Medicine has done a much better job of making us live longer, and the problem is, as we age, our organs tend to fail more, and so currently there are not enough organs to go around.

And as a consequence, today there is just not enough spots for the many more people who want and deserve a high quality education.

Because the demographics are really going to leave us with lots of jobs that need doing and that we, our society, is going to have to be built on the shoulders of steel of robots in the future.

And in order to do this work, we, of course, because of the limitation in health workers, had to recruit refugees to be a specialized new category of health worker.

The other condition is in societies living in marginal or fluctuating environments, such as the Arctic or deserts, where there are periodic food shortages, and occasionally there just isn't enough food to keep everyone alive.

When food was scarce, our ancestors' survival depended on conserving energy, and regaining the weight when food was available would have protected them against the next shortage.

And funding, I think as well, if you're underfunded at first but you're gaining traction, especially in today's age, it's very, very easy to get intense funding.

He told me, "It seems like the United States has run out of jobs, because they're just making some up: cat psychologist, dog whisperer, tornado chaser."

Here, Nightingale's coxcomb was the inspiration to organize data on thousands of federal energy subsidies, scrutinizing the lack of investment in renewables over fossil fuels.

And these and many similar experiences convinced me that there are just tons of bright kids in Africa -- inventive kids, intellectual kids -- and starved of opportunity.

But I learned that there was a desperate shortage of skills, especially mathematical skills, in industry, in government, in education.

Almost all projects of this kind fall apart within a decade because too many people drop out of the study, or funding for the research dries up, or the researchers get distracted, or they die, and nobody moves the ball further down the field.

Using rigorous scientific research, Dr. Hayden and other researchers came to the conclusion that it was simply the lack of opportunity to participate that caused their fitness levels to suffer.

Vast workforces, often made up of women and children, may be underpaid, lack the training to safely disassemble phones, and be exposed to elements like lead and mercury, which can permanently damage their nervous systems.

People worry that there won't be enough food, but we know, if we just ate less meat and fed less of the crops to animals, there is enough food for everybody as long as we think of ourselves as one group of people.

And what that thing is doesn't much matter -- whether it's not enough time, money or food.

And what these photos show on the one side, on the left side, is a three-month-old who has been stunted: not adequate nutrition, not adequate stimulation.

Carnivorous plants tend to grow in places with highly acidic soil, which is poor in crucial nutrients like nitrogen, phosphorus, and potassium.

But eventually, over the course of repeated contractions there may not be sufficient concentrations of potassium, sodium or calcium ions immediately available near the muscle cell membrane to reset the system properly.

There is a scarcity of retail, more specifically, fresh food retail, resulting in a city where 70 percent of Detroiters are obese and overweight, and they struggle.

Not by the latest combine and tractor invention, but by fertile land; not by pumps, but by fresh water; not by chainsaws, but by forests; and not by fishing boats and nets, but by fish in the sea.