Monday, October 8, 2012

Repost: CoE #9

Carnival of Evolution #9

03.01.09 | 7 Comments

Let’s skip the introductions and polite-talk and jump right in!
As an obsessed observer of the natural world and all that evolution has to offer us, I often get so caught up in the seemingly never ending ‘forms most beautiful’ that I completely miss the magnificent mistakes. Or, to put it more accurately, the things I would have designed differently if god existed and I were him. One topic in particular that comes to mind when I think of these long overdue upgrades is the female human pelvis and its role in parturition. I must admit, I found this topic to be so enthralling that I dedicated my undergraduate senior thesis to the topic, but because I care about your well-being I will spare you the fifty pages and 150+ citations and instead direct you to the post Breaking Eve over at Anna’s Bones, where the author takes us on an beautifully written journey, detailing the beauty and horror of human parturition:
If there was ever an original sin, it wasn’t reaching for the apple; it was reaching for it on two feet.
When looking at seemingly huge ‘mistakes’ such as this, it’s quite difficult to tease apart what it is evolution means when it says it selects for those best adapted to their environment. For instance, does evolution mean better and more complex? It’s an assumption often stated by those unfamiliar with evolutionary theory, yet, on a level quite different from the pejorative way in which it is used by these some, the statement has some truth to it according to Bjørn Østman over at Pleiotropy:
As living things evolve, they do in fact become better. Better at what? Better at reproducing. Better than who? Better than the previous generations. Natural selection favors those organisms that reproduce more, and so over time the population as a whole will become better at reproducing. But is this always so?
It’s quite a trip, and perhaps it is a semantic argument, but I charge you to go and see for yourself. If life is evolution, and evolution is progress (in some sense), then what to say about those organisms that Darwin himself dubbed “regressive”, however? Christie Lynn over at Observations of a Nerd has dedicated an entire post to just these degenerates - Darwin’s Degenerates - Evolution’s Finest:
If I ask you what group of organisms is an exhibition of evolution at its finest, what would you say? Most people, I think, would say human beings, or at least apex predators. After all, we have staggering intellect compared to our prey items and clearly dominate the planet, eat what we will, etc. Not only that, we’re insanely complex. Ask some scientists, and they might give you any number of answers. Cockroaches are likely to exist long after we do, as are rodents, so maybe they get the title. Or, being scientists, they might be biased to whatever organism they study. Maybe algae and plants, as the sustenance for all other life. But all of you, in my humble opinion, are wrong. That is, unless you choose parasites.
The smallest things may make the biggest difference…
So, we’ve learned from the parasites that you can’t judge a book by its cover, but the least you can do is figure out whether it was a product of convergent evolution by comparing it to other books that look remarkably similar (Sorry, my metaphor joo-joo is a little off today). So, when you’re walking about the world of fungi, a world I am ashamed to say I know absolutely nothing about, you find a striking resemblance between a certain lineage, Chytridiomycota, and quite a variety of species located elsewhere, outside of this lineage, on the great tree of life, including sponges, tunicates and coral, it’s okay if a “Wait…what?” or two pops into your head. Thankfully for us, the guys over at Southern Fried Science have the low down on this curious case. I highly recommend the post for a variety of reasons, but personally because it taught me a great deal about a topic I had little knowledge of:
A phylogeneticist will tell you that Mycology would better be served taught alongside Zoology. Fungi and Animalia form a single clade called Opisthokonta, meaning “tail-behind” for the single flagella that their earliest ancestors possessed. Fungi and Animals share a motile, flagellated common ancestor. A common ancestor that looks surprisingly like a choanoflagellate. This shared, protistan ancestor plied the aqueous world more than 460 million years ago. Should it then be a shock that the most basal fungi and the most basal animals are defined by flagellated cells (choancytes in animals, chytrids in fungi)?
From the other half of Southern Friend Science, whysharksmatter, we have a nice introduction into all that sharks have done for, and been done by, evolution since the origins of the lineage. Take a look at Blogging for Darwin: Sharks and Evolution for more information.
But, back to those pesky sponges for a bit… Over at The Oyster’s Garter, Miriam Goldstein gives us a little glimpse on the origins of sponges. According to a study recently published in Nature, sponges are likely to be at or over 635 million years old!
These ancient sponges eventually gave rise to all other animal life, though some of their descendants scorned higher organization for the loose & easy life. Since more than 90% of modern sponges resemble those ancient sponges, perhaps there’s something to be said for a simple life of filtering seawater and spawning.
As much as I enjoy learning about topics I know absolutely nothing about, it’s always good to return to something a bit more familiar…
Many of you may know that I am absolutely in love with the natural history of organs, particularly the vital organs of humans. It is somewhat of a sloppy science as fossils don’t preserve soft stuff the way we would like them to, but there is a great deal of experimentation we can do in the lab that will give us the ability to infer the evolutionary history of such structures. One of the more complicated of these structures, and certainly the most important to vitality, is the heart. It is a very complicated organ with an equally complicated natural history, but if you’re up for taking a journey in to the history of that very mechanism that keeps you alive day in and day out, you should definitely check out Irradiatus’s post over at Biochemical Soul fittingly titled Darwin and the Heart of Evolution:
In summary, the heart of Darwin’s theory of natural selection is the idea that evolution comes not through the “why.” It comes through the how - through the accumulation of minute individual variations that spread like wildfire when they contribute an advantage.  There remains no better demonstration of this principle than the myriad heart morphologies and functions we can trace today.
Each of you has most certainly inherited a cardiac variation, whether it be a major mutation in a gene, or a tiny change in one letter of your genetic code (a “single nucleotide polymorphism”).
Who knows…perhaps yours is the one upon which an entirely new evolutionary history will be built.
Who, me?
Continuing along with this mindless self-indulgence, I would like to direct you to a very enlightening post over at Neuroanthropology, Paleofantasies of the perfect diet. I have posted a few times here on the topic of what has become to be known as “evolutionary medicine” and the specious, adaptationist-programme arguments put forth by its proponents for solutions to modern medical problems. In this post, Greg Downey comments on an article recently published in the New York Times by Marlene Zuk on the ‘Paleolithic diet’ and all of the problems that come with such ideas:
Before we start waxing nostalgic about all the health benefits of a Pleistocene diet, perhaps we should remember that our ancestors’ food often came in this nasty packaging which tended to run away, attack them, or just go missing entirely when they were really hungry.
If you’re interested in this debate, or how some scientists are trying to use evolutionary biology in medicine (In a very non-effective way, in my opinion), then I highly recommend giving this post your undivided attention.
Speaking of evolution and medicine, there’s a new blog on just these two topics: Evolving Ideas. In a recent post, author Gustav Nilsonne takes us on a journey into the complicated world of cancer through the lens of game theory. It’s quite an enthralling read, so go take a peak:
It is in this complex tissue interplay that the tumour cells live and evolve. Cancer cells are genetically dissimilar from the people that are their hosts and progenitors, because they accumulate genetic changes of various kinds – mutations, deletions, amplifications, translocations – that enable them to proliferate independently and so on. One common first step in carcinogenesis is a genetic destabilisation, which leads to a much increased rate of genetic change.
Interesting, am I right? I think so. I’ll definitely be keeping my eye on this blog.
But, away from my personal taste and back to the topic at hand…
Perhaps no other sub-discipline has given us such great insight into how the mechanisms of evolution function over the past decades as computational biology. While it pains me to say it, as an individual partial to dirty paleontology, the methods of computational biologists have been able to extract information from the genomes of organisms that Darwin could have never dreamed would be possible. In a post entitled Having a BLAST with Darwin -or- “(One of many reasons) Why genomics matters” Joe D gives us an introduction to the usefulness of computational biology through the example of HoX genes. Go on over and take a look:
Darwin may have been interested to learn that the Hox genes, which contain this famously conserved motif, happen to be key in determining the layout of the body early in development. There is genetic conformity to match the phenotypic conformity in early development.
And, speaking of Darwin, I am sure all of you know that his 200th birthday was this month. It was celebrated all over the world, and particularly concentrated amounts of Darwin love was spread throughout the blogosphere. A few of the submissions to this edition of the CoE were directly related to this event and the celebration of Darwin’s birth, and as such I’ve decided to place them all in one neat group. The following is all about Darwin love:
People love polls. I love polls. I am a person, so I guess that just makes sense. We love polls because we love statistics, and we love statistics because they’re short bits of information we can memorize to throw in someones face at a later date, perhaps at a party when trying to compete with another guy over the girl in the corner: “[Bill Nye Voice]Did you know that[/Bill Nye Voice] only 39% of Americans say they ‘believe in the theory of evolution’?”, for instance… Perhaps it’s not the best topic for this type of competition, but depending on the girl…
Anyway, the reason I bring it up is Greg Laden has a post with a nice selection of statistics from a recent Gallup Poll on “belief in evolution.” The results, as he states, are not surprising, but they sure are interesting. In an attempt to not give it all away before you click on the link, here’s a little taste of America future:
In answer to the question “Can you tell me with which scientific theory Charles Darwin is associated?” only a little over half knew.
Along with this simple ignorance of Darwin and evolutionary biology, there has been a huge spike in the debate over what some of his writings meant, what he would say if he were here today, etc… Perhaps the most prominent of these clashes, however, is at the crossroads of religion and evolution. And, while this topic is a dead horse long beat to death, almost on a constant basis, I get a certain feeling that with all of this energy supporting Darwin this year, we have a chance to really focus our efforts. As a part of this effort to discuss the philosophy of science, particularly with respect to this question and secular humanism, Peter Buckland at Forms Most Beautiful has written a post entitled The danger of indoctrination. Go over and stir up some debate.
When you need to take a rest from the debate, perhaps you can help figure out this one…
When you think “consumer of evolution” you think academia, right? You think of those individuals whose job it is to experiment or observe, those individuals we owe our current understanding of evolutionary biology to, those individuals who must consume and process all of the articles constantly being published on evolutionary biology so they may be better equipped to direct their research. What doesn’t immediately come to your mind, I would think, are birders. Am I right so far?
Well, after taking a glance at Mike Bergin’s article Why Birders Dig Darwin,  the necessity of being in touch with evolutionary theory for the recreational activity of birding becomes obvious. Really, it does. I promise:
Birders are consumers of the fruits of evolution, celebrants of the processes of natural selection and genetic drift. It may be fair to say that birding has deeper ties to evolutionary theory than any other recreational activity in the world. Whether we realize it or not, those of us who track changes in avian taxonomy for year to year, who care about splits in scrub-jays orEmpidonax flycatchers, are end-users of the very biological processes that inspire so much controversy and confusion.
In light of Laden’s Gallup Poll post above, perhaps we should all simply be working to convert the U.S. population to one made up completely of birders. I know it’s a roundabout way to have evolutionary biology accepted by the public, but it’s worth a shot!
Anyway, as I mentioned, when we’re discussing evolutionary biology and the way it propagates itself as a scientific theory throughout academia and into the public sphere we often focus intently on those producing new information, producing new understanding to add to the mix - the academic biologist. What we often fail to see, however, is that the most important element in the equation of dissemination is the k-12 teacher. This is the person on the front line, encountering every day the minds of tomorrow (And of course their parents). Us in academia are, for the most part, quite separated from the nonsense of creationism and religious dogma, and so we simply ignore the threat it poses because, to us, it really poses little threat at all. However, to the k-12 science teacher, and especially the high school biology teacher, this is not a conflict that can simply be ignored.
In a post entitled Blogging for Darwin: Happy Birthday, Dear Darwin! over at FYI Science, a high school biology teacher on the front lines gives us a little peak into the world of public school science education, and much more:
I can’t blame the biology teachers of the past very harshly.  Controversy is painful; if you’re a new teacher or one of the only science teachers in your district, the lack of support can be deadly.  Add to that the fact that most administrators and school board members don’t have a background in science, and you’re heading for disaster.
And yet, avoiding the controversy in their classrooms 25 years ago means that the controversy is still raging in classrooms today.
It’s a great blog, and a great cause. The battle for acceptance of evolutionary biology does not lie in the hands of the evolutionary biologist - there is so much evidence supporting the theory that more evidence really isn’t the issue - it is in the hands of the biology teacher, the individual responsible for shaping the minds of tomorrow.
On a less serious note, and as a nice conclusion to the carnival, and particularly to the 200th birthday of Darwin, if you are interested in a little peak into the Darwin’s Zoology Notes, a collection of the notes he took verbatim on his trip upon the HMS Beagle, I recommend taking a trip on over to Malaria, Bedbugs, Sea Lice, and Sunsets and Rick Macpherson’s post Pioneering Observations:
Far from a simple catalog of specimen names and descriptions (though there is that too) the young Darwin frequently combined observations with speculation and reasoning. The true treasures in Zoology Notes for me, and as pointed out by Zoology Notes editor Richard Keynes, are some of his initial pioneering observations on the unique fit and modifications he observed of organisms from one environment to the next.
I hope you have enjoyed this edition of the Carnival of Evolution. It was truly a treat to read all of the submissions, and even more so because I learned a great deal in the process. For the housekeeping: if any of you are interested in reading past editions of the CoE, or in hosting future editions, click on the link to the CoE and shoot Irradiatus an e-mail. It’s a great carnival and, while young, has a lot to offer. Please, all of you who have submitted for this edition submit in the future, and those reading, please consider a submission. I promise we don’t bite!
There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” - Charles Darwin

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