The following is a Want ad for a 21st-century father.

Wanted: A 21st-Century Father Who Can Wear Many Hats THE LOVING HAT Responsibilities Include: Raising children, not yelling, taking mom out to romantic dinners, listening, “being there. Benefits: You’ll be loved right back. THE MONEY HAT Responsibilities Include: Holding down a good job, making enough money to support family and pay for vacations. Benefits: Who doesn’t want a good job? Plus, vacations with the family. THE FUN HAT Responsibilities Include: Taking family to baseball games in summer, going sleigh riding in winter, being goofy, dancing. Benefits: What good is life if you don’t have any fun? Family outings become memories that last a lifetime. THE HANDYMAN HAT Responsibilities Include: Taking care of the house and yard. Must know basic carpentry, landscaping, plumbing, and electrical work. Benefits: You’ll get to have a really cool set of tools, including power tools.

Across the rich world, well-educated people increasingly work longer than the less-skilled. Some 65% of American men aged 62-74 with a professional degree are in the workforce, compared with 32% of men with only a high-school certificate. This gap is part of a deepening divide between the well-education well off and the unskilled poor. Rapid technological advance has raised the incomes of the highly skilled while squeezing those of the unskilled. The consequences, for individual and society, are profound.

The world is facing as astonishing rise in the number of old people, and they will live longer than ever before. Over the next 20 years the global population of those aged 65 or more will almost double, from 600 million to 1.1 billion. The experience of the 20th century, when greater longevity translated into more years in retirement rather than more years at work, has persuaded many observers that this shift will lead to slower economic growth, while the swelling ranks of pensioners will create government budget problems.

But the notion of a sharp division between the working young and the idle old misses a new trend, the growing gap between the skilled and the unskilled. Employment rates are falling among younger unskilled people, whereas older skilled folk are working longer. The divide is most extreme in America, where well-educated baby-boomers (二战后生育高峰期出生的美国人) are putting off retirement while many less-skilled younger people have dropped out of the workforce.

Policy is partly responsible. Many European governments have abandoned policies that used to encourage people to retire early. Rising life expectancy, combined with the replacement of generous defined-benefit pension plans with less generous defined-contribution ones, means that even the better-off must work longer to have a comfortable retirement. But the changing nature of work also plays a big role. Pay has risen sharply for the highly educated, and those people continue to get rich rewards into old age because these days the educated elderly are more productive than the previous generation. Technological change may well strengthen that shift: the skills that make up for computers, from management knowhow to creativity, do not necessarily decline with age.

During my years as a health and medical journalist, I once found myself in the unexpected role of editing a magazine devoted to healthy cooking. Each issue contaitied dozens of recipes, which were all tried by the staff, including me. Once or twice a week we’d gather in the test kitchen and sample whatever new dish was in the works. Not all of the food that came out of the kitchen made the cut some of it looked and tasted extremely unappetizing. But I always looked forward to recipe-test days because you just never knew what you’d get served to you.

Although I didn’t stay at that job very long, I thought about it a lot after reading “Invasive Eats,” which begins on page 34. When Assistant Editor Marisa Sloan first began writing this story, it never occurred to me that I could do my part against invasive species by simply eating them.

What would my old test-kitchen colleagues say if they were asked to prepare a dish of, say, fried murder hornets with a side of kudzu? And that’s just two of the several invasive ingredients you’ll find in this inventive piece. Obviously, we don’t expect you all to try these dishes (unless you really want to!) but Marisa shares a novel way to look at a common and growing problem. In the U.S. alone, nearly 6.500 invasive species are thriving. causing an alarming ecological and economic challenge.

Even if you’d never try these dishes, we hope you enjoy devouring this story, as well as the others we’ve served up for you in this issue. My career as a food editor may have been at another magazine entirely, but I like to think of each issue of Discover as a recipe we prepare for you, spicing the meal with a variety of ingredients. Some items on the menu may not always be to your usual or preferred tastes, but we hope they still satisfy your appetite.