At over three feet, you’d think the solo coral grouper would be threatening enough. Threatening sure, but a successful lone hunter? Well, not so much, according to National Geographic News Watch:

When hunting alone, groupers only catch their prey about 1 out of every 20 attempts.

So the grouper teams up with the even fiercer moray eel, or the very large Napolean wrasse, to go hunting. The fish are looking for smaller coral reef fishes that hide from their predators under rocks and coral. When the grouper detects the hiding prey, it signals its hunting friend and together they both flush the prey out of hiding.

The cooperation, however, ends there. Whoever gets the prey, eats it whole. There’s no sharing of the spoils. Still, for the grouper, it’s worth the shared hunting, says National Geographic News Watch:

When they have help, the ratio is significantly better—about one out of seven.

What’s most significant about this shared hunting are the signals the grouper makes to its partner during the hunt, say scientists. Researchers studying the fish observed dozens of events where groupers performed upside-down headstands with concurrent head shakes to indicate the presence and location of particular prey to cooperative partners. Their study, published last week in Nature Communications, call the groupers’ signals “referential gestures”. From the abstract:

In humans, referential gestures intentionally draw the attention of a partner to an object of mutual interest, and are considered a key element in language development. Outside humans, referential gestures have only been attributed to great apes and, most recently, ravens.

It’s likely that these gestures have been understudied in non-primate species, say Academy researchers, who point to hunting dogs and even bee dances as potential consideration for referential gestures.

The researchers of the study say that the mental processes underlying these gestures in fish, apes and ravens are unclear and may well vary among these taxa. Their findings point to the fish having developed cognitive skills according to their particular ecological needs.

Whatever the cause, these hunting tactics are pretty extraordinary. Videos of the behaviors can be found here. For more information on the study, visit the University of Cambridge website.

Image: jon hanson/Wikipedia

Not everything is passed down through genes. Many of our human actions result from cultural influences: “a collective adoption and transmission of one or more behaviors among a group” (from ScienceNOW).  The skills, knowledge, materials, and traditions that humans learn from each other help explain how we have come to dominate the globe as a species.

But we’re not the only species on our planet with culture. Scientists are discovering that more and more animals—from mammals to birds to fish—use cultural transmission for species survival. Studies in this week’s Science focus on two: humpback whales off the coast of Maine and vervet monkeys in South Africa.

Humpback whales around the world hunt small fish collectively by producing “bubble nets”—the whales blow bubbles around a school of fish while slowly advancing toward their next meal. In 1980, in Maine, one whale was observed hitting the water with its tail before producing the bubble nets. This innovation, called “lobtail feeding,” spread throughout the population over several decades. By 2007, nearly 40% were doing it.

Researchers believe that a crash in the herring population that these humpbacks fed upon drove them to new solutions to catch other fish, primarily sand lance.

Co-author of the study, Luke Rendell, of the University of St. Andrews, says, “Our study really shows how vital cultural transmission is in humpback populations—not only do they learn their famous songs from each other, they also learn feeding techniques that allow them to buffer the effects of changing ecology.”

St. Andrews researchers also found that vervet monkeys learned from each other in a changing environment. In the initial study, the scientists provided a group of monkeys in the wild with a box of corn dyed pink and another dyed blue. The blue corn was made to taste repulsive and the monkeys soon learned to eat only pink corn. Another group was trained in this way to eat only blue corn.

A new generation of vervet monkeys were later offered both colors of food—neither tasting badly—and the adult monkeys present appeared to remember which color they previously preferred.

Almost every infant copied the rest of the group, eating only the one preferred color of corn. The crucial discovery came when males began to migrate between groups during the mating season. The researchers found that of the ten males who moved to the group eating a different colored corn to the one they were used to, all but one switched to the new local norm immediately.

Erica van de Waal, lead author of the study, says, “The copying behavior of both the new, naïve infants and the migrating males reveals the potency and importance of social learning in these wild primates, extending even to the conformity we know so well in humans.”

Her colleague, co-author Andrew Whiten, agrees. “It may make sense in nature, where the knowledge of the locals is often the best guide to what are the optimal behaviors in their environment, so copying them may actually make a lot of sense… ‘When in Rome, do as the Romans do.’”

Image: Erica van de Waal

Now, an international team of researchers has sequenced the genome of one of the two living species of coelacanths. The results are published in this week’s Nature.

The endangered African coelacanth (Latimeria chalumnae) has more up its sleeve than just the living fossil thing. Scientists have long thought that this group of fishes gave rise to the first four-legged amphibious creatures to climb out of the water and up on land. Lobe-finned fishes (with fins like limbs) are genealogically placed in-between the ray-finned fishes, such as goldfish and guppies, and the tetrapods—the first four-limbed vertebrates and their descendants, including living and extinct amphibians, reptiles, birds, and mammals.

Results from the genomic study place the coelacanths behind lungfish, another lobe-finned living fossil, as the closest fishy relative to tetrapods. But other data from the study still make coelacanths incredibly interesting.

These prehistoric-looking fish are evolving at a very leisurely pace. “We found that the genes overall are evolving significantly slower than in every other fish and land vertebrate that we looked at,” says co-author Jessica Alföldi, of the Broad Institute of MIT and Harvard.

“We often talk about how species have changed over time,” says Kerstin Lindblad-Toh, another co-author from the Broad Institute. “But there are still a few places on Earth where organisms don’t have to change, and this is one of them. Coelacanths are likely very specialized to such a specific, non-changing, extreme environment—it is ideally suited to the deep sea just the way it is.”

Researchers also found several key genetic regions that may have been “evolutionarily recruited” to form tetrapod innovations such as limbs, fingers, and toes, and the mammalian placenta. One of these regions, known as HoxD, harbors a particular sequence that is shared across coelacanths and tetrapods. Tetrapods likely co-opted this sequence from the coelacanth to help form hands and feet.

“This is just the beginning of many analyses on what the coelacanth can teach us about the emergence of land vertebrates, including humans, and, combined with modern empirical approaches, can lend insights into the mechanisms that have contributed to major evolutionary innovations,” says the paper’s lead author, Chris Amemiya of the Benaroya Research Institute.

Image: Ballista/Wikipedia

With six research papers in the current issue of Science, and numerous articles and blog posts surrounding those papers, Australopithecus sediba is the hominin du jour.

The papers reveal different anatomical features of Au. sediba and discuss their similarities to, and differences from, early human features. One news article calls them a “hodgepodge,” while another describes them as a “mosaic.”

“Amalgam” is how Zeray Alemseged, the Academy’s curator of anthropology, describes Au. sediba’s combination of human-like and more primitive features. Take the species’ heel. You and I walk by putting our broad and robust heel down and rolling to our toes, but Au. sediba’s heel was so narrow, these hominins couldn’t land on their heel, and likely walked on the sides of their feet and then pronated.

Similarly, Au. sediba’s torso had a conical and quite primitive shape, and their shoulders were “shrugged.” Alemseged explains, “With short necks and a narrow clavicle, they appeared to be ape-like with a substantial adaptation for climbing.”

However, the lower ribs were slightly human-like and the teeth were a mixture “of primitive and human traits,” according to an accompanying article in Science.

The findings are based on fossils found in South Africa by Lee Berger’s team in 2008, and include three skeletons.  The recent studies pinpoint Au. sediba’s existence to around 1.98 million years ago and make a few proposals on how to place the species in our lineage. In fact, Berger suggests that Au. sediba could be the direct ancestor to our genus, Homo.

“Lee is a good colleague, but I happen to disagree with him about that,” Alemseged says. “It’s a fascinating discovery and the quality of preservation of the fossils and number of skeletons are great,” but Alemseged sees no evidence that Homo descended from Au. sediba. “The fossil record indicates that by 2.33 million years ago, Homo already exists,” predating Au. sediba, Alemseged explains.

In addition, the findings (especially in regards to the dental study) suggest that Au. sediba was closely related to Australopithecus africanus, but not Australopithecus afarensis, the species Alemseged studies. He finds the evidence linking Au. sediba and Au. africanus solid, but that doesn’t leave Au. afarensis out. Given the timing, Au. afarensis, which lived between 3.8 and 2.9 million years ago, was likely the ancestor of Au. africanus, which lived between 3.3 and 2.1 million years ago and in turn was the ancestor of Au. sediba.

Alemseged notes that the studies underscore the diversity of our lineage. “It’s not surprising, in the natural world, to find multiple species of any given group,” so why should our family tree be any different?

Despite his scientific disagreement with his colleague, Alemseged lauds Berger’s generous sharing of the fossils and studies related to Au. sediba. “He’s introduced a new culture in paleontology of being very open.”

Finally, the image accompanying many of the articles (above right) is very similar to an animation comparing Au. afarensis, humans and chimpanzees in the Academy’s current exhibit, Human Odyssey that Alemseged curated. If you haven’t visited it yet, it explores Australopithecus, Homo, and more!

Image: Lee R. Berger And The University of the Witwatersrand

That’s what a recent paper in PLoS Biology asks—and doesn’t really answer.

Instead, it lays out a great argument, giving the pros and cons of using the controversial technique in addressing conservation issues. It also urges the two parties—synthetic biologists and conservation biologists—to get in the same room and talk about the possibilities and problems with open minds. In fact, the authors of paper organized a meeting this week in the United Kingdom, bringing the two groups of scientists together. (Ed Yong has an article about the meeting at National Geographic.)

The paper describes several examples of how synthetic biology could work to help conservation efforts—restoring habitats, supporting endangered species, and even reviving extinct species. It also lays out several examples of how synthetic biology could wreak havoc on the natural world. (The open-access article is very readable. We encourage you to review it or at least take a look at the examples in Table 1.)

The paper and meeting come on the heels of huge media coverage on de-extinction. National Geographic’s April issue on the topic garnered a lot of press and generated public interest. In some cases, these articles say, de-extinction could be just a few years away, if not closer.

The PLoS paper and de-extinction topic seemed to be a great opportunity to speak to Terry Gosliner, the Academy’s Dean of Science and Research, about the subject.

“Do you really want to encounter a saber-toothed cat in Muir Woods?” Terry joked when we sat down.

He sees huge potential risks in using synthetic biology for conservation, but admits that the meeting and discussion are a great idea. “Open dialogue is the only way to explore the topic, see the potential and understand what the concerns and dangers are,” he says. “Bad things happen when there isn’t discussion. Informed dialogue is the best way to deal with controversial issues.”

Terry believes some aspects of synthetic biology in the natural world could work, with appropriate regulation.

But he also sees that synthetic biology may not be the right approach. When thinking about threatened species, the problem is usually “habitat loss, not necessarily genetic constraints.” He uses the re-emergence of California condors as an example of this.

And in some cases, extinction is a natural process, Terry reminds us. Synthetic biology could just be more of humans interfering with nature, and not in a good way.

The resources going toward de-extinction could be better used to protect life before it goes extinct, Terry thinks. “If we use the same resources to address climate change and how we use energy,” Terry says, “We literally could save hundreds and thousands of species.”

And those energy and climate resources could be from synthetic biology. The PLoS paper cites a 2009 report on synthetic biology: “Many believe that synthetic biology will be one of the transformative technologies necessary to combat climate change, energy shortages, food security issues and water deficits.”

What do you think? Can synthetic biology save wildlife? Where do you stand on the issue?

Protecting biodiversity is essential to our health and longevity on this planet. But can we quantify that value? Especially the economic value?

Late last year, researchers from the US and France attempted to put dollar amounts on the importance of biodiversity by correlating it to the prevalence of tropical disease in developing countries. According to their introduction in PLoS Biology:

Along with 93% of the global burden of vector-borne and parasitic diseases (VBPDs), the tropics host 41 of the 48 “least developed countries” and only two of 34 “advanced economies.”

They contend that economic growth falters when people get sick. (Seems reasonable.) And the spread of disease among humans, many scientists argue, can increase or decrease depending on factors in the natural environment, including biodiversity.

The more diverse an ecosystem, the greater the chance that a pathogen is diluted among numerous and potentially less-than-ideal host species and, therefore, the less abundant the disease. In 2002, researchers found this to be true with Lyme disease. NPR sums it up well:

If you have a rich community of tick hosts, like squirrels, mice and other small mammals, the disease is diluted among them. But if the habitat is degraded, and ticks carrying Lyme have only white-footed mice as hosts, the disease risk to humans can rise dramatically.

The Academy’s microbiologist, Shannon Bennett, weighed in on biodiversity’s impact on human diseases. In a recent email, she wrote:

I am sure biodiversity influences the transmission of infectious diseases one way or another.  Over 75% of new, emerging or re-emerging human diseases are caused by pathogens from animals, according to the World Health Organization. That means that the ecological communities we live in, and how pathogens cycle through the different players, are key to human health. Biodiversity is one way that we measure the complexity of these communities. In what way biodiversity is important, or how these communities specifically affect infectious diseases and risk, depends on the pathogen ecology and life history, and host species relationships.

Stanford researchers brought up this same point last month—“depends on the particulars,” as Bennett put it—in a study in Ecology Letters. A summary from the Stanford Report states:

The researchers found that the links between biodiversity and disease prevalence are variable and dependent on the disease system, local ecology and probably human social context.

The role of individual host species and their interactions with other hosts, vectors and pathogens are more influential in determining local disease risk, the analysis found.

That dovetails exactly with the research Bennett and Academy entomologist Durrell Kapan are conducting. They’re currently studying mosquito vector communities and the relationships between their biodiversity, the diversity of their microbes, and the presence of pathogens.

As for putting a price tag on biodiversity, Bennett encourages the PLoS study’s authors:

I find the authors’ argument intriguing and certainly a significant angle to consider in support of the health value of biodiversity, and one that is unique—no one has teased out the financial correlations between biodiversity and human societies. That it includes human health and infectious diseases is the angle I find particularly intriguing and worth following up on with empirical studies.

And on these studies of human disease and biodiversity in general? Bennett is excited about the possibilities of further research, including her own:

Increasingly we are recognizing and appreciating that humans are members of complex communities of other species, and that the make-up of these communities, whether they live inside of us or outside, can be very important to human health, as well as the health of all life. Human health and the health of life on this planet are coupled. We need to understand those coupling mechanisms better to ensure sustainability of that life, and the best way to understand those coupling mechanisms is with a multi-disciplinary approach, bringing together human health researchers with ecologists and evolutionary biologists, to name a few!

Some organizations have sprung up to do just that. Bennett points to two examples: the One Health Initiative and the EcoHealth Association. Whatever dollar value we assign to biodiversity and other ecosystem services, let’s wish these organizations luck in improving human health and well-being.

Image: CDC

“They started to fall on their face, to die like crazy. We’ve been doing this 30 years, and we’ve never experienced this kind of loss before.” That’s a Montana beekeeper in last week’s New York Times describing the death of his honeybees.

Bees continue to die from Colony Collapse Disorder (CCD) while scientists race to discover the cause—and to determine the effects of the drastic loss in the population of these important pollinators.

The last couple weeks have witnessed incredible acceleration in the race to save bees. It started on March 21st, when beekeepers and environmentalists sued the EPA over neonicotinoid, urging the agency to ban the pesticide linked to CCD.

Then, last Wednesday, a study in Nature Communications demonstrated the effects of pesticides on bee brains. The researchers looked at neonicotinoid and another type of pesticide, coumaphos, and found within 20 minutes of exposure, neurons in the major learning center of the brain stopped firing. A parallel study earlier this year in the Journal of Experimental Biology found that bees exposed to the combined pesticides were slower to learn—or completely forgot—important associations between floral scent and food rewards. These findings provide a possible underlying cellular mechanism for the observed disruption and altered foraging behavior seen in bees during CCD.

Finally, two studies published in Science last Friday, describe the loss of diversity of bees and the effect that loss and the decline of all bee species is having on crops that humans depend on. The news is not good. According to a related article in the journal, the studies find “that native wild pollinators are declining… [and] that managed honeybees cannot compensate for this loss.”

For those of us who enjoy the fruits of the bees’ labors—from almonds and apples to onions and watermelons—we should hope that the lawsuit, the research, and the attention will lead to a rapid solution to bee decline.

Invasive species often worry scientists—how will native species respond to competition in their ecosystem? The Academy’s Brian Simison shares this concern, but he looks a little deeper. He asks: how does invasive species’ DNA affect that of native species?

Studying slider turtles (Trachemys) is a good way to this address this question. Some species, like the abundant red-eared slider, are invasive all over the world. Others are threatened native species. The invasive and native species often mate with each other, creating offspring. This mixing of two species genomes through crossing, that is, hybridization, can have a profound effect on the evolution of these species and on ecosystem health.

Recently Brian and Academy Research Associate James Parham of CSU Fullerton published a paper on slider populations in the Caribbean. The native sliders there “are endangered, largely because of habitat destruction, and being harvested for food,” Brian explains.

In some places, natives are also threatened by invasive species like the Cuban slider on Jamaica or the red-eared slider in Puerto Rico. “It appears that people have been moving turtles around for hundreds of years, and for some islands there may have been different sources of the introductions,” Brian says.

The recent study reveals a lot of hybridization among the invasive and native species. “We used genetic data to show that there are multiple hybridization events, both recent and ancient, both from natural contact and because of human activities,” Brian describes. “This pattern also shows that the past and ongoing movement of turtles by humans is impacting their DNA.”

But Brian suspects that human impacts may not be the only reason for hybridization. “In addition to the genetic pollution caused by people moving turtles into the range of other turtles, different species also contact each other naturally. So hybridization may be an important part of the natural evolution of these turtles. We have to keep this in mind when reconstructing their evolutionary history. We also need to be very careful determining whether evolution is the result of unnatural (human) or natural processes.”

If hybridization is due to unnatural, human causes, conservation efforts are a top priority in protecting the native turtles from the invasive species. Brian and his colleagues are also confronting these hybridization and conservation issues in the US. “The turtle project is a long-term multi-component project that will last for decades. This publication about Caribbean turtles is a small piece of the entire slider puzzle, which we are unraveling piece by piece.”

And the project goes beyond turtles. “Another facet of the current study addresses how we study genomic data in species that are hybridizing. In other words, we demonstrate how the presence of hybridization confounds certain methods that people are using to reconstruct how different species are related.”

These turtles get to the root of Brian’s work. “Asking, testing and answering evolutionary questions is why I became a scientist,” he explains. “Turtles are one of the few vertebrates that hybridize across deep historical divisions, which provides my colleagues and me the opportunity to test some of the most fundamental questions about the processes of speciation, the engine generating biodiversity.”

Image: James Parham