The IncreasingDisorder computer was suffering from a deficit of internet over the past week. The modem had broken AND there were problems with the line. At least I got all the problems sorted out at once. But I was severely restricted by what science bits and general browsing I could do – stabbing at an iPhone screen to browse via 3G is not as fun as it sounds.
Everything’s OK now through. So it’s high time for a science round-up. What have I found so far?
- some lizards just like to fight
- turtles got busted having sex – 47 million years ago!
- stressed-out grasshoppers have a different elemental composition to laid-back ones
Them’s fightin’ words….
From NewScientist, and published in the Journal of Zoology, we have a fun story about pugnacious lizards. Most animals do not like to fight, with notable exceptions to this convention being my cat (a feisty piece indeed), and the Dalmatian wall lizard (Podarcis melisellensis). Generally, if one must fight, it’s usually against the same species, and for reasons such as food availability or sex rivalry. But the Dalmatian wall lizard is aggressive and likes to fight – and it will fight even if unprovoked. The reasons for this behaviour is unknown, although the researcher pointed out that he’d put the wall lizards into artificial situations with other species of lizards that they normally don’t hang out with. Social etiquette be damned. Next time I’m on a bus or somewhere with a lot people I don’t know, I’ll start a fight.
Ref: Lailvaux et al. 2012 Journal of Zoology online early DOI: 10.1111/j.1469-7998.2012.00943.x
Various news outlets, including Science mag (ScienceNOW in fact), are reporting on the finding of a pair of turtles caught having sex, published in Biology Letters (but not yet available to us proles who don’t work for ScienceNOW). The notable aspect of this is that the turtles are fossils and are about 47 million years old. Nine pairs of turtles have been found from the Messel pit in Germany, which was a lake a long, long time ago. The Messel pit has provided many high quality specimens of animals, but never any copulating. How did the palaeontologists know what these turtles were doing? Several things provided clues: the size of both turtles. All the pairs had a large and a small turtle, and freshwater turtles even today display sexual dimorphism, the relative positioning of the turtles to each other, and that in two pairs, the male’s tail was wrapped around that of the female’s – a turtle sex thing apparently.
The main question, however, was how did they die caught in the act? One hypothesis is that the Messel lake had anoxic (no oxygen) water in its deeper areas, and because turtle sex can take some time, pairs sinking a bit while taking a break could find themselves in depths with too little oxygen to survive. Either way, I’m sure the Science journalists had fun writing the article.
Stressed grasshoppers taste different….
Well, possibly, but that’s not the point of the article. Published in Science, is some research examining how the elemental composition of herbivore insects varies with exposure to predators, and what that means for soil community function. Grasshoppers that are stressed out because of exposure to spider predators have a higher carbon to nitrogen ratio than those that have no predators nearby. What this means is that decomposition of biomass in soils is slower in areas where herbivores are predated on because of the different chemical composition of the herbivores and the volume of herbivores returned to the soil. From the paper:
…predator-induced changes in the nutritional composition of herbivore biomass dramatically slow the decomposition of plant litter through legacy effects on soil communities.
Ref: Hawlena et al. 2012 Science 336, 1434-1438.
Some cosmic prettiness in the form of an infrared photo of the Pleiades, from NASA, via the BBC website.