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Unit 1 – Diversity of Living Things
The international year of Biodiversity 2010
http://www.youtube.com/watch?v=V1VYmpTikgw
International day of Biodiversity - May 22 2014
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. WilsonCoined 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 Disadvantages
Widely used by scientists
Not applicable to different plants species that can hybridize under natural conditions orIf species reproduce asexually
Advantages and disadvantages to the following definitions of a species:
b) Morphological species concept
Advantages Disadvantages
Simple to useIncorporates 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
•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
Why is studying biodiversity important?
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
– 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
Carolus Linnaeus (Li-nay-us)(1707-1778), a Swedish naturalist•created rules for classification based on organism shared characteristics:
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):
DomainKingdomPhylumClass Order Family Genus Species
• Can you come up with a mnemonic device for 7 taxa?
• King Phillip Comes Over For Great Soup
All Living Things
Domain Bacteria
Domain Archaea
Domain Eukarya
Kingdom Bacteria
Kingdom Archaea
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Three Domains and Six Kingdoms Classification
System
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
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 humpisDoes not have a pointy hump.....go to 5 5. Has ears .........Deerus purplinis Does not have ears ......Deerus deafus
Many possible answersAs long as your key works
With tail
Without tail
1-loop tail
2-loop tail
oval body
humpback body
….. Deerus ovus
….. Deerus humpis
body with dark spots
body with faint spots
….. Deerus darkus
…..Deerus tetragis
….. Deerus tailess
4 legs
8 legs ….. Deerus octagis
AnnouncementLab 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• Phylogeny = the study of the
evolutionary relatedness between and among species
Family Tree Phylogenetic tree(also cladogram)
Commonancestor
Goi
ng b
ack
in ti
me
1. Which organisms in the above cladogram have hard shelled eggs?2. Which organisms in the cladogram have a backbone?3. Which shared a common ancestor most recently – a bird and a crocodile or bird
and a monkey?
Looking at clades in a cladogramA 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 Guelphhttp://www.uoguelph.ca/~phebert/
International Barcode Of Life Project
• DNA sequence of Arctic warbler (Phylloscopus borealis) looks like:
• CCTATACCTAATCTTCGGAGCATGAGCGGGCATGGTAGGC....
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
Review1. Which group is more specific, order or class?• Order2. 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 _____________
(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
What are the 3 levels of biodiversity?