Post on 28-Dec-2015
Chapter 17 – Organizing Life’s Diversity
I. Classification – grouping of objects or organisms based on a set of criteria; 2 scientists
A. Aristotle (394-322 B.C.):
Greek philosopher who
grouped organisms aseither plants or
animals
B. Carolus Linnaeus (1707-1778) – Swedish naturalist who grouped organisms based on morphology, behavior, & habitat
1. Taxonomy – branch of Biology where species are identified, named, & classified based on natural relationships
II. Binomial Nomenclature – a system that gives each species a scientific name that has 2 parts
A. 1st part: genus name; capitalized
2nd part: specific epithet/name; it IDs the species;
lowercased
B. Writing Scientific names 1. italicized when typed:
Homo sapiens2. in handwriting: Homo
sapiens
C. Latin is the language of Binomial Nomenclature – why?
It is no longer used in conversation and, therefore, does not change
D. Common names are confusing & vary in use
1. A starfish isn’t a fish2. A sea horse is a fish, not a horse3. Sea cucumbers are not plants
III. Taxonomic Categories – these are a nested, hierarchical system, where each category is contained within another from broadest to
most specific
A. The broader the characteristics, the more species the taxon contains
1. Species – smallest taxon; organisms that are able to interbreed & produce fertile offspring in a natural setting
2. Genus – group of species that are closely related & share a common ancestor
3. Family – group of similar, related genera (plural of genus)
4. Order – group of related families
5. Class – group of related orders
6. Phylum / Division – group of related classes
7. Kingdom – group of related phyla/divisions
8. Domain – largest taxon; group of related Kingdoms
B. Example in Humans:
Taxon Name Shared with?
D-Dear Eukarya all other organisms w/ nuclei & organelles in their cells
K-King Animalia all other animals
P-Phillip Chordata with a spinal cord
C-Came Mammalia hairy; young are fed milk
O-Over Primate opposable thumbs
F-For Hominidae primates w/ social skills & complex intelligence
G-Good Homo all humans, including those that are extinct
S-Spaghetti
sapiens us – the only humans alive
C. Dichotomous Key – a key made up of sets of numbered yes/no statements
1. Has green colored body ......go to 2
Has purple colored body ..... go to 4
2. Has 4 legs .....go to 3
Has 8 legs .......... Deerus octagis
3. Has a tail ........ Deerus pestis
Does not have a tail ..... Deerus magnus
4. Has a pointy hump ...... Deerus humpis
Does not have a pointy hump.....go to 5
5. Has ears .........Deerus purplinis
Does not have ears ......Deerus deafus
IV. Phylogeny – the evolutionary history of a species, based on characters (inherited, varied features)
A. Morphological – similar parts suggest a relationship
beaks of Galapagos finches
bones in vertebrate limbs
B. Biochemical – similar amino acids & nucleotides in DNA suggest a
relationship
1. Cauliflower & Broccoli look different, but have almost identical DNA (mustard)
C. Cladogram – a branching diagram that represents the proposed phylogeny or evolutionary history of a species or group
D. The 3 Domains w/ 6 Kingdoms – differ in cell type & structure (pg. 502)
Domain Kingdom Characteristics
Bacteria (Eu)Bacteria cell walls w/ peptidoglycan,unicellular
Archaea Archaea(bacteria) cell walls w/o PG, unicellular
Eukarya Protista cell walls w/ cellulose in some, unicellular or multicellular
Fungi cell walls w/ chitin, mostly multicellular,
heterotrophs
Plantae cell walls w/ cellulose, multicellular, autotrophs
Animalia no cell walls, multicellular,heterotrophs
Eu
kary
ote
sP
rokary
ote
s
Au
totro
ph
s OR
Hete
rotro
ph
s
Evolution of the 6 Kingdoms of Life
Common Ancestor
Older, Less
Complex
Newer, More
Complex
ArchaeaBacteria
Protista
Animalia FungiPlantae
The 6 Kingdoms of Life