Sunday, April 23, 2017

Albinism - Nature's "error" yet vital to evolution and perpetuation of species

Dr Abe V Rotor

Are albinos really pigmentless? I found it lately, and the answer is no.

Here are photos of my pet fish - Oscar. I took the photos at two different times of the day - under bright sunlight, and under waning light. In both cases the fish exuded beautiful colors and patterns. They are simply magnificent.

Yet with the naked eye, one would dismiss them as "forgotten" creatures - Nature failed to transmit to them the pigment genes of their parents.

The first three photos were taken from an outdoor aquarium under direct sunlight
Lower two photos were taken under waning light from
the same outdoor aquarium with the same school of fish.

Normally Oscar fish are multicolored with black, yellow, gold and orange dominating the color scheme in distinct and sharp patterns. Among local aquarium fish, to me, they are the most attractive, and because there is no standard pattern, each fish is an original piece of art. I used to study their designs, associating them with maps of land masses, countries and islands, of shapes of creatures and objects. As a biologist I wondered how colors and patterns help the fish's survival through nature's laws of offense and defense - or by mimicry to be able to integrate themselves with other species to form a community.

I failed to buy the colorful normal Oscar. Pet shops say they are rare, although my son was able to secure five colorful ones which he raised to maturity and became a centerpiece of a biological laboratory of a college in Manila. Because of the rarity of the colorful ones, I settled for the albinos - ten of them - which I got for a good bargain.

Now, if albinos lack the colors endowed to their normal siblings because Nature "committed an error" how come they are still around? Are they not vulnerable - or even inviting - to predators? I surmise that their mere presence within the population would certainly predispose them victims to cannibalism by the normal members. And how can they be protected by the harmful rays of the sun and other forms of radiation?

Human albino. Albino whale, albino bat, albino blackbird,

Albinism is not rare - kangaroo, peacock, turtle, crocodile

Questions about albinism are many indeed. We know that colors are necessary to hide the internal organs, they make the tissues opaque, and the protective coat like a shield. We also know that the fins become pronounced if colored, giving the impression that the fish is solid and bigger than the light colored ones. Albinos don't only look smaller than their actual size, but have the "glass or ghost effect" because they appear naked to the bones, their heart beating and lungs expanding and contracting - as can be traced in these photographs. 

I did some research. I went back to my genetics I learned from my professors: Dr. Nemesio Mendiola, dubbed the plant wizard of the Philippines, and Dr. Ruben Umaly who became a director of a biological institute in Indonesia. And I updated myself with today's molecular biology.

It's true that pigments are phenotypic traits. Their absence means their pigment genes were not transmitted to the offspring. Under Mendelian law, if two recessive genes for pigment are paired instead of being joined to a dominant gene, no pigment appears, and therefore the affected offspring becomes an albino.Yes, there is an albino (white) carabao, there is an albino boa constrictor, there is even a human albino. Albinos are found in other animals, in plants and protists.

There are simply white colored organisms that are not albino, such as the white rhino, sheep, horses, seashells, and the like. These are genetically normal, they are true to type to the parents, and the population for that matter.

Albinos however, are not really without colors. They do have but their colors are not the same to all viewers. Flowers are seen by bees or butterflies different from the colors we humans perceive. The bull cannot differentiate red from other colors. It charges not because of the red banner and colorful attire of the torrero, but by the teasing movement and perceived threat at that moment. Wonder how an owl spots a mice in the dark, how an eagle swoops on its prey from up high.

An albino after all has pigments carried by the recessive genes, only that these pigments may be masked and discreet. They appear only under ultraviolet rays, they are spotted by infrared, amplifying the colors and patterns. For all we know, the unusual characteristics of the albino from their normal counterparts may somehow keep them alive in the wild, under natural conditions of their habitat - at least for some time.
White elephants are regarded sacred in Thailand and other countries. Lucky for the albinos protected by our culture. Religious beliefs have saved certain albino animals, like the albino (white) elephant which is held sacred in Thailand and other parts of Asia and Africa. Otherwise if it is used as draft animal, it would certainly succumb to heat stroke. This is also true with the albino carabao.

How can nature correct its so-called "mistake"? Or could it be that nature planned albinism as an advantage in evolution? But to what extent? Otherwise albinism will lead to speciation, that is, gradual dissociation of the albino from the population, and crosses the genetic border to become ultimately into a new species.

It is also likely that albinos are decoys of predation saving the normal and stronger members of the population in the process. Albinos are repository of recessive genes that would otherwise spread out and weaken the whole population. The mechanism involved in albinism is a universal genetic phenomenon. Traits carried by the pairing of recessive genes do occur in each generation.

The intention of nature, I believe, is purification of the species. Albinos have less chance to survive in the wild. Most do not reach sexual maturity. Therefore, the recessive gene dies with them. And even if they reproduce, they have more chances of producing normal offspring than albinos like themselves, thus keeping the possibility of perpetuating the albino character. Thus the level of albinism is then maintained at a dynamically low rate within the population.

Nature is right after all - albinism is a purification process of the gene pool, it is ensuring the fitness of the species in Darwin's parlance - the preservation of the species through the long and tedious process of evolution. ~

NOTE: The aphorism, White Elephant, may have a negative connotation - refering to a superstructure that has very little use, if there is at all.

Home, Sweet Home with Nature, AVRotor (Manuscript); acknowledgement: Photos from Internet, except photos of Oscar fish. by the author.  

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