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

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. 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?

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

– 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

Taxonomic Classification of Grey Wolf- an example

Becoming more specific

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

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

Dichotomous key: more examples

ibis

heron

spoonbill

cardinal

eagle

Please do Practice Exercise now

Use a dichotomous key to identify creatures on planet Pamishan

Practice creating a dichotomous keyAssign 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 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/

DNA Barcoding

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?

Threats to Biodiversity

1. Overhunting/Over-fishing

2. Habitat Loss

3. Invasive Species

4. Climate change

Human is the cause of the current mass extinction