Download Bot3404_11_week6.2 - Ecological Evolution – E

Announcements
Urban Forestry data and photos due next week after
the break.
Reading.
Writing assignment due Oct 18.
Choose one of the characteristics out of Table 1, find
an interesting citation. Find that citation on the Web
of Science and discuss 3 other papers that have
cited the citation you chose.
“Forests” ~300 million years ago – Prototaxites
TREES
High levels of genetic diversity but slow
mutation and speciation rates.
High local genetic diversity with high rates of
gene flow. (paradox?)
Species integrity despite apparent interspecific
gene flow.
TREES
“Wood” is produced by most plants. Another
example that evolution primarily builds upon
existing genes, instead of evolving new ones.
PHYLOGENETICS
reconstruction of the historical
relationships among organisms.
An important framework for
understanding the evolution of
adaptive traits –
– Is it convergence?
– Has it happened multiple times?
– What is the sequence of events?
MOLECULAR SYSTEMATICS
Polymerase chain reaction – probably one of
the most useful and important discoveries in
biological research.
Amplifies a specific region of DNA out of the
entire genome, so that you go from having a
few copies to having millions of copies.
MOLECULAR SYSTEMATICS
The 3 different genomes in a plant cell
provide different information about the history
of the organism.
The chloroplast has been extensively used
because it has several good qualities: structure
is very stable and it is primarily inherited
through the mother plant.
MOLECULAR SYSTEMATICS
Different parts of the genome evolve at
different rates.
These different rates provide insight into
different depth of history.
– Exons vs. introns
– 3rd vs. 1st and 2nd positions in codons
– Balancing vs. Directional selection
MOLECULAR SYSTEMATICS
Next-gen sequencing
Whole genomes are routinely being
sequenced now.
This will eclipse PCR as the next major
revolution in biology.
BIOINFORMATICS
This field is also rapidly changing and will be
on the frontier of discovery for the next decade.
Our ability to gather and process information
has greatly outpaced our ability to understand
and interpret it.
MOLECULAR SYSTEMATICS
Sequence alignment is critical and sometimes
difficult.
With genomics, we can now look at structural
features, like major inversions, translocations,
or copy number changes.
MOLECULAR DATA
Ribosomal DNAs
Low copy number genes
Expressed Tag Sequences
MOLECULAR DATA
“Saturation” - information has been erased
through time.
Long branch attraction