Poison ivy

The woods near my house are cool and quiet this time of year. All is buried beneath a blanket of leaves, and the weak winter sunlight streams easily through the bare tree branches.

Nowhere to be seen is the scourge of summertime, poison ivy. Its leaves are gone but its living roots sleep beneath the soil, waiting for warmth to spread forth again its deadly bouquet of beauty.

For poison ivy is a lovely plant -- thus does it fool many the neophyte. If not for its nasty itch factor, it would surely be sold in every garden center and happily cultivated around the world.

Your dog can gleefully roll in poison ivy. A goat can eat it. Birds gorge themselves on the berries. But you, poor human, cannot even so much as touch the damn leaves unless you really enjoy scratching your skin to shreds.

Why?

We share this sensitivity only with our closest cousins in the primate world.

Apparently, at some point in our common evolution we must have picked up a gene for ivy-misery that lower forms of life do not have. How, I wonder, when the stuff, native to America, predates the arrival of humans to these shores, and no other higher primates even live here (in North America) outside of zoos and maybe Bigfoot.

Evolution, genetics, chemistry ... life is rich with so many questions that no one has answered yet.

Meditation upon the mosquito

Consider the lowly mosquito.

What empires this wretched insect has helped to topple, what military campaigns has it sapped!

Who wouldn’t wish for its extinction, this vector of annoyance, debilitation and disease?

It joins the list of loathsomes one might hold up to argue against the existence of an All-wise, loving Creator.

But it also seems to me to present a challenge to the doctrines of evolution.

You see, some opponents of evolution will say that a trait, such a wing, could not gradually evolve, because it would serve no purpose until it reached its final stage of development. What good is a wing that doesn’t work for flight?

The counter: a wing-in-progress might not be developed enough to enable flight in the purest sense, but a survival advantage could still be conferred by its use in simple gliding or slowing a fall.

I can agree with that.

But what of the mosquito’s blood-seeking snout?

It appears to be evolved from some ancestral tool used for drinking plant juices, the way the male’s still is.

But how could there be an intermediate stage between sipping plants and sipping animal blood? And if there wasn’t, we are forced to conclude that one day, millions of years ago, a mutant mosquito was born with a sharper, fully-functional probiscus, as well as the instict to jab it into some critter’s flesh to ante up her protein supply.

From whence came that instinct, which has no apparent connection to any genes responsible for sharp-snout manufacture? Without that instinct, she’d just keeping on drinking sap despite her new, sharper needle.
Did the sharper needle come first and provide an advantage in tapping plants? Did some later mosquito with brain damage and a pointier probiscus get a little confused at some later point and jab a dinosaur when she meant to jab a fern frond? Could a genetic predisposition for animal-plant confusion have thus been passed on to her progeny, who out-competed their cousins whose eggs were nurtured only on sap, and who then passed the instinct along?