There You Gogh

I spent the day getting some new hanging baskets of flowers for my porch, hoping the shade of the porch doesn't send these plants to an early grave, and cleaning said porch of the mountains of tree sperm (a.k.a. pollen) so that I could enjoy the weather without looking like I engaged in a losing battle with a horny pine tree. This is normally more time than I generally spend with the reproductive structures of plants (whole plants yes, specifically plant genitalia no), and so it put me in the flower frame of mind. Hence, today's post.

The evolution of flower shape and symmetry is of particular interest and importance because it can affect pollinator behavior. Affect pollinator behavior and you affect who is successful at reproducing. All of a sudden our cute, and even sexy, talk of flowers becomes a talk of genetics. A new paper in PLoS Genetics takes a somewhat novel approach to this question: Classic art.

Vincent van Gogh's Sunflower paintings are well known and duplicated many times by many artists. When you look at the paintings you notice the vibrant colors, the angles, and the detail (down to differences in petal structure). Now, I'm not an artist, art critic, or art historian. Heck, I'm proud that I can draw stick figures that don't look like they have suffered head trauma or just got a prescription for Viagra. However, I do notice elements about van Gogh's Sunflower paintings that make me go "huh." Particularly the symmetry of the flowers. Look closely. Do those look like the sunflowers that you are used to seeing? As it turns out, when van Gogh painted his famous sunflower pictures in France in 1888 and 1889, he was painting mutant sunflowers. These flowers were double-flowered (dbl) sunflower mutants in which the disc florets develop bilateral symmetry rather than their typical radial symmetry.

Actinomorphic flowers exhibit radial symmetry; No matter which diameter you halve it along the halves will be equal. This type of floral symmetry is considered to be the ancestral state. Zygomorphic flowers exhibit bilateral symmetry; They can be divided by only a single plane into two mirror-image halves. This type of floral symmetry has arisen several times during the evolution of flowering plants. Those species exhibiting this anatomy tend to be from more speciose clades, likely because the symmetry increases pollinator specificity. Common (or wild type) sunflowers have a composite flower head that has a single whorl of large, flattened yellow ray florets on the outer perimeter with hundreds of disc florets that can produce seeds. Contrast this to the dbl mutant which exhibits flowers with multiple bands of yellow florets and much fewer internal disc florets. You've got that all worked out in your mind's eye, right? Well, as described by the authors and in the terms we just defined, Vincent van Gogh's sunflowers exhibit zygomorphic symmetry rather than the actinomorphic symmetry characterized in the sunflowers we are used to.

So what causes this (genetically speaking) and how do you find it? Remember good ole Gregor Mendel and his pea plant experiments? Well, that's how you find it. These scientists crossed the wild type variety of sunflower with the double-flowered variety. At first they thought a single, dominant gene was responsible for the change in the flower, but subsequent crosses revealed a third flower type of intermediate form. This intermediate form results from a gene recessive to both the wild type and the dbl variety. That means that something less-simple is going on.

Figure 1: Entire inflorescences (A, C, E) and individual florets (B, D, F) from wildtype (A, B), double-flowered (C, D) and tubular (E, F) sunflower individuals. Florets are arranged left to right from the inner florets to the outer florets. (G) “Sunflowers (Still Life: Vase with Fifteen Sunflowers)” by Vincent van Gogh (1888) with double-flowered heads pointed out with arrows.

Their next step was to sequence the genes. It is known that the genetic control of floral symmetry involves CYCLOIDEA (CYC)-like TCP transcription factors. The gradient of the expression of this gene can control the different types of petals that form. The genetic sequencing showed that dbl mutants had an insertion into the promoter region of a CYC-like gene (HaCYC2c). This is normally expressed in the wild type flowers but in dbl flowers it is expressed throughout the inflorescence causing it to lose actinomorphy. This same gene was disrupted in other types of sunflower mutants.

Very long story short: They found the genes that caused the van Gogh's mutant sunflowers. Does this change how you view the painting? Perhaps. Perhaps not. But it does solve a decades-long question, and in my book that is truly neat.

Read the paper here:

Chapman, Mark A., et al. (2012) Genetic analysis of floral symmetry in Van Gogh's Sunflowers reveals independent recruitment of CYCLOIDEA genes in the Asteraceae. PLoS Genetics: 8(3), e1002628 (DOI: 10.1371/journal.pgen.1002628)

Brush up on your Sunflower's painting history at the Van Gogh Gallery

Read more over at Science Daily's article "Scientists Reveal Genetic Mutation Depicted in Van Gogh's Sunflower Paintings"

(images via Pacific Bouquets & Fine Gifts, Inc and Fantasy Art History, respectively)

Itty Bitty Basil

Look! New basil plants! If plants can be cute, these plants are cute. And I'm not just saying that because I grew them, although I'm not denying that that plays a role. I'm biology-nerd enough to think baby plants and new spring baby leaves are cute. I'm also biology educated enough to know that more seeds germinated in this little pot than I thought and that soon it will become the botanical version of The Hunger Games. Care to pick a winner?

Wind Map

Click on the picture to take you to an uber-cool wind map of the United States.

The wind map is a personal art project that maps and puts into motion surface wind data from the National Digital Forecast Database. These near-term forecasts, revised once per hour, create a living portrait of the winds of the U.S.

If the link is broken, use this url: http://hint.fm/wind/index.html

Clock Blocked

(via WTFContent)

A Drop of Water

Jim Kramer takes absolutely amazing photographs of water droplets. He uses paints and other colors to make the shots even more beautiful. He will also sometimes use additives like glycerol and dishwashing soap to alter the water’s consistency. Kramer uses a highly precise system, comprised of valves, stop shot sensors, and cameras for a perfect timing.

From the Archives: This one is from one of his first sessions with glycol (c) Jim Kramer

Red & Teal: Glycol collision against a stained glass background (c) Jim Kramer

Blood From Under: Another Solid Surface Crown -  if you look closely you can see the the red food coloring comes from under the cream (c) Jim Kramer

Red and Blue: 3 strobes through a red background and blue gels over the front strobes for this shot (c) Jim Kramer

Triple Color Crown: Heavy cream (lightly colored blue) being dropped onto a piece of black glass with a 'primer' drop is in the landing zone and 3 drops of food coloring to the outer edges of the primer drop (c) Jim Kramer

See more of these photos ZME Science's story "Water drops art by Jim Kramer"
and at the Jim Kramer's Flickr account

DIY DNA Extraction

This is cool. Extract your own DNA at home using some simple household materials.

Challenger Deep Expedition

What do you do when you are the most successful filmmaker in recent history? You dive to the deepest point on the planet. Duh.

James Cameron was born in Canada and moved to the U.S. in the early 1970's, majoring in physics at California State University. After school, he quickly rose in the film industry, making such well known films as The Terminator (1984), Aliens (1986), The Abyss (1989), Terminator 2: Judgement Day (1991), True Lies (1994), Titanic (1997), and Avatar (2009). That's just to name a few. These movies have broken all kinds of box office records and racked up several Academy Awards. Today, he is one of the most sought-after directors in Hollywood. As you may have noticed, many of Cameron's films have water or the ocean as a central theme, and many of them use machines as an important plot point or weapon. To say that Cameron has a fascination with the ocean and it's depths would be an understatement. He is an avid explorer, with 72 submersible dives to his credit.

“I’ve always dreamed of diving to the deepest place in the oceans. For me it went from a boyhood fantasy to a real quest, like climbing Everest, as I learned more about deep-ocean exploration and became an explorer myself in real life. This quest was not driven by the need to set records, but by the same force that drives all science and exploration … curiosity. So little is known about these deep places that I knew I would see things no human has ever seen. There is currently no submersible on Earth capable of diving to the ‘full ocean depth’ of 36,000 feet. The only way to make my dream a reality was to build a new vehicle unlike any in current existence. Our success during seven prior expeditions building and operating our own deep-ocean vehicles, cameras, and lighting systems gave me confidence that such a vehicle could be built, and not just with the vast resources of government programs, but also with a small entrepreneurial team. It took more than seven years to design and build the vehicle, and it is still a work in progress. Every dive teaches us more, and we are continuing to improve the sub and its systems daily, as we move through our sea trials.” —James Cameron

Most recently, Cameron has made history with National Geographic's DEEPSEA CHALLENGE Expedition. DEEPSEA CHALLENGE, a joint scientific expedition by Cameron, National Geographic and Rolex to conduct deep-ocean research and exploration. Scripps Institution of Oceanography is the primary science collaborator, working explore and study the deep sea and its marine life. It has been 50 years since man has descended 35,800 feet (10,912 meters) to the deepest point in the ocean, known as the Challenger Deep in the Mariana Trench. With a team of engineers, Cameron co-designed a submersible that incorporated the newest technologies, designs, and material available that could carry a human pilot to the deepest sites in Earth's oceans and perform work with significant bottom time for research activities. This submersible was also designed to dive repeatedly to gather data, samples, and imagery of the deep oceans.

The submersible was launched into the Pacific Ocean some 200 miles (322 km) southwest of Guam on Monday, March 26. The voyage down to the Challenger Deep took 2 hours and 36 minutes, the stay at the bottom lasted about three hours, and the return trip took only 70 minutes. During the time at the bottom they were able to collect research samples, still photographs, and moving images. This amazing trip makes James Cameron the first person since 1960 to reach the very bottom of the world. And he wouldn't be the filmmaker he is without documenting this for a new 3-D feature film, which will be broadcast on the National Geographic channel in the future. Look for it. I know I will!

One of the first images from the expedition

Visit National Geographic's DEEPSEA CHALLENGE website for more information, updates, videos, and great pictures.

Read more at National Geographic's Press Release Detail about the expedition.

Scripps Institution of Oceanography's webpage about the dive.

(images via the DEEPSEA CHALLENGE website and Live Science)

An Early Spring Isn't Always a Good Thing

It is pretty well agreed upon within the scientific community that climate change is happening. It has become increasingly urgent that we nail down all of the individual facets of this very large change and the operation of environmental drivers. One of these is the operation of weather as a driver for population dynamics.

It is important at this stage to define weather versus climate. Weather is the state of the atmosphere at a particular time and place such as heat, cloudiness, dryness, sunshine, wind, rain, etc. Climate is the weather conditions prevailing in a place over a long period of time. So when we talk about weather, it is as a single climate driver that may have detectable effects on populations of organisms. These effects can be direct density-independent, have indirect effects on populations (act of food sources, predators, etc.), or act of population dynamics (age structure, life stages, etc.).

A new study, published in Ecology Letters, takes a look at how a single climate parameter can determine population dynamics in a butterfly species. The focal butterfly species they chose to work with was the Mormon Fritillary (Speyeria mormonia) because it is a species that is distributed throughout the North American Rocky Mountains and has non-overlapping generations. The adults of this species feed on nectar (the preferred floral nectar host is Erigeron speciosus) and young males feed from mud, dung and carrion. The females will mate once and lay their eggs singly in some leaf litter located near a host plant.The larvae will over-winter as unfed first instars and will develop into adults in about 6 weeks. Previous studies have shown that the fecundity of adult females declines linearly with their food intake with their eggs deriving up to 80% of their carbon composition from the sugars taken up by the adults. The host plants are useful in that they can be counted for flour availability which can be a broad indicator of nectar (food) availability for these females. Then add in the weather component. Frosts occurring early in the growing season will kill developing flower buds, reducing the food availability in the system. Keeping this in mind, the researchers hypothesized that snow melt time in the first year would affect butterfly fecundity through flower abundance (a delayed density-dependent indirect effect). In the year following this they predicted that snow melt time would directly affect the developing larvae. Remember, the larvae overwinter and mortality could occur due to exposure (a density-independent direct effect).

To test this, the researchers set up study sites in the Rocky Mountains of Colorado. They determined the floral hosts preferences and distribution of the hosts plants of the butterflies. They counted the blooms every other day in teach of their plots every year from 1975 to 2009 (except 1990). They also caught butterflies, took their demographics (size, sex, etc.), numbered their wings, and observed their feeding behaviors. Finally they recorded the snow melt timing within their sites.

After all kinds of population growth analysis that I'm not going to go into (you're welcome), they found that the timing of the snow melt affects the population dynamics of these butterflies both directly and through the density-dependent indirect effects on flower availability. The early snow melt reduced the flower (and therefore the food) supply, adversely affecting the butterfly population growth rate. In the second, consecutive year, the combined effects explained more than four-fifths of the variation in the population growth rate. Just a single weather parameter (in this case snow melt) can have multiple effects on population growth. This study is among the first to demonstrate these indirect effects as well as documenting the multiple effects that a single weather parameter can have on population dynamics. These researchers were able to take long-term data and apply it to data models to understand both the effects on a single species as well as understanding species interactions in the context of climate change. These types of experiments and models can help to predict changes in populations in the future and even across populations and species.

Here's the paper:


Boggs, Carol L. and David W. Inouye. (2012) A single climate driver has direct and indirect effects on insect population dynamics. Ecology Letters: published online March 14, 2012 (DOI: 10.1111/j.1461-0248.2012.01766.x)

Science Daily article about this paper:  Early Spring Drives Butterfly Population Declines: 'Ahead-of-Time' Snowmelt Triggers Chains of Events in the Mormon Fritillary Butterfly

(image from http://www.wildutah.us/html/butterflies_moths/nymphalidae/h_btfly_fritillary_mormon.html)

A Biologist's St. Patrick's Day Song

Hail to Saccharomyces cerevisiae! Happy St. Patrick's Day!

X-Ray Yoga

Interesting x-ray pictures (or even just renderings) are...well...interesting. The X-Ray Pin-up post from a while back is one of my favorite examples. When I was in my yoga class last night and finally achieving lift-off in crow pose I was totally aware of how funny I must look (because I always feel awkward and funny in crow pose). Following that train of thought, I was reminded of these x-ray yoga images I had seen over at Science Photo Library.

Lotus pose

Downward facing dog position

Side Bend

Tree pose (front)

Tree pose (side)

Scorpion pose

Namaste

Cell Savvy

Science. Geek. Cute.