Download Classification of Earth`s Diversity - OG

Classification of Earth’s
Diversity
Biodiversity
• Biodiversity – the variety of
organisms on earth is the result of
3.5 billion years of evolution
• Approx 8 million species on earth!
• To make sense of all of them, they are
organized into meaningful groups
• Species are becoming extinct at an
increasing rate, so there is a rush to
catalog them
Common vs Scientific Names
• Common names are convenient, but there
are problems:
- same names are used for different species
(robin here, robin Europe)
- can be more than one name for same
species (mt lion, cougar, puma)
- very ambiguous (not very descriptive)
Common vs. Scientific Names
• Advantages of scientific names:
– Provide a consistent naming system for all
– Show evolutionary relationships
– Systematics – the science of naming and grouping
organisms according to biological meaning
– Groups are called taxa (singular: taxon)
Binomial Nomenclature
•
•
•
•
•
Bi = two, nomial = name
Scientific names have two parts
Always typed in italics (or underlined)
First word is capitalized, second is not
First word - genus – a group of similar
species
• Second word - species – unique to
ONLY that species
Use Latin language
Brown bear
Polar bear
•
•
•
•
Ursus arctos
Ursus americanus
Ursus maritimus
Ursus thibetanus
Black bear
Asian black bear
Linnaean Classification
• Carolus Linnaeus developed 1st
system
• Originally 4 levels of hierarchy, or ranks
– Used mostly physical characteristics
• Today there are 7:
– Now also use evolutionary history and
DNA sequencing to compare organisms
• Kingdom, Phylum, Class, Order,
Family, Genus, Species
• Mnemonic for remembering
• King Phyl Came Over For Good Spaghetti
Kingdom- Ex: p.514
•
•
•
•
•
Largest and most inclusive taxon
Who can be part of the Animal Kingdom?
Be multicellular
Be heterotrophic (need food from others)
Lack cell walls
Phylum
• Contains groups of organisms that are
different but share important characteristics
– There are NINE phlya in the Animal Kingdom
• Phylum Chordata features organisms with a
nerve cord along the back
• Within the phylum, are groups called
Classes…
Class
• Classes are groups that narrow down the
differences even further
• Class Mammalia includes all animals that are
• warm-blooded, have body hair/fur, and
produce milk for their young
• Within a class are groups called
orders…then… family… genus… and species
Kingdom Animalia (write!)
Give yourself ½ a page for each one
1.
2.
3.
4.
5.
6.
7.
8.
Phylum Porifera
9. Phylum Chordata
Phylum Cnidaria
10. Subphylum Vertebrata
Phylum Platyhelminthes 11. Class Agnatha
Phylum Nematoda
12. Class Chondrichthyes
Phylum Annelida
13. Class Osteichthyes
Phylum Mollusca
14. Class Amphibia
Phylum Arthropoda
15. Class Reptilia
Phylum Echinodermata
16. Class Aves
17. Class Mammalia
Characteristics that differentiate animals:
(You need to read up on these! Make concept
map of vocab: CH 25.2)
• Levels of organization (cells, tissues, organs, organ systems)
• Body symmetry (none, radial or bilateral)
• Germ layers (endoderm, mesoderm, ectoderm)
• Body cavity (acoelom, pseudocoelom, coelom)
• Type of body: Segmentation (repeating parts), cephalization
(getting a head), limb formation (legs, flippers, wings)
• Systems (digestive, circulatory), Reproduction (asexual or
sexual), Homeostasis (body temperature)
• Type of skeleton (endo- or exoskeleton)
Identifying Organisms
• Dichotomous keys
NOT like these
• Used to VISUALLY identify organisms
• Has series of “couplets” or paired statements
that describe visual traits (color, size, unique
features, etc.)
• Each statement describes the presence or
absence of a visible trait
• Each set of choices helps to narrow down the
identity of the organism
•
•
•
•
•
DIRECTIONS:
The most useful tool for such identifications is the
dichotomous key, which contains information useful in
identifying similar kinds of organisms, but is arranged in a
way that allows the information to be used quickly.
A dichotomous key is a list of paired statements (each
statement is called a lead) that guides you to the identification
of a specimen.
The paired leads (the pair of leads together is called a couplet)
are contrasting descriptions of certain characteristics.
In a good key, couplets are written so that you must choose
one or the other of the leads as being true for your specimen.
Couplet leads should always be mutually exclusive
In addition, the leads in a couplet should be parallel; that is,
both should ask questions about the same character(s).
Can you figure out the key?
• Help! Scientists have discovered quite a few
new creatures on planet Pamishan. They
need your help to identify and classify
them. Use the dichotomous key on the next
page to identify these creatures.
• ALWAYS start with step 1, and go to
whichever step the key tells you