The Eyes Have It! Evolution’s Witness: How Eyes Evolved
According to an old proverb, the eyes are the windows of the soul. They’re also one of the most important accomplishments of evolution, nature’s perfect camera providing us with a vivid visual sense of the world around us.
However, did you ever wonder how the eye came to be? What caused the eye to be formed to begin with? How did it evolve and develop to fit the specific needs for all current and past species on Earth?
Dr. Ivan Schwab wanted to find out how animals were able to see. As he got further into his research, he realized he also wanted to learn about the origins of the eye itself and how it developed through years of evolution.
So how did it begin? What was the stimulating factor that set off what would become the eye? Dr. Schwab simply points to the sun and the energy its produces.
“The eye didn’t start as an eye as we know it, for sight,” he says.
Indeed, what would become the eye first started as the means for transferring the sun’s energy into energy for the cells.
“This was done by a variety of molecules… the best one is related to Vitamin A, the same vitamin you get from carrots or mangoes,” according to Dr. Schwab. “That particular chemical will transform the light rays of the sun into energy for the cell so that it can perform its internal mechanics.”
When the first eye, as we know it, appeared is kind of a guessing game, says Dr. Schwab, since the eye doesn’t fossilize most of the time due to its soft parts. The eye gradually evolved into an organ capable of seeing light and dark and perhaps some form.
Dr. Schwab imagines that the first real eye saw very poorly, registering blurry images and used, perhaps, to find where to capture energy or locate enemies.
Once eyes appeared, they evolved in different ways, developing into at least 10 to 12 varied forms. Each species’ eyes are developed into one that fits its specific niche.
One example is the the marine crustacean, the stomatopods, or mantis shrimp. Dr. Schwab says, since this creature tends to live near coral reefs, it has eyes with more color receptors than we have. As a result, they can see more colors than we can – 16 pigments compared to the three pigments humans can detect.
The human eye is referred to as camera-style eye since its mechanics resemble those of a film-loaded camera.
Dr. Schwab describes them as a sphere with a front element called the cornea. Another element is the lens, which does the focusing. The back of the eye, or retina, creates the visual image that is delivered to the brain.
Another type of eye style is the telescopic eye.
As an example, Dr. Schwab cites the “jumping spider.” Jumping spiders have excellent vision, with one of the highest acuities among invertebrates. Its eyes are small and compact, utilizing telephoto-type optics to maximize its vision.
Since this spider can’t move its eyes externally, like we can, it must do so internally.
“It’s like a raster scan on your TV,” says Dr. Schwab. “It lays out a line of dots, another line, another line, until it’s formed a whole image, but, of course, it does so rapidly.”
Dr. Schwab says that, although eyes will continue to evolve, the eyes of many species are already at a mature level so they’re not going to evolve much further in terms of the optics themselves. So where our eyes or vision will improve, speculates Dr. Schwab, is probably in the interpretation of the visual signals the eye produces.
Dr. Schwab, joins us this weekend on the “Science World” radio program to talk about his new book, the eye’s first appearance and its subsequent evolution and development.
>>>> Listen to the interview here…
Other stories we cover on the “Science World” radio program this week include:
Science Scanner: Scientists Find Fried-egg Nebula Which Dwarfs the Sun
This picture of the nebula around IRAS 17163-3907. The star and its shells resemble an egg white around a yolky center, leading astronomers to nickname it the Fried Egg Nebula. (Photo: ESO/E. Lagadec)
Astronomers have found nebulae that resemble a horse’s head, a check mark, a crab, an owl and a fried egg.
New pictures of a hyper-giant star, formally known as IRAS 17163-3907, show it’s surrounded by a huge double shell. The star and its shells resemble an egg white around a yolky center, so University of Manchester scientists – along with others involved in the research – have nicknamed it the Fried Egg Nebula.
The star is about 13,000 light-years from Earth, making it the closest known yellow hypergiant to our planet. Its 1,000 times bigger and 500,000 times brighter than the sun.
To put the star’s size into perspective, scientists say if you placed it in the center of our Solar System, the Earth would lie deep within the star itself and the planet Jupiter would be orbiting just above its surface.
Add in surrounding nebula and it would then engulf all of the Solar System’s planets, dwarf planets and even some of the comets that orbit far beyond the orbit of Neptune. The outer shell has a radius of 10,000 times the distance from the Earth to the Sun.
The 2009 video, shot by Bernardi in the island nation of Palau, shows an orange-dotted tuskfish dig a clam out of the sand and then swim over to a rock, where it repeatedly slams the clam against the rock in order to crush it.
Tool use was once thought to be a strictly human trait. Then, in the 1960’s, Jane Goodall stunned the scientific community when she reported tool use by chimpanzees. In the years since, many other animals – various primates, several kinds of birds, dolphins, elephants and others – have been observed using tools, too.
Bernardi says his movie shows fish are capable of forward thinking, such as taking a number of steps to reach a goal like getting dinner.
“For a fish”, Bernardi says, “it’s a pretty big deal.”
An illustration of how Acherontisuchus guajiraensis, a 60-million-year-old ancestor of crocodiles, would have looked in its natural setting. You can also see titanoboa (world's largest snake) in the upper left side of image. (Danielle Byerley, Florida Museum of Natural History)
While these two creatures probably competed for the same food, researchers believe the huge super-snake, which had a more generalized diet than the crocodile, could easily have feasted on the croc’s young, too.
This photograph shows the size difference in the jawbones of two 60-million-year-old crocodile ancestors found in northeastern Colombia - (Photo by Kristen Grace/ Florida Museum of Natural History)
By the way, the titanoboa’s remains were found in 2009. They measured up to 15 meters in length and weighed about 1,135 kilograms.
The study’s authors say this discovery should give scientists a better understanding of the diversity of animals that inhabited the oldest known rainforest ecosystem, which was much hotter than the rainforests of today. It could also prove useful in helping us better understand the impact of a warmer climate in the future.
The ancient crocodile had a long, narrow snout full of pointed teeth. According to scientists, these physical characteristics allowed the new species to specialize in hunting lungfish and relatives of bonefish, which inhabited the water of their habitat.
Was Einstein Wrong?
Albert Einstein (circa 1921) (Photo: wikipedia)
If a finding released Thursday by scientists in Geneva proves to be true, the world’s most famous equation – Albert Einstein‘s E=MC2 – could be moot, undoing our current understanding of the physical world.
Einstein revealed that equation in his special theory of relativity released in 1905. It asserted that energy equals mass times the speed of light squared, and helped shape our understanding of the physical world.
The scientists in Geneva fired a beam of neutrinos – elementary particles which don’t hold an electrical charge and pass through ordinary matter with virtually no interaction – from CERN‘S particle accelerator to a lab in Italy about 730 kilometers away.
The speed of light is 299,792.458 kilometers per second. The Geneva scientists found their sub-atomic particles traveled to Italy 60 nanoseconds faster than the speed of light – or 300,006 kilometers per second.
That appears to break the limit set by Einstein.
An illuminated globe at the European Organization for Nuclear Research, CERN, outside Geneva, Switzerland. (AP Photo/Anja Niedringhaus)
In fact, CERN’s announcement was greeted with more skepticism than usual by the physics community, with many calling for independent verification of the findings.
However, the CERN scientists, many of whom remain skeptical themselves, expected the uproar. They carefully examined their results and recalculated their findings for nearly six months before publicly announcing them. They’re even asking colleagues everywhere to double check the findings and calculations.
The inevitable verification process will take place in two steps. The first would be to evaluate the results and supporting data, which are available on Cornell University’s physics website. The second step, which could take place in a couple of months, will require the duplication of the CERN neutrino experiment in another laboratory.
In the meantime, you can bet physicists everywhere will scour CERN’s data for even the tiniest glitch, miscalculation or other anomaly which will debunk the findings and restore Einstein’s calculations that nothing is faster than the speed of light.
Other stories we cover on the “Science World” radio program this week include:
Smoothed view of brain showing visual cortex (in orange and yellow) (Photo: Mark Lythgoe & Chloe Hutton-Wellcome Images)
Since the brain is so complex to study as a whole, computers with the team’s special programming were used to divide the brain into small, three-dimensional cubes known as volumetric pixels, or “voxels.” Each individual “voxel” described how shape and motion information in the viewed movie was mapped into brain activity.
The subject’s brain activity was then recorded for each set of videos they watched.
From the first set of videos the brain activity data was fed into a program that learned, on a second by second basis, how to associate visual patterns contained within the movie with the corresponding brain activity.
Then the brain activity created by the second set of clips was fed into the computer to test the team’s movie reconstruction algorithm, which contained some 18 million seconds of random YouTube videos. By scanning this tremendous amount of video, the reconstruction program was able to predict the brain activity that each film clip would most likely evoke in each subject.
Finally, the 100 clips that the computer program decided were most similar to the clip that the subject had probably seen were merged together to produce a blurry yet continuous reconstruction of the original movie.
With further study and experimentation, researchers hope the practical applications of this technology will also lead to a better understanding of what goes on in the minds of people who cannot communicate verbally, such as stroke victims, coma patients and those with neurodegenerative diseases.
Science Scanner: Social Networking Could Hinder Freedom Movements
Egyptians carry an injured protester during clashes with anti-riot police in Cairo, Egypt, Saturday, Jan. 29, 2011. (AP Photo/Ben Curtis)
Online social networking sites like Twitter and Facebook have recently been hailed as powerful and effective communications tools for social and political movements throughout the world.
However, according to a new study from Penn State University researchers, these popular sites may not be as uniformly beneficial or robust as suggested.
For example, in nations like Egypt which recently experienced civil strife, the study found these online tools were not only used by freedom fighters, but also by governments to repress their people.
The study suggests the media’s depiction of these revolutions being caused by this technology may be an over-generalization.
During anti-government protests during this year’s Egyptian revolution, citizens there turned to online communications such as blogs, text messaging and social networks to spread information criticizing the government.
Reports at the time indicated that approximately 56,000 Egyptians became members of a Facebook page about the movement and around 15,000 citizens used Twitter accounts to find and pass along information about the protests and anti-government activity.
But, as the study’s researchers point out, the government itself, led then by Hosni Mubarak, took action to quickly crack down on bloggers, actually taking over Egypt’s Internet and text messaging services.
Furthermore, key mobile network operators – such as Vodafone, Mobinil and Etisalat – honored government requests to suspend service.
However, other telecommunication companies, especially those outside of Egypt, stepped in to help the protesters circumvent the ban.
The study raises key questions about the role of telecommunication companies and when it’s appropriate for governments to step in and block communication.
The study was presented today at the workshop, “New ICTs + New Media = New Democracy?” in Washington, D.C.
Construction of New James Webb Space Telescope Progresses
The five-layer James Webb Space Telescope sunshield. Designed to block solar light and keep the Observatory operating at cryogenic temperatures. (Photo: NASA/Northrop Grumman)
Work continues on the James Webb Space Telescope. NASA’s next generation of space observatory, after the astoundingly successful Hubble, will give us an even sharper, more in-depth view of the cosmos.
NASA is testing part of the sun-shield which will protect the telescope’s mirrors and instruments during its mission to observe the most distant objects in the universe.
According to NASA, this sun-shield will consist of five tennis court-sized layers which allow the Webb telescope to cool to its cryogenic operating temperature of minus 233.17 degrees Celsius, or 40 degrees Kelvin.
The tests, expected to be finished within two weeks, will be the final step of the sun-shield’s development program.
Once testing of the sun-shield layers concludes, they’ll be sent to Northrop Grumman in Redondo Beach, California.
There, engineers will verify the process of just how the layers will unfurl in space and then fold the sun-shield layers, much like a parachute, to be stowed for launch.
A swarm of Western Honey Bees (Photo: Alan Vernon)
We’ve long heard about how highly structured and organized the honey bee societal system is. Yet, despite more than a century of research, much remains unknown about the biochemical factors behind this fascinating caste system.
However, scientists in China and Ethiopia, who’ve been conducting research into these mysterious honey bee societies, are providing some insight.
You might recall, from long-ago school lessons, that there is usually one queen bee in a colony, which develops and emerges from larvae. She is fed royal jelly, a protein-rich substance that’s made from the secretion of glands on the heads of worker bees.
While the queen is receiving the “royal treatment,” the other larvae in the colony develop into female workers or male drones.
Even though they both share almost identical genes, the female queen bee tends to grow large in size. Her specialty within the colony is reproduction, while the worker bees are responsible for maintaining the colony itself.
Their life spans also vary, with the queen living for one to two years while the workers live for about six or seven weeks.
The scientists looked at proteins inside the cells of larvae destined for queen and worker status. In the early stages of a honey bee’s life – in the activity of proteins with cell structures that produce energy for cells – they found differences in the amounts of protein produced in cells as well as in the activity of those proteins.
With pre-queen larvae, the proteins involved in carbohydrate and energy metabolism were much more active than in the larvae of bees destined to become workers.
The researchers say this suggests that proteins with metabolic enhancing activities play a significant role in determining the colony’s caste system and hierarchy.
Spanish scientists have developed a so-called “intelligent t-shirt,” which can wirelessly monitor and record a patient’s vital signs.
But that’s not all, say researchers at Carlos III University in Madrid. This “intelligent” t-shirt can also locate and track patients within the closed spaces of the health care facility, even going so far as to determine if the patient is sitting, lying down, walking or running.
Right now, to monitor a patient’s vital signs, hospitals usually attach sensors and probes with connecting wires that tether the patient to a fixed area.
The t-shirt offers a non-intrusive way to measure and monitor a number of a patient’s physiological parameters such as body temperature, heart rate and other cardiac information usually provided by an electrocardiogram unit.
It also gives health care workers a way to find wanderers if their patient gets too carried away with the freedom and portability being wireless offers.
The system, which is currently designed for use in hospitals, is split into two parts. First, there’s the system’s fixed infrastructure, which would be installed in the hospital itself. The second unit would be the mobile devices or “intelligent” t-shirts themselves, which would move with the patients.
The t-shirt is washable. Along with cardiac monitoring, the garment comes with a removable device containing the thermometer and accelerometer, which shows whether the patient is sitting, walking or standing as well as the patient’s current level of physical activity.
The monitoring data is sent by wireless communications to a central information management system that processes, records and stores the information so doctors and other health care workers can retrieve it for future study, analysis or reference.
Another benefit is that the t-shirt system provides a variety of programmable alarms, which could alert medical workers when certain vital signs exceed or dip beneath the optimum limits for the patient. When an alarm sounds, a message will appear on the system’s information screen and can also send the alarm to the patient’s doctor or health care worker’s mobile phone via an SMS text message.
The garment could eventually allow patients to be monitored in their own homes, instead having to stay in the hospital for longer periods of time.
The t-shirt, which is in the prototype stage now, is still being developed to allow for improvements and additional features.
Lifelong Musicians Hear Better Than the Rest of Us
Study reveals that older lifelong musicians retain better hearing than non-musicians. (left photo: Vi Khoa Duong - right photo: Bach Tran)
Lifelong musicians are less likely to experience age-related hearing problems than non-musicians, according to a new Canadian study.
They examined the hearing abilities of musicians and non-musicians from 18 to 91 years old. The genres of music played by these musicians varied from rock and pop to classical.
One of the study’s goals was to determine if lifelong musicianship protected against normal hearing decline in later years. Also, it specifically examined the central auditory process that’s associated with understanding speech.
What they found was that the musicians’ hearing advantage over non-musicians widened as both groups aged.
An average 70-year-old musician was able to decipher speech in a noisy environment as well as the average 50-year-old non-musician.
Phil Collins formerly of Genesis (left) and The Who's Pete Townsend (right) both have suffered hearing loss after years of being exposed to high sound levels while playing their music for fans around the world. (Photos: Townsend, AP Photo/Beth A. Keiser - Collins, AP Photo/Luca Bruno)
The findings suggest being a lifelong musician can delay this age-related decline by 20 years.
But what about the famous rock musicians who played loudly for years and now suffer from hearing loss? Zendel says the actual physical structure of the ear has been damaged in these cases, limiting its ability to send an auditory signal to the brain. He points out that his study focuses on hearing ability in the brain and not within the ear itself.
It is once the signal gets to the brain for processing that musicians have a huge advantage over non-musicians, according to the findings.
Zendel, joins us this weekend on the “Science World” radio program to talk about his team’s research and how lifelong musicians were able to maintain better hearing ability than those who weren’t musicians.
>>>> Listen to the interview here…
Other stories we cover on the “Science World” radio program this week include:
The exoplanets (planets found outside of our Solar System) include 16 super Earths – planets with a mass between one and 10 times that of Earth. While there aren’t any super Earths in our Solar System, scientists say they appear to be quite common around other stars.
One of the newly discovered planets, a super Earth called HD-85512-b, is located at the edge of the habitable zone – a narrow area around a star where water might be present in liquid form if conditions are right – of its solar system. Discoveries of planets like HD-85512-b can prove exciting because they could potentially support life.
3D movies and television are all the rage now, but most 3D systems require the viewer to wear special eye glasses to get the full effect. The glasses can be cumbersome and tiring for the viewer to wear.
They’re working to make 3D possible without such visual aids and hope to develop a new four-camera system which would be able to handle live transmissions.
The researchers use special autostereoscopic displays to produce 3D without special glasses. But, since we don’t sit absolutely still when watching the screen, the displays use between five and 10 different images to account for any head movement.
To film or televise programming using this system, multiple cameras must be used, but that can be an extremely intricate and time consuming process.
So, to reduce the time needed to make these special productions, researchers are working on a four-camera assistance system which will reduce the amount of time needed for calibration from days to minutes.
The research scientists presented the first prototype of this new system at the IBC trade show in Amsterdam.
Good News/Potentially Bad News For Oil Spill Clean-up Workers
A shrimp boat motors through a ribbon of oil during clean-up operations from the Deepwater Horizon oil rig spill, May 18, 2010. (AP Photo/Charlie Riedel)
New studies of air and water near the Deepwater Horizon oil spill show that clean-up workers might have escaped harm from one of the most potentially toxic groups of substances found in the oil.
However, according to an article in the American Chemical Society’s Chemical and Engineering News magazine, a separate group of possibly harmful chemicals did escape from the water and could create a health hazard for those who assisted in the cleanup.
The 2010 Deepwater Horizon oil spill in the Gulf of Mexico released about 4.9 million barrels of crude oil in the largest accidental marine oil spill in the history of the petroleum industry.
According to the article, the research shows the chemicals benzene, toluene, ethylbenzene, and xylene, known collectively as BTEX, remain dissolved in the Gulf of Mexico, and did not vaporize into the air where they could be inhaled by clean-up workers.
But, in a case of good news/bad news regarding the health of the workers, the study did express concern that other substances, which don’t dissolve as well in water, may have been released by the crude oil.
If these chemicals did become airborne during the disaster, researchers say that this could pose a possible health threat to those involved in the cleanup.
Genetics might play a role in how optimistic you are or how much self-esteem you have.
Life scientists at UCLA say that, for the first time, they’ve identified a particular gene’s link to three critical psychological resources for coping well with stress and depression.
The gene is called the oxytocin receptor gene (OXTR). Oxytocin is a hormone that increases in response to stress and is associated with good social skills, such as empathy and enjoying the company of others.
Previous research revealed that an increase in oxytocin tends to lead to more social behavior, especially under stress and especially in females.
The researchers says that the study – published online in Proceedings of the National Academy of Sciences (PNAS) – implies that people would benefit if they could train themselves to be more optimistic, have higher self-esteem and a higher sense of mastery to improve their ability to cope with stressful events.
“Would you describe your pain as being sharp, aching, or throbbing, in nature or do you feel pressure?”
“On a scale of one to 10, how much pain would you say you’re experiencing right now?”
That subjective quiz has pretty much been the method doctors have used for years to determine the kind and severity of pain their patients experience.
But now, researchers from Stanford University in California might be on their way to developing a diagnostic tool which will provide doctors with an objective physiologic assessment of whether someone is in pain.
By using MRI scans of the brain – along with advanced computer algorithms – the researchers were able to accurately predict thermal pain 81 percent of the time in healthy research subjects.
Publishing their findings in the online journal PLoS ONE, the researchers say advances in neuroimaging techniques have renewed interest in pursuing the elusive goal of developing tools to measure pain on a strictly physiologically basis.
They hope their research will eventually result in better methods of detection and treatment of chronic pain.
The researchers point out that their studies, so far, have really only looked at thermal pain. They stress that further work and study will need to be done in order to determine whether their testing methods can determine other kinds of pain, such as chronic pain, and whether they can properly and accurately distinguish between physical pain and other emotionally arousing states, such as anxiety or depression.
A tool that can accurately measure pain could also have legal ramifications, according to Stanford law professor Hank Greely, an expert on the legal, ethical and social issues involving the biosciences.
“A robust, accurate way to determine whether someone is in pain or not would be a godsend for the legal system,” said Greely, who was not associated with the study.
The idea for the study took root at a 2009 Stanford Law School event organized by Greely, in which neuroscientists and legal scholars discussed how neuroimaging pain could be utilized, as well as abused, in legal proceedings.