I was reading a book last night, and there was a dinky section about " island dwarfism." Or rather, island dwarfism. The theory says that birds on small islands probably get smaller than their mainland counterparts due to limited resources .... and eventually they get so small that they can no longer interbreed successfully with the mainland population and have become a separate species. And there's also "island gigantism" ...yes, the birds get bigger, and this is "explained" by the idea that they are filling a vacant niche ... that niche being the one that large mammals aren't there to fill. Now that seems a bit a bit weak to me ... I can hear the sound of barrels being scraped. And as for the "dwarfism" explanation, surely if resources were scarce, some of them would die, and then the resources would be sufficient for the now smaller population. Plus ... what about all the other organisms on said island ... the woodlice, the rats, the pottos, the moles, the spiders .... do they get smaller/bigger ... and if not, why not? And what about all the lice and ticks on those birds ... do they get smaller/bigger too ? And then there's the problem of the island getting smaller .. which it probably is, what with all that heavy seawater and its payload of pebbles and old beer cans bashing against its shores for eternity. Thetruth is, thnigs are otfen a lot more coplicasticated than they seem. Right then ...music time .... oh, and it's complicated, some now and some later ...
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AuthorThat's the author up there ... I was young and sprightly then. Archives
October 2022
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