September 18, 2008

Another dethronement of human uniqueness! (Yawn)

Early morning sculptureProbably something most dog owners know, but nice to see formally documented and tested: Dogs catch human yawns (Biology Letters 4:5 October 23, 2008, p446-448) It also contradicts earlier claims that yawn contagion is purely human or that it is just found among primates.

Some other interesting articles from the same journal:

Sea lice are good at escaping onto the predator when it eats their host

Immune response impairs learning in bumble-bees - there seems to be either competition for energy between the nervous system and the immune system, or some of the immune responses mess things up for the CNS.

The pattern of fossil feathers can likely be inferred - the dark in the fossils is apaprently remnants of melanosomes, showing where there were colour. It is hence possible to deduce feather patterns and possibly (using electron microscopy) even colouring.

The Robin Hood parasite - a plant parasite that has deleterious effects on the most fecund hosts and apparently beneficial effects on the least fecund hosts. The cause might be that the fecund host lines trade off their "immune system" for reproduction, or that the least fecund hosts overcompensate for the parasite damage.

Dino in museumMore than 50% of old dinosaur species are actually invalid - but paleontology is getting better these days than the victorian bone-hunters. One should in any case not trust species lists too naively.

Hierarchical social networks among mammals have the same scaling pattern - Each level of organisation is about 3 times as large as the previous, with the possible exception for orcas (where it is 3.8).

Female guppies select areas with higher predation risk to get away from sexual harassment - but on the other hand, females of swordtail fish prefer males with a particular spotted tail pattern that has a high risk of getting melanomas, hence keeping the otherwise detrimental gene in the population.

Posted by Anders3 at September 18, 2008 06:24 PM