Week 14 Lecture
20 May 2014
Classification of living things
Adaptations
• The successive presence of traits which are
best suited to support an organism to survive
in its habitat
• Can be:
– Structural (related to structure of organism)
– Behavioural (related to what organism does to
survive)
– Physiological (related to how an organism
functions on the inside)
Evolution
• Basis of theory is
that all derive from
a common ancestor
• Shows increasing
levels of complexity,
as described in
vertebrate
cladogram below
• The large diversity
of life is the result
of ongoing process
of evolution
Taxonomy- the classification of living
things
• Based on grouping organisms
according to similarities in
physical characteristics
• Basic framework was developed
by Carolus Linnaeus (1735) in
‘Systema Naturae’)
• Relationships between organisms
(how they evolved) has been
enhanced by genetic studies
Principles of classification
• Reflects evolutionary distances and
relationships between organisms
• Organisms that have the same common
ancestors are members of the same family
tree
• Organisms are classified into levels from
broadly similar (kingdom) to the same species
• At each level certain characteristics will be the
same for all organism in that grouping.
Levels of classification
• Some levels can be
divided into sub-levels (eg
subclass of mammalia are
the monotremes)
• Increasing number of
groups at all levels
• A species is a group of
organisms that are able to
reproduce to create viable
offspring
• A species share the ‘same’
DNA
Humans
• ½ of all
animal
species are
insects
• 4% species
are
chordates
• 0.4%
species are
mammals
Kingdoms
• There are five kingdoms (classified
according to cellular arrangement,
locomotion and method of nutrition
– Animalia (sponges, worms, insects fish,
amphibians, reptiles, birds and mammals)
– Plantae (mosses, ferns, pines, woody and
non-woody flowering plants)
– Fungi (fungi, molds, yeasts and smuts)
– Viruses and prions
– Protista (protozoans and algae)
– Monera (bacteria, blue-green algae and
spirochetes)
Phylum
• There are 33 phylum in the animal
kingdom
– Egs
• Athropoda (external skeleton, jointed bodies and
limbs such as spiders, insects, centipedes,
lobsters)
• Mollusca (soft segmented bodies, enclosed in
hard shells such as snails)
• Chordata (elongated, bilaterally symmetrical
bodies, have gills slits at one point in their lives,
have a notochord at some stage in their
development, have digestive system such as
humans, mammals, birds, fish as well as sea
squirts)
Class
• There are 7 classes in the vertebrate phyla.
• These classes are grouped according to their skeletal
system, environmental adaptation and reproductive system
• There are:
– Three classes of fish (jawless fish/sharks and rays/bony fish)
– Amphibia (frogs, toads and salamanders which live on land and
breed in the water)
– Reptilia (have lungs, has an amniote, leathery egg including
snakes, lizards and alligators)
– Aves (amniote egg which is laid off the ground, and include
birds)
– Mammalia (have live young, feed them milk, have strong jaws,
are warm blooded and include primates, whales, platypus etc)
Classification of living things
• Watch the following You-tube video and note
down the levels of classification for species
shown
Classification of Living Things by Mark Drollinger
www.youtube.com/watch?v=vqxomJIBGcY
Homework• Work on your SAE2 case study report!
• See conditions of assessment and SAE2
information on wiki
• Birds and plastic waste-