93rd Skeptic’s Circle!
For those of you who have yet to partake in the skeptical arts, check out the latest edition of the 93rd Skeptic’s Circle Blog Carnival, by City of Skeptics, who hosted the latest edition using a clever ironic Tarot reading (with the final card shown here).
My own most recent post about the second coming of an alien Jesus was graciously included in this edition.
If any of you have your own Skeptical Writings, consider submitting them to the Skeptic’s Circle. The 94th edition will be hosted by Reduce to Common Sense. Go here for submission guidelines.
Hilarious Conversation with E.T.
Today on Digg, an article was linked in which it talked about some astronomers who think that we will likely contact extraterrestrial civilizations within the next two decades.
However, the point of this post is to highlight what may well be the funniest comment I've ever read on a Digg post. The second comment down, by someone named Dumbledorito wrote:
"Hey."
"Hey."
"Got warp drive, or something?"
"Nope. You?"
"Nope."
"That's too bad. Our world is kinda fucked."
"Ours, too."
"Want to trade porn?"
"Why not?"
Priceless...
Will Tequila Plants Fuel Our Vehicles?
I read a couple of interesting articles today about a plant of which I have become very fond: the Agave plant. The first is Drink it or Drive it: The Promise of Agave for Ethanol, by Sarah Lozanova, and the second is Mexico & Agaves: Moving from Tequila to Ethanol
For you non-botanists, the Agave is a cactus-like plant that grows in semi-arid lands such as Mexico and the American southwest. Some species are known as “Century Plants” because of the exaggerated claim that it takes them a century to bloom (which is actually more like 25 years). Of course, any avid tequila drinker also knows that this is the plant from which the infamous killer of inhibitions is distilled.
As Sarah Lozanova of CleanTechnica.com writes, the Agave may be one of many potential saviors in the world of ethanol-based fuel production. In her article, she talks about the fact that Agaves contain very high sugar content, which make them an excellent source for producing ethanol. They also have very high cellulosic biomass, which may up their potential use by many factors, assuming we can perfect a method for making ethanol from cellulose.
However, ignoring the cellulosic content, Agave has many other characteristics that may make it a prime crop for ethanol production. For one, it requires very little water or irrigation. It also can grow in almost any type of soil because it is a “nitrogen-fixer,” meaning it essentially fertilizes its own soil from the air, leaving the soil in better condition than it was before.
Thus, considering the vast expanses of semi-arid land in the southwest and Mexico, it might be cultivated without having major impacts on traditional crop farmlands. In many ways, it is even better than using sugar cane, which as is well-known, promotes deforestation of rain forests.
There may or may not be other issues with using Agave, but it seems to me that it very well may at minimum become a small piece of our energy-independence puzzle. In my own opinion, though I am about as far from an expert on economics and trade politics there is, my guess is that this could have at least some impact on the whole immigration issue. I have no idea how many jobs would be created by a fuel-fueled increase in Agave cultivation, but I can’t imagine that it would be insignificant.
As a side note, the images you see above are of my own Agave plant. Almost forty years ago, my grandmother’s sister stole a plant from across the border in Mexico. My grandmother has been growing the original plant in Texas ever since. In 2000, she gave me an asexual offshoot from that plant (they send out many baby side-shoots that will grow into full plants). I now have half a dozen Agaves from the one she gave me. Without a doubt, it is the plant with the most sentimental value for me.
Science Takes Another Step Toward Understanding Human Evolution
In a previous post I highlighted one of the great questions facing science today: how did we evolve and what specific genes make us different from our cousins in the animal kingdom?
In a new study reported in this month’s issue of PLoS Genetics, Carolin Kosiol and colleagues have demonstrated the most complete analysis of the human, chimpanzee, macaque, mouse, rat, and dog genomes to date, highlighting many genes and pathways that have contributed to our own evolution as mammals and primates.
Evolution fundamentally occurs at the gene level. If a gene becomes mutated, thus making an organism (or population) more likely to pass on that gene, that gene can be said to have undergone “positive selection.” The environment has positively selected that gene to become more prevalent.
Just to give you a very quick primer on gene evolution, one thing necessary to understand is that all mammals (and indeed all vertebrates) contain a large number of genes that we share in common. For instance Tbx20, a gene involved in heart development (which I used to study), exists in all organisms from flies to humans. The function of this gene is the same or similar in these organisms, though there are many specific differences between them as well.
It is these genes that we share with the other organisms that these researchers compared. What the authors of this study have done is to look at the differences in the sequences of these mammalian genes to determine which sets of genes have changed the most – i.e. which genes have undergone positive selection during evolution. They highlighted several pathways that have undergone the “strongest” positive selection, such as defense/immunity, chemosensory perception, reproduction and taste perception.
Surprisingly, to me, they did not find pathways and processes in the brain that have a high number of positively selected genes. It seems to me that this can be explained by a few different possibilities: 1) only a few specific genes have evolved strongly, but these few genes resulted in huge changes in the brain, 2) new genes have arisen (which were not looked at in this study – again, only genes that we share were compared), or 3) the brain genes that changed weren’t exclusively part of “brain processes” (for example, the gene I mentioned above, Tbx20, is involved in both heart and brain development).
Regardless, this is a very interesting study, and it brings us one small step closer to understanding what exactly makes us who we are as humans, as primates, and as mammals. And it opens us to new questions of how these specific genetic changes evolved in the first place.