Mysterious fruit shown to be the oldest known fossils of the Frankincense and Myrrh family

Early in the 1970s, a paleontologist working on the outskirts of an Indian village found small, bead-like fossils embedded in the gray chert dotting the surrounding fields. The site was notorious for turning up plant fossils that were difficult to identify, including the fruit of an extinct species resignedly given the name "Enigmocarpon." The new fossils proved just as frustratingly intractable; more of them were discovered in India over the next several decades, but scientists had little luck deciding what type of plant they belonged to.

Now, researchers say they've solved the mystery. Using CT scanning technology, Steven Manchester, curator of paleobotany at the Florida Museum of Natural History, created 3D reconstructions of the original fossil specimens and others collected since.

He showed these to a colleague, who noticed something odd about the five triangular seeds inside.

"When I showed him the 3D images, he said "those aren't seeds.

Pyrenes are woody dispersal pods that give seeds an extra layer of protection.

Examples include the hard stones at the cores of cherries, peaches, dates and pistachios, which prevent the seeds from being digested along with the rest of the fruit.

Distinguishing a seed from a pyrene, especially when they're the size of snowflakes, requires close scrutiny.

Traditional methods of paleobotany, which involve incrementally dissolving fossils in acid and observing each new layer under a microscope, had proven insufficient.

"If we had specimens that fractured at just the right plane, I would have been able to recognize them, but with the material we had on hand, I couldn't tell," Manchester said.

There are only a few plant groups that produce pyrenes, fewer still with fruits that contain five seeds arranged in a pentagram.

Through a process of elimination, Manchester and Judd determined the fossils belonged to an extinct species in Burseraceae, the Frankincense family.

Fossilized wood, leaves, fruits and flowers from this family have been found elsewhere in India, often sandwiched between thick slabs of basalt created by one of the largest volcanic eruptions in Earth's history.

At the time, India was an island off the southeast coast of Africa.

India's continental plate was slowly inching toward Europe and Asia, and as it rafted past Madagascar, it broke the seal on a thin layer of Earth's crust.

Rivers of liquid rock poured onto a landscape the size of California and Texas combined.

The eruptions occurred intermittently for nearly a million years, and they repeatedly killed any vegetation that grew during the interludes.

"The fossils were preserved at times of quiet between the eruptions," Manchester said.

"Ponds and lakes formed on the relatively fresh lava flows, and vegetation, including wood and seeds, were washed into them and covered by sediment."

The shield volcano responsible for the destruction was active just before and after the asteroid impact that drew the curtains on the Cretaceous, and both are thought to have contributed to the extinctions that followed.

Most fossils from the Frankincense family have, up until now, been recovered from rocks that postdate the asteroid impact.

The original fruits discovered in the 1970s were fossilized before that event.

This makes them the oldest Burseraceae fossils discovered to date, which has important implications for the family's origin.

Scientists have a good idea of when plants in the group initially evolved, but it's still unclear where they came from.

Ancient species of Burseraceae are a common component of fossil beds in southern England, the Czech Republic and parts of North America.

Beginning roughly 50 million years ago, however, Earth's climate began a long cooling process that ultimately resulted in the most recent Ice Ages.

As temperatures fell, species in the Frankincense family seemed to reverse their preference for hemispheres.

Today, there are more than 700 Burseraceae species, and most of them grow south of the equator.

The ancestors of modern Burseraceae species are thought to have first appeared somewhere in the north.

Alternatively, a few early species may have had a global distribution but became isolated as continents drifted apart.

The fossils from India suggest the southern hemisphere may have been the real birthplace of the family.

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Fruit, nectar, bugs and blood: How bat teeth and jaws evolved for a diverse dinnertime

They don't know it, but Darwin's finches changed the world. These closely related species -- native to the Galapagos Islands -- each sport a uniquely shaped beak that matches their preferred diet. Studying these birds helped Charles Darwin develop the theory of evolution by natural selection.

A group of bats has a similar -- and more expansive -- evolutionary story to tell. There are more than 200 species of noctilionoid bats, mostly in the American tropics. And despite being close relatives, their jaws evolved in wildly divergent shapes and sizes to exploit different food sources. A paper published Aug. 22 in Nature Communications shows those adaptations include dramatic, but also consistent, modifications to tooth number, size, shape and position. For example, bats with short snouts lack certain teeth, presumably due to a lack of space. Species with longer jaws have room for more teeth -- and, like humans, their total tooth complement is closer to what the ancestor of placental mammals had.

According to the research team behind this study, comparing noctilionoid species can reveal a lot about how mammalian faces evolved and developed, particularly jaws and teeth. And as a bonus, they can also answer some outstanding questions about how our own pearly whites form and grow.

"Bats have all four types of teeth -- incisors, canines, premolars and molars -- just like we do," said co-author Sharlene Santana, a University of Washington professor of biology and curator of mammals at the Burke Museum of Natural History & Culture. "And noctilionoid bats evolved a huge diversity of diets in as little as 25 million years, which is a very short amount of time for these adaptations to occur."

"There are noctilionoid species that have short faces like bulldogs with powerful jaws that can bite the tough exterior of the fruits that they eat. Other species have long snouts to help them drink nectar from flowers. How did this diversity evolve so quickly? What had to change in their jaws and teeth to make this possible?" said lead author Alexa Sadier, an incoming faculty member at the Institute of Evolutionary Science of Montpellier in France, who began this project as a postdoctoral researcher at the University California, Los Angeles.

Scientists don't know what triggered this frenzy of dietary adaptation in noctilionoid bats. But today different noctilionoid species feast on insects, fruit, nectar, fish and even blood -- since this group also includes the infamous vampire bats.

The team used CT scans and other methods to analyze the shapes and sizes of jaws, premolars and molars in more than 100 noctilionoid species. The bats included both museum specimens and a limited number of wild bats captured for study purposes. The researchers compared the relative sizes of teeth and other cranial features among species with different types of diets, and used mathematical modeling to determine how those differences are generated during development.

The team found that, in noctilionoid bats, certain "developmental rules" caused them to generate the right assortment of teeth to fit in their diet-formed grins. For example, bats with long jaws -- like nectar-feeders -- or intermediate jaws, like many insect-eaters, tended to have the usual complement of three premolars and three molars on each side of the jaw. But bats with short jaws, including most fruit-eating bats, tended to ditch the middle premolar or the back molar, if not both.

"When you have more space, you can have more teeth," said Sadier. "But for bats with a shorter space, even though they have a more powerful bite, you simply run out of room for all these teeth."

Having a shorter jaw may also explain why many short-faced bats also tended to have wider front molars.

"The first teeth to appear tend to grow bigger since there is not enough space for the next ones to emerge," said Sadier.

"This project is giving us the opportunity to actually test some of the assumptions that have been made about how tooth growth, shape and size are regulated in mammals," said Santana. "We know surprisingly little about how these very important structures develop!"

Many studies about mammalian tooth development were done in mice, which have only molars and heavily modified incisors. Scientists are not entirely sure if the genes and developmental patterns that control tooth development in mice also operate in mammals with more "ancestral" sets of chompers -- like bats and humans.

Sadier, Santana and their colleagues believe their project, which is ongoing, can start to answer these questions in bats -- along with many other outstanding questions about how evolution shapes mammalian features. They're expanding this study to include noctilionoid incisors and canines, and hope to uncover more of the genetic and developmental mechanisms that control tooth development in this diverse group of bats.

"We see such strong selective pressures in these bats: Shapes have to closely match their function," said Santana. "I think there are many more evolutionary secrets hidden in these species."

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You say tomato, these scientists say evolutionary mystery

Biologists at the University of Massachusetts Amherst have found evidence for evolutionary "syndromes" -- sets of traits that occur together -- that help to explain how tomatoes first evolved their distinctive blend of color, sweetness, acidity and aroma. The research, represented by a pair of papers recently published in Plants People Planet and The American Journal of Botany, not only shines a light on how fruits evolve in the wild, but will also be valuable to crop-improvement efforts aimed at breeding more nutritious and appealing varieties of fruits.

"Have you ever held a fresh tomato in your hand and wondered why it looks good, smells good and tastes delicious?" asks Jacob Barnett, graduate student in organismic and evolutionary biology at UMass Amherst and the papers' lead author. It turns out that the juicy, red tomatoes with their unique flavor have a long and circuitous evolutionary history.

Barnett and his co-authors, including Ana Caicedo, professor of biology at UMass Amherst, turned to the relatives of our modern tomatoes, a group of several wild species growing in the western coast of South America, from Chile to Ecuador, to explore this question. And those wild species are nothing like what you'd find in your sandwich or salad today.

"For one thing, they're tiny," says Barnett, "about the size of a blueberry. And most of them are green when ripe. Many smell like apples, melons or even cucumbers, and a number of them taste terrible."

So how did we get from a tiny, green, terrible-tasting, melon-smelling fruit to the sublime blend of color, sweetness, acidity and umami that makes tomatoes so beloved in pasta sauces, salads and pizzas?

It turns out that fruits in the wild tend to have sets of traits that occur together, which biologists call syndromes. For example, many fruits are small, brightly colored and high in sugar. But evidence of evolutionary syndromes in wild tomatoes has been hard to gather, because no previous researchers had grown all the species of wild tomatoes together at the same time.

"These two studies are the first to look at fruit traits across all species in the entire tomato group," says Caicedo. "We have been able to tell a comprehensive story of how wild tomatoes compare to each other and to our modern, cultivated varieties."

Part of that story involves the collecting efforts of Charles Rick, from the University of California Davis, who traveled through South America in the 1950s and 1960s collecting seeds from wild species and bringing them back to what would become the C.M. Rick Tomato Genetics Resource Center. Barnett and Caicedo acquired seeds from 13 species of wild tomato, as well seeds from multiple variants within each species, and then grew them at the UMass Crop and Animal Research and Education Farm in South Deerfield, Massachusetts.

When mature, the plants were "wild and scraggly," says Caicedo, and at one point Barnett had to hack his way through them with a machete on his way to gathering their fruits and leaves. Back in the lab, the team scanned the fruits for color and shape, measured sugar and acid content and analyzed the DNA in the leaf samples. With the help of co-author Denise Tieman, research assistant professor at the University of Florida, Barnett measured and classified each sample's volatile organic compounds -- the chemicals responsible for tomatoes' smell.

Not only did the team discover that smell, flavor and color are syndromatic, they also discovered that there is what Barnett calls an "honest signal" -- a match between the outside appearance of the tomato and the inside nutritional content. This match supports a controversial hypothesis that animal preferences shaped the evolution of fruit syndromes, because animals will choose some fruits over others if they learn to associate the fruit's looks with its unique nutrient reward.

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Global diet study challenges advice to limit high-fat dairy foods

Unprocessed red meat and whole grains can be included or left out of a healthy diet, according to a study conducted in 80 countries across all inhabited continents and published today in European Heart Journal, a journal of the European Society of Cardiology (ESC).1 Diets emphasising fruit, vegetables, dairy (mainly whole-fat), nuts, legumes and fish were linked with a lower risk of cardiovascular disease (CVD) and premature death in all world regions. The addition of unprocessed red meat or whole grains had little impact on outcomes.

"Low-fat foods have taken centre stage with the public, food industry and policymakers, with nutrition labels focused on reducing fat and saturated fat," said study author Dr. Andrew Mente of the Population Health Research Institute, McMaster University, Hamilton, Canada. "Our findings suggest that the priority should be increasing protective foods such as nuts (often avoided as too energy dense), fish and dairy, rather than restricting dairy (especially whole-fat) to very low amounts. Our results show that up to two servings a day of dairy, mainly whole-fat, can be included in a healthy diet. This is in keeping with modern nutrition science showing that dairy, particularly whole-fat, may protect against high blood pressure and metabolic syndrome."

The study examined the relationships between a new diet score and health outcomes in a global population. A healthy diet score was created based on six foods that have each been linked with longevity. The PURE diet included 2-3 servings of fruit per day, 2-3 servings of vegetables per day, 3-4 servings of legumes per week, 7 servings of nuts per week, 2-3 servings of fish per week, and 14 servings of dairy products (mainly whole fat but not including butter or whipped cream) per week. A score of 1 (healthy) was assigned for intake above the median in the group and a score of 0 (unhealthy) for intake at or below the median, for a total of 0 to 6. Dr. Mente explained: "Participants in the top 50% of the population -- an achievable level -- on each of the six food components attained the maximum diet score of six."

Associations of the score with mortality, myocardial infarction, stroke and total CVD (including fatal CVD and non-fatal myocardial infarction, stroke and heart failure) were tested in the PURE study which included 147,642 people from the general population in 21 countries. The analyses were adjusted for factors that could influence the relationships such as age, sex, waist-to-hip ratio, education level, income, urban or rural location, physical activity, smoking status, diabetes, use of statins or high blood pressure medications, and total energy intake.

The average diet score was 2.95. During a median follow-up of 9.3 years, there were 15,707 deaths and 40,764 cardiovascular events. Compared with the least healthy diet (score of 1 or less), the healthiest diet (score of 5 or more) was linked with a 30% lower risk of death, 18% lower likelihood of CVD, 14% lower risk of myocardial infarction and 19% lower risk of stroke. Associations between the healthy diet score and outcomes were confirmed in five independent studies including a total of 96,955 patients with CVD in 70 countries.

Dr. Mente said: "This was by far the most diverse study of nutrition and health outcomes in the world and the only one with sufficient representation from high-, middle- and low-income countries. The connection between the PURE diet and health outcomes was found in generally healthy people, patients with CVD, patients with diabetes, and across economies."

"The associations were strongest in areas with the poorest quality diet, including South Asia, China and Africa, where calorie intake was low and dominated by refined carbohydrates. This suggests that a large proportion of deaths and CVD in adults around the world may be due to undernutrition, that is, low intakes of energy and protective foods, rather than overnutrition. This challenges current beliefs," said Professor Salim Yusuf, senior author and principal investigator of PURE.

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Apes may have evolved upright stature for leaves, not fruit, in open woodland habitats

Anthropologists have long thought that our ape ancestors evolved an upright torso in order to pick fruit in forests, but new research from the University of Michigan suggests a life in open woodlands and a diet that included leaves drove apes' upright stature.

The finding sheds light on ape origins and pushes back the origin of grassy woodlands from between 7 million and 10 million years ago to 21 million years ago, during the Early Miocene.

Fruit grows on the spindly peripheries of trees. To reach it, large apes need to distribute their weight on branches stemming from the trunk, then reach out with their hands toward their prize. This is much easier if an ape is upright because it can more easily grab onto different branches with its hands and feet. If its back is horizontal, then its hands and feet are generally underneath the body, making it much harder to move outward to the smaller branches of a tree -- especially if the ape is large bodied.

This is how modern day apes reach fruit, and, it's been theorized, that's why apes evolved to be upright, according to U-M researchers Laura MacLatchy and John Kingston.

But new research centered around a 21-million-year-old fossil ape called Morotopithecus and led by MacLatchy suggests this might not be the case. Instead, researchers think early apes ate leaves and lived in a seasonal woodland with a broken canopy and open, grassy areas. The researchers suggest this landscape, instead of fruit in closed canopy forests, drove apes' upright stature.

Their results are published in Science and are bolstered by a companion paper examining these paleo grassy woodland habitats, published in the same issue of the journal.

"The expectation was: We have this ape with an upright back. It must be living in forests and it must be eating fruit. But as more and more bits of information became available, the first surprising thing we found was that the ape was eating leaves. The second surprise was that it was living in woodlands," said MacLatchy, a paleoanthropologist and professor in the U-M Department of Anthropology.

The two papers grew out of a U.S. National Science Foundation-funded collaboration of international paleontologists, collectively known as the Research on Eastern African Catarrhine and Hominoid Evolution project or REACHE, each of whom focus on different aspects of early ape paleoenvironments. The study led by MacLatchy focuses on a 21-million-year-old site called the Moroto site in eastern Uganda.

There, the group, which included U-M researchers William Sanders and Miranda Cosman, examined fossils found in a single stratigraphic layer, including fossils of the oldest, clearly documented ape, Morotopithecus. Also within this layer were fossils of other mammals, ancient soils called paleosols, and tiny silica particles from plants called phytoliths. The researchers used these lines of evidence to recreate the ancient environment of Morotopithecus.

MacLatchy and Kingston discovered that the plants living in this landscape were what's called "water stressed," meaning they lived through seasonal periods of rain and of aridity. This also means that at least part of the year, apes had to rely on something other than fruit to survive. Together, these findings indicate that Morotopithecus lived in an open woodland punctuated by broken canopy forests composed of trees and shrubs.

"These open environments have been invoked to explain human origins, and it was thought that you started to get these more open, seasonal environments between 10 and 7 million years ago," MacLatchy said. "Such an environmental shift is thought to have been selected for terrestrial bipedalism -- our ancestors started striding around on the ground because the trees were further apart.

"Now that we've shown that such environments were present at least 10 million years before bipedalism evolved, we need to really rethink human origins, too."

The first clue that these ancient apes were eating leaves was in the apes' molars. The molars were very "cresty": they were craggy, with peaks and valleys. Molars like this are used for tearing fibrous leaves apart, while molars used for eating fruit are typically more rounded, MacLatchy said.

The researchers also examined the apes' dental enamel, as well as the dental enamel of other mammals found in the same stratigraphic layer. They found that isotopic ratios -- the abundance of two isotopes of the same element -- in their dental enamel showed that the apes and other mammals had been eating water stressed C3 plants that are more common in open woodland or grassy woodland environments today. C3 plants are primarily woody shrubs and trees while C4 plants are arid-adapted grasses.

"Putting together the locomotion, the diet and the environment, we basically discovered a new model for ape origins," MacLatchy said. "In anthropology, we care a lot about ape evolution because humans are closely related to apes and features like lower back stability represent an arboreal adaptation that may have ultimately given rise to bipedal humans."

Early Miocene C4 grasses and open woodlands

Previously, researchers believed equatorial Africa during the Early Miocene was thickly carpeted with forest, and that open seasonal woodlands and grasslands evolved only between 7 million and 10 million years ago.

But the second paper uses a set of environmental proxies to reconstruct the vegetation structure from nine fossil ape sites across Africa, including the Moroto site, during the Early Miocene. These proxies revealed that C4 grasses were "everywhere" during that time period, said Kingston, a biological anthropologist and associate professor in the U-M Department of Anthropology.

"This paper looks at all these sites, pulls all this data together, and says, 'Look, no matter how you evaluate the data, there's no way you can escape the fact that all these proxies are converging on the same place -- namely, that these environments are open, and they're open with C4 grasses," he said.

"For the first time, we're showing that these grasses are widespread, and it's this general context of open seasonal woodland ecosystems that were integral in shaping the evolution of different mammalian lineages, including and especially in our case, how different ape lineages evolved."

The nine sites are scattered across eastern equatorial Africa, enough to develop a "regional picture" of what the sites' landscapes looked like in the Early Miocene, Kingston said. During this time, the East African Rift was forming. Earth was pulling apart. As a result, the entire region was uplifted, causing huge variation in topography, and therefore, regional climate and vegetation.

"There's mountains and volcanoes, there's cliffs and escarpments and valleys," Kingston said. "The landscape is just physically highly variable, and that, no doubt, is related to the vegetation heterogeneity."

To reconstruct the paleoenvironment at each location, the researchers used carbon isotope analyses of ancient soil organic matter, plant wax biomarkers and phytoliths found at each site. The carbon isotope analyses revealed that a wide range of plants lived in the grasslands, ranging from those that comprise closed canopy to wooded grasslands.

The wax biomarkers -- left over from the waxy material that protects leaves -- also indicate a large variety of shrubs and trees as well as grasses. Phytoliths -- microscopic biosilica bodies that give plants their structure as well as a defense against being eaten -- can tell the researchers the proportion of C4 grasses at a given site and provide further evidence for abundant C4 grasses.

After using these proxies to rebuild the paleoenvironments at these nine sites, the researchers found that C4 grasses were abundant across eastern equatorial Africa, and were a key part of the landscape's heterogeneous habitats. Their data also pushes back the oldest evidence of C4 grass-dominated habitats in Africa and globally by more than 10 million years.

"The findings have transformed what we thought we knew about early apes, and the origin for where, when and why they navigate through the trees and on the ground in multiple different ways," said Robin Bernstein, program director for biological anthropology at the National Science Foundation.

Read more at Science Daily

Diet plays key role in ADHD symptoms in children

 Here's a good reason for children with attention deficit hyperactivity disorder (ADHD) to eat their fruits and vegetables: It may help reduce inattention issues, a new study suggests.

As part of a larger study, researchers asked parents of 134 kids with ADHD symptoms to complete a detailed questionnaire about the typical foods the children ate, including portion sizes, over a 90-day period.

Another questionnaire asked parents to rate symptoms of inattention -- a hallmark of ADHD -- in their kids, such as having trouble staying focused, not following instructions, difficulty remembering things, and difficulty regulating emotions.

Results showed that kids who consumed more fruits and vegetables showed less severe symptoms of inattention, said Irene Hatsu, co-author of the study and associate professor of human nutrition at The Ohio State University.

"Eating a healthy diet, including fruits and vegetables, may be one way to reduce some of the symptoms of ADHD," Hatsu said.

The study was published online recently in the journal Nutritional Neuroscience.

The data for this research was collected as part of the Micronutrients for ADHD in Youth (MADDY) Study, which examined the efficacy of a 36-ingredient vitamin and mineral supplement to treat symptoms of ADHD and poor emotional control in the 134 kids aged 6 to 12.

The study that evaluated the effectiveness of the supplement showed that children who took the micronutrients were three times as likely to show significant improvement in their ADHD and emotional dysregulation symptoms than those who took a placebo. That study was published last year in the Journal of the American Academy of Child and Adolescent Psychiatry.

Another study involving the same children, published earlier this year in the journal Nutrients, showed that kids whose families had higher levels of food insecurity were more likely than others to show more severe symptoms of emotional dysregulation, such as chronic irritability, angry moods and outbursts of anger.

The three studies all paint a similar picture, Hatsu said: A healthy diet that provides all the nutrients that children require can help reduce the symptoms of ADHD in children.

"What clinicians usually do when kids with ADHD start having more severe symptoms is increase the dose of their treatment medication, if they are on one, or put them on medication," Hatsu said.

"Our studies suggest that it is worthwhile to check the children's access to food as well as the quality of their diet to see if it may be contributing to their symptom severity."

Children in the MADDY study, all of whom met the criteria for ADHD, were recruited from three sites: Columbus, Ohio; Portland, Oregon; and Lethbridge, Alberta, Canada. The study took place between 2018 and 2020. Participants were either not taking medication or stopped using it two weeks before the study began.

The studies on fruit and vegetable intake and the role of food insecurity were based on data collected when the children were first enrolled in the study, before they began taking the micronutrient supplement or placebo.

Why may diet be so important in ADHD?

Researchers believe that ADHD is related to low levels of some neurotransmitters in the brain -- and vitamins and minerals play a key role as cofactors in helping the body make those important neurochemicals and in overall brain function, Hatsu said.

Food insecurity may play an additional role.

"Everyone tends to get irritated when they're hungry and kids with ADHD are no exception. If they're not getting enough food, it could make their symptoms worse," she said.

Also, the stress of parents who are upset about not being able to provide enough food for their children can create family tension that could lead to more symptoms for children with ADHD.

The MADDY study is one of the first to look at the relationship between ADHD symptoms and diet quality among children in the United States and Canada, Hatsu said.

That's important because Western diets are more likely than many others, such as the Mediterranean diet, to fall short on fruit and vegetable intake, she said.

"We believe clinicians should assess the food security status of children with ADHD before creating or changing a treatment program," Hatsu said.

Read more at Science Daily

Beetle in the coconut: Fossil find sheds new light on Neotropical rainforests

Tiny beetles that feed on fruit from the palm family may have developed their taste for coconuts long ago, according to a Penn State-led team of scientists studying suspected insect damage in a 60-million-year-old fossil.

"We found this remarkable fossil coconut that has clear signs of insect tunneling," said L. Alejandro Giraldo, a graduate student in geosciences at Penn State. "After studying the damage in detail, we were able to pinpoint the insect culprit: a group of beetles commonly referred to as palm bruchines that today still eat lots of palm fruit -- coconuts included."

The findings represent the earliest fossil evidence of seed beetles feeding on palm fruit and shed new light on the Neotropical rainforests that emerged in modern day South America following the Cretaceous-Paleogene extinction event 66 million years ago that wiped out the dinosaurs and reshaped life on Earth, the scientists said.

"These were the first Neotropical forests as we know them today," said Giraldo, whose adviser is Peter Wilf, professor of geosciences at Penn State. "We know these forests had similar plants compared to today, and the next step is knowing what was happening to these forests -- for example how insects were interacting with the plants."

Previous studies have focused on insect damage to fossil leaves, the most abundant plant parts found in the fossil record, the scientists said. Examples of insect damage to fruit and seeds are less common, but scientists found six suspected insect holes on a coconut fossil from a site in modern day Colombia.

The fossil contained damage to the outer and inner layers of the fruit, revealing a three-dimensional path that suggests the holes had a biological origin -- like from larvae eating their way through the coconut, the scientists said.

The team analyzed the number, position and size of the holes and the scar tissue left behind and compared that with damaged caused by modern insects, especially those that feed on plants from the palm family. The damage was consistent with a sub-group of modern beetles called palm bruchines, the scientists reported in the journal Review of Palaeobotany and Palynology.

"There are thousands of different insect species that can feed on seeds, but not many of them feed on palm seeds, so that was the way to start," Giraldo said. "After that it was doing a lot of detective work, really digging into the literature and studying different morphological features in terms of how this damage occurs. And it paid off."

This kind of relationship between specific plants and insects -- called specialized interactions -- plays an important role in creating and maintaining plant diversity in modern Neotropical rainforests. By eating and destroying seeds, these highly specialized insects help prevent any one group of plants from dominating the landscape.

The findings suggest that palm bruchines have consistently eaten palm fruits for at least 60 million years and that the specialized interactions that define modern-day Neotropical rainforests have occurred through geological time, the scientists said.

"This is something that we see 60 million years ago, and it's something that is still occurring today," Giraldo said. "Our contribution is that we pinpoint this specific group of insects as the culprit, and that group is still living today and attacks the same coconuts and same palms as it did in the past."

Read more at Science Daily

How apples get their shapes

Apples are among the oldest and most recognizable fruits in the world. But have you ever really considered an apple's shape? Apples are relatively spherical except for that characteristic dimple at the top where the stem grows.

How do apples grow that distinctive shape?

Now, a team of mathematicians and physicists have used observations, lab experiments, theory and computation to understand the growth and form of the cusp of an apple.

The paper is published in Nature Physics.

"Biological shapes are often organized by the presence of structures that serve as focal points," said L Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, of Organismic and Evolutionary Biology, and of Physics at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and senior author of the study. "These focal points can sometimes take the form of singularities where deformations are localized. A ubiquitous example is seen in the cusp of an apple, the inward dimple where the stalk meets the fruit."

Mahadevan had already developed a simple theory to explain the form and growth of apples but the project began to bear fruit when the researchers were able to connect observations of real apples at different growth stages and gel experiments to mimic the growth along with theory and computations.

The research team began by collecting apples at various growth stages from an orchard at Peterhouse College at University of Cambridge in the U.K., (the alma mater of another famous apple lover, Sir Isaac Newton).

Using those apples, the team mapped the growth of the dimple, or cusp as they called it, over time.

To understand the evolution of the shape of the apple and the cusp in particular, the researchers turned to a long-standing mathematical theory known as singularity theory. Singularity theory is used to describe a host of different phenomena, from black holes, to more mundane examples such as the light patterns at the bottom of a swimming pool, droplet breakup and crack propagation.

"What is exciting about singularities is that they are universal. The apple cusp has nothing in common with light patterns in a swimming pool, or a droplet breaking off from a column of water, yet it makes the same shape as they do," said Thomas Michaels, a former postdoctoral fellow at SEAS and co-lead author of the paper, now at University College London. "The concept of universality goes very deep and can be very useful because it connects singular phenomena observed in very different physical systems."

Building from this theoretical framework, the researchers used numerical simulation to understand how differential growth between the fruit cortex and the core drives formation of the cusp. They then corroborated the simulations with experiments which mimicked the growth of apples using gel that swelled over time. The experiments showed that different rates of growth between the bulk of the apple and the stalk region resulted in the dimple-like cusp.

"Being able to control and replay morphogenesis of singular cusps in the laboratory with simple material toolkits was particularly exciting," said Aditi Chakrabarti, a postdoctoral fellow at SEAS and co-author of the paper. "Varying the geometry and composition of the gel mimics showed how multiple cusps form, as seen in some apples and other drupes, such as peaches, apricots, cherries and plums."

The team found that the underlying fruit anatomy along with mechanical instability may play joint roles in giving rise to multiple cusps in fruits.

"Morphogenesis, literally the origin of shape, is one of the grand questions in biology," said Mahadevan. "The shape of the humble apple has allowed us to probe some physical aspects of a biological singularity. Of course, we now need to understand the molecular and cellular mechanisms behind the formation of the cusp, as we move slowly towards a broader theory of biological shape."

Read more at Science Daily

Oldest known mammal cavities discovered in 55-million-year-old fossils suggests a sweet tooth for fruit

A new U of T study has discovered the oldest known cavities ever found in a mammal, the likely result of a diet that included eating fruit.

The cavities were discovered in fossils of Microsyops latidens, a pointy-snouted animal no bigger than a racoon that was part of a group of mammals known as stem primates. It walked the earth for about 500,000 years before going extinct around 54 million years ago.

"These fossils were sitting around for 54 million years and a lot can happen in that time," says Keegan Selig, lead author of the study who recently completed his PhD student in Professor Mary Silcox's lab at U of T Scarborough.

"I think most people assumed these holes were some kind of damage that happened over time, but they always occurred in the same part of the tooth and consistently had this smooth, rounded curve to them."

Very few fossils of M. latidens' body have been found, but a large sample of fossilized teeth have been unearthed over the years in Wyoming's Southern Bighorn Basin. While they were first dug up in the 1970s and have been studied extensively since, Selig is the first to identify the little holes in their teeth as being cavities.

Cavities form when bacteria in the mouth turns foods containing carbohydrates into acids. These acids erode tooth enamel (the hard protective coating on the tooth) before eating away at dentin, the softer part of the tooth beneath the enamel. This decay slowly develops into tiny holes.

For the research, published in the journal Scientific Reports, Selig looked at the fossilized teeth of a thousand individuals under a microscope and was able to identify cavities in 77 of them. To verify the results, he also did micro-CT scans (a type of X-ray that looks inside an object without having to break it apart) on some of the fossils.

As for what caused the cavities, Selig says the likely culprit was the animal's fruit-rich diet. While primates would have been eating fruit for quite some time before M. Latidens, for a variety of reasons fruit became more abundant around 65 million years ago and primates would have started eating more of it.

An interesting discovery was that out the fossil teeth studied, seven per cent from the oldest group contained cavities while 17 per cent of the more recent group contained cavities. This suggests a shift in their diet over time that included more fruit or other sugar-rich foods.

"Eating fruit is considered one of the hallmarks of what makes early primates unique," says Selig, whose research looks on reconstructing the diets of fossil mammals.

He adds that M. Latidens would naturally want to eat fruit since its full of sugar and contains a lot of energy. "If you're a little primate scurrying around in the trees, you would want to eat food with a high energy value. They also likely weren't concerned about getting cavities."

The study, which received funding from the Natural Sciences and Engineering Research Council of Canada (NSERC), not only includes the largest and earliest known sample of cavities in an extinct mammal, it also offers some clues into how the diet of M. Latidens changed over time. It also offers a framework to help researchers look for cavities in the fossils of other extinct mammals.

Selig says identifying cavities in fossils can tell us a lot about the biology of these animals. It can help figure out what they were eating and how they evolved over time based on their diet. For example, while evolutionary changes in the structure of a jaw or teeth suggest broader changes in diet over time, cavities also offer a window into what that specific animal was eating in their lifetime.

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The aroma of distant worlds

Spices

Asian spices such as turmeric and fruits like the banana had already reached the Mediterranean more than 3000 years ago, much earlier than previously thought. A team of researchers working alongside archaeologist Philipp Stockhammer at Ludwig-Maximilians-Universität in Munich (LMU) has shown that even in the Bronze Age, long-distance trade in food was already connecting distant societies.

A market in the city of Megiddo in the Levant 3700 years ago: The market traders are hawking not only wheat, millet or dates, which grow throughout the region, but also carafes of sesame oil and bowls of a bright yellow spice that has recently appeared among their wares. This is how Philipp Stockhammer imagines the bustle of the Bronze Age market in the eastern Mediterranean. Working with an international team to analyze food residues in tooth tartar, the LMU archaeologist has found evidence that people in the Levant were already eating turmeric, bananas and even soy in the Bronze and Early Iron Ages. "Exotic spices, fruits and oils from Asia had thus reached the Mediterranean several centuries, in some cases even millennia, earlier than had been previously thought," says Stockhammer. "This is the earliest direct evidence to date of turmeric, banana and soy outside of South and East Asia." It is also direct evidence that as early as the second millennium BCE there was already a flourishing long-distance trade in exotic fruits, spices and oils, which is believed to have connected South Asia and the Levant via Mesopotamia or Egypt. While substantial trade across these regions is amply documented later on, tracing the roots of this nascent globalization has proved to be a stubborn problem. The findings of this study confirm that long-distance trade in culinary goods has connected these distant societies since at least the Bronze Age. People obviously had a great interest in exotic foods from very early on.

For their analyses, Stockhammer's international team examined 16 individuals from the Megiddo and Tel Erani excavations, which are located in present-day Israel. The region in the southern Levant served as an important bridge between the Mediterranean, Asia and Egypt in the 2nd millennium BCE. The aim of the research was to investigate the cuisines of Bronze Age Levantine populations by analyzing traces of food remnants, including ancient proteins and plant microfossils, that have remained preserved in human dental calculus over thousands of years.

The human mouth is full of bacteria, which continually petrify and form calculus. Tiny food particles become entrapped and preserved in the growing calculus, and it is these minute remnants that can now be accessed for scientific research thanks to cutting-edge methods. For the purposes of their analysis, the researchers took samples from a variety of individuals at the Bronze Age site of Megiddo and the Early Iron Age site of Tel Erani. They analyzed which food proteins and plant residues were preserved in the calculus on their teeth. "This enables us to find traces of what a person ate," says Stockhammer. "Anyone who does not practice good dental hygiene will still be telling us archaeologists what they have been eating thousands of years from now!"

Palaeoproteomics is the name of this growing new field of research. The method could develop into a standard procedure in archaeology, or so the researchers hope. "Our high-resolution study of ancient proteins and plant residues from human dental calculus is the first of its kind to study the cuisines of the ancient Near East," says Christina Warinner, a molecular archaeologist at Harvard University and the Max Planck Institute for the Science of Human History and co-senior author of the article. "Our research demonstrates the great potential of these methods to detect foods that otherwise leave few archaeological traces. Dental calculus is such a valuable source of information about the lives of ancient peoples."

"Our approach breaks new scientific ground," explains LMU biochemist and lead author Ashley Scott. That is because assigning individual protein remnants to specific foodstuffs is no small task. Beyond the painstaking work of identification, the protein itself must also survive for thousands of years. "Interestingly, we find that allergy-associated proteins appear to be the most stable in human calculus," says Scott, a finding she believes may be due to the known thermostability of many allergens. For instance, the researchers were able to detect wheat via wheat gluten proteins, says Stockhammer. The team was then able to independently confirm the presence of wheat using a type of plant microfossil known as phytoliths. Phytoliths were also used to identify millet and date palm in the Levant during the Bronze and Iron Ages, but phytoliths are not abundant or even present in many foods, which is why the new protein findings are so groundbreaking -- paleoproteomics enables the identification of foods that have left few other traces, such as sesame. Sesame proteins were identified in dental calculus from both Megiddo and Tel Erani. "This suggests that sesame had become a staple food in the Levant by the 2nd millennium BCE," says Stockhammer.

Two additional protein findings are particularly remarkable, explains Stockhammer. In one individual's dental calculus from Megiddo, turmeric and soy proteins were found, while in another individual from Tel Erani banana proteins were identified. All three foods are likely to have reached the Levant via South Asia. Bananas were originally domesticated in Southeast Asia, where they had been used since the 5th millennium BCE, and they arrived in West Africa 4000 years later, but little is known about their intervening trade or use. "Our analyses thus provide crucial information on the spread of the banana around the world. No archaeological or written evidence had previously suggested such an early spread into the Mediterranean region," says Stockhammer, although the sudden appearance of banana in West Africa just a few centuries later has hinted that such a trade might have existed. "I find it spectacular that food was exchanged over long distances at such an early point in history."

Stockhammer notes that they cannot rule out the possibility, of course, that one of the individuals spent part of their life in South Asia and consumed the corresponding food only while they were there. Even if the extent to which spices, oils and fruits were imported is not yet known, there is much to indicate that trade was indeed taking place, since there is also other evidence of exotic spices in the Eastern Mediterranean -- Pharaoh Ramses II was buried with peppercorns from India in 1213 BCE. They were found in his nose.

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This fruit attracts birds with an unusual way of making itself metallic blue

There's a reason why blue fruits are so rare: the pigment compounds that make fruits blue are relatively uncommon in nature. But the metallic blue fruits of Viburnum tinus, a popular landscaping plant in Europe, get their color a different way. Instead of relying solely on pigments, the fruits use structural color to reflect blue light, something that's rarely seen in plants. Researchers reporting August 6 in the journal Current Biology show that the fruits use nanostructures made of lipids in their cell walls, a previously unknown mechanism of structural color, to get their striking blue -- which may also double as a signal to birds that the fruits are full of nutritious fats.

"Structural color is very common in animals, especially birds, beetles, and butterflies, but only a handful of plant species have ever been found to have structural color in their fruits," says co-first author Miranda Sinnott-Armstrong, a postdoctoral researcher at the University of Colorado-Boulder. "This means that V. tinus, in addition to showing a completely novel mechanism of structural color, is also one of the few known structurally colored fruits."

Senior author Silvia Vignolini, a physical chemist at the University of Cambridge, has been interested in the plants for nearly 10 years. "I actually found this Viburnum in a garden in Italy and observed that they looked weird, so we measured them at the time but didn't have conclusive results. It was kind of always on the back of my mind," she says. As her team grew, they become more interested in V. tinus and eventually had the capability to examine the structure of the fruits using electron microscopy. "Before we got the images, we were just seeing all these blobs," she says. "When we found out that those blobs were lipids, we got very excited."

While most plants have cell walls made of cellulose, used to make cotton and paper, V. tinus fruit cells have much thicker walls with thousands of globular lipids arranged in layers that reflect blue light. The structure formed by this so-called lipid multilayer allows the fruits to create their vibrant blue color while containing no blue pigment. "This is very strange because globular lipids like these are not usually found in this arrangement in the cell wall, as they are normally stored inside the cell and used for transport," says co-first author Rox Middleton, a physicist who studied the optical response of the fruits during her PhD and is now a postdoctoral researcher at the University of Bristol. "We also believe that this lipid may contribute to the fruit's nutrition. That means that the fruit can demonstrate how nutritious it is by being a beautiful, shiny blue."

This extra nutrition would be important for V. tinus's main consumers: birds that disperse the plant's seeds. Although the researchers can't say for sure whether the lipids are used as fat by the birds that consume them, there is reason to believe they might be. If so, the researchers suggest that the metallic blue color made by the lipid multilayer could indicate to the birds that if they see this striking blue, the fruit in question will have enough nutrients to make it a worthwhile meal. "While birds have been shown to be attracted to blue fruits," says Vignolini, "other blue fruits that we have studied essentially don't have any nutritional value."

Going forward, the researchers want to see how widespread blue structural color is in fruits to understand its ecological significance. They had never seen this type of lipid multilayer in a biomaterial before, but since their discovery, they've begun to take notice of other species. "We actually realize now that there are some older electron microscopy pictures from other plants where you can see the blobs. The researchers didn't know that they were lipids at the time, or that lipids could even form this type of structure, but our research suggests that they very well could be, meaning this structure may not be limited to Viburnum," Vignolini says.

Additionally, learning how V. tinus can use such a unique mechanism to make color may have implications for how we color our own foods. "There are lots of problems connected to food coloration," says Vignolini. She adds that once this mechanism is better understood, it could potentially be used to create a healthier, more sustainable food colorant.

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