1. Biology 11 Citadel High School 2010
Classification
Biology 11
Citadel High School
2010

2. What is classification and why do we classify?
Classification is the action of grouping objects in useful units.
Scientists are always discovering new species of organisms.
We classify organisms in order to better understand them and how they relate to other organisms.

3. What is the science of classifying?
Taxonomy is the science of classifying organisms. It consists in classifying organisms according to similar and different characteristics. The characteristics used in classification can vary.

4. The history of classification
Aristotle ( BC) was one of the first taxonomists. He classified the plants into grasses, bushes, and trees.
He classified the animals depending on whether they lived on the earth, in water, or in air. (It didn't explain the fact that some birds were in water and air.)

5. Natural Classification
One of the objectives of the modern taxonomy is to establish a natural classification founded on evolution.
Related organisms have more features in common than the distantly related organisms.

6. Carolus Linnaeus
A Swedish botanist who elaborated a classification that is used again today. Linnaeus established binomial nomenclature.

7. Binomial Nomenclature
The binomial nomenclature is a set of scientific names formed of two words. The first name designates the Genus (a group of similar species), and the second designates the species.
Ex. sugar maple  Acer saccharum

8. Binomial Nomenclature
Ex. sugar maple  Acer saccharum
The Genus is written with a capital and the species with a lower-case letter and the two names are in italic or underlined.
As binomial nomenclature is in Latin, scientists all over the world can understand it, whatever their maternal language.

9. Why dont we use common names?
Common names are not used because they are not precise.
Ex: cougar, puma and mountain lion are all the same animal!
Merle: is a different bird in different Canada and in France.

10. The groups … Categories Example English kingdom Animalia Animal phylum
Chordata
Chordates
sub-phylum
Vertebrata
Vertebrates
class
Mammalia
Mammalian
order
Primates
family
Pongidae
Pongidae (big monkeys)
genus
Gorilla
species
Gorilla Gorilla
subspecies
Gorilla Gorrilla beringei
mountain Gorilla

11. Phylogeny
Phylogeny is the history of the evolution of the species. Scientists compared some modern shapes to fossils of similar shapes.
According to the biologists, new species appeared as the organisms adjusted (evolved) and the populations changed.

12. Phylogenetic Trees (pg
The representation of this classification looks like a tree, the modern species are indicated at the end of the branches.
The groups closer in the tree have a lot of common features ; the distant groups are very different and they are probably not closely related.

13. To determine the relations
Taxonomists compare the
appearance,
the internal structures,
the stages of development,
the chemical composition, etc.
All organisms are related either closely or quite distantly.

15. Ernst Haeckel middle of the 19th century
                                             
One of the first to describe the evolutionary relationships between living organisms.