Jayne and Jon Cornwill, an Australian couple, recently came to America with a bit of trouble.

The trouble? Boys.

They have three little boys, and three rambunctious boys were quite enough for the Cornwills, thank you. What the Cornwills wanted was a little girl.

But all they got were boys. And this led to what is known in the sex selection business as profound "gender disappointment."

"It's like mourning the death of a child you never had," Jayne Cornwill told British TV.

Let that one sink in for a moment, will you?

"My husband wanted a little girl that one day he could walk down the aisle," she continued. "I wanted a daughter so I could have that relationship … and our sons wanted a little sister."

So they turned to modern science, which many believe can solve the problems of the modern age. And they found an answer to gender disappointment:

Pre-implantation genetic screening, or genetic gender selection.

Currently, among people who think they already have too many boys or girls, or those who belong to cultures that prize one sex over the other, the troublesome gender can be discovered through amniocentesis, or now even through a blood test, and then the "trouble" is aborted.

In some cultures, China for example, the birthrate of boys is higher. Families often abort girls because of the government-mandated one-child-per-family rule. But genetic sex selection can do away with all that. The Cornwills could implant a female embryo into Jayne and have that girl. And that's just what they did.

However, in Australia, pre-implantation genetic screening remains illegal. The Australians are worried about what happens to human beings when we use genetics to select the traits of our children.

What's next? Height, aggression, hip-waist ratio, eye color, arm strength?

IQ?

Imagine the possibilities when we order up a master race.

Happily for Jayne and Jon, the procedure isn't illegal in the United States. Reportedly, they found an American clinic, paid $50,000 and had that girl of their dreams.

Actually, I'm not all that interested in the pathologies of random Australians depressed at having boys. Boys are trouble indeed. They're messy, they get mud everywhere, they kick soccer balls in the house and they let the dog run on the carpet with wet paws. But my wife and I happen to like boys very much.

The thing is, whatever we'd been blessed with, we'd be thankful.

What I am interested in is what this means to the future of humankind. So I called someone who would know.

Dr. Leon Kass, the renowned bioethicist. Kass is no relation. But years ago, I used to tell Chicago Tribune science writers when they'd visit the University of Chicago to say hi to my Uncle Leon.

I've admired his mind for many years, and interviewed him recently on the radio.

"One should say right away that no person who is honest with themselves can be an enemy of medical technology," Kass said. "Many of us are alive, or our loved ones are alive and well, thanks to astonishing advances in medical science and technology.

"But these devices and techniques that are used to heal disease and relieve suffering are pushing against the boundaries that make us human," he said.

People want children, and healthy children, but medical advances also allow them "to begin to [produce] children who satisfy parental wishes and whims," he said. "And this is the first step along that road."

Think of it. This business of genetic sex selection moves procreation into manufacturing. It gives parents mastery over the next generation.

"This is the difference between the traditional understanding of procreation in which children are not made, but begotten, that they are the issue of our love and not the product of our will," he said. "We don't try to produce a particular child as we might buy a particular brand of soap. We stand in relation to our children as recipients of a gift, and these we learn to accept as gratefully as we can."

Genetic engineering for intelligence is far away. But Kass noted that ads placed in college newspapers often seek egg and sperm donors, with height and SAT score requirements.

Having children become products of our wills, beings we shape in accordance with our wants and desires, is a "very, very dangerous new orientation between parents and children."

And this is how the world changes, or ends, with a silly Australian couple and their need to satisfy their whims with a gender-specific child.

Humanity won't wake one morning some 50 or 100 years from now to find that we've been transformed into something completely unrecognizable.

In the famous Kafka story, Gregor Samsa wakes after a night of anxious dreams to find he'd been turned into a gigantic insect. Gregor's transformation took only a few hours, so the insect knew he'd once been a man. He could remember it. That's fiction.

But in reality, our transformation likely will be gradual, perhaps imperceptible. It won't merely be a matter of style or different languages or dialects. We will have forgotten the questions.

John Kass is a columnist for the Chicago Tribune. His e-mail address is jskasstribune.com, and his Twitter handle is @John_Kass.