Ants have been farming for far longer than humans have existed. They discovered fungus farming around fifty or sixty million years ago in the wet rainforests of South America, and have continued tending their underground fungus gardens through countless years as the planet changed and changed, and changed again. Much more recently — just a few years ago — I wrote about the fungus-farming ants (called “attine ants”), trying to imagine how they might view human agriculture. Our imaginary attine author closed with the hope that studying humans might help the attines understand their own history, “such as how the transition from primitive to advanced agriculture occured in our own ancestors”, and now a study by a group of humans has shed light on that very question. Continue reading
As long ago as forever and as far away as home, life was withering away wherever you looked. At the end of the Permian, around 250 million years ago, the creatures of Earth were devastated by an extinction that outstripped any seen before or since. Marine species suffered the most — 96% of them died out — but even among their terrestrial cousins, seven out of every ten species were lost. For countless generations, life struggled towards recovery, but it took 10 million years to rebuild the lost diversity. The cause of the catastrophe has long puzzled scientists; global warming, massive volcanos, ocean acidification, and widespread oceanic oxygen depletion have all been implicated. In a paper appearing in Science, researchers from the UK, Germany and Austria showed that increased carbon released into the atmosphere eventually acidified the oceans just as the Permian extinction reached its peak; comparing their findings with how quickly our societies release carbon, they reveal an alarming difference together with a sobering insight.
Clarkson MO, Kasemann SA, Wood RA, Lenton TM, Daines SJ, Richoz S, Ohnemueller F, Meixner A, Poulton SW, & Tipper ET (2015). Ocean acidification and the Permo-Triassic mass extinction. Science (New York, N.Y.), 348 (6231), 229-32 PMID: 25859043
It’s probably not a surprise that humans aren’t the only animals with a sense of numbers. While they’re probably not actually counting, a variety of species seem to be able to tell the number of objects in a group; they can distinguish between groups with greater or fewer objects and react with surprise when the number changes unexpectedly. However, a recent study suggests that this numerical understanding may go deeper than we’ve previously thought. Continue reading
On March 29, 2011, a TEXUS-49 rocket took off from northern Sweden for a short trip into space and back through Earth’s sheltering blanket of atmosphere. This amazing feat of engineering has become surprisingly routine — we humans have gotten to the point where launching a vehicle into space to carry out an experiment or deliver a satellite into orbit no longer inspires awe and wonder. Sounding rockets are commonly used as sub-orbital research platforms. In this case, one of the experiments on the mission was a test of how well DNA molecules can survive the temperatures involved in plummeting back through Earth’s atmosphere. The results, published earlier this year in PLOS ONE, show that DNA is tough enough to make it through atmospheric re-entry after a quick jaunt in space. Continue reading
Since plants generally can’t move around, they have to rely on other strategies to cope with animals eager to turn them into a meal. Chemical weapons are a significant part of plants’ defensive arsenal. For example, thousands of plant species produce precursors of the deadly poison hydrogen cyanide; when an animal eats the plant, the precursors get converted into cyanide, which kills the offending animal. Continue reading
This is a story about a gene which makes nursing mice produce more nutritious milk while also making their offspring less demanding. The gene serves to balance nutrient supply and demand between the mother and pup. If the gene is knocked out, the mother’s milk is less rich, but the pups are more demanding, evening out the impact. Things only go wrong when there’s a mismatch. If pups with a defective copy of the gene feed from a normal mother, their increased demand makes them grow larger than normal. Conversely, pups with a good copy end up smaller if they feed from a mother lacking a working copy, since her milk is less nutritious. Continue reading