How genetic plunder transformed a microbe into a pink, salt-loving scavenger
Most cells would shrivel to death in a salt lake. But not the Halobacteria. These microbes thrive in brine, painting waters a gentle pink or crimson red wherever they bloom. The Halobacteria live in every salt lake on this planet, from the Dead Sea of Israel to the vast salt flats at the feet of the Sierra Nevada. But these hardy microbes haven’t always called salty depths their home. Their genomes reveal a tale of a dramatic transformation through genetic plunder.
Organisms that can survive in waters of extreme salinity are called ‘halophiles’ – or salt lovers. There exist salt-tolerant algae, fungi and even shrimp. But of all the salt lovers in the world, the pink Halobacteria are the most passionate. They don’t just cope with brine. They embrace it.
Most halophiles do their best to keep their cells clear of salt. But the Halobacteria just don’t care. The insides of their cells are as salty as the lakes they live in. This strategy, the Halobacteria have come to utterly dependent on salt, up to the point were fresh water is as deadly for them as salt water is for others. Placed in a freshwater lake, their cells would swell and pop like bloated water balloons.
Confusing enough, Halobacteria are not bacteria, but archaea, which have a completely different biochemistry. As a general rule, archaea are more hardy and robust than their bacterial counterparts, living in a wider range of extreme environments.
Microbiologists have long noted something odd about the Halobacteria. In all their evolutionary analyses, they found that Halobacteria are part of a branch of archaea called the ‘methanogens’. What bothers microbiologists is that as microbes, methanogens and Halobacteria couldn’t be more different. In every scheme ever devised to differentiate among micro-organisms, methanogens and Halobacteria end up on opposing sides of the divide. If microbes were spices, methanogens would be the pepper to the halobacterial salt.
Methanogens are the self-reliant survivalists, able to liberate energy from the most basic of molecules. A pinch of hydrogen (H2), a dash of carbon dioxide (CO2) and a spoonful of minerals is all a methanogen needs to carve out a living. This sober lifestyle has earned them the moniker of ‘rock eaters’ (lithotrophs).
Halobacteria, on the other hand, fancy their molecules ready-to-eat. They are scavengers, scrounging the salty waters for carbon compounds that they burn using oxygen (methanogens loathe oxygen). As an alternative energy supply, halobacteria are also able to harvest energy from sunlight.
Two types of microbes with radically different life strategies, yet one evolved from the other. So how did the Halobacteria cross the line?
Shijulal Nelson-Sathi thinks he has found the answer. In their latest paper, he and his colleagues show that the ancestor of all Halobacteria acquired as much as a thousand genes from another microbe, a bacterium. And through this act of plunder, the microbiologists write, the Halobacteria left their methanogenic ways behind, becoming salt-loving scavengers in the process.
Crassulacean acid metabolism (CAM) is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions. In a plant using full CAM, the stomata in the leaves remain shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide (CO2). The CO2 is stored as the four-carbon acid malate, and then used during photosynthesis during the day. Clever stuff. But sometimes saving water is more important than fixing CO2.
A new campaign aims to start giving popular names to the hundreds of alien planets that have been discovered around the Milky Way galaxy.
The space-funding company Uwingu announced this “Adopt-a-Planet” effort today (May 1), asking the public to propose and vote on names for the many and varied worlds now known beyond our solar system.
Any moniker that receives at least 1,000 votes earns its nominator the chance to “adopt” (and name) the exoplanet of his or her choice. Such winners will also receive an adoption certificate, links to detailed information about the adopted planet and $100 in Uwingu store credits, company officials said.
Nominating a name costs $4.99, and voting will set you back 99 cents. Uwingu (whose name means “sky” in Swahili) will use the money raised by Adopt-a-Planet to fund grants in space exploration, research and education, which is the company’s main purpose, Stern added.
Ginkgo Trees Stand Test of Time
“Living fossil” is an informal term used by biologists to describe species that lack living relatives. While you might not personally think being called a fossil is a compliment, these organisms are actually quite impressive survivors. The Ginkgo biloba tree, for example, is strange and unique amongst contemporary plants but incredibly similar to fossils dating back to the Permian, almost 270 million years! This means that even though every single other lineage of the Ginkgo’s relatives changed and adapted beyond recognition or died out, there are still Ginkgo trees growing today that would be indistinguishable from trees from hundreds of millions of years ago. If that fails to impress you, consider this: in Hiroshima, Japan there are still a handful of Ginkgo trees that survived the dropping of the atom bomb in 1945 living to the present day! If these hardy trees can withstand a disturbance of an A-bomb’s magnitude, it is no wonder they have managed to remain viable when so many other ancient plants could not.
Guest post written by Reggie Henke
Window Socket - Kyuho Song & Boa Oh
So this is an absolutley brilliant idea! Just attach the plug on to a window and it will harness solar energy. A small converter will convert it into electricity which can be freely used as a plug when you are in the car, on a plane or outside.
Love this design and I really think it has a great potential.
How Bees and Butterflies See
Butterflies and bees can both sense pigments in the center of flowers that we can’t see. UV photography techniques pioneered by Klaus Schmitt and others capture this better than anything else I’ve seen. See how the center of the flower gets darker as the UV fades in? Bulls-eye.
And what’s up with the glowing butterfly?! Living in a UV world would be awesome, except for all the DNA damage to your retinas thanks to the unfiltered radiation.
Click here to watch the latest episode of It’s Okay To Be Smart for more on how bees and butterflies have evolved to see flowers in a new light. And subscribe! It’s free.
The Center of the Earth Is as Hot as the Sun
Crushed by the weight of the thousands of kilometers of liquid iron and sulfur, superheated metal and minerals and cool crustal rock above, the Earth’s core is under immense pressure. Heated from within by friction and by the decay of radioactive material and still shedding heat from the initial formation of the planet 4.5 billion years ago, the planet’s core is blisteringly hot. In new research, scientists studying what the conditions at the core should be like found that the center of the Earth is way hotter than we thought—around 1,800 degrees hotter, putting the temperature at a staggering 10,800 degrees Fahrenheit.
This superheated core, says the BBC, is about as hot as the surface of the Sun.
Scientists know the Earth’s core, a multi-layered structure with a solid iron core spinning in a sea of liquid iron and sulfur, is hot. But, cut off from direct study by all the stuff in between the core and the surface, getting an accurate idea of the core’s properties is a daunting feat.
Led by Simone Anzellini, the French research team did their best bet to reproduce the core’s properties in the lab: they took a bunch of iron and crushed it between two pieces of diamond. Then they shot it with a laser. The apparatus produces massive pressures and superheated temperatures. This let them study how the iron behaved under such intense conditions and gave them a window into the conditions found at the planet’s center.
Knowing how hot the Earth’s core is can add to our understanding all sorts of wonders, from the existence of the planetary magnetic field, to the propagation of seismic waves after an earthquake, to the birth of the Earth itself.
While in flight, hummingbirds have the highest metabolisms of all vertebrates, in order to support their rapid beating of their wings (up to 80 times per second!). Their heart rate can reach 1260 beats per minute.
At night, the bird reduces its metabolism, slowing their heartbeats to 50-180 beats per minute to reduce their need for food.
To provide themselves with energy, hummingbirds consume more their own weight in nectar every day. They select flower species which have more sugar in their nectar.
As the bird burns through its food so fast, they are constantly hours away from starving to death, storing just enough energy to last through the night. They must continually eat to survive.
Danny Perez Photography on Flickr
“Maybe we’re on Mars because of the magnificent science that can be done there - the gates of the wonder world are opening in our time. Maybe we’re on Mars because we have to be, because there’s a deep nomadic impulse built into us by the evolutionary process, we come after all, from hunter gatherers, and for 99.9% of our tenure on Earth we’ve been wanderers. And, the next place to wander to, is Mars. But whatever the reason you’re on Mars is, I’m glad you’re there. And I wish I was with you.” — Carl