biological classification. why classify? to study the diversity of life, biologists use...

Biological Classification

Why Classify?• To study the diversity of life, biologists use

classification systems to group organisms according to evolutionary relationships (common ancestry). This makes the diversity of life easier to study.

• Taxonomy – discipline to group organisms hierarchically and assign each organism a universally accepted name.

Carl Linneaus

• The modern system of taxonomy used today was created by Carl Linnaeus in the 1700s.

• It included a naming system called binomial nomenclature which literally means two-name naming system.

Binomial Nomenclature (scientific names)

Generic name specific name

Group of closely related species

Group of organisms maintained by biological mechanisms that result in their breeding mostly with their type (interbreeding)

Rules:

1. One binomial name for each species

2. Capitilzed Generic, lowercase specific. Ex: Homo sapiens, Tyrannosaurus rex

3. Constructed according to rules of Latin or Greek grammar

4. Discoverer of species gets naming rights

5. Typed in italics, underlined when written

Specific names can’t stand alone!

Centropyge bicolor

Baeolophus bicolor

Boletus bicolor

Labio bicolor

Ecsenius bicolor

Loxocemus bicolor

Phyllobates bicolor

Euphorbia bicolor

Gila bicolor

Epalzeorhynchus bicolor

Rhamnusium bicolor

Chilobrachys bicolor

Calendula bicolor

Lespedeza bicolor

Flabellina bicolor

Eucomis bicolor

Androctonus bicolor

Saguinus bicolor

Specific names can’t stand alone!

Match the binomial name to the bear

A. Brown (Grizzly) Bear

B. American Black Bear

C. Giant Panda

D. Polar Bear

___ Ursus arctos

___ Ursus maritimus

___ Ursus americanus

___ Ailuropoda melanoleuca

Convergent Evolution

Convergent evolution produces analogies, which are NOT useful in classification

Divergent Evolution

Divergent evolution produces homologies (from a common ancestor) which are useful in classification

DNA Comparisons

Similar DNA sequences are molecular homologies which are useful in classification

Embryo Comparisons

Embryos reveal homologies which are useful in classification

adult tunicate

What’s a Blue Tang?

Acanthurus coeruleus

Atlantic

Paracanthurus hepatus

Indo-Pacific

Paracanthurus hepatus is commonly called

• blue tang• regal tang• hippo tang• palette surgeon fish• flagtail surgeon fish• blue surgeon fish• other languages?

Biological Classification is Hierarchical

King

Philip

Cut

Open

Five

Green

Snakes

Which taxonomic group has the most diversity? The least?

Which taxonomic group has organisms that are most closely related? Least?

Taxonomic

Classification

Blue Tang Yellow Tang

Kingdom Animalia Animalia

Phylum Chordata Chordata

Class Actinopterygii Actinopterygii

Order Perciformes Perciformes

Family Acanthuridae Acanthuridae

Genus Paracanthurus Zebrasoma

Species P. hepatus Z. flavescens

Taxonomic

Classification

Blue Tang Percula Clownfish

Kingdom Animalia Animalia

Phylum Chordata Chordata

Class Actinopterygii Actinopterygii

Order Perciformes Perciformes

Family Acanthuridae Pomacentridae

Genus Paracanthurus Amphiprion

Species P. hepatus A. percula

Taxonomic

Classification

Blue Tang Great White Shark

Kingdom Animalia Animalia

Phylum Chordata Chordata

Class Actinopterygii Chondrichthyes

Order Perciformes Lamniformes

Family Acanthuridae Lamnidae

Genus Paracanthurus Carcharodon

Species P. hepatus C. carcharias

Taxonomic

Classification

Blue Tang Human

Kingdom Animalia Animalia

Phylum Chordata Chordata

Class Actinopterygii Mammalia

Order Perciformes Primate

Family Acanthuridae Hominidae

Genus Paracanthurus Homo

Species P. hepatus H. sapiens

Caiman Parrot T. rex

Animalia Animalia Animalia

Chordata Chordata Chordata

Reptilia Aves Reptilia