Report, hosted by Paul Wilson (email@example.com)
The Evolution Report is a series
of audio programs on evolutionary topics. It is primarily
intended to be supplemental instruction for BIOL 322 Evolutionary
Biology. Students say that they don't have enough time to study more
than they are already studying, but many spend tons of down-time
in their cars and relaxing before bed. Our idea then was to produce
an entertaining show that could be listened to during this down-time
and that would not consume high-quality time. The goal is to make evolutionary
topics more familiar. The Evolution Report is not meant
to be a thing that itself can be studied. Instead, after listening to
the Evolution Report we imagine that material in class will be
absorbed more easily and be more interesting. We also hope that the
Evolution Report will entertain and inform people not in 322 who take
an interest in the origins of adaptations and the diversity of life. Funding
for the Evolution Report has been provided by a grant by the NIH
to Dr. Maria Elena Zavala for supplemental instruction in the biomedical
sciences, particularly so-called "gatekeeper courses", i.e., those that
students of the biomedical sciences need to do well in early during their
college careers. Click here for
our list of supplemental materials, and here for more on the NIH-funded
minority programs at CSUN. Additional funding has been provided
by a Judge Julian Beck Grant administered by CSUN. Episodes do not depend
on one another. Students taking 322 might want to listen to them
in the following order. Clicking on the title will open an .mp3
file of about 27 MB. Most people have their browsers set to just
play the file. If you want to get it on your .mp3 player, you
should probably right click or hold down control while clicking so as
to "download link to disk", then copy over to your .mp3 player.
- Dr. Jim Hogue who teaches evolutionary biology at CSUN talks about
what he want 322 students to incorporate into their daily thinking
(as opposed to what we can test them on). What Dr. Hogue calls
"Selection Thinking" is central to his course. We also talk
about other bits of evolutionary logic, like "Tree Thinking".
Program - In 1979 Gould and Lewonton offered a critique of the
adaptationist's program in which they criticized people for believing
the first story that came to mind about the origins of a trait.
The eventual response was an expansion of the range of interpretations
of the historical origins of traits and a strengthening of how one
makes ainferencesbout adaptations. This topic is reviewed
with Dr. Rick Shine (University of Sydney), a prolific evolutionary
biologist who mainly studies reptiles.
Locus Evolution - Dr. Polly Schffiman, who teaches 322, simplifies
evolution down by considering a single genetic locus. She relates Hardy-Weinberg
equilibrium as "control conditions," and explains mutation,
selection, gene flow, drift, and hitchhiking as causes of evolution.
This is the foundational explanation upon which more complex evolutionary
scenarios are built.
- "Speciation" is defined as the origin of reproductive isolating
barriers. Dr. Dave Gray, who teaches 322 at CSUN has done extensive
studies of speciation in crickets. He tells of his work in this
interview, using it to illustrate many of the factors that may be
involved in speciation.
Evo Devo Ginger Banana
- Dr. Chelsea Specht (UC Berkeley) explains the joining of evolutionary phylogenetics
with developmental genetics, particularly in plants. She works on the Zingiberales,
containing bananas and gingers. She explains the a-b-c model of floral development
and how the genes involved are found not only in flowering plants.
Breeder's Equation - Dr. David Houle (Florida State University)
rearranges the equation that is usually expressed as ResponseTOselection
= Heritability × SelectionDifferential,
changing it to ResponseTOselection = AdditiveGeneticVariance ×
Selection Gradient. The multivariate form of this is R = Gß, which he explains in terms of the adaptive landscape. Life
history variables turn out to have a high "evolvability".
Only the Good Die
Young - Dr. David Reznick (UC Riverside) explains life history evolution.
A life table is a schedule of survivorship lx and fecundity
mx for each age class x; these numbers are components
of fitness. Using an example he has studied extensively, guppies from high
predation sites have shorter lives, reproduce sooner, and store less fat
than guppies from low predation sites. However, they do not meet the prediction
that high predation should cause accelerated scenescence compared to low
predation, invoking more complex explanations that are also rooted in the
math of life tables.
- My father Richard Wilson reads excerpts from On the Origin of Species
Inplace or Assembled - Dr. Carlos Herrera (Estación
Biológia de Doñana) tells of the two fields
of explanation for how the organisms in a community are apt to one
another. At one end of the spectrum, these organisms specifically
have adapted to one another in this community; at the other end of
the spectrum, they evolved in many other places under many other
circumstances and were assembled in this community because they can
use each other. Examples are given concerning birds-n-fruits,
pollinators-n-flowers, and bugs-n-leaves.
Engine of Macroevolution - Dr. Richard Squires of the Geology
department at CSUN gives an account of the history of life on Earth,
emphasizing how plate tectonics has caused many of the great changes.
Tectonic changes result in global climate change, the rise and fall
of sea levels, vicariance and exchanges, and volcanism. Ultimate & Proximate - Dr. Maria Elena
Zavala (who also administers the grant that funds the Evolution
Report) explains the complementary roles of ultimate and proximate
explanations in biology. Her training in evolutionary biology still
sets the stage for her scholarship in cell biology.
& Their Prey - Dr. Geerat Vermeij (UC Davis) tells of the evolutionary
effects of predation and more generally competition. Various adaptations
arise in prey and in predators. Predators have power over prey, and because
losing a life is worse than losing a diner, heavy investment in defense ensues,
particularly in high-energy environments. Communities are prone to escalation
when both opponents can be hurt. Losers fill in the intersticies of the
economy. After a crash, first quick metabolizers are favored, eventually
the community becomes more complex. Top predators are drawn from other
guilds, and their monopoly rarely last for long. This interview abstracts
much of Vermeij's (2004) book, Nature: an Economic History.
Uses of Trees - Dr. Kevin Omland (University of Maryland Baltimore
County) explains how one uses phylogenies (especially near the species
level) for ancestral state reconstruction, seeing the relative recency
of common ancestors, dating divergences, studying convergent evolution,
asking if two phylogenies are concordant as one would expect from cospeciation,
and as a basis for circumscribing taxonomic groups.
The Meanings of
Sex - Mia Adreani and Janna Fierst (former master's students)
talk about how evolutionary biologists use the words 'sex' and 'sexual',
and how sex is a central topic in our field, but not entirely for
the reasons that first come to mind. Sex, sexual: (1)
the systematic reorganization of the genome through meiosis and fertilization;
(2) gender strategies for reproduction; (3) pertaining to relationships
between the genders; (4) in certain organisms copulation, copulatory.
Selection Benefits - Dr. Leonard Nunney (UC Riverside) explains
why the adaptations of individuals are not usually fashioned for the
good of the species, then untangles other levels of selection, such as
kin selection, selection among cells, and selection among lineages. He
explains why we get so many types of cancer and why most species remain
& Herbivores - Dr. Conchita Alonso explains classical views
of how herbivores such as caterpillars evolve on diverse plants and how
plants have evolved in face of these enemies. She addresses the adaptive
nature of defensive traits, tradeoffs, and key innovations. Mating Systems in Plants - Dr. Steven Weller (University
of California Irvine) traces the paths of evolution from one mating
system to another in plants, including discussion of the evolution of
selfers, gynodioecy (females + hermaphrodites), dioecy (females + males),
and heterostylous species.
Changin Times in
Species Exploration - Dr. Marshal Hedin (San Diego State U) explains
the flood of work in molecular systematics caused by genetic tools breaking
the dam behind which difficult problems have been accumulating for 300 years
since Linneaus. Topics include a critique of species barcoding, detecting
cryptic species, studying population genetic structure in low-dispersal groups,
and unraveling the origin of cave-dwelling species. Systematics provides a
biologically relevant organization for knowledge of various organisms. Good
classifications, including good species concepts, are based on multiple lines