Today, the National Restaurant Association rolled out a new healthy eating initiative called Kids Live Well. Expect to see more healthy snacks like “apple fries” at places better known for the classic deep-friend potato version: Burger King, Friendly’s, Sizzler, and Au Bon Pain are all participating in the program.
In addition to a small red apple logo stamp that signifies the healthier option (and yes, only one healthy option is needed to qualify here), the initiative could usher in a wider acceptance of “optimal defaults.”
Basically, optimal defaults mean that instead of having the option to supersize your BK® Kids Meal, parents will be asked, “Would you like apple fries or French fries?” Fat-free milk or juice will automatically come with kids’ meals. In other words, you’re going to have to ask for fries and a soda, which could be a small nudge in the right direction.
Optimal defaults for healthier drinks and snacks first took hold at Disney’s resorts in 2006, and, as you can see in the chart above, the ordering changes were significant. (The same holds true for things like organ donation: A much higher percentage of people donate in countries where you have to opt out if you don’t want to donate your organs.)
In their book, Nudge: Improving Decisions about Health, Wealth and Happiness, Richard Thaler and Cass Sunstein call this kind of change “libertarian paternalism”—a subtle behavior cue that doesn’t take away our freedom of choice. As I’ve written before, though, tiny nudges are just a starting point; given what we’re up against, we may need a shove. Next up: Big advertised discounts for apple fries?
Teeth are like tiny biological time capsules. They tell stories about ancient diets and environments long after their owners have died and landscapes have changed.
After bones break down, tooth enamel stays hard and unchanged, even in fossilized teeth that have been buried under sediment and rock for millions of years and are now being uncovered by erosion or excavation.
Tooth enamel forms when an animal is young, and it remains chemically stable for the rest of that animal’s life. The food an animal eats and the water it drinks during its youth leave chemical signals within the enamel.
Because of that, hidden within the enamel of fossilized teeth, scientists can find traces of extinct forests, expanding savanna grasslands, shifting climates and evolving animal communities.
A small group of oryx forage in the open savanna of Awash National Park in Ethiopia, with scattered acacia trees and dry grasses illustrating the park’s semi-arid environment. Zelalem Bedaso
Over the past 30 years, my colleagues and I have been analyzing chemical traces in fossil teeth from Ethiopia’s Afar region in the East African Rift Valley – often referred to as the cradle of humanity – to uncover what animals ate there millions of years ago, around the time early human ancestors were evolving, and what the world looked like around them.
These clues from ancient meals are enabling scientists to reconstruct pictures of entire ecosystems, including forests, wetlands and grasslands that existed at the time. It’s a reminder that in a very real sense, organisms are what they eat.
Traces of ancient diets in fossil teeth
To determine which plants ancient animals ate, my colleagues and I collect a small amount of enamel powder from fossilized teeth. We then analyze this powder in the laboratory using specialized instruments that detect chemical signals preserved in the enamel.
Trees and grasses have different ways of using photosynthesis to convert sunlight into energy. These methods leave distinct chemical patterns in plant tissues, which then become incorporated into the teeth of animals that eat those plants.
By examining these chemical patterns in tooth enamel, we can determine whether animals primarily fed on trees and shrubs or on grass, providing insight into the vegetation that once covered the ancient landscape.
The author conducts fieldwork in the East African Rift, collecting samples from ancient lake and river deposits. Courtesy of Zelalem Bedaso
We can then figure out how an environment changed over time by collecting fossil teeth from different rock layers. Each layer formed at a different time in the past, so teeth found in deeper layers are typically older than those closer to the surface.
By analyzing tooth enamel from fossils across these layers, we can compare the chemical signals preserved in the teeth and see how animal diets and the plants growing in the landscape changed through time.
Adding that knowledge to data from different types of fossils, we can track long-term shifts in vegetation, climate and ecosystems.
A changing landscape in the last 4 million years
Four million years ago, the Afar region looked very different from the dry landscape you will see there today.
Fossils, including tooth enamel, reveal that the area supported a diverse range of environments. Rivers flowed through wooded areas, lakes were scattered across the landscape, and grassy plains stretched across the basin.
Fossilized teeth from animals like antelopes, giraffes, pigs, horses, hippos and elephants show a wide range of diets. Some animals browsed on leaves and shrubs, while others grazed on grass in open habitats.
The chemical signals in the teeth indicate that grasslands were expanding at the time, but forests still played an important role. They show that animals moved through this environment and adapted to the food sources around them.
Ethiopia’s Afar Depression and Awash Valley, shaped by rifting and erosion, are among the world’s most important regions for fossil discoveries of human ancestors. Some of those fossils date back 3 million to 4 million years. Zelalem Bedaso
Around 2 million to 3 million years ago, the environment shifted more drastically toward open grasslands.
Animals that relied on grass flourished, and the populations of those that didn’t adapt declined. Horses and certain antelopes, for example, developed teeth that could grind tough, gritty plants. This adaptation is recorded on their enamel.
Early humans in a mosaic world
Early human ancestors, like the famous “Lucy,” whose skeleton was discovered in the Afar region, lived in this dynamic landscape.
Fossil teeth from Australopithecus afraensis, an early human that lived in eastern Africa between about 2.9 million and 3.8 million years ago, indicate that early human relatives did not rely heavily on grass. Instead, the chemical signal in their enamel indicates mixed diets and dietary flexibility, which included fruits, leaves and roots, depending on what was available.
In a landscape that combined woodland patches and open savanna, that adaptability may have been key to survival.
This period of environmental change coincided with several important evolutionary developments and morphological changes in pre-humans. Early human ancestors were walking upright. Brain size also gradually increased, allowing for more complex behavior and problem-solving.
During this time, early humans began making and using stone tools, marking a major step in technological innovation and helping them adapt to changing environments.
Diet shapes destiny
The dietary changes in the East African Rift Valley over the past 4 million years, documented through tooth enamel, are providing important clues for reconstructing the environment in which humans’ ancestors lived and how those environments changed.
They also show that species that adjusted their diets as landscapes changed were the ones most likely to survive.
This ongoing research helps explore profound questions of how environmental shifts shaped life on Earth, including human trajectories. And that is helping humanity unlock its collective past.
Photo credit: Sam Droege/USGS Bee Lab via Flickr – This wild ground bee, Andrena nothoscordi, is typically found in the U.S. Midwest and Southeast and loves false garlic flowers.
North America’s bee populations are in trouble, but don’t blame the honey bees. While some people argue that an overabundance of managed honey bees – those raised to help pollinate crops and produce honey – is causing native bees to disappear, the evidence doesn’t support the claim.
What is true is that populations of many species of bees, including honey bees, are struggling.
Half of all honey bee colonies die every winter in the United States, on average. Commercial beekeepers experienced their highest losses on record – more than 60% of their colonies – in the winter of 2024-25. Overall, one-fifth of pollinators in North America are considered to be at risk for extinction due in large part to habitat loss, rising temperatures, extreme weather, diseases and pesticides.
We studybeesand othervitalpollinators, and we can tell you that there are good reasons to love all the bees. In fact, they’re essential.
Bees help farmers grow the foods people love to eat, everything from apples to almonds.
Along with other pollinators – such as flies, butterflies and moths – bees help nearly 80% of flowering plants produce fruit and seeds, which in turn support birds and other wildlife.
Among the pollinators, honey bees are the most important for agriculture crops. Managed honey bees, which beekeepers can move from field to field, are particularly essential in intensively farmed areas that lack the natural habitat to support wild bees.
So, why are people concerned about honey bees?
Honey bees were introduced to North America by European settlers in the early 1600s.
Since honey bees are not a native species, the most common concern you might hear is that they will outcompete wild bees for pollen and nectar. This is typically portrayed as a numbers game: If resources are limited, the more bees present on the landscape, the less food there is to go around.
Honey bees live in large social colonies and are adept at capitalizing on high-quality patches of flowers, leading to the concern that this species in particular may have a rapid, outsized effect on native bees that share the same food.
The queen bee is marked with nontoxic green paint to make her easy to find when examining the health of this Apis mellifera European honey bee hive in Maryland. David Illig via Flickr, CC BY-NC-SA
Why don’t studies find a honey bee impact on native bees?
Humans actually know little about bee interactions. The U.S. has more than 4,000 native bee species, but there is enough data to estimate population sizes and ranges for less than half of them. Meaningful data examining the effects of honey bees on other species are even more scarce.
In a recent analysis, we found that only 15% of 116 published studies on resource competition involving honey bees measure how competition from honey bees affects the survival, reproductive output and long-term population trends of native species.
Bee populations face several threats, including pesticides and losing habitat to urbanization and agriculture. Andony Melathopoulos
The majority of published studies on honey bee and wild bee competition address different versions of a narrow question: Do honey bees and native bees visit the same plants?
Because honey bees are “super generalists” that thrive worldwide well beyond their native range, most scientists would predict that the answer to this question is a resounding “yes.”
However, about half of the research suggests that honey bees don’t change the way native bees go about their day at all. From the perspective of a wild bee, the honey bees simply don’t exist in their world.
Different bee species can coexist with very little evidence of direct interaction. An analysis of bee communities measured across diverse agricultural, urban, grassland and forested environments found the abundance of honey bees and the abundance of native bees were positively associated about five times as often as they were negatively associated. In other words, rather than landscapes supporting one bee species at the expense of another, the same habitatssupport both.
Bees species can be found just about everywhere in the U.S., as this map, modeled from 3,158 species found in museum collections, shows. But some regions, such as the Southwest deserts, are particularly rich in bee species, with the color scale representing the estimated number of species. Paige R. Chesshire, et al., 2023, CC BY
Calls to restrict honey bees from certain locations also often miss a key reality: Native bee hot spots and urban and commercial beekeeping rarely overlap.
Beekeeping is anchored in agricultural lands. North America’s rarest bees thrive in environments like the Sonoran Desert – habitats that are poorly suited for managed colonies.
Research that has artificially introduced hives into natural areas like the high Sierra – places beekeepers don’t typically go – has generated competition that left less pollen and nectar for the native bees. But frequently competition involves common native bees that are not under threat.
Bumble bees transport pollen on their legs as they move from flower to flower, bringing some of it home while pollinating plants in the process. Andony Melathopoulos
So, if honey bees aren’t to blame, what is?
The top drivers of pollinator declines are considered to be land use – the spread of cities and agriculture, as well as the way land is managed – along with rising temperatures, extreme weather and pesticide use.
Agriculture and urbanization reduce the amount and diversity of flowering plants, and droughts can reduce plant flowering and the resources bees rely on. Pesticides can reduce bees’ ability to lay eggs and care for their offspring, or they can kill bees outright.
As temperatures rise, wild bee populations are expected to decline there. Warmer winters mean bees active in spring emerge earlier from their nests, and increased spring rain and temperature fluctuations can limit their ability to feed their offspring, meaning fewer bees.
The western bumble bee, Bombus occidentalis, was once widespread and abundant across western North America, but it has been in decline since the late 1990s. Long-term monitoring of its populations from 1998 to 2020 shows the primary reasons are land management changes, increasing temperature, drought and pesticide use.
What can you do to support pollinators?
The biggest threat to pollinators is the disappearing variety of flowering plants.
You can help reverse this by filling your garden with more flowering plants, trees and shrubs to give bees, butterflies and other pollinators a variety of food sources.
Planting wildflower gardens in your yard can help many kinds of pollinators, including bees. Clare Rittschof
You can also advocate for bee-friendly behavior in your community, such as creating pollinator habitats in public and private spaces and reducing the use of harsh pesticides and herbicides. Planting more flowers in parks and along roadsides, and protecting wildlands where the rarest native bees live, can help keep these wonderful species thriving.
This finding, based on my team’s synthesis of six decades of research, may come as a surprise. Gender differences in adults’ social sensitivity are famous. Women outperform men at recognizing faces and emotions, and they score modestly higher on measures of empathy. They are likelier to take jobs working with people, such as in teaching and health care, whereas men are likelier to choose jobs working with “things,” such as in engineering or plumbing.
But how early do these differences emerge, and are they a matter of evolution or social learning? For years, some theorists have argued the former: that the difference is innate, built into the brain hardware of girls and boys through Darwinian selection. But this perspective relies almost exclusively on just one high-profile, yet deeply flawed, study of 102 newborns.
Mining the neonatal research trove
Realizing that psychologists have been studying newborns’ social orientation for decades, my team of neurobehavioral researchers and I set out to collect all the data – every published study that has compared boys’ and girls’ attention to social stimuli in the first month of life. Our goal was to better test the hypothesis of an inborn gender difference in attention to, or interest in, other people.
Our study was a systematic review, meaning we searched through every published report indexed in both medical and psychological databases from the 1960s onward.
We cast a wide net, looking for any research that measured newborns’ attention to or preference for human faces or voices and that reported the data separately by gender. Importantly, we did not limit our search to the terms “gender difference” or “sex difference,” since these would bias the collection by potentially excluding studies that failed to find boy-girl differences..
As expected, we unearthed dozens of studies comparing newborn boys and girls on social perception: 40 experiments reported in 31 peer-reviewed studies and involving nearly 2,000 infants. The majority of studies measured the amount of time newborns spent looking at faces, either at a single face or comparing a baby’s preference between two faces of differing social value, such as their own mother versus a woman who was a stranger.
Our data collection was large enough that we were able to carry out meta-analysis, which is a statistical method for combining the results of many studies. Meta-analysis essentially turns many small studies into a single large one. For studies measuring neonates’ looking time at faces, this included 667 infants, half of them boys and half of them girls.
The result was clear: nearly identical social perception between baby boys and girls. There was no significant difference between genders overall, nor was there a difference when we focused only on studies measuring babies’ gaze duration on a single face, or only on studies measuring babies’ gaze preference between two different faces.
Our search also netted two other types of studies. One focused on a remarkable behavior: newborns’ tendency to start crying when they hear another baby cry. An early study found this “contagious crying” to be marginally more common in girls. But when we performed meta-analysis on data across nine contagious-crying experiments, including 387 infants, there was again no solid evidence for male-female difference.
The last dataset we analyzed compared babies’ orientation to both social and inanimate objects using a newborn behavior assessment scale developed by legendary pediatrician T. Berry Brazelton. Across four studies involving 619 infants, girls did pay somewhat greater attention to the social stimuli (a human face or voice), but they also paid more attention to the inanimate stimuli (a ball or the sound of a rattle).
In other words, girls in this test seemed a bit more attuned to every type of stimulus, perhaps due to a general maturity advantage that they hold from fetal development through puberty. But there was nothing special about their interest in people, according to the Brazelton assessment.
Boys, too, prefer faces
Our findings align with other well-designed studies, including one finding that 5-month-old boys and girls equally prefer looking at faces over toy cars or other objects, and another finding that 2-month-old boys actually perform better than girls at detecting faces. So taken together, current research dispels a common myth that girls are innately “hardwired” to be more social than boys in early life.
The truth is that all babies are wired for social engagement at birth. Boys and girls are both primed to pay attention to human faces and voices, which, after all, belong to those who will keep them fed, safe and comforted.
Despite their best intentions, most parents cannot help but stereotype their infants by gender and begin treating boys and girls differently early on. Presuming that sons are already less social is not a recipe for remedying this bias. Our research can help dispel this myth, giving every child, male or female, the best possible start for connecting with and caring about other people.
