Tag Archives: Retina

Are human bodies poorly designed? Is the human retina a bad design?

Christianity and the progress of science
Christianity and the progress of science

I think this “sub-optimal” argument against a Designer is stupid, because designs are always trade-offs between different quality goals, but just to put this one to bed, here is Evolution News.

Excerpt:

Now a new paper in Nature Communications, “Müller cells separate between wavelengths to improve day vision with minimal effect upon night vision,” has expanded upon this research, further showing the eye’s optimal design. According to the paper, Müller cells not only act as optical fibers to direct incoming light through the optic nerve, but are fine-tuned to specific wavelengths to ensure that light reaches the proper retinal cells. From the Abstract:

Vision starts with the absorption of light by the retinal photoreceptors — cones and rods. However, due to the ‘inverted’ structure of the retina, the incident light must propagate through reflecting and scattering cellular layers before reaching the photoreceptors. It has been recently suggested that Müller cells function as optical fibres in the retina, transferring light illuminating the retinal surface onto the cone photoreceptors. Here we show that Müller cells are wavelength-dependent wave-guides, concentrating the green-red part of the visible spectrum onto cones and allowing the blue-purple part to leak onto nearby rods. This phenomenon is observed in the isolated retina and explained by a computational model, for the guinea pig and the human parafoveal retina. Therefore, light propagation by Müller cells through the retina can be considered as an integral part of the first step in the visual process, increasing photon absorption by cones while minimally affecting rod-mediated vision.

(Amichai M. Labin, Shadi K. Safuri, Erez N. Ribak, and Ido Perlman, “Müller cells separate between wavelengths to improve day vision with minimal effect upon night vision,” Nature Communications, DOI: 10.1038/ncomms5319 (July 8, 2014).)

The paper presents Müller cells as a direct answer to the view that the vertebrate eye has a suboptimal wiring:

[T]he mammalian retina and the peripheral retina of humans and primates are organized in a seemingly reverse order with respect to the light path. This arrangement places the photoreceptors, responsible for light absorption, as the last cells in the path of light, rather than the first. Therefore, the incident light must propagate through five reflecting and scattering layers of cell bodies and neural processes before reaching the photoreceptors. This ‘inverted’ retinal structure is expected to cause blurring of the image and reduction in the photon flux reaching the photoreceptors, thus reducing their sensitivity. It has been recently reported that retinal Müller cells act as light guides serving to transfer light across the retina, from the vitreo-retinal border towards the photoreceptors.

I just had someone push this idea that human beings are badly designed as a response to the cosmic fine-tuning argument of all things. Her list of objections was all speculations (multiverse, aliense, design of humans could be better).

This argument that humans are poorly designed strikes me as literally insane. But since this argument is still in use, I guess I had better say something.

First, the argument assumes that the designer of human beings has to design for our comfort and pleasure. Apparently, God – if he were to exist – would be obligated to design creatures who never got sick, never grew old, and never suffered at all. This makes sense to atheists, for some reason – that the God of the universe has to create creatures that last forever and never suffer. There is this perception out there among atheists and very small narcissistic children (but I repeat myself) that God should be our cosmic butler, waiting at our beck and call to do whatever makes us happiest. From the Christian perspective, this is nonsense. Human beings only think about ultimate questions because, as C.S. Lewis wrote, we suffer pain and have limited lifespans. If were designed to be happy and live forever, we would never think about a relationship with God. By nature, humans want to avoid God, because we don’t want to be accountable to him for our rebellion against him and the harm we cause by disobeying the moral law.

The second problem with the argument from imperfection is that it has no understanding of how engineers work in practice. Engineers are used to trading off non-functional requirements against each other. If the laptop has a fast processor, then it runs hotter. If the laptop has great battery life, it’s heavier because of the larger battery. If the laptop has lots of memory, it costs more to buy. There is no way to get every design goal met because they conflict with each other.

Sometimes, I think that atheists are just little children who have stopped growing in maturity and wisdom. I once heard one particularly stupid atheist in a debate claim that his belief in God had ended when he asked God to help him find his cricket bat, and God had not cosmic butlered to his satisfaction. This happened when the atheist was a child, of course. And this is when most atheists become atheists. It’s not a conclusion that is reached for intellectual reasons. It’s just multiverse, aliens, science fiction, and sexual immorality all the way down. Give me what I want when I want it, and don’t judge me for being self-centered and immoral.

New study: scientists discover that inverted retina / blind spot is not a “bad design”

Apologetics and the progress of science
Apologetics and the progress of science

Here’s what atheist Richard Dawkins says about the inverted retina:

Any engineer would naturally assume that the photocells would point towards the light, with their wires leading backwards towards the brain. He would laugh at any suggestion that the photocells might point away from the light, with their wires departing on the side nearest the light. Yet this is exactly what happens in all vertebrate eyes. Each photocell is, in effect, wired in backwards, with its wires sticking out on the side nearest to the light. This means that the light, instead of being granted an unrestricted passage to the photocells, has to pass through a forest of connecting wires, presumably suffering at least some attenuation and distortion (actually probably not much but, still, it is the principle of the thing that would offend any tidy-minded engineer!)

Source: Dawkins, Richard (1986). The Blind Watchmaker. London: Penguin Books; pp. 93-94.

Now let’s look at a new study reported in Science Daily.

They write:

From a practical standpoint, the wiring of the human eye — a product of our evolutionary baggage — doesn’t make a lot of sense. In vertebrates, photoreceptors are located behind the neurons in the back of the eye — resulting in light scattering by the nervous fibers and blurring of our vision. Recently, researchers at the Technion — Israel Institute of Technology have confirmed the biological purpose for this seemingly counterintuitive setup.

“The retina is not just the simple detector and neural image processor, as believed until today,” said Erez Ribak, a professor at the Technion — Israel Institute of Technology. “Its optical structure is optimized for our vision purposes.” Ribak and his co-authors will describe their work during the 2015 American Physical Society March Meeting, on Thursday, March 5 in San Antonio, Texas.

Ribak’s interest in the optical structure of the retina stems from his previous work applying astrophysics and astronomy techniques to improve the ability of scientists and ophthalmologists to view the retina at high detail.

Previous experiments with mice had suggested that Müller glia cells, a type of metabolic cell that crosses the retina, play an essential role in guiding and focusing light scattered throughout the retina. To test this, Ribak and his colleagues ran computer simulations and in-vitro experiments in a mouse model to determine whether colors would be concentrated in these metabolic cells. They then used confocal microscopy to produce three-dimensional views of the retinal tissue, and found that the cells were indeed concentrating light into the photoreceptors.

“For the first time, we’ve explained why the retina is built backwards, with the neurons in front of the photoreceptors, rather than behind them,” Ribak said.

You can read more on some other reasons why the inverted retina is not a bad design in this article by agnostic scientist Michael Denton. But this study is a good reminder of why Christians need to keep up with science and how we need to talk about science.

The importance of having a narrative

All Christians should be familiar with the following basic pieces of evidence which fit the war between science and naturalism narrative:

  1. The origin of the universe
  2. The cosmic fine-tuning
  3. The origin of life (biological information)
  4. The sudden origin of the Cambrian phyla
  5. The habitability/observability correlation

It’s very important to present these five basic evidences to non-Christians in the historical context. And here is the story you must tell: “In the beginning, there was the naturalism, and the naturalism tried to argue from ignorance that God was not Creator and God was not Designer. And then came the science, and now people have to give up their naturalism in order to not be crazy and irrational”. That’s the narrative you use when talking to non-Christians about science.

In the beginning was the naturalism:

  1. In pre-scientific times, atheists maintained that the universe was eternal
  2. In pre-scientific times, atheists maintained that a life-permitting universe was as likely as a life-prohibiting universe
  3. In pre-scientific times, atheists maintained that the cell was a simple blob of jello that could spontaneously emerge in some warm pond
  4. In pre-scientific times, atheists maintained that the sudden origin of the Cambrian phyla would be explained by subsequent fossil discoveries
  5. In pre-scientific times, atheists maintained that there was nothing special about our galaxy, solar system, planet or moon

But then science progressed by doing experiments and making observations.

Here are some examples of discoveries that undermined the primitive atheism:

  1. Scientists discovered redshift and the cosmic microwave background radiation (evidence for a cosmic beginning) and more!
  2. Scientists discovered the fine-tuning of gravity and of the cosmological constant and more!
  3. Scientists discovered protein sequencing and exposed the myth of “junk DNA” and more!
  4. Scientists discovered an even shorter Cambrian explosion period and the absence of precursor fossils and more!
  5. Scientists discovered galactic habitable zones and circumstellar habitable zones and more!

Atheism, as a worldview, is not rooted in an honest assessment about what science tells us about reality. Atheism is rooted in a religion: naturalism. And the troubling thing we learn from looking at the history of science is that this religion of naturalism is insulated from correction from the progress of science. Nothing that science reveals about nature seems to be able to put a dent in the religion of naturalism, at least for most atheists. Their belief in naturalism is so strong that it repels all scientific evidence that falsifies it. Atheists simply don’t let science inform and correct their worldview.

Positive arguments for Christian theism

New study: scientists discover that inverted retina / blind spot is not a “bad design”

Here’s what atheist Richard Dawkins says about the inverted retina:

Any engineer would naturally assume that the photocells would point towards the light, with their wires leading backwards towards the brain. He would laugh at any suggestion that the photocells might point away from the light, with their wires departing on the side nearest the light. Yet this is exactly what happens in all vertebrate eyes. Each photocell is, in effect, wired in backwards, with its wires sticking out on the side nearest to the light. This means that the light, instead of being granted an unrestricted passage to the photocells, has to pass through a forest of connecting wires, presumably suffering at least some attenuation and distortion (actually probably not much but, still, it is the principle of the thing that would offend any tidy-minded engineer!)

Source: Dawkins, Richard (1986). The Blind Watchmaker. London: Penguin Books; pp. 93-94.

Now let’s look at a new study reported in Science Daily.

They write:

From a practical standpoint, the wiring of the human eye — a product of our evolutionary baggage — doesn’t make a lot of sense. In vertebrates, photoreceptors are located behind the neurons in the back of the eye — resulting in light scattering by the nervous fibers and blurring of our vision. Recently, researchers at the Technion — Israel Institute of Technology have confirmed the biological purpose for this seemingly counterintuitive setup.

“The retina is not just the simple detector and neural image processor, as believed until today,” said Erez Ribak, a professor at the Technion — Israel Institute of Technology. “Its optical structure is optimized for our vision purposes.” Ribak and his co-authors will describe their work during the 2015 American Physical Society March Meeting, on Thursday, March 5 in San Antonio, Texas.

Ribak’s interest in the optical structure of the retina stems from his previous work applying astrophysics and astronomy techniques to improve the ability of scientists and ophthalmologists to view the retina at high detail.

Previous experiments with mice had suggested that Müller glia cells, a type of metabolic cell that crosses the retina, play an essential role in guiding and focusing light scattered throughout the retina. To test this, Ribak and his colleagues ran computer simulations and in-vitro experiments in a mouse model to determine whether colors would be concentrated in these metabolic cells. They then used confocal microscopy to produce three-dimensional views of the retinal tissue, and found that the cells were indeed concentrating light into the photoreceptors.

“For the first time, we’ve explained why the retina is built backwards, with the neurons in front of the photoreceptors, rather than behind them,” Ribak said.

You can read more on some other reasons why the inverted retina is not a bad design in this article by agnostic scientist Michael Denton. But this study is a good reminder of why Christians need to keep up with science and how we need to talk about science.

The importance of having a narrative

All Christians should be familiar with the following basic pieces of evidence which fit the war between science and naturalism narrative:

  1. The origin of the universe
  2. The cosmic fine-tuning
  3. The origin of life (biological information)
  4. The sudden origin of the Cambrian phyla
  5. The habitability/observability correlation

It’s very important to present these five basic evidences to non-Christians in the historical context. And here is the story you must tell: “In the beginning, there was the naturalism, and the naturalism tried to argue from ignorance that God was not Creator and God was not Designer. And then came the science, and now people have to give up their naturalism in order to not be crazy and irrational”. That’s the narrative you use when talking to non-Christians about science.

In the beginning was the naturalism:

  1. In pre-scientific times, atheists maintained that the universe was eternal
  2. In pre-scientific times, atheists maintained that a life-permitting universe was as likely as a life-prohibiting universe
  3. In pre-scientific times, atheists maintained that the cell was a simple blob of jello that could spontaneously emerge in some warm pond
  4. In pre-scientific times, atheists maintained that the sudden origin of the Cambrian phyla would be explained by subsequent fossil discoveries
  5. In pre-scientific times, atheists maintained that there was nothing special about our galaxy, solar system, planet or moon

But then science progressed by doing experiments and making observations.

Here are some examples of discoveries that undermined the primitive atheism:

  1. Scientists discovered redshift and the cosmic microwave background radiation (evidence for a cosmic beginning) and more!
  2. Scientists discovered the fine-tuning of gravity and of the cosmological constant and more!
  3. Scientists discovered protein sequencing and exposed the myth of “junk DNA” and more!
  4. Scientists discovered an even shorter Cambrian explosion period and the absence of precursor fossils and more!
  5. Scientists discovered galactic habitable zones and circumstellar habitable zones and more!

Atheism, as a worldview, is not rooted in an honest assessment about what science tells us about reality. Atheism is rooted in a religion: naturalism. And the troubling thing we learn from looking at the history of science is that this religion of naturalism is insulated from correction from the progress of science. Nothing that science reveals about nature seems to be able to put a dent in the religion of naturalism, at least for most atheists. Their belief in naturalism is so strong that it repels all scientific evidence that falsifies it. Atheists simply don’t let science inform and correct their worldview.

Positive arguments for Christian theism