Talk:Insular dwarfism

Hmmm...I agree about the merger. They seem to be different versions of the same thing, and except for the list of examples, Insular dwarfism has a more developed explanation and is an actual name for the process. --Kaz 21:50, 12 June 2006 (UTC)[reply]

"Human beings along the islands off the coast of India, especially Homo floresiensis" is misleading? Homo floresiensis was found in Flores, Indonesia

Balance

I was talking to a paleontologist today, and he told me that actually there is an optimal size for woods mammals (about a small dog) and another for plains mammals (like a four-legged human). However species diverge from these sizes when there are other factors besides energy balance. The example he put was elephants who are big to defend themselves from predators. If an elephant species is left alone in an island it evolves towards the optimal size, hence the dwarfism. If it is a small species who becomes isolated, we'll have insular gigantism.

Did I understand it right? Should this theory appear in the article? --Error 23:32, 11 November 2006 (UTC)[reply]

We should hold off on inserting this into the article until we see more examples of it in scientific literature. Or at least until we come across a layperson-friendly translation--Mr Fink 02:08, 12 November 2006 (UTC)[reply]

There are a couple of theories like this floating around - for instance, I was just reading a paper (Brown, J., Marquet, P.A. and M.L. Taper. 1993. Evolution of body size: consequences of an energetic definition of fitness. American Naturalist 142(4):573-584) where the authors hypothesize that the optimum body size for mammals is about 100 grams, based on a trade-off between metabolism (larger animals have relatively lower metabolic rates) and the "cost" of an offspring (where smaller animals can make offspring more cheaply). In other words, if you're too big, it's easier to accumulate energy, but your offspring are more expensive to make; if you're too small, offspring are cheap but you have to forage constantly just to keep yourself alive. If there are other ecological factors involved - predators driving you to defend yourself, or similar-sized competitors that eat the same things you do - there may be some degree of selection away from this optimum size, but in the absence of those other factors organisms will evolve back to this size.

That's that theory, anyway. Obviously Brown et al.'s calculations come up with a different result than the ones described above, but it's probably the same sort of energetic trade-off theory - the article cites a couple other sources that came up with different results, so the above-mentioned paleontologist may be explicitly referring to one of them (which I haven't read) or amalgamating some of them together. I'm not sure how widely accepted this explanation is, but hopefully I've at least contributed towards your layperson-friendly translation. DaveOTN 19:14, 29 November 2006 (UTC)[reply]

Japanese people

Are the Japanese really any shorter than other Asians? I was of the opinion that they were actually a little taller than average. Haplolology 22:17, 29 December 2006 (UTC)[reply]

I am not really sure humans are subject to this effect at all. I think the smallness of those other island peoples is due to the fact that they were derived from short mainland populations which had been that way for many thousands of years. Haplolology 00:58, 6 January 2007 (UTC)[reply]

Come on, the islands of Japan, especially Honshu, are very big. Living on an island per se cannot cause anything. "Continent"s themselves are very big island.