During a visit to the National Museum of Natural History and Science (
During the three years ensuing that visit, I have pondered that question again and often: What would I do, where and when would I go, and what event in time do I want to see? This is a series of responses to that question. Sorry, Mark; life is not that simple to provide one answer.
Spring is here in
During my drive to town with a slight scent of skunk lingering on my clothes, I contemplated going back in time to find the ancestor with the culprit scent gland before it mated with the scentless ancestor of our modern skunk and removing it from the evolutionary chain.
The skunk family Mephitidae (derived from Mephitis, Latin for "bad odor") comprises of 11 species in four genera. Nearly all carnivores have scent glands, but they are especially enlarged in skunks and relative families, with skunks taking that enlargement to an extreme. Rather than a duct like it’s close ‘cousins’, the skunk scent glands at the base of the tail has a nipple. The glands contain approximately 15 cc of a yellowish, oily liquid. With highly coordinated muscle control, the skunk can aim and direct the spray as far as 15 feet and spay up to six times in succession. The only relief is that it takes up to 10 days to replenish the supply of liquid after full discharge.
The odoriferous liquid contains various thiols (sulfur compounds) and thioacetates (salts of sulfur compounds). The principle compound in skunk musk is butyl mercaptan, similar to the popular laboratory compound mercaptoethanol used to cleaving disulfide bonds in organic solutions (to this day I cannot go into a lab without cringing at the smell of mercaptoethanol). Being sprayed in a direct hit can cause temporary blindness, nausea, convulsions, loss of consciousness and burns of the skin.
To neutralize skunk odor, the thiols have to be changed into compounds that have little or no odor. This can be done by oxidizing the thiols to sulfonic acids. Common oxidizing agents are hydrogen peroxide and baking soda (sodium bicarbonate) and are mild enough to be used on pets and yourself although it may change hair color. For clothes and inanimate objects sodium hypochlorite solutions (liquid laundry bleach) works well.
Scent glands are ubiquitous throughout the class of mammals and serve as a form of olfactory communication. Distinctive and long-lasting smells are distributed in urine, sweat, or released by rubbing. These scents are deposited on the ground, on territorial boundaries, on offspring or mates, or their habitats. Yet the skunk has evolved to use their scent glands as a defensive weapon. Tail up, point, aim and shoot. Anyone taking a direct hit can attest to burning eyes, gagging, inability to breathe and rubbing any exposed skin to rid thyself of the noxious semi-viscous fluid and its aerosols.
What ancestor provided this adaptive trait? The oldest fossil identified as a skunk was discovered in
At some point in time, a weasely mammal sauntered up to a close relative and whispered in its ear “Hey baby, I have a secret weapon. Want to see it work?” Thus the lineage of the cute little furry buggers avoided becoming someone’s dinner. And they multiplied, with the semi-viscous stench dictating survival and adaptation.
I wonder if they had scent gland firing ranges for practice.