Rudimentary Behaviours

Biting Birds and Piloerection

Anybody who knows that the kiwi is foremost and for all a bird (and not a fruit) knows that this New Zealander has no wings – only a few rudimentary bones remain of what were once the winsgs of its ancestors. Whales have no hind limbs, so the entire pubic girdle became vestigial. Certain toes are often superfluous and consequently through the process of selection have diminished in size or disappeared completely as in the horse and other hoofed animals. Teeth, too, as with our so-called wisdom teeth can be vestigial and eye rudiments in cave organism are another example. The anatomical concept of rudimentary organs is therefore easily understood, but we could ask ourselves whether there might not also be something like a rudimentary behaviour or functionally useless action steeped in evolutionary history. Continue reading

Suicides

zoology-suicide death biology benno meyer rochow florian nock

The famous British-Indian geneticist J.B.S. Haldane is often quoted to have said he was quite willing to die for two siblings and 8 cousins, a statement, which is of course based on genetic relatedness, later expounded mathematically by William D. Hamilton in his studies on kin selection. Altruism and putting oneself in danger to protect or save other individuals, usually closely related ones, is not confined to humans but actually widespread in animals. —>

zoology-biology-benno-meyer-rochow-florian-nock photoreceptors physics electricity

The Incomparable Sense

Electroreception

Luigi Galvani and Alessandro Volta’s observations ca. 250 years ago on frogs, whose legs twitched due to muscular contractions when touched with two different metals, can be regarded as the start of electro-biological studies. Although an animal’s nerves are not telephone wires and the muscles aren’t electromotors, activities such as thinking and moving are indeed registrable as electric events: one may think, for example, of the electrocardiogram, the electroencephalogram, or the electroretinogram. The trouble is that the electric events accompanying the various activities of live animals are so weak in nature that sophisticated electronic gadgetry is required to amplify and record them. But there are animals, which can detect bioelectricity with particular sense organs, which the zoologist calls electroreceptors. —>