acer rubrum & Chenopodium rubrum
5. The science of classification is called
_____________
What are the 3 levels of biodiversity?
(1) Genetic Diversity among organisms of
the same species
(2) Species Diversity
-Variety of species within an ecosystem
and the # of individuals within each
species
-Helps to determine the health of the
ecosystem
(3) Ecosystem Diversity
Threats to Biodiversity
1.
2.
3.
4.
Overhunting/Over-fishing
Habitat Loss
Invasive Species
Climate change
Human is the cause of the current
mass extinction