Tetrachromatic Vision

Tetrachromatic Vision

It is very rare that the articles I regularly post on twitter attract much attention. I get the odd like or comment but twitter as a platform is not my primary source of viewership. However, recently my article on the missing mutations touched off something of a firestorm. For context, read the article here.  As part of the debate I sparked, I challenged evolutionists to produce a beneficial mutation.  One of the examples they put forth was that of tetrachromatic vision. This article will focus on tetrachromatic vision and discuss whether it is a mutation at all, and if so, is it beneficial.

Tetrachromatic vision is not a term used every day except in certain sections of the scientific community.  The term refers to having four types of cone cells in the eye, rather than the three most humans have.  These cone cells act as color receptors. Having a fourth one permits the organism to see in shades most humans cannot. Hundreds if not thousands of species come equipped with tetrachromatic vision as standard issue. Some fish, birds and hundreds of insect species along with at least one species of mammal are naturally tetrachromatic.

The advantage of tetrachromatic vision for animals is two fold. In birds and insects, the increased color perception allow them to find their food easier. Birds are able to find camoflauged insects or half buried nuts easier due to having the ability to see in more shades of color, while insects, particularly pollinators, are able to see the shades of color the flower of their choice reflects.  This allows insects to pollinate the correct plants and get the nectar they need to survive.  In reindeer, the one mammal known to have tetrachromatic vision, it functions a bit differently. Since reindeer live in areas of the world that are low light, their eyes are specially designed to take the blue and UV light they receive, and paint a colorful clear picture of the world around them.  This enables them to find their way around in the darkness of the Arctic.

Tetrachromatic vision does occur in humanity as well, in a very small section of the population. It is found on the X chromosome. Since women carry two copies of the X chromosome, they have the potential to carry two different sets of information for rod cells in the eye.  In less than twelve percent of the female population, these different sets of information are both expressed. Based on current information, only the female members of the human population will express this trait. Since men only have one X chromosome, they carry only one copy of the information for rod cells and thus can only every express three kinds of rod cells.

The observant reader may have noticed that there has been no mention of tetrachromatic vision being a mutation. That is deliberate. Tetrachromatic vision in humans and other animals is not a mutation. Rather it is a normal part of the genetic code, albeit one not commonly seen.  Evolutionists claim that all creatures used to see in tetrachromatic but a mutation removed this ability. The only evidence we have to that is their word. Tetrachromatic vision is spread through such a wide swath of evolutionarily unconnected creatures that making such a claim is specious at best and dishonest at worst.

Further, tetrachromatic vision is not always a benefit. One woman, an artist who sees in tetrachromat, said this to the BBC about her vision. “The grocery store is a nightmare. It’s like a trash pile of color coming in at every angle. People find that extraordinary that white is my favorite color, but it makes sense because it is so peaceful and restful for my eyes. There is still a lot of color in it, but it’s not hurting me.”  Essentially this woman is admitting that her brain cannot handle the onrush of color generated by tetrachromatic vision all the time.  Such mundane tasks as purchasing produce become painful to her brain due to having to process so much extra color. To soothe her brain, she resorts to looking at white objects because they generate less color. While she is an extreme case due to her training as an artist and painter other tetrachromats likely have similar issues but do not know why. This is hardly the description of a beneficial mutation.

Like other evidences trotted out for evolution, tetrachromatic vision looks good on the surface. However, once you dig into it a little as I have above you can see that it is not evidence for evolution. No mutation has taken place and those who bear tetrachromatic vision are not completely blessed.  Tetrachromatic vision is a designed feature of some animals and is a design option for humanity, nothing more.


PS: Click here for the BBC article I quoted above.



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s