Snowflake the Albino Gorilla the Product of Inbreeding
Snowflake, the only known albino gorilla, got the way he did via inbreeding, a new study reveals.
Born in the wild in Equatorial Guinea, Snowflake called the Barcelona Zoo home for almost 40 years before dying of skin cancer in 2003, during which time he fathered 22 offspring with three different females.
Despite repeated efforts to explain the genetic cause of his lack of pigment, however, scientists were unable to identify the cause of his albinism. The closest they ever came was in identifying the gene containing Snowflake's condition, though no causative mutation was found.
However, a project led by Tomas Marques-Bonet of the Institut of Biologia Evolutiva at the University of Pompeu Fabra includes the sequencing of the gorilla's entire genome and, as a result, something previous researchers never saw.
Snowflake's albinism, the scientists report, can be traced back to a single gene, known as SLC45A2, which he inherited in a mutant form from both of his parents. And while typically recessive, the scientists discovered Snowflake's parents were closely related, as evidenced in shared genetic material.
Based on the number of common genes - approximately 12 percent - scientists conclude Snowflake's parents were likely uncle and niece and, as a result, Snowflake's recessive gene was pulled to the forefront.
The study is the first to uncover inbreeding in wild Western lowland gorillas, suggesting the behavior is rare though possible.
As to how it happened, the scientists point to several possibilities.
One lies in the practice in which females transfer groups several times during their lifespan after their initial dispersal from the natal group, possibly landing them in a group where they are related to a male present.
Another possibility is that of a multi-male group where female gorillas are allowed to remain and have their first birth in their natal group. However, the scientists argue, this option is far less likely given that such behavior is mostly true for other kinds of gorillas and has rarely been documented among those Snowflake originated from.
Finally, as Marques-Bonet told LiveScience, it's possible that gorillas are struggling to disperse as a result of habitat depletion as humans continue to move in on the animal's traditionally expansive area.
"If we are reducing much more the space that they have now, it is more likely that they will be forced to stay in the group and that will increase the consanguinity," or shared blood, he said.
Ultimately, the sequencing of Snowflake's genome is one part of a much large project designed to sequence the genomes of wild-born chimpanzees and gorillas, according to researchers, with the goal of understanding how much genetic variation is in the wild ape population and how it compares with that seen in humans.