December 11, 2009
Hammerhead Sharks Have Better Eyes Than
We Do
Some of these creatures have a full 360 degree view and
excellent depth perception.
Hammerhead Sharks Have Better Eyes Than
We Do
Some of these creatures have a full 360 degree view and
excellent depth perception.
SUMMARY: Three scientists set out to dispel a "myth" often repeated on TV
shows--that hammerhead sharks have unusually good vision because of their
wide heads. Michelle McComb of Florida Atlantic U. and two colleagues set out
to prove that hammerheads instead could not possibly have binocular vision or
good depth perception because of their wide-out eye placement. However, they
discovered they were wrong, and, in fact, these sharks may have even better
vision than the TV shows suggested.
Already in 1984 it had been proposed that the wide eye separation could give
the sharks better depth perception by allowing objects to be seen from two very
different angles at once. McComb's team didn't accept that idea though and
wanted to disprove it.
Since hammerheads come in many forms, the team decided to work with
species with heads ranging from the narrowest to the widest. They tested the
field of view of the sharks by sweeping a weak light around each eye and
recording the eye's electrical activity. The scalloped hammerheads had the
largest single-eye visual field at 182 degrees while lemon sharks at 159
degrees had the narrowest angle. The researchers were surprised that the
visual fields of each eye overlapped, up to 69 degrees for the scalloped
hammerheads. Wide heads clearly improve binocular visual and depth
perception.
Even more surprising, the team decided that bonnethead and scalloped
hammerheads must have excellent stereo rear-view vision, for they have a
full 360 degree view of the world. The findings were published in the Nov. 27
issue of the Journal of Experimental Biology.
(Picture of a scalloped hammerhead from Wikimedia.)
To read the entire article, click on this link to WORLD SCIENCE.
COMMENT: Wouldn't it be great if we humans had 360 degree vision?
Nobody could sneak up behind us and we wouldn't need rear-view mirrors in
our automobiles. It certainly would be helpful for soldiers in battle, hunters
doing their thing in the woods, or teachers monitoring recess on the
playground. Yet, why have these relatively primitive sharks (they supposedly
have been around since before the dinosaurs) been able to "figure out"
how to evolve such improved vision, and we "highly evolved" homo sapiens
can only marvel at what these fish can do?
Actually, we have been blessed with creative and inventive minds that more
than make up for our limited vision. We have invented rear-view mirrors and
even camera-TV systems for automobiles when drivers need to back up. We
have created television cameras and communication satellites that allow us to
see instantly all around the world. We have telescopes that help us see to the
far reaches of the universe. No hammerhead, or eagle for that matter, has
been able to do that.
The evidence from nature is that each creature has been given exactly what it
needs to get along in this world. The Creator of everything knows what is best
for each living thing, and His signature is everywhere if people open their eyes
to see it.
Some people have better vision than others. Yes, there are those "eagle eyes"
who have perfect 20/20 vision while other people need powerful glasses to see
well or may have lost their vision completely. But the best vision of all is the
spiritual vision that has been given to us to enable us to see our sins and the
Savior who died for them. We all would be wise to open our eyes and
acknowledge Jesus Christ as the One who has rescued us and opened the
door to heaven, where all believers will one day absolutely have both perfect
physical and spiritual vision.
**************************************************************************************
Want to be automatically notified each time there is a new post? Just e-mail
your request to [admin@lutheranscience.org].
**************************************************************************************
QUESTION OF THE DAY
How much water can be saved by shortening one's shower?
**************************************************************************************
shows--that hammerhead sharks have unusually good vision because of their
wide heads. Michelle McComb of Florida Atlantic U. and two colleagues set out
to prove that hammerheads instead could not possibly have binocular vision or
good depth perception because of their wide-out eye placement. However, they
discovered they were wrong, and, in fact, these sharks may have even better
vision than the TV shows suggested.
Already in 1984 it had been proposed that the wide eye separation could give
the sharks better depth perception by allowing objects to be seen from two very
different angles at once. McComb's team didn't accept that idea though and
wanted to disprove it.
Since hammerheads come in many forms, the team decided to work with
species with heads ranging from the narrowest to the widest. They tested the
field of view of the sharks by sweeping a weak light around each eye and
recording the eye's electrical activity. The scalloped hammerheads had the
largest single-eye visual field at 182 degrees while lemon sharks at 159
degrees had the narrowest angle. The researchers were surprised that the
visual fields of each eye overlapped, up to 69 degrees for the scalloped
hammerheads. Wide heads clearly improve binocular visual and depth
perception.
Even more surprising, the team decided that bonnethead and scalloped
hammerheads must have excellent stereo rear-view vision, for they have a
full 360 degree view of the world. The findings were published in the Nov. 27
issue of the Journal of Experimental Biology.
(Picture of a scalloped hammerhead from Wikimedia.)
To read the entire article, click on this link to WORLD SCIENCE.
COMMENT: Wouldn't it be great if we humans had 360 degree vision?
Nobody could sneak up behind us and we wouldn't need rear-view mirrors in
our automobiles. It certainly would be helpful for soldiers in battle, hunters
doing their thing in the woods, or teachers monitoring recess on the
playground. Yet, why have these relatively primitive sharks (they supposedly
have been around since before the dinosaurs) been able to "figure out"
how to evolve such improved vision, and we "highly evolved" homo sapiens
can only marvel at what these fish can do?
Actually, we have been blessed with creative and inventive minds that more
than make up for our limited vision. We have invented rear-view mirrors and
even camera-TV systems for automobiles when drivers need to back up. We
have created television cameras and communication satellites that allow us to
see instantly all around the world. We have telescopes that help us see to the
far reaches of the universe. No hammerhead, or eagle for that matter, has
been able to do that.
The evidence from nature is that each creature has been given exactly what it
needs to get along in this world. The Creator of everything knows what is best
for each living thing, and His signature is everywhere if people open their eyes
to see it.
Some people have better vision than others. Yes, there are those "eagle eyes"
who have perfect 20/20 vision while other people need powerful glasses to see
well or may have lost their vision completely. But the best vision of all is the
spiritual vision that has been given to us to enable us to see our sins and the
Savior who died for them. We all would be wise to open our eyes and
acknowledge Jesus Christ as the One who has rescued us and opened the
door to heaven, where all believers will one day absolutely have both perfect
physical and spiritual vision.
**************************************************************************************
Want to be automatically notified each time there is a new post? Just e-mail
your request to [admin@lutheranscience.org].
**************************************************************************************
QUESTION OF THE DAY
How much water can be saved by shortening one's shower?
**************************************************************************************
If somebody takes a daily shower and shortens it by
5 minutes each time, at least 9,000 gallons of water
a year can be saved.
Source: Woman's Day, reported in Bottom Line
Personal (December 1, 2009)
5 minutes each time, at least 9,000 gallons of water
a year can be saved.
Source: Woman's Day, reported in Bottom Line
Personal (December 1, 2009)
1 Comment
6p01053498834c970b said...Our eyes on Christ is the best vision of all. It is
truly amazing how God designed his creation. Humans like to think they have
knowledge to understand the world through science. Still there are so many
unanswered questions. The adage, "The more you know, the less you know"
is appropriate in this case.
6p01053498834c970b said...Our eyes on Christ is the best vision of all. It is
truly amazing how God designed his creation. Humans like to think they have
knowledge to understand the world through science. Still there are so many
unanswered questions. The adage, "The more you know, the less you know"
is appropriate in this case.
| LSI stands for the Lutheran Science Institute, an organization of WELS and ELS Lutherans interested in science and health issues with a special emphasis on the creation and evolution controversy. This blog's purpose is to search the Internet to find articles of interest to Christians. Views expressed are those of the author (Warren Krug) and are not necessarily those of the Lutheran Science Institute, Inc. |