Diversity of Life

Activity 1

• Record the names of as many different organisms as you can.

• Examine the list you created

How many were animals? Plants?

Are any in your list living things other than plants or animals?

Our list represent a small fraction of the diversity of organisms on earth

How many species have been classified ?

Biologist have named & classified almost 2 million species

Biodiversity

variety of organisms considered at all levels from population to

ecosystems

Activity 2

Below are some images of living things on earth

How many of these organisms can you correctly identify?

A. D.

B. E

C.

ANSWERS

A= hydra B= paramecium C=lichen

D= evergreen E= bacteria F=squirrel

Because there is such a wide range of different organisms on earth, scientists

organize them according to certain characteristics that they have in common

The science of describing, naming and classifying organisms

TAXONOMY

TAXONOMY

was created to group organisms into categories

and to understand evolutionary relationships

*** LIBRARY ANOLOGY

What is the name of any particular group within a

taxonomic system

Taxon (plural taxa)

Classification of organisms

Throughout human history we have been observing & classifying organisms

• Prehistoric Humans - Hunting and gathering societies lives depended on recognizing editable and the harmful

• About 2,400 years ago Aristotle classified organisms into two taxa either plant or animal.

He grouped animals according to whether they lived on land, in water or in the air.

He grouped plants based on differences in their stems

Classification of organisms• Since then different classification systems were

developedFor example

Classifying plants into herbs, shrubs, pre-shrubs and trees.

Classifying animals into quadrupeds, birds, fish and snakes

Classifying plants based on visual similarities and differences

What not classify organisms by their common names ?

Common names vary from place to place & many don’t accurately define a species

Classification of organisms

• 1735 Swedish naturalist Carolus Linnaeus produced Systema Naturae

Categorized thousands of organisms into a hierarchy categories according

to form and structure range from species building to higher taxa

including two kingdoms

Linnaeus system

Original system had seven levels “categories” Each category

represented a level of grouping from larger more general

categories to smaller more specific categories

linnaeus system

levels of classification

Modern version of Linnaeus’s System

• Added more kingdoms

• Added domain level above kingdom

Linnaeus’s System

• 2 kingdoms animals & plants

• Categorized organisms by form & structure

• Grouped organisms by visual similarities

Modern system

Classification of organisms

• 1866 Ernest Haeckel organized a “Tree of Life”

• 1894 he redrew its branches into three kingdoms

• 1959 Whittaker Five kingdoms• 1977 Woese Six kingdoms

• 1990 Three domains

The future As new organisms are identified and as advancing technology allows for the study

of more characteristics of previously classified organisms some scientists are

starting to further divide some of the kingdoms into newer kingdoms with their

own sets of criteria

ANY QUESTIONS?

HOMEWORK

• Read Ch 17 p 336 – 340