Electroreception, again...

[MGmirkin]

The old "Thunderbolts Forum 1.0" had an interesting thread on "electroreception." Still working on reconstructing ye olde forum. Need to sit down with it again, and try to get the links working... Small steps.

Anyway, ran across some more articles on electroreception. Thought they were interesting and others might enjoy them:

(Platypus Paradoxes)
http://www.science-frontiers.com/sf075/sf075b08.htm

(Platypus Bill An Electrical Probe)
http://www.science-frontiers.com/sf045/sf045p11.htm

(The star of the star-nosed mole)
http://www.science-frontiers.com/sf088/sf088b07.htm

(Electric Snakes; {?} Perhaps a stretch?)
http://www.science-frontiers.com/sf096/sf096b09.htm

(Why the hammer head?)
http://www.science-frontiers.com/sf065/sf065b06.htm

(From The Depths Of The Amazon)
http://www.science-frontiers.com/sf112/sf112p06.htm

(Trees talk in w-waves)
http://www.science-frontiers.com/sf063/sf063b11.htm

Cheers,
~Michael Gmirkin

[Grey Cloud]

Thanks for the links on electroreception. The Platypus was one of my favourite animals when I was a lad, not that there were many of them where I lived (NW UK).
I think Platypus Bill should get his own cartoon series.
We still have so much to learn from the flora and fauna.

[MGmirkin]

Thanks for the links on electroreception. The Platypus was one of my favourite animals when I was a lad, not that there were many of them where I lived (NW UK).
I think Platypus Bill should get his own cartoon series.
We still have so much to learn from the flora and fauna.

If nothing else, the platypus an the giraffe should tell us that the universe has a sense of humor... *wink*

Kidding, of course... But, yes, there's plenty yet left to learn about the goings-on of life, the universe, and everything.

~Michael Gmirkin

[MGmirkin]

(Why do electric fish swim backwards?)
http://www.science-frontiers.com/sf089/sf089b05.htm

(Electric Fish Not Backward In Data Processing)
http://www.science-frontiers.com/sf089/sf089b06.htm

Cheers,
~Michael Gmirkin

[StefanR]

Was doubting if I should post it here or in the tensegrity-thread, but I will cross-link there.
As there is some Darwin-fuss this year, this will be my contribution to that, of course in the linked article one has
see were the humor starts, but still.....

Ahead by a tail

You’d think that in 100+ posts we’d be starting to exhaust the territory, but there are vast swaths of sauropod vertebral morphology that we haven’t even touched. Like fused vertebrae. Sauropods fused their vertebrae all the time. Some of those fusions are age-related, many are pathological, and some are…hard to classify.

Exhibit A: fused distal caudals in a specimen of Mamenchisaurus hochuanensis described by Ye et al. (2001). In contrast to the terminal caudals comprising the tail club of Shunosaurus, the centra here are not ballooned out. The one in the middle is clearly waisted, as in “narrower in the middle than at the ends” (not the same clearly wasted as your college roommate). The neural, uh, elements are expanded and fused into something that the authors describe as resembling the comb of a rooster. I can’t improve on that metaphor so I won’t try. Here’s the full weirdness, straight from the authors (p. 39):

The posterior caudals are fused with each other, their centra are not expanded, the neural arch is remarkably expanded and the size of the neural canal and the height of the neural spines increased. In lateral view, the posterior caudals are cockscomb-shaped.

That’s all pretty weird. The authors go on to speculate that the expanded neural canal indicates that the tail club fin thingy served as some kind of special sense organ. I don’t think that idea is too bold. I don’t think it’s bold enough.

Hypothesis: Mamenchisaurus had a pseudohead on the end of its tail, with fused verts to form a pseudoskull and a big nerve bundle to give the pseudomouth (probably articulated chevrons) and pseudoeyes (possibly heat-sensitive like rattlesnake pits) some lifelike movements and relay thermal images up to the brain. It probably started out as a predator-confusion thing. The carnosaurs would obviously like to attack the inattentive end of the sauropod but these push-me-pull-yous were on the lookout fore and aft! And if the carnosaurs did attack, there was a 50/50 chance they’d bite off the wrong head. Then the pseudohead, which evolved to simulate attention, got so good at it that it was exapted into an actual lookout post at the individual’s farthest extremity. ........

http://svpow.wordpress.com/2009/02/02/ahead-by-a-tail/

[MGmirkin]

Deer, of all things? Really?

(Deer Disoriented by Power Lines)
http://www.livescience.com/strangenews/ ... lines.html

To aesthetes, high-voltage power lines are a blight on the rural landscape. But zoologists at the University of Duisburg–Essen in Germany welcome them as a tool for testing the power of large ruminants to perceive Earth's magnetic field.

Last year, a team led by Hynek Burda and Sabine Begall discovered that free-ranging cattle and deer tend to align their bodies in a north–south direction. The animals sure seemed to be responding to the geomagnetic field.

If so, the zoologists reasoned, they should lose their orientation when they graze or rest near power lines, because the current passing in the lines distorts Earth's magnetic field. If not, and the animals are reacting instead to the sun or some other cue, power lines should have no effect.

By observing wild roe deer and studying aerial images from Google Earth of cattle in European fields, Burda, Begall and three colleagues confirmed their hypothesis.

In general, the animals faced every which way near the lines. (East–west power lines were an intriguing exception; cattle tended to align with them, for reasons still unclear.) What's more, cattle gradually regained their north–south body orientation the farther they moved away from the lines.

The study is the first strong demonstration of magnetic alignment in mammals other than rodents or bats. An internal compass could well be handy equipment in the roaming lifestyle of grazing animals.

The findings were published in the Proceedings of the National Academy of Sciences.

Interesting... I guess maybe it's more magnetoreception than electroreception, but still. It's rather interesting...

Regards,
~Michael Gmirkin