Researchers studied records of more than 36 million births and found the birth weight of the average full term single baby actually decreased over a 15 year period. (Photo courtesy of the Library of Congress)
American moms are giving birth
to smaller babies. Rebecca Williams
reports on a new study that suggests
this recent trend might be the
reversal of American babies getting
bigger and bigger of the past half-
century:
Transcript
American moms are giving birth
to smaller babies. Rebecca Williams
reports on a new study that suggests
this recent trend might be the
reversal of American babies getting
bigger and bigger of the past half-
century:
A few giant babies made the news last year. One was even 15 pounds.
“At guess at some point you can’t make bigger babies (laughs) so maybe we’ve maxed out.”
That’s Dr. Emily Oken with Harvard Medical School. She says babies are getting smaller. She studied records of more than 36 million births and found the birth weight of the average full term single baby actually decreased over a 15 year period.
But it was just a couple of ounces. Dr. Oken says that’s not a big deal for most healthy babies.
“But, is there an underlying reason why perhaps babies might be getting a little bit smaller and does that exposure have a short or longer term health implication for babies?”
She says she ruled out factors such as age, race, tobacco use, and birth complications. Dr. Oken says next, she wants to study mother’s diets, exercise, stress, and exposure to environmental toxins as possible causes.
Oliver Pergams used a tiny caliper to measure the mice, tracking changes in size over the years. (Photo by Gabriel Spitzer)
The Field Museum of Natural History in Chicago has a hundred years of dead mouse specimens stored in
white metal cabinets. (Photo by Gabriel Spitzer)
Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much
faster than nearly anyone thought. Gabriel Spitzer has more on those
changes, and how they seem to be linked to humans:
Transcript
Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much
faster than nearly anyone thought. Gabriel Spitzer has more on those
changes, and how they seem to be linked to humans:
Tall Trees Park is a little patch of green in Glenview, Illinois – a
northern suburb of Chicago. About a hundred years ago, a lot of this area
looked a lot like this. It was mostly farms and pasture and forest. And now
of course it’s a lot of strip malls and subdivisions and stuff. And the
population has grown seventyfold. The climate has changed, too. It’s
gotten a little warmer, a little wetter.
And all this has made life a lot different for the northern white-footed
mice who live here. It’s actually not just made life different for the
mice, it’s changed the mice themselves.
That gets back to a guy named Oliver Pergams. He’s an ecologist, and in
the mid-90s, he was looking at deer mice who live on the Channel Islands
off the coast of California. And he was taking these mice and comparing
them to museum samples of the same kind of mice from the same place, but
decades earlier.
“And I found something kind of strange – that the older specimens were
larger than the newer specimens, so they shrunk in size over a period of
about 30 or 40 years.”
That got him wondering if those relatively quick changes are happening in
other places. So years later, now on the faculty at the University of
Illinois at Chicago, he gathered up some of those White Footed Mice from
the Chicago suburbs. And he went to the Field Museum of Natural History…
(sound of a cabinet opening)
… where they have a hundred years of dead mouse specimens stored in
white metal cabinets.
“Here we have trays and trays of the northern white-footed mouse.”
With a tiny caliper, he’d measure their skulls, their feet, the distance
from their eyes to their noses.
“So this one here was collected by Aikley in 1903.”
And he compared mice from before and after 1950.
“Here are some skulls, this one was collected in 1989.”
Lo and behold, these mice had grown: by more than 10% on some measures.
This phenomenon goes way beyond Chicago. Pergams measured more than 1,300
rodents from four different continents – Alaskan lemmings, Mexican
gophers, Filipino rats. Some of them got bigger, some smaller. But across
the world, most of the animals have changed over time spans thought to be
mere evolutionary eyeblinks.
The next step is to figure out why.
“You can’t get in a time machine and go back and look to see what
actually happened. So the next best thing is to see if there’s
associations or correlations with big factors.”
He found the variations correlate with changes in climate and human
population density. The exact reasons aren’t clear – more people might
mean more yummy trash for the mice to eat, for example. That’s going to
take more research to figure out, and these critters might be overdue for
some extra attention.
“One of the questions is, well, why didn’t anybody notice this before?
And I think the answer is, they haven’t looked.”
Larry Heaney curates the Field Museum’s mammal collection. He says
Pergams’s research opens up new questions about how animals respond to
changes driven by humans.
“The implication is, these animals are changing very, very rapidly. So in
a sense, it’s good: they can change. But the other side of the coin is,
they’re having to change.”
Now, the question is, is this happening in other species, too? What about
birds or bugs or plants?
“There’s been this default attitude that if you go to one place and you
capture or you observe animals or plants, that essentially there’s going
to be the same animals or plants 50 years or 100 years later. I don’t
think that’s possible to assume at all. We have to include the fact of
this change in all of our decisions, from ecology to evolutionary biology
to conservation.”
Pergams’s findings show that even the most common creatures have more to
teach us – when we ask the right kinds of questions.
Most nuclear power plants are huge
multi-billion-dollar operations that take
ten years to build. But they can be much
smaller. Lester Graham reports on a company
that’s planning hot-tub sized reactors:
Transcript
Most nuclear power plants are huge
multi-billion-dollar operations that take
ten years to build. But they can be much
smaller. Lester Graham reports on a company
that’s planning hot-tub sized reactors:
It’s difficult to get political and financial backing for building big nuclear power plants.
But one company plans to build miniature nuclear reactors.
John Deal is the CEO of Hyperion.
He says the small reactor invented at the Los Alamos National Laboratory could be
useful for isolated areas. It could also be used by smaller cities to provide most of
their power needs.
“You might have a community of 20, 30, 40 thousand people and they can have their
own power plant. And then they might feed back their excess or draw down from
some centralized facility for when they’ve got power spikes or peak demand.”
There’s a lot of interest. But for right now Hyperion is not taking orders for the mini-
nukes from Western nations. Deal says Hyperion is first trying to bring power to
isolated areas in the developing world.
For The Environment Report, this is Lester Graham.
It is predicted that the dead zone in the Gulf of Mexico could be the largest ever (Photo courtesy of NASA)
A researcher is predicting farm
fertilizers will cause record “Dead Zones”
in the Gulf of Mexico and Chesapeake Bay
this year. Lester Graham reports:
Transcript
A researcher is predicting farm
fertilizers will cause record “Dead Zones”
in the Gulf of Mexico and Chesapeake Bay
this year. Lester Graham reports:
These dead zones are areas where oxygen is depleted. No oxygen and much of the
marine life leaves or dies. It’s caused by nitrogen-based farm fertilizers that are
washed off the fields and into the water.
Donald Scavia is a researcher at the University of Michigan. Using U.S. Geological
Survey data, he predicts the dead zone in Chesapeake Bay will be the sixth largest
on record.
“The six other ones are also not that much bigger than what we’re predicting for this
year.”
Heavy rains and flooding across the Corn Belt washed nitrogen fertilizers into the
Mississippi River system and then on to the Gulf of Mexico. Scavia predicts the
dead zone in the Gulf could be the largest ever.
“What you put down on the land is what gets flushed in those rainstorms. And we’re
putting too much fertilizer on the land. So,
what’s changed over the last three decades is agricultural practices. What changes
from year-to-year is the weather.”
Scavia says better methods of farming could reduce the dead zones.
For The Environment Report, this is Lester Graham.
The Hill's cows getting a sip of water while waiting for milking (Photo by Kinna Ohman)
From left to right, Stephanie Hill, their daughter, and Ray Hill outside their new section of the barn where they make and sell yogurt (Photo by Kinna Ohman)
Inside the Hill's barn during milking time (Photo by Kinna Ohman)
In many areas of the country, small farms
are now the exception, not the norm. Farming,
especially with livestock, can mean thousands and
thousands of animals, and often distant, corporate
ownership. Even the smallest farms are pressured
to get bigger. So when a family decides to make
their farm smaller, they’re rebels. Kinna Ohman
reports:
Transcript
In many areas of the country, small farms
are now the exception, not the norm. Farming,
especially with livestock, can mean thousands and
thousands of animals, and often distant, corporate
ownership. Even the smallest farms are pressured
to get bigger. So when a family decides to make
their farm smaller, they’re rebels. Kinna Ohman
reports:
It’s five o’clock in the evening on the Hill’s dairy farm. Ray Hill just finished cleaning
out the milking equipment and is moving into the barn.
(sound of milking equipment and door)
Cows look around curiously, and afternoon light streams through the windows. Hill
moves comfortably among these cows, calling each of them by name, and cleans their
udders for milking.
(Ray describing the process)
Ray Hill and his wife Stephanie are full time farmers. They milk ten cows, twice a day.
They sell raw milk and yogurt directly from their farm. But getting to this point hasn’t
been easy. To survive, they’ve had to step away from the conventional approach to dairy
farming.
When the Hills got into farming eight years ago, they listened to the advice of farm
experts. They had more than forty cows, a tractor, and were selling their farm’s milk to the
regional processors.
But within a couple of years, they were deep in debt. Hill says the experts told him to get
more cows. He says he couldn’t see how that would help.
“Financially it just didn’t work. There wasn’t money to hire help. I had a couple of
kids and my wife and we were all running ragged and it just wasn’t fun. And there
were many days where I threatened to sell every cow in the barn.”
It’s common for farm experts and even bankers to push family farmers like the Hills to
‘get big or get out.’ Darrell Emmick’s with the Natural Resources Conservation Service.
He says he’s seen regions lose more than fifty percent of their dairy farms when using
this conventional standard.
“Getting bigger or get out really didn’t help a lot of the farmers. They got bigger
and they still went out of business.”
For a farm to get bigger, farmers confine hundreds or even thousands of dairy cows inside
large barns. That means farmers spend a lot of money and time bringing food to their
animals and hauling manure away.
Darrell Emmick says that model of agriculture started
in the 1940s when fuel was pretty cheap. But these days, it makes good economic sense
for farmers to go back to letting their milk cows out of the big barns to eat grass.
“Nothing can harvest a ton of feed any cheaper than the cow or the sheep or the
horse can by itself. Bringing food to animals is something I think we’re going to see a lot
less of, especially here and now with fuel prices going over four dollars a gallon.”
The Hill’s have made that switch on their farm. Ray Hill says his cows are healthier. He
believes their milk is better quality, too. And he’s excited about providing healthy
food for his community. Ray Hill says he wants their farm to be a place where people
come to buy quality food, and definately let him know if they have concerns.
“I want to have control over how I take care of my animals. I want to have control
over how I process or don’t process my milk. I want to have control over the price,
the quality. If there’s a quality issue, it’s up to me to take care of it, not say ‘let me
call so and so.’ I don’t think you can find anyone who’d that would tell you I’d
rather talk to a corporate person than the person who produced my food.”
But bucking against the system is not easy. There are days when no one comes to their
farm to buy their milk or yogurt. The Hills know they’re taking a risk. But they feel, at
least they’re not at the mercy of the industry, the banks and the whims of the market.
Vegetables are a great way to get vitamins and minerals. But studies show techniques for faster-growing and bigger vegetables could be producing plants that actually have less of these health benefits. (photo by Justin Richards)
Vegetables are less nutritious than they were 50 years ago. That’s according to a new study that tested 43 different garden crops. The Great Lakes Radio Consortium’s Chris Lehman reports:
Transcript
Vegetables are less nutritious than they were 50 years ago. That’s the finding of a new study that tested 43 different garden crops. The Great Lakes Radio Consortium’s Chris Lehman reports:
Researchers analyzed U.S. Department of Agriculture nutrition data from the past 50 years. They found that levels of several vitamins and minerals decreased by as much as 38% in garden crops over the time period. Don Davis is the lead author of the study. He’s with the University of Texas Biochemical Institute. He says the decline could be the result of decades of breeding plants to produce more and bigger vegetables.
“There’s emerging evidence that when you genetically select for higher yields, you get a plant that grows bigger and faster but it isn’t necessarily able to produce nutrients or uptake minerals from the soil at the same faster rate.”
Davis says despite the fact that vegetables have fewer nutrients in them, he says they’re still the most efficient way to get vitamins and minerals into your system.
For the Great Lakes Radio Consortium, I’m Chris Lehman.
Researchers studied records of more than 36 million births and found the birth weight of the average full term single baby actually decreased over a 15 year period. (Photo courtesy of the Library of Congress)
