Comments for ...In Light of Evolution

Comment on “Evolutionary Game Theory as a Framework for Studying Biological Invasions” by Alex Kula

Alex Kula — Wed, 21 Dec 2011 21:42:07 +0000

Thought this was an interesting read
http://www.nytimes.com/2011/12/21/us/in-great-lakes-states-a-divide-over-the-asian-carp.html?_r=1

Comment on The evolution of hyperactivity, impulsivity and cognitive diversity by Chantel Caldwell

Chantel Caldwell — Thu, 15 Dec 2011 21:09:42 +0000

I have never been a supporter of ADHD (at least in the masses that we see today) but this paper was intriguing since I also never understood it on the evolutionary or genetic level. I have never disagreed with the fact of ADHD existing, I just think our society has been to quick to diagnose. I really appreciated the video from Nicole, I think he hits a lot of important points. ADHD has significantly increased over the past years, highly correlated to the amount of media present in our lives. Kids and young adults have grown up with the constant entertainment and at a fast pace. What would you expect when you sit these kids in a classroom for 8 hours straight?
An interesting point that has recently been added to this argument is home life. They are now trying to correlate the single family homes, or two working parents as a lack of involvement (possibly a controversial study). Overall, many people are questioning if the lack of parent involvement or discipline is adding to a higher ADHD diagnosis. Teachers are being blamed and punished for kids not succeeding in the classroom, yet it is rare for schools to address the lack of parent involvement in the after hours…
You guys are mentioning how you can grow out of ADHD, well now there are new advertisements for adults with ADHD. How they expected that they grew out of it but they find themselves easily distracted… then the advertisement ends with a test they can take to see if they need medication. I find this really disturbing.
When diagnosing ADHD, I wonder if they include some of the evolutionary supported personality traits?

Comment on Ecological and Evolutionary Consequences of Coastal Invasions: A review by Chantel Caldwell

Chantel Caldwell — Thu, 15 Dec 2011 20:46:58 +0000

I enjoyed this paper, and agree with Alex, it was nice to see a study that looked at different levels. Most invasive studies concentrate on a specific population and how the invasive is negatively impacting it. Very rarely do they address the entire habitat and the adaptations experienced from both native and invasive populations. As we all know impacts caused by invasive populations occur at all levels of the food web and therefore impact the entire habitat.
The comment of keeping ecology and evolution separate on some level reminds me of many debates on management. Throughout the year we have all experienced the challenge of keeping idealistic approaches and studies separate from realistic (in the sense of time, money and community). Management practices are concerned about the areas in their jurisdiction, they aim for them to be in good health, self-sustaining, and usable for profit. This means looking at it from a ecological stand point, aka a shorter time period. While our papers this year have focused on the natural habitat (what populations have historically been found in the area, what the food web was, what genetics were in the area) and how the natural habitat has changed usually due to anthropogenic influence. Bringing this back to natural vs. invasive, I agree with Mike. Communities will consider a population natural when it is a self-sustaining population and of course not tearing down the food web. Looking at the alewife, it was considered invasive when they consumed all the phytoplankton; causing local cisco and perch populations to decrease. Although with the introduction of salmon, this population is now under control. In the ecological sense, the population has become naturalized but evolutionary it will never be considered naturalized since historically their genes were never found here.

Comment on Predator-Driven Trait Diversification in a Dragonfly Genus: Covariation in Behavioral and Morphological Antipredator Defense by Meg

Meg — Mon, 12 Dec 2011 16:28:53 +0000

This was the second paper that had to do with phenotypic plasticity this week! I wonder why the authors did not do the “common garden experiments” as I believe they could have had much stronger results with such findings. From my research on phenotypic plasticity, it seems that much of the literature on this topic is in the field of entomology. This fact makes me wonder if insects in general have higher phenotypic plasticity compared to vertebrates. If so, could this fact explain the evolutionary history of the extremely diverse and wide spread arthropods? Unfortunately, my Invertebrate Zoology course in undergrad did not take an evolutionary approach to the topic. I believe this would be useful in any Biology course, not just in Evolution classes.

Comment on Ecological and Evolutionary Consequences of Coastal Invasions: A review by Meg

Meg — Mon, 12 Dec 2011 15:32:00 +0000

I really liked this paper and I think it provided a nice framework for future scientists that are looking to take an ecological and evolutionary approach to biology (not just coastal invasions). One aspect in particular that I found interesting is the concept of phenotypic plasticity as an aspect of evolutionary consequences. Invaders are often refered to as “plastic” and this term has come up a couple of times in our class discussions. Whitman and Agrawal wrote a nice chapter on the phenotypic plasticity of insects. They state that: “Phenotypic plasticity, the capacity of a single genotype to exhibit variable phenotypes in different environments… All plasticity is
physiological, but can manifest as changes in biochemistry, physiology,
morphology, behavior, or life history. Phenotypic plasticity can be passive,
anticipatory, instantaneous, delayed, continuous, discrete, permanent,
reversible, beneficial, harmful, adaptive or non-adaptive, and generational.
Virtually any abiotic or biotic factor can serve to induce plasticity, and
resulting changes vary from harmful susceptibilities to highly integrated and
adaptive alternative phenotypes. Numerous physiological mechanisms
accomplish plasticity, including transcription, translation, enzyme, and
hormonal regulation, producing local or systemic responses. The timing,
specificity, and speed of plastic responses are critical to their adaptive value.
Understanding plasticity requires knowing the environment, physiological
mechanisms, and fitness outcomes. Plasticity is thought to be evolutionarily
favored under specific conditions, yet many theoretical predictions about
benefits, costs, and selection on plasticity remain untested. The ecological
consequences of plasticity range from simple environmental susceptibilities
to mediating interspecific interactions, and extend to structuring of ecological
communities, often through indirect effects. Phenotypic plasticity, through
its ecological effects, can facilitate evolutionary change and speciation.”

Plasticity, therefore, is pretty all encompassing. It is not just variation within a population, but the ability of an individual to vary. Plasticity is an important concept to understand invasion biology and ecological and evolutionary biology.

Comment on “Rapid evolution of sessility in an endemic species flock of the freshwater bivalve Corbicula from ancient lakes on Sulawesi, Indonesia” by Michael Hassett

Michael Hassett — Mon, 12 Dec 2011 09:00:27 +0000

I’m confused when you say the clams aren’t affected by the Wallace Line. Are Corbicula native on both sides of the line, or are you saying that humans helped them cross the line? I suppose they could do it on their own if they were able to gain a salinity tolerance, move across the line, and then lose their salinity tolerance in modern times. I’m just not sure how they’d be going upstream without human assistance or a well-placed hurricane.

Comment on Discordant molecular and morphological evolution in buffalofishes by Michael Hassett

Michael Hassett — Mon, 12 Dec 2011 08:05:59 +0000

While normally I might agree with the genetic analysis in this paper, I think that in this scenario it is better to organize the overlapping buffalofish species by their morphological characteristics and keep them split as separate species, for the time being. This isn’t because I think that either morphology or genetics is better or worse than the other, but because the authors do a fair job of showing that gene flow is occurring. We can see what the different species (or subspecies / populations / races / or whatever you want to call them) of buffalofish are doing now, and we have an educated guess as to what things were like in the past, but we don’t know what will happen as a result of their current selection pressures and introgression. To me, it seems like trying to count chickens before they hatch. The Ictobius genus might need to be re-organized down the road, but until then, I say organizing by morphology is the way to go.

Has anyone else tried looking up I. labiosus? There seems to be very little information about it online, but it looks like the only known place it is found is the site the authors sampled. Sure it’d be more convincing if the authors had more sampling sites, but you can’t really blame them in this case!

Comment on Metabolic evolution of energy-conserving pathways for succinate production in Escherichia coli by Miguel Rojas

Miguel Rojas — Mon, 12 Dec 2011 04:18:57 +0000

I agree with Alex, that the best way to describe these organisms would be best adapted to certain conditions rather than more evolved. The term “more evolved” makes it seem that when compared to another something else, an organisms that is “more evolved” is in some way better. I guess a simplified example would be if evolution is selecting for more evolved organisms based on complexity, why do the less complex organisms persist. In this case the KJ073 and KJ060 were the strains most efficient at producing succinate. However, this functional response may not reflect their ability to compete in a mixed microbial community.

Comment on “Genetic diversity of ‘satellite’ bacteria present in cultures of marine diatoms” by Michael Hassett

Michael Hassett — Mon, 12 Dec 2011 01:19:35 +0000

I have to agree with the authors and Katie in that future studies should involve axenic algal cultures and known cultures of bacteria. I’ve never done this work before, but to quantify co-evolution, you’d do something like measure allele frequencies in all of the species (algae and all of the bacteria) in your study over time, and see how closely those changes sync up with each other and with some sort of selective pressure, right? I think that if you tried to do this with 1 algae and 50 or so bacteria species all at once, it’d be too difficult to determine whether you were measuring co-evolution, competition among the bacteria species, or some other variable. I suppose that if one of the species consistently died when you tried to create a viable monoculture of it, that in itself could suggest the two organisms had co-evolved.

Comment on Ecological and Evolutionary Consequences of Coastal Invasions: A review by Alex Kula

Alex Kula — Sun, 11 Dec 2011 23:47:38 +0000

The thing I found most interesting about this article was how the research group looked at the different levels of the coral reef. I felt like this was very interesting because many of the ecological papers that I have read have only focused on a particular region or one how an invasive species only affects a certain population. This may have been done because the ecosystem of a coral reef is very delicate and every species can impact the coral reef ecosystem. Now it would be interesting to see if how the different protection practices of coral reefs are impacting the rate at which invasive species can successfully populate the coral reef. I feel like this would be a worthy study because every country has a different rules regarding the fishery management and habitat protection. I am sure that those countries that have a more strict restrictions have a reduced impact of invasive species in those coral reefs.
What I find more interesting is the impact that alien seaweed has on coral reefs. The spread of alien seaweed I feel have a much greater impact on coral reefs due to the fact that the can not be eaten by the native species, spread very easily, destroy native habitats, and out compete the native species fairly easily. These alien seaweeds are not as well studied and not easily distinguished from native seaweed species. The reason that I feel alien seaweed provides a greater chance to destroying a coral reef is that it can be spread by almost anything that goes in the water.