Classification – Chapter 18Pennington

Chapter 18Pennington

Introduction:

• Why do we classify? To organize and group things in a logical manner. We know of 2,000,000 organisms. Scientists estimate there are 1 – 10 million unknown.

• This discipline is called taxonomy.• What is this creature?

It is Felis concolor!• But depending on where you live, it is known as puma,

mountain lion, cougar etc..• For this reason in the 1700’s a Swedish man, Carolus

Linnaeus, developed a 2 word naming system we call binomial nomenclature. There are 8 categories.

Domains:

• Recently scientists recognize the highest level as a Domain, there are 3:

• 1) Eukarya – all eukaryotes (have real nucleus)• 2) Archaea – “ancient” bacteria that live in extreme

condition like: geysers, volcanos, salt flats…• 3) Eubacteria – the rest of the bacteria, E. coli, anthrax etc..

Kingdoms:

• Now we recognize 6:– 1. Plantae – plants 5. Protista – amoeba, algae– 2. Animalia – animals 6. Eubacteria – most bacteria– 3. Fungi – mushrooms, molds– 4. Archaebacteria - extremophiles

Phyla:Basically there are 2 big ideas here –1) Invertebrates 8 Phyla (most numerous) and 2) Chordates

Under chordates we will go in to “classes” – 5:

• 1)Fish (Chondrichthyes, Osteichthyes)• 2) Amphibians• 3) Reptiles• 4) Aves ( Birds or Avians)• 5) Mammals

Order, Family, Genus and Species

• Getting down to very distinct groups of organisms that are similar in several ways.

• Species can interbreed and produce fertile offspring.• Know these common ones:• Ursus arctos

Ursus maritimus:

Canis lupus familiaris, Canis lupus

Felis domesticus and Panthera leo

Here’s us:

• Kingdom: Animalia

• Phylum: Chordata•

Subphylum: Vertebrata

• Class: Mammal• Order: Primates

• Family: Hominidae

• Genus: Homo

• Species: sapiens

LINNAEAN  CLASSIFICATION  OF  HUMANS

18 – 2 Modern Classification

• Biologists now group organisms into categories based on lines of evolutionary descent – not just physical similarities.

• Cladogram – diagram that shows relationships.• DNA and specific genes help us see which organisms are

most closely related (us and chimps 99% similar bases)