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Eye of the Giant

Soccer ball-sized eyes may help giant squid see distant predators in the deep, dark ocean.

By | March 15, 2012

image: Eye of the Giant Giant squid incased in ice, Melbourne AquariumWikimedia Commons, Fir0002/Flagstaffotos

Giant squid incased in ice, Melbourne AquariumWIKIMEDIA COMMONS, FIR0002/FLAGSTAFFOTOS

There is no competition. The giant squid has the largest known eyes in the animal kingdom—three times the diameter of the largest eyes of any other animal. Yet there has been no clear explanation for why giant squid need such big peepers.

Now, researchers at Lund University in Sweden have a theory: giant squid eyes are uniquely suited for detecting large predators at far distances. The theory, published today (March 15) in Current Biology, can be used to model other visual systems in deep, inaccessible aquatic environments, the authors said.

“It’s the first time I’ve ever seen such a close analysis of the selective pressures determining the size of an eye,” said Howard Howland of Cornell University, who has studied vision for over 50 years and was not involved in the research. “They’ve done a tremendous job analyzing the visual environment of the squid.… It’s very convincing.”

When Dan-Eric Nilsson and colleagues at Lund first began calculating vision based on eye size, they quickly determined that as small eyes get bigger, the range of vision in the ocean increases dramatically. But only up to a point: when the eyes reach about 9 centimeters in diameter, that range stops improving due to absorption and scattering of light in water, explaining why the eyes of fish do not exceed that size. “It pays to make eyes larger up to about the size of an orange, but then it pays less and less,” said Nilsson. But the giant squid’s eyes measure some 27 centimeters, about the size of a soccer ball.

To find out why the deep-sea squids had evolved such enormous eyes, the team developed a mathematical model to predict the eyes’ ability to detect different types of objects under various lighting conditions. The researchers concluded that giant squid eyes are not especially advantageous for detecting prey or mates. But they are uniquely suited for identifying very large predators, such as sperm whales, at distances of 120 meters and depths below 500 meters, where only low levels of light penetrate. As sperm whales move through the deep sea, they upset organisms like plankton in the water, which show their irritation by glowing, a phenomenon called bioluminescence, which the giant squid can detect thanks to their massive eyes.

Whale attack display from the Museum of Natural History, NYC
Whale attack display from the Museum of Natural History, NYC
MIKE GOREN, WIKIMEDIA COMMONS

Particularly helpful are the squid’s large pupils, which the team estimated to be about 9 centimeters across, about the size of a softball, based on a 1981 photograph of a freshly caught giant squid in Hawaii and the body of an adult colossal squid that had been caught and deep-frozen in New Zealand in 2007. In the squid’s dark habitat, an especially large pupil is necessary to detect differences between a large target and its background, such as the dim glow of upset plankton against the black ocean.

Thanks to their impressive vision, giant squid can monitor a huge volume of ocean for predators, the researchers concluded—about 7 million cubic meters. Unfortunately for the squid, whale sonar range is about 200 meters—some 80 meters longer than the squid’s visual range—so whales are likely to locate their prey before the squid see them. But the ability to detect incoming whales gives the squid a chance to prepare an evasive manuver, said Nilsson. Squid, unlike whales, can cut quick, 90-degree turns. It is possible, therefore, that predation by sperm whales led to the evolution both of giant eyes and big, powerful bodies. “Both being giant and having large eyes help a squid avoid being taken by sperm whales,” said Nilsson.

The team next plans to use their model to predict how smaller eyes are used in the deep sea. “It’s poorly known because it’s so hard to access those places,” said Nilsson. “Now we can make predictions to tell what different eye sizes in different animals can actually see.”

“I’m sure this theory, which they’ve pioneered, will be used in a number of other investigations,” added Howland. “It’s a spectacular article.”

D.E. Nilsson et al., “A unique advantage for giant eyes in giant squid,” Current Biology, doi:10.1016/j.cub.2012.02.031, 2012.

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Comments

Avatar of: David Carlson

David Carlson

Posts: 1457

March 17, 2012

The ability of cephalopods to see by the light of disturbed bioluminescence may stem from their origin in Oort-cloud compound-comet oceans of the Ordovician period, rather than from their transplanted home on earth. 

The Appalachian Basin Platform may be one such compound comet core from the inner Oort cloud that formed around the resonances of a companion star (Nemesis) orbiting our sun.  Oort cloud comets may still be forming around the resonances of Nemesis today (such as the hypothesized Younger Dryas comet impact 12,900 B.P.) in the same way that asteroid-belt planetesimals formed around the resonances of Jupiter 4.5 Ga.

http://hillscloud.wordpress.co...

Avatar of:

Posts: 0

March 17, 2012

The ability of cephalopods to see by the light of disturbed bioluminescence may stem from their origin in Oort-cloud compound-comet oceans of the Ordovician period, rather than from their transplanted home on earth. 

The Appalachian Basin Platform may be one such compound comet core from the inner Oort cloud that formed around the resonances of a companion star (Nemesis) orbiting our sun.  Oort cloud comets may still be forming around the resonances of Nemesis today (such as the hypothesized Younger Dryas comet impact 12,900 B.P.) in the same way that asteroid-belt planetesimals formed around the resonances of Jupiter 4.5 Ga.

http://hillscloud.wordpress.co...

Avatar of:

Posts: 0

March 18, 2012

How did the squid avoid the whales while its big eyes were
supposedly evolving over millions of years? Partially-evolved eyes over
supposed millions of years does no good. Natural selection wouldn’t have
preserved them. This squid’s eyes were designed for its obvious purpose.

 

Natural selection in nature doesn’t produce anything. It can
only “selectâ€쳌 from variations that are possible and which have survival value.
There are limits to evolution and natural selection in nature. Only evolution
within biological “kindsâ€쳌 is possible (such as varieties of dogs, cats, horses,
cows, etc.). Evolution is not possible across biological “kinds,â€쳌 is not
possible. The genes already exist in all species for micro-evolution (evolution
within “kindsâ€쳌) but not for macro-evolution (evolution across “kindsâ€쳌).

 

Genetic information cannot happen by chance. Genetic and
biological similarities between species are better explained due to a common
Designer who designed similar functions for similar purposes in all the various
forms of life.

 

Also, "Junk DNA" isn't junk. These
"non-coding" segments of DNA have recently been found to be vital in
regulating gene expression. Read my popular Internet article: HOW FORENSIC
SCIENCE REFUTES ATHEISM

 

How did species survive if their vital tissues, organs,
reproductive systems, etc. were still evolving? Read my Pravda Internet
article: WAR AMONG EVOLUTIONISTS! I discuss: Punctuated Equilibrium, "Junk
DNA," genetics, mutations, natural selection, fossils, genetic and
biological similarities between species.

 

Evolution is possible only if there’s information (genes)
directing it. Only variations of already existing genes are possible, which
means only limited evolution and adaptations are possible. Nature has no
ability to invent new genes via random mutations caused by random environmental
forces. That’s evolutionary faith, not science.  Evolutionists hope and believe that random genetic mutations
caused by the environment over, supposedly, millions of years will produce new
genetic information. That’s blind faith, not science.

 

THE SCIENCE
SUPPORTING CREATION (Google this title to access this site of mine). The site
presents a collage of evidences from science supporting creation and refutes
arguments by evolutionists (i.e. "flaws" in design of human eye,
"junk" DNA, embryonic recapitulation, age of the earth, fossils,
origin of life, etc.).  Also, read my Internet article ANY LIFE ON MARS
CAME FROM EARTH. In the Earth's past, powerful volcanic activity spewed
life-containing dirt into space very possibly reaching Mars.

 

I am not going to take the time to argue and debate. My
articles provide the answers to most questions and arguments. Just google my
name and go to my website to review my articles.  Also, visit the Institute for Creation Research site where you
can read excellent scientific articles by creation scientists.

 

Babu G. Ranganathan

 

(B.A. theology/biology)

Avatar of: Babu G. Ranganathan

Babu G. Ranganathan

Posts: 1457

March 18, 2012

How did the squid avoid the whales while its big eyes were
supposedly evolving over millions of years? Partially-evolved eyes over
supposed millions of years does no good. Natural selection wouldn’t have
preserved them. This squid’s eyes were designed for its obvious purpose.

 

Natural selection in nature doesn’t produce anything. It can
only “selectâ€쳌 from variations that are possible and which have survival value.
There are limits to evolution and natural selection in nature. Only evolution
within biological “kindsâ€쳌 is possible (such as varieties of dogs, cats, horses,
cows, etc.). Evolution is not possible across biological “kinds,â€쳌 is not
possible. The genes already exist in all species for micro-evolution (evolution
within “kindsâ€쳌) but not for macro-evolution (evolution across “kindsâ€쳌).

 

Genetic information cannot happen by chance. Genetic and
biological similarities between species are better explained due to a common
Designer who designed similar functions for similar purposes in all the various
forms of life.

 

Also, "Junk DNA" isn't junk. These
"non-coding" segments of DNA have recently been found to be vital in
regulating gene expression. Read my popular Internet article: HOW FORENSIC
SCIENCE REFUTES ATHEISM

 

How did species survive if their vital tissues, organs,
reproductive systems, etc. were still evolving? Read my Pravda Internet
article: WAR AMONG EVOLUTIONISTS! I discuss: Punctuated Equilibrium, "Junk
DNA," genetics, mutations, natural selection, fossils, genetic and
biological similarities between species.

 

Evolution is possible only if there’s information (genes)
directing it. Only variations of already existing genes are possible, which
means only limited evolution and adaptations are possible. Nature has no
ability to invent new genes via random mutations caused by random environmental
forces. That’s evolutionary faith, not science.  Evolutionists hope and believe that random genetic mutations
caused by the environment over, supposedly, millions of years will produce new
genetic information. That’s blind faith, not science.

 

THE SCIENCE
SUPPORTING CREATION (Google this title to access this site of mine). The site
presents a collage of evidences from science supporting creation and refutes
arguments by evolutionists (i.e. "flaws" in design of human eye,
"junk" DNA, embryonic recapitulation, age of the earth, fossils,
origin of life, etc.).  Also, read my Internet article ANY LIFE ON MARS
CAME FROM EARTH. In the Earth's past, powerful volcanic activity spewed
life-containing dirt into space very possibly reaching Mars.

 

I am not going to take the time to argue and debate. My
articles provide the answers to most questions and arguments. Just google my
name and go to my website to review my articles.  Also, visit the Institute for Creation Research site where you
can read excellent scientific articles by creation scientists.

 

Babu G. Ranganathan

 

(B.A. theology/biology)

March 23, 2012

Now see, you've gone and stirred up the cuckoos!  Yo, Babu, I know you won't debate (how convenient!), but how's come your Designer threw in scoffers like me to sully the perfect Plan?  Oh, and Who (What, what!?) designed the Designer? Silly me!  It's turtles all the way down, right!?  And David... whoa dude! Can I get a leetle toke of that stuff?  Cosmic calamari, Batman!!!

Avatar of:

Posts: 0

March 23, 2012

Now see, you've gone and stirred up the cuckoos!  Yo, Babu, I know you won't debate (how convenient!), but how's come your Designer threw in scoffers like me to sully the perfect Plan?  Oh, and Who (What, what!?) designed the Designer? Silly me!  It's turtles all the way down, right!?  And David... whoa dude! Can I get a leetle toke of that stuff?  Cosmic calamari, Batman!!!

Avatar of:

Posts: 0

April 18, 2012

Babu writes:
"Also, visit the Institute for Creation Research site where you
can read excellent scientific articles by creation scientists."

Excellent and creation science..now there is an oxymoron.

Avatar of: Paul Decelles

Paul Decelles

Posts: 1

April 18, 2012

Babu writes:
"Also, visit the Institute for Creation Research site where you
can read excellent scientific articles by creation scientists."

Excellent and creation science..now there is an oxymoron.

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