Chapter 18 Seeking order Amidst Diversity

1
Chapter 18 Seeking order Amidst Diversity
2
1. Earth Unity of Diversity

• Scientist believe there are between 5 million and
  30 million species on earth.
• To date1.5 million species have been
  identified.
• 1.25 million animals
• 250,000 plants

3
Systematics.

• The science of determining the evolutionary
  relationships among organisms
• Classification is not arbitrary! Classification
  reflects overall similarity, and especially,
  evolutionary history
• Organisms grouped together are similar
• because they share common ancestry.

4
1. Earth Unity of Diversity

• To organize all of these organisms, scientist
  classify species into categories.
• Taxonomy the naming and classifying of
  organisms.

5
1. Earth Unity of Diversity

• There are 3 Domains and 6 Kingdoms of life
• 1. Eubacteria (prokaryotic)
• 1. Eubacteria (Monera) Bacteria
• 2. Archaea (prokaryotic)
• 2. Archaebacteria
• 3. Eukarya (eukaryotes)
• 3. Protista Simple multi or unicellular
• animals
• 4. Plantae Plants
• 5. Fungi Yeast and mushrooms
• 6. Animalia Animals (invert and vertebrate)

6
(No Transcript)
7
1. Earth Unity of Diversity

• Taxonomic groups are ranked into a hierarchy from
  MOST to LEAST INCLUSIVE.
• 1. Domain
• 2. Kingdom
• 3. Phylum
• 4. Class
• 5. Order
• 6. Family example Western Pond Turtle
• 7. Genus ------ Clemmys
• 8. Species ------ marmorata

8
The Major Lineages of Life
9
Monera

• Generally unicellular prokaryotes

10
Protista

• Generally unicellular eukaryotes

11
Fungi

• Mostly multicellular eukaryotes that absorb
  externally digested nutrients

12
Plantae

• Mostly multicellular eukaryotes that obtain
  nutrients by photosynthesis

13
Animalia

• Mostly multicellular eukaryotes that ingest food
  and digest it internally

14
Phylogenetics

• The tracing of evolutionary relationships
  (phylogenetic tree)
• Linnaeus
• Binomial
• Genus, specific epithet
• Homo sapiens
• Taxon (taxa)

15
Phylogenetic Trees

• Cladistic Analysis taxonomic approach that
  classifies organisms according to the order in
  time at which branches arise along a phylogenetic
  tree (cladogram)
• Clade each evolutionary branch in a cladogram
• Types
• 1- Monophyletic single ancestor that gives rise
  to all species in that taxon and to no species in
  any other taxon legitimate cladogram
• 2- Polyphyletic members of a taxa are derived
  from 2 or more ancestral forms not common to all
  members does not meet cladistic criterion
• 3- Paraphyletic lacks the common ancestor that
  would unite the species does not meet cladistic
  criterion

16
Constructing a Cladogram

• Sorting homology vs. analogy...
• Homology likenesses attributed to common
  ancestry
• Analogy likenesses attributed to similar
  ecological roles
• and natural selection
• Convergent evolution
• species from different
• evolutionary branches
• that resemble one another
• due to similar ecological
• roles

17
A Cladogram