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When Animals Evolve On Islands, Size Doesn't Matter
Science Daily ^ | 11-8-2007 | Imperial College London.

Posted on 11/08/2007 2:05:43 PM PST by blam

When Animals Evolve On Islands, Size Doesn't Matter

ScienceDaily (Nov. 8, 2007) — A theory explaining the evolution of giant rodents, miniature elephants, and even miniature humans on islands has been called into questions by new research.

The new study refutes the 'island rule' which says that in island environments small mammals such as rodents tend to evolve to be larger, and large mammals such as elephants tend to evolve to be smaller, with the original size of the species being the key determining factor in these changes. (Credit: iStockphoto/Andy Diamond)

The new study refutes the 'island rule' which says that in island environments small mammals such as rodents tend to evolve to be larger, and large mammals such as elephants tend to evolve to be smaller, with the original size of the species being the key determining factor in these changes.

The new research findings suggest that the tendency to either evolve larger or smaller on islands varies from one group of species to another, irrespective of original size. The research team, from Imperial College London, suspect instead that a number of external factors, including the physical environment of the particular island, the availability of prey, the presence of predators and the presence of competing species all play a role in determining the size evolution of island mammals.

Dr Shai Meiri from the NERC Centre for Population Biology at Imperial College London, lead author on the paper, explains: "If the island rule was correct, then most large mammals living on islands would be smaller than their continental relatives, and most small island mammals would be larger those living on continents. Our large dataset of mammal body sizes shows that this isn't the case: there is evidence that most mammal groups show no tendency to consistently either grow larger or smaller, in contradiction to the island rule."

Dr Meiri, who carried out the work with Professor Andy Purvis and Natalie Cooper from the College's Department of Life Sciences, added: "The island rule suggests that the smallest mammals such as mice will exhibit the most evolutionary growth on islands, whilst the largest mammals like elephants will dwarf the most, with all mammals in between on a sliding-scale.

"Our analyses showed this isn't the case, and the relationship between mammal size and evolutionary size change on islands is not that straightforward. Crucially, when we examined size change in light of the evolutionary relationship between different species, there was no connection between an evolution towards large size and greater degree of dwarfism on islands, or between evolution towards small size and island gigantism."

The research team concluded that although there does appear to be a weak correlation between the size of a mammal and how its size then evolves in an island habitat, this reflects some groups' specific tendencies towards gigantism or dwarfism, and not the general course of evolution. "The course of size evolution is dependent on a complex interplay of many other factors, that have led to the evolution of fascinating miniature and giant species of mammals on islands," concludes Dr Meiri.

This research was published November 7, 2007 in the Proceedings of the Royal Society B: Biological Sciences.

Adapted from materials provided by Imperial College London.


TOPICS: News/Current Events
KEYWORDS: animals; evolve; godsgravesglyphs; islands; size

1 posted on 11/08/2007 2:05:44 PM PST by blam
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To: SunkenCiv

GGG Ping.


2 posted on 11/08/2007 2:06:09 PM PST by blam (Secure the border and enforce the law)
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To: blam

LOL! Well, why did they believe it in the first place?

It sounds like a Brothers Grimm children’s fantasy. Miniature animals on miniature continents, heh.


3 posted on 11/08/2007 2:14:10 PM PST by donna (Duncan Hunter: US Army, 1969-1971, with service in Vietnam)
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To: blam

I forget who said, “Evolution will prove to be the biggest lie perpetrated on mankind.”


4 posted on 11/08/2007 2:14:27 PM PST by Resolute Conservative
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To: blam
Coconut Crab. Saw a great show on these on the discovery channel. Big!


5 posted on 11/08/2007 2:14:55 PM PST by Doomonyou (Let them eat lead.)
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To: blam
Count down to the first drive-by creationst who comes along and pretends that the validity of all evolutionary theory hangs on the merits of insular dwarfism...

5...4...3....

6 posted on 11/08/2007 2:16:31 PM PST by Alter Kaker (Gravitation is a theory, not a fact. It should be approached with an open mind...)
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To: blam

.


7 posted on 11/08/2007 2:17:50 PM PST by skinkinthegrass (just b/c your paranoid, doesn't mean they're NOT out to get you....Run, Fred, Run. :^)
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To: blam

Of course not. Macroevolution is NOT real!


8 posted on 11/08/2007 2:19:12 PM PST by Doc Savage (The tree of liberty needs to be refreshed from time to time with the blood of patriots and tyrants)
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To: donna
It sounds like a Brothers Grimm children’s fantasy. Miniature animals on miniature continents, heh.

Because it's true.... there are lots of cases of miniature animals on islands. The Channel Islands off the coast of California, for example, were home to a miniature species of 4 foot tall mammoths, called the Pygmy Mammoth until just 12,000 years ago. Scientists thought that insular dwarfism and insular gigantism followed predictable rules. This study seems to indicate that maybe the situation is more complex.

9 posted on 11/08/2007 2:21:23 PM PST by Alter Kaker (Gravitation is a theory, not a fact. It should be approached with an open mind...)
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To: Resolute Conservative

You forgot the wrong part. The misguided statement should be forgotten.

On topic, think Key deer


10 posted on 11/08/2007 2:25:12 PM PST by bert (K.E. N.P. +12 . Moveon is not us...... Moveon is the enemy)
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To: Doomonyou

All I need on that Island is some melted butter, beer and a crab cracker.


11 posted on 11/08/2007 2:29:34 PM PST by Trueblackman (Terrorism and Liberalism never sleep and neither do I)
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To: blam

Can’t wait to see how small people in Hawaii are in a couple years - lol.


12 posted on 11/08/2007 2:29:48 PM PST by Chili Girl
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To: Alter Kaker
"The Channel Islands off the coast of California, for example, were home to a miniature species of 4 foot tall mammoths, called the Pygmy Mammoth until just 12,000 years ago"

George Carter claims to have found remnants of camp fires and charred bones where humans roasted those little guys.

13,000 year old Arlington Springs Man skeleton was found there too.

13 posted on 11/08/2007 2:33:57 PM PST by blam (Secure the border and enforce the law)
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To: Alter Kaker
Because it's true.... there are lots of cases of miniature animals on islands.

Hmmm, so how does all this explain all these monstrous Hawaiians at the gym? Feel like I am in a NFL weight room at times.

Whatever it is, they developed on an island in the opposite direction from miniaturization......

14 posted on 11/08/2007 2:34:19 PM PST by doorgunner69
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To: Trueblackman

I’ll bring the cook pot and the fire.


15 posted on 11/08/2007 2:34:27 PM PST by Doomonyou (Let them eat lead.)
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To: Chili Girl

Hobbits of Indonesia were different human species

16 posted on 11/08/2007 2:37:21 PM PST by blam (Secure the border and enforce the law)
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To: blam
A theory explaining the evolution of giant rodents, miniature elephants, and even miniature humans on islands has been called into questions by new research.

Oh well...

back to the evolution board.
17 posted on 11/08/2007 2:37:40 PM PST by adorno
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To: Trueblackman

Here's your Crab Cracker.....

18 posted on 11/08/2007 2:42:52 PM PST by Red Badger ( We don't have science, but we do have consensus.......)
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To: Trueblackman

There’s a triple pun in there if you think about it....


19 posted on 11/08/2007 2:44:04 PM PST by Red Badger ( We don't have science, but we do have consensus.......)
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To: doorgunner69
Hmmm, so how does all this explain all these monstrous Hawaiians at the gym?

Insular gigantism, a parallel but opposite phenomenon resulting from a lack of predators on some islands. Another Hawaiian example: Moa-nalo, a now-extinct species of giant Hawaiian ducks the size of small deer, so large they could only waddle around. No historical records exist reporting how they did in the gym.

20 posted on 11/08/2007 2:44:48 PM PST by Alter Kaker (Gravitation is a theory, not a fact. It should be approached with an open mind...)
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To: Alter Kaker
Count down to the first drive-by creationst who comes along and pretends that the validity of all evolutionary theory hangs on the merits of insular dwarfism...

5...4...3....

Sadly, the actual count was -1. The Democrats get to play "Keep Away" with our lunches once again.

21 posted on 11/08/2007 2:59:24 PM PST by BlazingArizona
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To: blam

In theology, this would fall under ‘presuppositional apologetics’.


22 posted on 11/08/2007 3:01:26 PM PST by PAR35
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To: Alter Kaker
Because it's true.... there are lots of cases of miniature animals on islands.

IANAB (...biologist), but I think it's more a matter of natural selection going weird in a situation of small sample size. That's why New Zealand, to take one example, got the three-eyed lizard, the six-foot earthworm that glows in the dark, and the alpine parrot that has an IQ higher than most politicians.

23 posted on 11/08/2007 3:04:44 PM PST by BlazingArizona
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To: BlazingArizona
That's why New Zealand, to take one example, got the three-eyed lizard, the six-foot earthworm that glows in the dark, and the alpine parrot that has an IQ higher than most politicians.

Sounds like the bar scene in Star Wars. :-)

24 posted on 11/08/2007 3:06:39 PM PST by Alter Kaker (Gravitation is a theory, not a fact. It should be approached with an open mind...)
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To: Alter Kaker; blam
Same situation with Steamer ducks. They are native to the Falkland Islands and a few other small islands off the coast of South America. Big, flightless ducks.


25 posted on 11/08/2007 3:10:27 PM PST by CholeraJoe (Be unique. It makes it easier for the rest of us to identify the morons.)
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To: BlazingArizona
"...the alpine parrot that has an IQ higher than most politicians."

Beautiful bird. The Kea pictures.

26 posted on 11/08/2007 3:31:47 PM PST by blam (Secure the border and enforce the law)
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To: blam

Aren’t pygmies from that island called Africa?


27 posted on 11/08/2007 3:32:49 PM PST by kcar
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To: blam
When Animals Evolve On Islands, Size Doesn't Matter..

And just how will this knowledge change the world for the better???

28 posted on 11/08/2007 3:51:54 PM PST by USMA '71
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To: Resolute Conservative
“Evolution will prove to be the biggest lie perpetrated on mankind.”

The "biggist lie perpetrated [up]on mankind" is the idea that stupid, insane, and dishonest people are as likely to be correct as those who are intelligent, rational, and honest, because "everyone is entitled to their own opinion".

29 posted on 11/08/2007 3:56:11 PM PST by 3niner (War is one game where the home team always loses.)
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To: CholeraJoe

Tachyeres brachypterus is the flightless Steamer Duck...there is a flying Steamer Duck:

http://www.arthurgrosset.com/sabirds/flyingsteamer-duck.html

Tachyeres patachonicus

The Flying Steamer-duck is distributed in southern Chile, the extreme south of Argentina, Tierra del Fuego and the Falkland Islands. It is the only steamer-duck that is found on inland water-bodies as well as at the coast...


30 posted on 11/08/2007 4:00:11 PM PST by Fred Nerks (Fair dinkum!)
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To: Alter Kaker

I think they’re here.


31 posted on 11/08/2007 4:07:38 PM PST by EveningStar
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To: blam
Meanwhile, DownUnder there's a flightless bird that SWIMS. Cassowaries have been seen to swim between Whitsunday Islands and the Mainland.

http://www.damisela.com/zoo/ave/ratities/casuario/casuarius/indexe.htm

The Southern Cassowary (Casuarius casuarius) is natural of the coastal area to the northeast of Queensland, Australia. It is also present on low elevations regions of New Guinea and some of the smaller nearby islands. Usually stays at low elevations. This species is the one with southern most distribution among the three cassowaries, that is why it is called the “Southern Cassowary”.

The Southern Cassowary prefers the thick vegetations, such as the tropical jungles of forests.

Normally stays solitary and hidden inside the vegetation. It is hard to observe this bird in its natural habitat since it remains where the vegetation is abundant. Occasionally it comes out to clearings or the edges of the jungle, but never far into the opening. They have also been seeing crossing rivers swimming, which it can do rather well...

32 posted on 11/08/2007 4:35:00 PM PST by Fred Nerks (Fair dinkum!)
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To: Fred Nerks

NEAT.

33 posted on 11/08/2007 4:45:16 PM PST by blam (Secure the border and enforce the law)
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To: blam
dangerous - approach with caution!

dinosaur footprints...

34 posted on 11/08/2007 5:31:00 PM PST by Fred Nerks (Fair dinkum!)
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To: blam; StayAt HomeMother; Ernest_at_the_Beach; 1ofmanyfree; 24Karet; 3AngelaD; 49th; ...

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Thanks Blam.

To all -- please ping me to other topics which are appropriate for the GGG list.
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35 posted on 11/08/2007 10:06:12 PM PST by SunkenCiv (Profile updated Thursday, November 8, 2007. https://secure.freerepublic.com/donate/)
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To: blam

Another ‘theory’ debunked!


36 posted on 11/09/2007 5:15:49 AM PST by Dustbunny (The BIBLE - Basic Instructions Before Leaving Earth)
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To: blam

Interesting! Evolution on islands is a great topic. I remember reading about lizards on different islands having the same morphology but different genomes. The explanation was that as the different founder populations spread into new environments they evolved the same set of characteristics in similar environments. Therefore even though all the mountain lizards populations looked alike they were genetically closer to the beach lizards on the same island than the mountain lizards on the next island.


37 posted on 11/09/2007 5:37:38 AM PST by Varda
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To: blam

Tell that to the females.


38 posted on 11/09/2007 3:30:36 PM PST by wildbill
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To: blam

· join list or digest · view topics · view or post blog · bookmark · post a topic ·

 
Gods
Graves
Glyphs
Just updating the GGG info, not sending a general distribution.

To all -- please ping me to other topics which are appropriate for the GGG list.
GGG managers are SunkenCiv, StayAt HomeMother, and Ernest_at_the_Beach
 

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39 posted on 06/08/2009 6:43:38 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/__Since Jan 3, 2004__Profile updated Monday, January 12, 2009)
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