I found out about this on "Wait Wait, Don't Tell Me: The NPR News Quiz."
‘Monster mice’ are eating island’s seabirds
Rodents evolved to triple normal size, attack much larger chicks
The island effect produces giant tortoises, giant (flightless) pigeons, and my favorite, giant monitor lizards (Komodo dragons). For some unknown reason, it also produces dwarf humans (Homo florensis) and dwarf elephants (which, according to island biogeographer David Quammen, were originally the chief prey of Komodo dragons).
EDIT: I originally spelled the name "Kwammen," for some reason
‘Monster mice’ are eating island’s seabirds
Rodents evolved to triple normal size, attack much larger chicks
The island effect produces giant tortoises, giant (flightless) pigeons, and my favorite, giant monitor lizards (Komodo dragons). For some unknown reason, it also produces dwarf humans (Homo florensis) and dwarf elephants (which, according to island biogeographer David Quammen, were originally the chief prey of Komodo dragons).
EDIT: I originally spelled the name "Kwammen," for some reason
Wait, wait, don't tell me. Seriously.
Date: 2005-07-30 04:43 pm (UTC)Re: Wait, wait, don't tell me. Seriously.
Date: 2005-07-30 05:01 pm (UTC)Re: Wait, wait, don't tell me. Seriously.
Date: 2005-07-30 05:09 pm (UTC)Someone has an irritating personality, and is annoying for 10 minutes. The first 30 seconds makes you kind of chuckle, the remaining time makes you drink more.
Re: Wait, wait, don't tell me. Seriously.
Date: 2005-07-30 05:20 pm (UTC)no subject
Date: 2005-07-30 04:44 pm (UTC)no subject
Date: 2005-07-30 05:03 pm (UTC)no subject
Date: 2005-07-30 07:05 pm (UTC)In other news, I replaced the ballcock thing with the only thing they had at the hardware store - damn home depot, why must you be so far away?! - and it works, kinda. The original fancier one had a special doohickey that hooked up to the water in pipe that made water flow into the bowl. The cheapass mofo of a thing that I got doesn't have that so no water is going in through those holes (but the bowl still fills fine). Nothing more fun than lying on your back on the damp tile floor trying to figure out why the freaking thing doesn't work.
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Date: 2005-07-30 11:18 pm (UTC)no subject
Date: 2005-07-31 03:49 pm (UTC)no subject
Date: 2005-07-30 04:45 pm (UTC)no subject
Date: 2005-07-30 04:49 pm (UTC)no subject
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Date: 2005-07-30 04:54 pm (UTC)Most mammals compensate for island living by getting smaller because there's less to eat, and a smaller body needs less food. The same thing happened with dinosaurs when part of Romania was an island, too. Island-dwelling mammals usually get smaller. However, mice are generalist critters, so they can evolve in multiple directions more quickly because they can survive in a wider range of conditions than can elephants or humans, which are much more specialized animals. Big, carnivorous mice aren't that surprising... there used to be giant rats on some islands off South America (I think) that were also carnivores and got as big as dogs. Rodents are the most adaptable family of mammals; just look at naked mole rats!
Tortoises are very low-energy creatures, so if they don't have competition for food, their genetics tend to select for larger and larger size. In the Galapagos, there aren't many (if any) other grazers, so the tortoises have all the grass to themselves, and they can afford to get so big that no potential predator will other with them. Not much eats tortoises to begin with.
All it takes is a founder effect, with the founders having a bunch of recessive and/or breakable genes, and speciation picks up very quickly if there's little competition and a new niche or two to exploit.
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Date: 2005-07-30 05:05 pm (UTC)I said unknown because the mouse article claimed that scientists disagreed about the reasons for the island effect.
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Date: 2005-07-30 05:24 pm (UTC)I don't have a link handy (this is stuff I learned in biology classes), but if you search around for information about things like "founder effect," "genetic drift," natural selection, etc., you should be able to find lots of information about this. Really, the "island effect" is just particular set of pressures that, all together, addup to natural selection.
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Date: 2005-07-30 07:07 pm (UTC)no subject
Date: 2005-07-30 07:20 pm (UTC)no subject
Date: 2005-07-30 07:22 pm (UTC)no subject
Date: 2005-07-30 07:09 pm (UTC)Carnivorous is one thing - many rodents are. Predatory is something entirely different.
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Date: 2005-07-30 07:33 pm (UTC)That's the thing about nature; no matter what any given human thinks of as the norm, there really isn't one. I've met millipedes that have hit me with something resembling tear gas in my own backyard. Who'd have thunk it?
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Date: 2005-07-30 07:44 pm (UTC)Don't lots of insects and such emit horrible sprays to deter their predators?
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Date: 2005-07-31 02:14 am (UTC)Some insects do, but most don't. Only the ones I forget to be careful with while I'm photographing them consistently have solid defenses.
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Date: 2005-07-31 03:48 pm (UTC)Seems like pretty much any animal will happily evacuate when they're nervous. :)
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Date: 2005-07-30 07:14 pm (UTC)There weren't mosquitos on Hawaii prior to the mid 1820s.