Share 0
Share
A- A A+

Article from:

Creation  Volume 39Issue 3 Cover

Creation 39(3):56
July 2017

Вид на русском языке
View in Russian
Free Email News
By Design
by Dr Jonathan Sarfati

US $15.00
View Item
God the Master Designer


US $10.00
View Item
One Small Speck to Man, 2nd edition
by Vij Sodera

US $65.00
View Item
Exploring the World of Biology
by John Hudson Tiner

US $14.00
View Item

Why reindeer eyes turn blue in winter

by

The golden-coloured eyes of Arctic reindeer (caribou, Rangifer tarandus) turn deep blue in winter. A researcher involved with this 2001 discovery, neuroscientist Glen Jeffery, studies vision at University College London. Describing the colour difference as “dramatic”, he said, “It has taken us 12 years to slowly find out what is going on and why.”1,2

arctic-reindeer

It turns out the colour change is because the reindeer seasonally change the wavelength reflection from their tapetum lucidum (TL)—the reflective surface commonly known as ‘cat’s eye’3 behind the retina.

In the Arctic summer, with up to 24 hours sunlight each day, the reflection from the TL is golden as most light is reflected back directly through the retina. By contrast, in winter, when the darkness lasts as long as summer’s light, the deep blue appearance of the eyes is associated with less light—and of shorter wavelengths—reflected out of the eye.

This change in the TL’s reflectivity is due to reduced spacing between its collagen fibres, likely from compression due to the increased eyeball pressure noted in winter animals. This in turn may be because of partial blockage to the eye’s fluid drainage as the pupil remains fully dilated during the long darkness (to maximize light entry). Additionally, the shift to blue may scatter light sideways through more photoreceptors rather than reflecting it directly—thus capturing more light and improving retina sensitivity (at the cost of visual acuity), also helpful in darkness.

The reindeer’s ability, the first of its kind discovered, is obviously an advantage in its unique environment. But establishing that something is useful is a far cry from showing that it evolved, rather than being designed; nor yet how it could have evolved.

Note that the adaptation here is not the same as when selection favours better-suited variants in a population. When that does happen,4 it is over generations, whereas this is an annual back-and-forth change within the individual’s lifetime.

Beyond calling this an “important adaptation”, the researchers make no attempt to explain how the mechanism enabling such a sophisticated seasonal adjustment could have arisen by Darwinian processes.

Such unsuspected layers of complexity make the evolutionary dilemma of eye origins5 even more intractable, and are strong evidence for creation and design, not evolution.

reindeer-eyes
Reindeer eyes change from gold (right) in summer to blue (left) in winter. (University College London)

Further Reading

References and notes

  1. Choi, C., Reindeer eyes turn blue in the winter, livescience.com, 30 October 2013. Return to text.
  2. Stokkan, K-A, and 7 others, Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer, Proceedings of the Royal Society B 280(1773): 22 December 2013 | doi:10.1098/rspb.2013.2451. Return to text.
  3. Like various other nocturnal creatures, cats’ eyes can seem to ‘glow in the dark’ when e.g. headlights illuminate their TL. Return to text.
  4. See creation.com/muddy. Return to text.
  5. Bergman, J., Did eyes evolve by Darwinian mechanisms?, J. of Creation 22(2):67–74, 2008; creation.com/eyes-evolve. Return to text.

We support belief in an intelligent designer—the God of the Bible. This site was also ‘intelligently designed’. But rather than six days, it’s taken thousands of days. Help us design more information for this site. Support this site

Comments closed
Article closed for commenting.
Only available for 14 days from appearance on front page.
Readers’ comments
Francis R., Zimbabwe, 29 May 2017

This is amazing. Is this characteristic unique to the reindeer or do other Arctic animals exhibit this ability also? If it pertains to reindeer only then the question arises: Why did God give this ability only to them?

Ian H., Australia, 28 May 2017

Creation is the Springboard or Icebreaker into people's minds. A simple Question, 'Do you know that One Cell in your body is more complex then the City of New York?, and you have Billions of different Cells n your Body! How did that Evolve?' will stop people in their tracks. The Apostle Paul used the same technique in Athens when talking to the Greeks, 'God that made the world and all things therein, seeing that he is Lord of heaven and earth, dwelleth not in temples made with hands;Neither is worshipped with men's hands, as though he needed any thing, seeing he giveth to all life, and breath, and all things;.......Acts 17:22-31 KJV. Put Stones into peoples shoes.

Copied to clipboard
11959
Product added to cart.
Click store to checkout.
In your shopping cart

Remove All Products in Cart
Go to store and Checkout
Go to store
Total price does not include shipping costs. Prices subject to change in accordance with your country’s store.