Week 14 Lecture20 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 Drollingerwww.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-