BIOLOGICAL DIVERSITY: CLASSIFICATION

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BIOLOGICAL DIVERSITY CLASSIFICATION
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Taxonomy is that branch of biology dealing with
the identification and naming of organisms.

• The ancient Greek philosopher _____________
• apparently began the discussion on taxonomy.
• British naturalist _____ ______ is credited with
  revising the concept of naming and describing
  organisms.
• During the 1700s, Swedish botanist Carolus
  __________ classified all then-known organisms
  into two large groups the kingdoms Plantae and
  Animalia.

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Whittaker

• Whittaker in 1969 proposed _______ kingdoms
  Plantae, Animalia, Fungi, Protista, and Monera.
  Other schemes involving an even greater number of
  kingdoms have lately been proposed, however most
  biologists employ Whittaker's five kingdoms.

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Taxonomy of a selected plant species. Note the
increasing inclusively of the "higher" taxonomic
ranks. __________ have a great deal more types of
creatures in them than do _________
Purves et al., Life The Science of Biology, 4th
Edition
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• Classification of a single species of animal.
  Note the similar composition of the animal
  kingdom above as compared to the plant kingdom.

Purves et al., Life The Science of Biology, 4th
Edition
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Linneus attempted to pigeon-hole (or classify)
all known species of his time (1753). Linnean
hierarchical classification was based on the
premise that the _______ was the ___________
unit, and that each species (or taxon) nested
within a higher category.

• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primates
• Family Hominidae
• Genus Homo
• species sapiens

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Linneus also developed the concept of ___________
_____________ , whereby scientists speaking and
writing different languages could communicate
clearly. Linneus settled on _________, which was
the language of learned men at that time. If a
scientist refers today to Homo, all scientists
know what organism/taxon he or she means.
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Construction of Phylogenetic Trees

• Taxonomy is part of a larger division of biology
  known as _________________. Determination of
  phylogeny is a goal of systematics. This is done
  by the construction of ________________ trees,
  which in a sense represent evolutionary
  hypotheses and attempts to define monophyletic
  groups.

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To build these trees, we must have _____,
which comes from the characteristics used in
classification. There are several methods of
classification traditional, phentic, and
cladistic. They differ in how they value certain
characters.
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Data used in traditional systematics
stresses both common ancestry (monophylesis) and
the amount of divergence among groups. The
traditional, dating to Linneaus view, is that
birds have __________, reptiles have ________,
and __________ have hair. Using this as a major
character, a classification like that above has
been constructed.
Purves et al., Life The Science of Biology, 4th
Edition
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• Fossils, evidence of past life, are not included
  in this classification. Since all of these groups
  have the aminiotic egg, or a modification of it,
  they would be united in a larger taxon. Linneus
  placed each of these groups in a separate class
  within the Phylum Chordata.

Purves et al., Life The Science of Biology, 4th
Edition
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Cladistics and Cladograms

• Cladistics is a type of systematics developed by
  the late German biologist _______ _________, who
  attempted to formulate a more objective method of
  classifying organisms. Cladists group organisms
  based on the presence of shared ____________
  characters, not the overall similarity of
  potential group members.

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• The amniotic egg would be used to unite a group
  sharing common ancestry, since it would NOT be
  present in a group that was not in the lineage.
  The use of feathers and hair to separate birds
  and mammals from reptiles would NOT factor into a
  cladistic hypothesis, or cladogram, since these
  are characters unique to only one taxon in our
  group.

Purves et al., Life The Science of Biology, 4th
Edition
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The example used above, if treated cladistically,
would produce a very different classification!
Note that __________________ have more in common
(in a cladistic sense) with birds than they do
with other reptiles. Birds and crocs form a
_______, or monophyletic group united by shared
derived characters not present in the other
groups. If we construct a Linnean group from this
cladogram, we have a class of birds and
crocodiles, a second class of lizards, snakes,
and turtles, and a third class of mammals
Purves et al., Life The Science of Biology, 4th
Edition
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Purves et al., Life The Science of Biology, 4th
Edition
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Giant Panda

• One of the more interesting applications of
  cladistics is to the question of the pandas. The
  giant panda was once thought to be a bear, but
  later its racoon-like characters caused it to be
  placed closer to racoons. The red (lesser) panda
  lives in the same areas of China as the giant
  panda, but has a far greater similarity with
  racoons.

Image from Purves et al., Life The Science of
Biology, 4th Edition, by Sinauer Associates
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Phenetics Phenetics is a process by which taxa
are clustered together based on the number of
their ___________ (or differences, depending on
the numerical coefficient employed). Traits are
measured and either converted into integers or
input directly as numerical data. Theses data are
then mathematically processed using an algorithm
that generates a similarity (or distance as the
case may be) matrix. There are a lot of problems
with this system. It is not very workable.
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Image from Purves et al., Life The Science of
Biology, 4th Edition, by Sinauer Associates