Some of the most beautiful images come from the wonderful world of science. Anywhere from the fractal imagery of bacteria to the swirling patterns of colliding galaxies to the double helix configuration of DNA, the beauty of nature is breathtaking. These images speak to both scientists and non-scientists in a way that both can understand and appreciate.
The International Science and Engineering Visualization Challenge is a competition sponsored by the journal Science (and the AAAS) and the National Science Foundation (NSF). Judges are appointed by these organizations, and they select winners in each of five categories: Photography, Illustrations, Informational Posters and Graphics, Interactive Games, and Non-Interactive Media. Winners have their art/media featured in a special section in Science and Science Online as well as on the NSF website, with one of the entries appearing on the front cover.
Watch the video below for the highlights on past winners and some images below from this year's and last year's winners:
Winner 2010 in Photography. Credit: Seth B. Darling and Steven J. Sibener
Sexual selection is an aspect of evolution that has been extensively studied. I've blogged about it in stories about pipefish, insects, and fish. If you'll recall from the Fish-stache post I described sexual selection in this way:
"When it comes to sexual selection in the animal world, it is the usually the sex that puts more effort (and has more to lose) into the results that gets to be the choosy sex. Usually this means females get to be picky. After all, eggs are more expensive than sperm and females often end up contributing quite a bit with parental care. This choosiness means that males need to impress females through the evolution of secondary sexual traits. This could be, and usually is, just about anything: elaborate feathers, complicated dances or mating calls, gift giving, etc."
These secondary sexual traits have diversified more than nonsexual traits, with sexual selection driving phenotypic diversification and speciation. The traits are associated with high levels of additive genetic variation and evolve in response to a change in natural selection. Because of this it is difficult to find examples where traits diverge primarily to sexual selection, even strong sexual selection on a particular heritable characteristic is insufficient to cause contemporary evolutionary change. So perhaps there is some kind of evolutionary limit on sexually selected traits in nature. A new paper published online in the Proceedings of the National Academies of Science demonstrates the existence of this limit for male attractiveness in fruit flies.
You can commonly find fruit flies (Drosophila spp.) buzzing around trash cans and unripe or overripe fruit, and they have been used as a model organism by geneticists for decades. They are easy to obtain from the wild, small in size (~2.5mm), easy to rear in the lab, have fecund females, have a relatively small genome, are relatively inexpensive to work on, have the entire genome sequenced and many genes identified, and there are a variety of mutants available to purchase for study. Add all that together and you've got yourself one great experimental species.
This studies uses Drosophila serrata. D. serrata females are known to discriminate among potential male partners on the basis of a combination of eight male cuticular hydrocarbons (CHCs). These CHCs act as contact pheromones and the sexual selection exerted by female choice causes them to evolve. The researchers genetically engineered a group of male flies to release these highly attractive pheromones. Then they released the males into a colony. In this colony the engineered males greatly outnumbered the average/wildtype males. They found that, initially, the females preferred the sexy smelling males. Then, after about seven generations, they found that the ratio of sexy males to average males had become almost even. Interesting. If females pick attractive males to mate with and those genes are passed along to the next generation of flies then why didn't they see the ratio stay the same or increase? The researchers conclude that there is likely a substantial fitness cost to sexy smelling flies. Essentially, the males were too sexy to survive. They died before they could reproduce and pass on their sexy genes. And this is that evolutionary limit that I presented above. The males lack the genetic variation that would allow an increase in sexual fitness while simultaneously maintaining high nonsexual fitness, and because the divergence in these traits is constrained to occur in the direction of greatest genetic variance, rather than sexual selection, the combination of high attractiveness and high survivorship can't be reached.
That must explain the rare unicorn, and by that I mean the single, straight, and attractive human male.
Here's the paper:
Hine, Emma, Katrina McGuigan, and Mark W. Blows. (2011) Natural selection stops the evolution of male attractiveness. PNAS: published online. (DOI: 10.1073/pnas.1011876108)
The Solar Decathlon is a challenge created by the U.S. Deparment of Energy where 20 collegiate teams design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. To win the competition a team has to blend affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency. The program started in 2002 and occurs biennially. It is considered one of the most prestigious solar competitions on the globe. It is open to the public free of charge and allows visitors to tour the houses for ideas that they can impliment in their own homes, learning about energy-saving features that can help them save money. It also educates students about clean energy and trains them to enter a clean-energy economy. The Solar Decathlon has been a successful program, involving 92 collegiate teams, instituting a multidisciplinary approach to designing and constructing the houses, and providing hundreds of thousands of house visits from the public.
This year the competing teams include Appalachian State University, Florida International University, Middlebury College, New Zealand: Victoria University of Wellington, The Ohio State University, Parsons The New School for Design and Stevens Institute of Technology, Purdue University, The Southern California Institute of Architecture and California Institute of Technology, Team Belgium: Ghent University, Team Canada: University of Calgary, Team China: Tongji University, Team Florida: The University of South Florida, Florida State University, The University of Central Florida, and The University of Florida, Team Massachusetts: Massachusetts College of Art and Design and the University of Massachusetts at Lowell, Team New Jersey: Rutgers - The State University of New Jersey and New Jersey Institute of Technology, Team New York: The City College of New York, Tidewater Virginia: Old Dominion University and Hampton University, University of Hawaii, University of Illinois at Urbana-Champaign, University of Maryland, and The University of Tennessee.
If you want to learn more about the Solar Decathlon, including how to apply for your school or how to visit one of the projects, then check out the U.S. Department of Energy's website at http://www.solardecathlon.gov/.
Happy Valentine's Day! Today I've got something special for you. Cake!
One of my favorite food blogs called Not So Humble Pie featured a Valentine's Day cake that is sure to make the anatomist in you clap your hands and dance around in glee. Presenting: The Bleeding Heart Cake.
Ms. Humble is actually borrowing the recipe and supporting the cause of one Lily Vanilli. Lily Vanilli is teaming up with the charity Trekstock this Valentine's Day to offer people the chance to send their own edible bleeding heart to the one they love. A single bleeding heart cake is is priced at £7 and comes in a cute perspex box tied with a pink or red ribbon with a personal note. The cake is available exclusively through their website and 20% of the proceeds go directly to charity.
If you decide to make the cake yourself Lily Vanilli also provides the recipe. The cake is simpler to make than it looks, it is basically red velvet sponge cake, cream cheese frosting, and blackcurrant & cherry "blood." So if you like baking that something special for your special someone then try this out.
Blogging about science is becoming a more and more popular endeavor. Considering all of the fantastic science being conducted all over the world, that can hardly come as a surprise. As the pace of improving technology increases and the public's appetite for information skyrockets, blogs have become an increasingly important medium to share information. After all, you are reading a science blog now, right? And, as younger and more Internet savvy individuals come into the science field you are starting to see more blogs written by scientists themselves. This can be both a good and a bad thing, from the scientist's prospective.
With the hiring pool filled to overflowing with recently graduated PhD's and postdocs, many departments are now looking at other aspects of a candidate's accomplishments in addition to teaching history and publication rate. One of those aspects is a good blog. Why? Well, think about your typical undergraduate student - always has a cell phone, on the Internet almost constantly, and very socially conscious. A blog offers a way for undergraduates to read and get excited about science. It also offers researchers an avenue to present and explain scientific findings to the public.
However, blogs, being the very public media that they are, can be both a help and a hindrance to a scientist's career. It's all about how said scientist goes about it and how the university they work at views it. Let's break it down into two categories by which universities are often classified: nonresearch institutions and research-intensive institutions. The first values blogs as a nonresearch activity that supports the traditional academic activities of teaching and outreach. Activities that pertain to and are valuable to the goals of their institution. Research-intensive institutions tend to view blogs at best as a harmless hobby and at worst as a liability.
The good about science blogging:
Reach a wide audience
Present research papers of all kinds, including ones that don't get a lot of attention or citing
A source of public outreach
A way to present individual research
A way to illustrate the types of research conducted at a particular institution
Have a "broader impact" (a term used by funding agencies)
Networking
Things to watch out for if you have or decide to start a science blog:
It is time consuming and may take away from research
Do not blog about unpublished research
Present but don't criticize the research of other scientists
Limit your blogging to research you admire to avoid negative blogging
Be delicate when blogging about your own research
Avoid controversial subjects like politics, religion, or academic controversies
And a pseudonym might not be a bad idea
Overall, scientific blogging is considered to be a good thing as long as it does not take away from the job of conducting science, and as long as a scientist takes certain precautions. Personally, I find it a way to keep myself up-to-date and reading the recent scientific literature and something to have fun with.
They also reference ScienceOnline 2011, a meeting on Science and the Web, that took place last month in Research Triangle, North Carolina, USA. This was a meeting of scientists, students, educators, physicians, journalists, librarians, bloggers, programmers, and others to discuss how the Web is changing the way science is communicated, taught, and conducted. You can read more about the meeting here: http://scienceonline2011.com/
Science Online London 2010 was a very similar meeting, with very similar goals, held back in September of last year in London, England. You can read more about the meeting here: http://www.scienceonlinelondon.org/
In the science of Sasquatch it's all about distribution. Where is he (or she) and how can I get a photo? The photo I'll leave up to you, and hope you are good at keeping your camera steady to avoid those embarrassingly blurry pictures. The where is he part can be figured out by utilizing user-friendly software, publicly available biodiversity databases, and ecological niche modeling (ENM).
A scientist named Grinnell proposed the ecological niche concept in 1917, so it isn't new. Overall, it's pretty simple. Each species needs a specific set of conditions to survive. The range where these conditions occur is where a species can maintain a population. Since 1917 the concept has been expanded, most notably by Elton in 1927 and MacArthur in 1972, to include a species as part of an ecological community. With this type of model it is possible to characterize the ecological needs of a species, predict and anticipate it's distribution, predict changes in it's distribution with changing land and climate, investigate patterns of speciation and niche divergence, and build scenarios for unknown conditions and behavior. "The basic premise of the ENM approach is to predict the occurrence of species on a landscape from georeferenced site locality data and sets of spatially explicit environmental data layers that are assumed to correlate with the species’ range." That's how the paper I'm presenting today describes it. What does it mean? Input known, locally collected data and make reasonable predictions of species occurrences given the current modelling technology. That known, locally collected data is becoming more and more available and accessible via museum databases and online data portals.
Sasquatch, or Bigfoot, is currently (pseudo-)classified as a member of a large primate lineage descended from the extinct Asian species (Gigantopithicus blacki), but there is some phylogenetic analysis indicating a possible membership in the ungulate clade. Regular reports have Sasquatch inhabiting the forested lands of western North America, although a type specimen is unavailable. This paper, from the Journal of Biogeography, presents ENMs for Sasquatch. They base their ENMs on putative sightings, auditory detections, and footprint measurements primarily obtained from the Bigfoot Field Researchers Organization (BFRO). Events were assigned geographic coordinates on USGS quad maps and atlases and the ENMs constructed using the maximum entropy niche modelling approach using the software MAXENT. Then environmental layers were constructed for 19 BIOCLIM variables in the WORLDCLIM dataset. The final set of environmental variables included annual mean temperature, mean diurnal range, isothermality, temperature annual range, mean temperature of wettest quarter, mean temperature of driest quarter, precipitation seasonality, precipitation of driest quarter, and precipitation of coldest quarter.
The ENM showed that Sasquatch should be broadly distributed in western North America, with a range comprising such mountain ranges as the Sierra Navadas, the Blue Mountains, the Selkirk Mountains, and the Cascades. The bioclimatic variable that was the best predictor was precipitation in the coldest quarter. And so, it is likely that the distribution will be altered due to global climate change.
Running with that result, the scientists examined the potential ramifications of climate change on remnant Sasquatch populations to predict how the frequency of sightings might change in the future. To do this they projected ENMs generated from the WORLDCLIM data into bioclimatic layers simulated for a doubling of atmospheric CO2. The model predicts that Sasquatch will abandon lower altitudes and lose habitat in coastal regions. But the species will potentially gain habitat in the northern part of the range as well as in several other montane areas. This means that, in the future, you should expect to sight Bigfoot in northern latitudes and at higher elevations.
Another suggestion: Look for American black bears (Ursus americanus) and you may sight Sasquatch. Now, I'm not advocating lurking around bear dens or walking right up on a black bear, but the predicted distribution of Sasquatch is similar to the range of the American black bear. So much so, that it is thought that some Bigfoot sightings were, in fact, misidentified black bears.
Up for a hike in California? Bring your camera.
Here's the paper:
J. D. Lozier, Aniello, P., and Hickerson, M.J. (2009) Predicting the distribution of Sasquatch in western North America: anything goes with ecological niche modelling. Journal of Biogeography: 36(9), 1623-1627. (DOI: 10.1111/j.1365-2699.2009.02152.x)
This week I saw a couple of articles in Nature about new exoplanets. I'm generally interested in new anything but didn't stop to read the articles as astronomy jargon can sometimes make me feel like I couldn't understand a third grade solar system diorama. But I noticed these articles getting picked up by the news media around the world and so decided to check them out.
Exoplanets, or extrasolar planets, are planets that reside outside of our solar system and do not orbit around our Sun/star. In the search for extrasolar planets we are, in effect, searching for evidence that our solar system is not unique, that there are other planets out there that are similar to our own. As of February 1, 2011 there are 526 confirmed exoplanets and 1,235 that are waiting for confirmation. Of these, 68 are approximately Earth-size, 288 are super-Earth-size, 662 are Neptune-size, 165 are Jupiter-size, and 19 are super-Jupiter-size.
How do you detect a planet orbiting a very (and in astronomical terms that 'very' is oh-so-huge!) distant star? You can start by looking for the wobble. When you have two large bodies (such as planets and stars) they orbit a common center of gravity and gravitationally push and pull on each other, causing them to wobble back and forth. By measuring the wobble of stars you can gain all sorts of information, like planet size and mass, even though you can't actually see the planet. This gravitational push and pull can be utilized for planet hunting in other ways as well. Astronomers also use the Doppler shift to find planets. Basically, they are measuring the velocities of the stars by measuring the changes in the light that comes from a star moving towards us versus away from us. If the star is wobbling then the light emitting from that star will shift too. Scientists can also look for radial velocity changes, looking at transitions in atomic lines. As atoms transition between energy levels they either absorb or emit a photon in constant ways, add that up with an entire star and we can see bright and dark lines in the continuum of light. When a star moves it causes these lines to shift back and forth in color - toward us blue and away from us red.
Getting away from the wobble, there is also the planetary transit method. This is when the planet, as it passes in front of the star, blocks some of the light from that star. Now, planets are tiny compared to stars, so they don't block a lot of light but they can block enough to be detectable. Of course, you need to be looking at a solar system edge-on for this to work. There is also the gravitational micro-lensing technique. Gravity affects light, just like it affects just about everything else. So if you put a high-mass object between you and the light source (the star) then the gravity from that object will bend the light behind it into your field of view. This will make the objects appear to suddenly brighten as the object passes in front of the light source/star.
Recently new imaging technologies have become available. Technologies that will allow astronomers to take the first images of planets circling other stars. One such technology is coronagraphs. This was originally invented to study our Sun by blocking light coming from the solar disk in order to see the Sun's corona. This is being refined and adapted to find exoplanets, but it still has its problems (see Planet Quest). Another technique is using mirrors. Replace one large mirror with a lot of smaller mirrors and combine their light using a process called interferometry. This way you can have the small mirrors, which obtain a resolution equal to a single telescope as big as the largest separation between the individual telescopes, and gather information to build a larger picture.
The Kepler spacecraft was launched in March 2010 in order to explore the structure and diversity of planetary systems. To find extrasolar planets, particularly Earth-size terrestrial planets in habitable zones. It's speciality is the transit method and it observes 156,000 stars in the constellation Cygnus looking for those little blinks of light. The new papers in Nature reveal that the Kepler spacecraft has located a solar system with 6 known planets orbiting the star Kepler-11, 2000 light-years away. The planets are named Kepler-11b, Kepler-11c, Kepler-11d, Kepler-11e, Kepler-11f, and Kepler-11g, going from innermost to outermost. None of the planets is identified as Earth-like (bummer), but they are close, ranging from 2 to 4.5 times the radius of Earth. The planets are mostly mixtures of rock and gases, possibly including water, with the planets closest to the star having the highest densities and so likely having the most rock and water. The planets range in size between the masses of Earth and Uranus, with three being gas giants with thick hydrogen and helium atmospheres.
Alright, so why all of the excitement? First of all, a whole solar system discovered is always an exciting event, and this is the largest group of transiting planets orbiting a single star to be discovered. Kepler-9 has been found to have 3 transiting planets, and the star HD 10180 has at least 5 Neptune-like planets orbiting. Additionally, these planets are among the smallest found for which both mass and size have been measured. The Kepler-11 solar system's structure is also interesting and unique. Five of the six planets orbit very close to their star. I'm talking closer to their star than Mercury orbits to our star. The sixth planet orbits at about the distance of Venus to our Sun. But, as Kepler-11 is a smaller, cooler star than our Sun that means that these planets fall within the system's habitatable zone. This structure also means that it is a really densely packed system. It is unclear as to why the planets are so densely packed, but it may shed some light on planet formation and solar system evolution. It is pretty much accepted that planets form from a cloud of dust around a newly formed star. However, how and where they form within this protoplanetary disc is still debated. Do they form far from their parent star (at the distance of Jupiter and Saturn) and move inward over time? Or do they form in place? Kepler-11d, Kepler-11e, and Kepler-11f have a significant amount of light gas which indicates that they formed within a few million years of the system's formation. How do we know this? Well, we know that free hydrogen only lasts around 5 million years around a star before it gets dispersed by the solar wind. If these planets have a significant amount of hydrogen gas then they must have formed within 5 million years of the star igniting. The team suggests that "the small eccentricities and inclinations of all five inner planets imply...that gas and/or numerous bodies much less massive than the current planets were present," and that "the lack of strong orbital resonances argues against slow, convergent migration of the planets, which would lead to trapping in such configurations." For the planets for form in place it would require a massive protoplanetary disk of solids near the star and the accretion of large amounts of gas by hot small rocky cores, but the very high temperatures close to a growing star would have been too high for ices to have condensed. And so the solar system's evolution is still unclear. The closely packed nature of the Kepler-11 system does allow for lots of gravitational tugging and so good information for further study. It's a mystery, for now.
Now for lots and lots of read-it and look-it-up on your own links. Many of which have fantastic information, infographics, and links. Let's start with the actual paper:
Lissauer, Jack J., et al. (2011) A closely packed system of low-mass, low-density planets transiting Kepler-11. Nature: 470 (7332), 53. (DOI: 10.1038/nature09760)
And here is an editorial and article about extrasolar planets, also published in Nature.
The hunt is on for a distant planet similar to our own. Astronomers should decide just how similar it needs to be, before the candidates start pouring in. Nature: 470(7332), 5. (DOI: 10.1038/470005a)
Reich, Eugenie S. (2011) Beyond the Stars. Nature: 470(7332), 24-26. (DOI: 10.1038/470024a)
And here's a short video from NASA Ames Research Center about the Kepler Mission, exoplanets, and specifically the Kepler-11 system:
