Post on 08-Jan-2018
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Classification
• The activity that involves grouping and naming is called classificationclassification.
• Biologists classify organisms into categories called Biologists classify organisms into categories called taxataxa..
• The branch of Biology that involves classification of organisms is called taxonomytaxonomy.
Not to be confused with taxidermy!
How to Classify
• Classification is artificial, but helps scientists deal with the great diversity of species and determine relationships.
• With the theory of evolution, we now classify organisms according to ancestry.
• The fossil record can help to make connections between species.
Introducing…. Carl Linnaeus
• Founder of modern Taxonomy• He gave us “binomical nomeclature”, the Two
word Latin name for identifying species:first name is the genussecond name is the species nameboth together we call the species name
1707-1778
There are There are 7 7
taxonomic taxonomic levels:levels:
1.1. KingdomKingdom2.2. PhylumPhylum3.3. ClassClass4.4. OrderOrder5.5. FamilyFamily6.6. GenusGenus7.7. SpeciesSpecies
TaxonomyGreat White Shark Human
Kingdom Animalia Animalia
Phylum Chordata Chordata
Class Chondrichthyes (cartilaginous fish)
Mammalia
Order Elasmobranchii (sharks and rays)
Primates
Family Selachii Hominidae
genus Carcharodon Homo
species carcharias sapiens
Based on three principles: 1.Groups of organisms are descended
from a common ancestor. 2.At each node (divergence of a
population), there are two branching lines of descendants.
3.Evolution results in modifications of characteristics over time.
A branching diagram that depicts species divergence from common ancestors.
They show the distribution and origins of shared characteristics.
We will use a dichotomous key: Presents with two statements that
describe certain characteristics. The statements should be mutually
exclusive (for example, 'it is either red or it isn't‘).
On selecting one, the reader is presented with the next couplet choice in the key and so on
to eventually arrive at an identification.