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BIOINFORMATICS LESSONS ON ENSIweb
Tutorial:
Investigating Evolutionary Questions Using Online Molecular Databases:
<http://www.indiana.edu/~ensiweb/lessons/p.tut.db.html>
SYNOPSIS Students are guided through a process in which three
questions are addressed by retrieving beta hemoglobin
sequences from online databases, and using online tools to compare
those sequences in student-selected animals. The questions: (1)
Are bats birds, or mammals?; (2) Are whales more closely related
to artiodactyls, or perissodactyls?; and (3) should birds be
included in the class Reptilia?
PRINCIPAL CONCEPT: Degrees of biological relationship can be
inferred from comparisons of selected molecules.
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Pseudogene
Suite (3 lessons: A,B,C): Vitamin C and Common Ancestry:
<http://www.indiana.edu/~ensiweb/lessons/psa.ball.html>
SYNOPSIS: Students compare the DNA sequence data for
a portion of the rat GULO gene (which helps make vitamin C) to
the corresponding sequence in the inactive human GULO gene by
translating the sequences and by aligning them. This lays ground
work for exploring pseudogenes and the significance of these
DNA sequences in recognizing shared common ancestry vs the notion
of "intelligent design" (Lesson B). Lesson C is a
tutorial which introduces students to the online tools for analyzing
DNA sequences.
PRINCIPAL CONCEPT: Mutation may create an inactive version of
a gene (an inactive allele), and, over generations, the active
gene (allele) may be lost from the species, leaving only the
inactive gene (pseudogene).
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Molecular
Sequences & Primate Evolution (beta Hemoglobin): <http://www.indiana.edu/~ensiweb/lessons/mol.prim.html>
SYNOPSIS: Students compare differences in amino acids in
the beta hemoglobin from representative primates, complete
a matrix of those differences, and from these data, construct
and interpret cladograms as they reflect relationships and timing
of divergence.
PRINCIPAL CONCEPT: Modern apes and humans evolved from a common
ancestor.
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Molecular
Biology & Phylogeny (cytochrome c): <http://www.indiana.edu/~ensiweb/lessons/mol.bio.html>
SYNOPSIS: Amino acid sequences in cytochrome-c are compared
for several different animals, and the number of differences
found are used to infer degrees of relationship. These data are
also compared with a cladogram constructed for those same animals
from their anatomical features, providing an example of independent
confirmation.
PRINCIPAL CONCEPT: Independent confirmation strengthens scientific
inferences.
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Chromosome
Fusion: http://www.indiana.edu/~ensiweb/lessons/c.fus.les.html
SYNOPSIS: The banding pattern of our long chromosome #2 closely
matches the banding patterns of two shorter chromosomes found
in apes. This suggests the likelihood that our #2 chromosome
was formed by the head-to-head fusion (merging) of those two
shorter chromosomes in an early human ancestor. To test that
hypothesis, students search for evidence of this fusion in the
DNA of chromosome #2, using online databases (or printouts of
same) to seek the sequences typical of terminal DNA (telomeres).
In the process, students see how patterns can reveal events of
the past, thereby merging elements of both experimental and historical
science. They discover the huge amount of DNA in a chromosome,
get a sense of gene size and the number of pseudogenes, correlate
visible chromosome bands and their contained DNA, and learn to
use an accessible resource for further study and inquiry.
PRINCIPAL CONCEPTS: Modern apes and humans evolved from a common
ancestor;
Investigative problem solving. Testing multiple lines of evidence.
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