classification of living things introduction. aristotle greek 4 th century bc animals by movement...
TRANSCRIPT
Classificationof Living Things
Introduction
Aristotle
• Greek• 4th Century BC• Animals by movement• Plants by size
John Ray
• English• 17th century• Goal was to collect, name,
classify all plants and animals in England
• Used internal anatomy• First to use the word “species”
Carolus Linnaeus
• Swedish
• 18th century
• Used similarities in structure
• Invented a 2 word naming system (binomial nomenclature)
Genus species
Modern System
• Groups according to basic traits• Gives a unique name to every kind of living
thing• Name is used universally (Latin or Greek)
• Common names can be misleading– Starfish– Puma, cougar, mountain lion
Classification
• Process of grouping organisms based on similarities
Taxonomy
• Science of naming and classifying organisms
• Naming of organisms should reflect the traits of the organisms
• The more characteristics two organisms share, the more closely related they are
• If 2 organisms share the same trait, they could share the same ancestor
Biological Relationships
• Living things evolve over time• Scientists try to discover how one species
evolved as compared with another• Species that share ancestors are grouped
together.
Biological Relationships
• Scientists compare a variety of traits– Size– Bone structure– Body shape
Sargassum Fish
Sargassum Seaweed
Sea Dragon Sea Horse
Animal
Algae
Same body shape
Fronds
Fish with
Leafy fronds
Physical Evidence
• Early scientists used their eyes and measuring devices as tools to compare
• Noted color, size, weight, how energy is obtained
• Later they used internal structure and appearance
• Used fossils to compare species of past with those of today
Physical Evidence
• Fossils can tell how extinct organisms moved, lived, ate.
• Physical evidence shows that all organisms are related by evolution.
• Lives west of Rockies• Solid black head• No white feathers
• Lives east of Rockies• Blue, black, and white head
Cyanocitta stelleri Cyanocitta cristata
Genetic Evidence
• DNA and computers can be used to compare components of one organism with another.
• Genetic evidence usually supports physical evidence, but not always.