I love my new winter coat. As a wimpy Vancouverite, I needed new gear to protect myself in the New York winters. I never understood why people wore the puffy coats but it is like wearing a fabulous sleeping bag – fantastic! But walking around the New York streets, I realized that choosing the white coat might have been a mistake. Not because I was going to get it dirty (I will) but because I stick out in the crowd.
I got the strange feeling that if there were hunters looking for a target in the crowd of black coats, they would fixate on me. It has given me a new appreciation for the ‘blonde’ seal that we saw in Antarctica.
This baby fur seal was very cute but his future seemed more unpredictable than his grey/brown friends. We didn’t see any adult white seals – but to be fair, we only saw the one white baby seal. Our naturalist said that he has seen several white baby fur seals but no adults. I wasn’t a huge fan of this naturalist because his facts seemed more like opinions so I’m hoping that this seal has a longer life than the naturalist predicted. According to websites, only one in 800 fur seals is ‘blonde’ but I don’t know if this is counted at birth or adults. I tried to count the number of black coats around me in Chelsea the other day but lost track after 150…
Related fun science-y thing: One of the websites is the cool IceCube to detect neutrinos at the South Pole.
Many people on our ship pointed out the ‘albino seal’ but he was not albino. He was leucistic. Albinos lack pigment in their hair, eyes and skin due to a lack of melanin. Melanin helps colour the retinal epithelium and iris so without this pigment, the colour of blood vessels can shine through leading to red eyes. If you look closely at our blonde seal, he has dark eyes. Leucism is not limited to melanin but results from a developmental defect in pigment cell differentiation and/or migration from the neural crest to the skin or hair. [Translation: if the cells don’t grow correctly or move to the right place, the colour doesn’t show up.] If no pigment cells develop properly, the whole body can be affected (blonde). There is a patchy (piebold) effect if only a subset of pigment gets to the right place and time. Because the pigment in the eyes comes from a different spot in development, the eyes are unaffected with leucism.
Phew – Thank you for letting me say that; to be polite on the ship, I had to swallow my corrections and it feels good to release some of that energy even years later.
There are a few different genes involved in the leucistic trait, including CD117 (cytokine receptor) and MITF (transcription factor). As far as I can tell, leucism is a recessive trait, meaning that both copies of the same gene would have be mutated. (Inheritance post: 50% is generally enough for wild type). It is easier to inherit the same mutated genes within related populations so does leucism indicate inbreeding? [I don’t know – most of the papers on leucism seem to be in Dutch or German and I can’t read them – please let me know if you have a better understanding of the genes involved.)
Why did I know and care about leucism? Well, I come from British Columbia where our official animal is the ‘Spirit Bear’ = Kermode Bear that is white and often mistakenly called albino instead of leucistic.
I’ll save my info about Antarctic fur seals for a future cute pic – coming soon.
UPDATED: I changed the photo of me in my white coat on Dec. 27. The new photo was taken during the Boxing Day Blizzard 2010. Yes, I appreciated the coat before the snow and I loved it during the blizzard walks.