Download Lesson 4

Review:
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taxonomy
six kingdom system
binomial nomenclature
phylogenetic tree
cladistics
Nov 23­2:54 PM
How do we classify unknowns?
'Dumbo' octopus (Grimpoteuthis sp.)
What appears to be an ancient gold treasure is a magnified crustacean, a tiny copepod collected this year from the Atlantic abyss
Nov 23­2:57 PM
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Methods to Classify Organisms
(a) Evidence from fossil records
(Radioactive dating)
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examining the decay of carbon 14 to find the age of some organisms
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by comparing age they can tell if fossils were ancestors of some organisms
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protein comparisons of some amino acid sequences can indicate similarities or differences
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for example the blood proteins in horseshoe crabs reveal that it is more closely related to spiders then crabs
Nov 23­2:56 PM
Nov 24­8:02 AM
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(b) Evidence from Anatomy:
(Structural information)
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comparison of bones found in certain animals
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for example the human arm, horse's leg, bats wing, and whale flipper are all similar
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similarities of bone structure indicate the same evolutionary origin
Nov 23­3:09 PM
Nov 24­8:03 AM
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(c) Evidence from Embryonic Development
(Comparative Embryology)
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the comparison of an organisms early embryo development
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if organisms share common features during their embryonic stage then they may be classified together
Nov 23­3:11 PM
Nov 24­8:04 AM
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(d) Evidence from Biochemistry (DNA)
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biochemical techniques can look at the arrangement of amino acids which form the basis of DNA
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for example human and baboon blood show very similar DNA patterns which suggest a close relationship between the two organisms
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the percentage of similarity of the DNA indicates the closeness of the relationship between the two species
Nov 23­3:12 PM
Nov 24­8:06 AM
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(e) Metabolic Behavior
­ comparison of digestion habits or the substances eaten
­ if an organism is a producer, consumer or decomposer can also be the basis of classification
Nov 23­3:15 PM
Readings:
Pages 113 ­ 119
Questions:
Page 121: #'s 1,2,3,5,6,7,10,12
Nov 23­3:18 PM
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