Cosmic mismatch Researchers used supernovas, cosmic microwave background radiation and patterns of galaxy clusters to measure the Hubble constant — the rate at which the universe expands — but their results were mismatched, Emily Conover reported in “Debate persists on cosmic expansion” (SN: 8/6/16, p. 10).
Reader J.R. Kennedy thought that light-dimming space dust and debris might explain the discrepancy.
Gas and dust in space can have an impact on the brightness of standard candles — objects with known brightness such as type 1a supernovas and some variable stars, Conover says. But astronomers correct for those discrepancies in their measurements. In the absence of gas and dust, a candle’s apparent brightness should decrease in relation to its distance from Earth. “But if there’s dust in the way, it can make the candle dim more than that,” Conover says. “However, this intervening material doesn’t dim the candle quite in the same way as distance does. It will dim the shorter, bluer wavelengths of light more than the redder ones. Astronomers can look for this effect to identify the impact of dust and correct for it.” So the mismatch stands. Great escape High-speed video captured how the offspring of red-eyed tree frogs prematurely break free from their eggs when in danger, Helen Thompson reported in “Under threat, tadpoles make early escape” (SN: 8/6/16, p. 32). Online reader myndflyte wondered if early hatching had any long-term de-velopmental effects on the tadpoles.
There’s definitely a trade-off involved in hatching early to escape a predator or some other threat, Thompson says. Past work by tree frog researcher Karen Warkentin, now at Boston University, shows that red-eyed tree frog embryos grow tails and mouthparts in the last few days of their roughly weeklong incubation. Those that hatch earlier, up to four days if threatened, tend to be underdeveloped with smaller bodies and shorter tails. “In the short term, this developmental deficit puts early hatchlings at greater risk of getting eaten by pond shrimp and fish than their older brethren,” Thompson says. “But there’s also evidence to suggest that early hatchers compensate down the line and grow at higher rates as tadpoles.”
More to the story Although the death rate from motor vehicle crashes in the United States has declined since 2000, the country still tops 19 other high-income nations in motor vehicle deaths, Alex Maddon wrote in “U.S. still leads in fatal motor vehicle crashes” (SN: 8/6/16, p. 5).
Some readers took issue with the conclusions presented and thought the researchers should have measured fatalities per miles driven instead of per population. “Using a per capita metric makes the U.S. look unsafe when the opposite is true,” John Underwood wrote. “Since A-mericans drive more miles per year than the other countries in the chart, we will have the highest fatality rate per 100,000 population.”
It’s true that fatalities per miles driven changes the ranking. Using the measure “per 100 million vehicle miles traveled,” the United States drops to fifth place, says Deputy M-anaging Editor, Features Cori Vanchieri. When the researchers looked at deaths per 10,000 registered vehicles, however, the United States still topped the list. The researchers’ overall message is that the United States could further reduce crash deaths if seat belt use goes up and alcohol-impaired driving and speeding go down.
Clarification “Under threat, tadpoles make early escape” (SN: 8/6/16, p. 32) states that the tree frog embryos gape their mouths to stretch out their egg membranes. Not all embryos gape their mouths, and ultimately, an enzyme secreted from the embryo’s snout breaks open the membrane.
Humankind’s bombs, plastics, chickens and more have altered the planet enough to usher in a new chapter in Earth’s geologic history. That’s the majority opinion of a group of 35 experts tasked with evaluating whether the current human-dominated time span, unofficially dubbed the Anthropocene, deserves a formal place in Earth’s geologic timeline alongside the Eocene and the Pliocene.
In a controversial move, the Anthropocene Working Group has declared that the Anthropocene warrants being a full-blown epoch (not a lesser age), with its start pegged to the post–World War II economic boom and nuclear weapons tests of the late 1940s and early 1950s. The group made these provisional recommendations August 29 at the International Geological Congress in Cape Town, South Africa. If eventually approved by the International Commission on Stratigraphy (ICS) — the gatekeepers of geologic time — and the Executive Committee of the International Union of Geological Sciences, the Anthropocene would usurp the current Holocene Epoch, which has reigned since the end of the last glacial period around 11,700 years ago. The Holocene would become the shortest completed epoch in history, just thousandths the length of the next shortest epoch.
“We’ve left an indelible mark on the Earth,” says Jan Zalasiewicz, a geologist at the University of Leicester in England and convener of the working group. “We now cannot go back to anything that’s ostensibly the same as the Holocene.”
Not all scientists are onboard with the plan. Critics say it’s grounded in politics and pop culture, not science, and that not enough time has passed to put just decades-old changes in context. Any proposal advocating for the Anthropocene will face strong skepticism, says Whitney Autin, a sedimentary geologist at the State University of New York at Brockport. “The idea of amending geologic time carries the same weight as eliminating an amendment to the U.S. Constitution,” he says. To build its case for the new epoch, the working group will spend the next two to three years scouring natural records, such as rocks, mud and tree rings, for evidence that humankind’s impacts have brought about a distinct new phase in the stratigraphic record. The group will then submit a formal proposal for approval.
“We’re leaving physical signals in sediments, in corals, in trees that are going to be long lasting if not permanent,” says Colin Waters, a geologist at the British Geological Survey in Keyworth and a member of the working group. “It’s not just history, it’s geology as well.” And those geologic changes merit official recognition as a new epoch, Waters says.
The goal of the geologic time scale is to label and formalize discrete phases in Earth’s stratigraphic record as a tool for geologists and other scientists. This time scale allows scientists to easily identify, describe and discuss rocks of similar age across the planet.
The term “Anthropocene” has risen in popularity among scientists and the general public in recent years, driven in part by its use in a 2002 article by atmospheric chemist and Nobel laureate Paul Crutzen. The article argued that humans’ exploitation of natural resources has reshaped the planet enough to bring about a new epoch.
While “Anthropocene” now appears in the titles of papers, conference talks and books about everything from climate change to philosophy, those who embrace the term nonetheless disagree on its definition. Some researchers pin the start of the epoch to when humans first started converting forests to farmland thousands of years ago, while others, such as Crutzen, use the start of the Industrial Revolution or the recent acceleration in fossil fuel burning.
The Anthropocene Working Group was convened by the ICS in 2009 to sort out the definition of the Anthropocene and assess whether the time interval should be formally added to the geologic time scale. Among its 35 members, the working group contains an international mix of geologists, climate scientists, archaeologists and other experts.
In January, members of the working group published a review of evidence for the Anthropocene in Science. Pro-Anthropocene arguments come from multiple areas of science, from biology to climate to chemistry, the researchers reported. For instance, humans have introduced species such as the domestic chicken worldwide and driven many others to extinction (SN Online: 8/26/15). Emissions from human activities such as fossil fuel burning have altered Earth’s climate (SN: 4/16/16, p. 22). Manufactured materials such as plastics, aluminum and concrete will remain embedded in the ground as “technofossils.” Fallout from nuclear weapons tests has left a radioactive mark in soil, marine sediments and even ice. These human impacts make the Anthropocene distinct in the stratigraphic record from the Holocene, the researchers concluded.
For the Anthropocene to become official, the working group will have to establish a starting point for the proposed epoch. That can be accomplished by picking a nice round number — the Hadean-Archean switchover is an even 4 billion years ago, for instance — or by linking the starting point to a physical marker in the global sedimentary record, an approach now favored by ICS.
The marker for the start of the Holocene, for instance, is linked to chemical and physical changes in the Greenland ice sheet caused by the warming that brought Earth out of its last bout of glacial growth. Such markers — also called “golden spikes,” similar to the ceremonial spike that marked the union of the first U.S. transcontinental railroad — are chosen for being ubiquitous and consistent throughout the world. Golden spikes are not necessarily important or even relevant to the differences that distinguish geologic time frames, says Stan Finney, a geologist at California State University, Long Beach, and former chair of the ICS. For instance, the Thanetian Age — a 3.2-million-year stretch during the Paleocene Epoch — is marked by just one of many reversals in Earth’s magnetic field.
While a golden spike’s geologic signal may be global, the official physical spike itself is literally a single point in the stratigraphic record somewhere on Earth. (A single point avoids the problem of using multiple points that could end up having different ages, muddling the time boundary.) The golden spike for the Holocene is inside an ice core collected from Greenland and kept chilled in a freezer at the University of Copenhagen.
The need for a golden spike shaped the working group’s Anthropocene proposal, Zalasiewicz says. While phases in human history such as early agriculture and the Industrial Revolution have had profound impacts on the planet, they didn’t have a simultaneous worldwide effect that could be used to mark the start of the new epoch. Had a major volcanic eruption spewed a distinctive layer of ash across the globe near the start of the Industrial Revolution, “it would have been a pretty good candidate,” Zalasiewicz says. Even though the eruption would have had nothing to do with human activity, the ash would have been a ubiquitous and easily identifiable marker for geologists.
Radioactive carbon and plutonium blasted from the ramp up in atmospheric nuclear tests during the 1950s is another story. And the timing is so recent that it opens up many new places to hunt for the proposed epoch’s golden spike, including in living organisms such as trees and corals. “We’re a bit like confused kids wandering around an enormous sweetshop wondering how we’re going to choose,” Zalasiewicz says.
Even if the group finds a golden spike, its proposal will face criticism from scientists who contend that the Anthropocene doesn’t warrant its own epoch. Radioactive fallout “is a widespread marker that qualifies for the rules that they need to follow to make a recommendation,” says William Ruddiman, a professor emeritus at the University of Virginia in Charlottesville, “but that doesn’t mean that it’s right, or that it makes sense.”
Not enough time has passed since the proposed start date of the Anthropocene to have enough perspective to put the observed changes in the sedimentary record in proper context, Autin says. “A lot of stratigraphers would say that maybe in thousands or millions of years there will be a distinctive demarcation in the rock record at this point in time, but right now it’s a proposal that’s premature.”
Placing the boundary so recently is “dubious, to say the least,” agrees Mike Walker, a professor emeritus at the University of Wales Trinity Saint David who helped establish the golden spike that represents the start of the Holocene. Divisions of geologic time “should have a utility for geoscientists, archaeologists, anthropologists, et cetera,” he says. “I see little of value to the wider science community in an epoch boundary at A.D. 1950.”
The formalization of the Anthropocene is not just scientifically motivated, but also driven by a desire to highlight humankind’s impact on the environment, suggests Lucy Edwards, a geologist with the U.S. Geological Survey in Reston, Va. “It’s a meme,” she says. “The thinking is that if you have a concept and you give it a new word, it carries more weight.”
The motivation behind the newly announced proposal isn’t overly focused on humankind being to blame for recent changes, Zalasiewicz responds. “If we had all the same changes, but caused by something else, like volcanoes or a meteorite or my cat, then it would be just as significant.”
More time isn’t needed to recognize that modern sediments are unique, he adds. After all, he says, if humans had been around 50 years after the environmental catastrophe that wiped out the dinosaurs about 66 million years ago, they would have clearly seen that Earth’s environment and ecology had permanently changed.
ORLANDO, Fla. — When sex chromosomes among common pill bugs go bad from disuse, borrowed bacterial DNA comes to the rescue. Certain pill bugs grow up female because of sex chromosomes cobbled together with genes that jumped from the bacteria.
Genetic analysis traces this female-maker DNA to Wolbachia bacteria, Richard Cordaux, based at the University of Poitiers with France’s scientific research center CNRS, announced September 29 at the International Congress of Entomology.
Various kinds of Wolbachia infect many arthropods, spreading from mother to offspring and often biasing their hosts’ sex ratios toward females (and thus creating even more female offspring). In the common pill bug (Armadillidium vulgare), Wolbachia can favor female development in two ways. Just by bacterial infection without any gene transfer, bacteria passed down to eggs can make genetic males develop into functional females. Generations of Wolbachia infections determining sex let these pill bugs’ now-obsolete female-making genes degenerate. Which makes it very strange that certain populations of pill bugs with no current Wolbachia infection still produce abundant females. That’s where Cordaux and Poitier colleague Clément Gilbert have demonstrated a second way that Wolbachia makes lady pill bugs — by donating DNA directly to the pill bug genes. The researchers, who share an interest in sex determination, have built a case that Wolbachia inserted feminizing genes into pill bug chromosomes. The bacterial genes thus created a new sex chromosome.
“Incredible,” said Steve Perlman after hearing the talk, not in disbelief but in wonder at the biology. Perlman, of the University of Victoria in Canada, studies symbiosis and parasitism and says this new example of far-flung gene transfer is part of “a big thing in the field now.” Such transfers provide exotic genetic variation that fuels evolutionary processes. Audience members Ellen Martinson and Vincent Martinson, both of the University of Rochester in New York, were themselves coauthors of a 2016 paper describing microsporidian fungus DNA that has become a venom gene in some wasps.
The world’s most minuscule machines operate on the molecular level and have won their creators the 2016 Nobel Prize in chemistry. The prize is shared between Jean-Pierre Sauvage of the University of Strasbourg in France, J. Fraser Stoddart of Northwestern University in Evanston, Ill., and Bernard Feringa of the University of Groningen in the Netherlands.
Sauvage and colleagues first linked two ring-shaped molecules together in 1983 to form a necklacelike chain. In 1991, Stoddart’s team created an atom-scale axle, paving the way to build molecular “muscles” and “elevators.” Through electrochemistry, Feringa and colleagues powered up the first light-powered molecular motor in 1999 and even designed a four-wheel drive, nano-sized car.
These fantastic machines have opened up the molecular world to manipulating and moving objects at the smallest levels imaginable. There are “endless opportunities,” Feringa said in a phone interview during the announcement ceremony.
Scaling up from one cell to many may have been a small step rather than a giant leap for early life on Earth. A single-celled organism closely related to animals controls its life cycle using a molecular toolkit much like the one animals use to give their cells different roles, scientists report October 13 in Developmental Cell.
“Animals are regarded as this very special branch, as in, there had to be so many innovations to be an animal,” says David Booth, a biologist at the University of California, Berkeley who wasn’t part of the study. But this research shows “a lot of the machinery was there millions of years before animals evolved.” Multicellular organisms need to be able to send messages between their cells and direct them to particular roles within the body. That requires a great deal of cell-to-cell coordination — something that unicellular organisms don’t have to deal with. But an amoeba (Capsaspora owczarzaki) employs many of those same tricks to switch its single-celled body between different life stages. That means that the earliest animals were probably “recycling mechanisms that were already present before,” says study coauthor Iñaki Ruiz-Trillo, a biologist at the Institute for Evolutionary Biology in Barcelona.
C. owczarzaki goes through three different life stages, acting independently in some stages and aggregating with other amoebas in others. Ruiz-Trillo and colleagues analyzed C. owczarzaki’s proteome — its complete set of proteins — during each life stage.
The amoeba made different amounts of its proteins in each life stage, the team found, suggesting that it was responding to new demands. But it went a step further, too, also shifting the way its proteins behaved during each stage.
Proteins can change their behavior by grabbing on to a molecular fragment called a phosphate ion. The phosphate ion’s effect depends on where it sticks to the protein and whether there are other phosphate ions stuck on nearby. C. owczarzaki showed distinct differences in the pattern of these phosphate add-ons between its three life stages. That parallels what’s seen in animals: Proteins in different organs within the same animal show similar modification differences.
The researchers also found changes in the molecules that control the protein modification process. Certain enzymes within a cell act like molecular concierges, helping phosphate ions latch on to proteins. The type of enzyme often determines where the ion sticks — and thus the effect it has. For instance, enzymes called tyrosine kinases often guide modifications that help multicellular organisms send messages between cells. Those enzymes aren’t thought to be widely used by single-celled species, says study coauthor Eduard Sabidó, a biologist at the Centre for Genomic Regulation in Barcelona. But C. owczarzaki uses these enzymes across all of its life stages, generating them in different quantities depending on the stage. Previous research showed that other single-celled organisms had the genes for tyrosine signaling, but this study shows how widely it’s actually used and how closely it’s linked to specific life changes, says Booth.
The shared molecular mechanisms suggest that the unicellular common ancestor of today’s animals and C. owczarzaki probably used these same tricks, too, paving the way for multicellular life. That’s not to say animals don’t get any credit, says Sabidó — they’ve expanded this toolkit further over time. But the perceived chasm between a simple single-celled existence and a complex multicellular one might not have required a flying leap to cross. “This gap,” Sabidó says, “maybe isn’t such a gap.”
To the bafflement of birders, yellow-shafted flickers (Colaptes auratus auratus) sometimes sport red or orange wing feathers.
Scientists have suggested that the birds, which inhabit eastern North America, might be products of genetic variation affecting the carotenoid pigments that produce their flight-feather colors. Alternatively, the birds might be hybrids from mixing with a subspecies that lives in the west, red-shafted flickers (Colaptes auratus cafer). Despite decades of study, no clear-cut explanation has emerged.
It turns out that diet may be to blame. Jocelyn Hudon of the Royal Alberta Museum in Canada and her colleagues tested the red flight feathers from two yellow-shafted flickers and found traces of rhodoxanthin, a deep red pigment found in plants, and a potential metabolite. This suggests that the birds’ bodies break down rhodoxanthin — a clue that the pigment enters the body through food. Spectral and biochemical tests of feathers from museum collections also point to rhodoxanthin and suggest that the pigment may mess with yellow carotenoid production as well.
Yellow-shafted flickers probably pick up the red pigment when they eat berries from invasive honeysuckle plants, which contain the ruby pigment and produce similar red hues in other birds, the researchers write October 12 in The Auk. The plants also happen to produce berries just around the time that flickers molt their flight feathers.
The Schiaparelli Mars lander, missing in action since its October 19 descent, dinged the surface of the Red Planet. A black spot framed by dark rays of debris mark the lander’s final resting place, the European Space Agency reports online October 27. Its parachute, still attached to the rear heat shield, lies about 1.4 kilometers to the south, new images from the Mars Reconnaissance Orbiter show. The front heat shield, ejected about four minutes into the descent, sits roughly 1.4 kilometers to the east of the impact site.
Radio contact with Schiaparelli was lost about 50 seconds before its planned landing. Early analysis of data from the lander indicate that the parachute was jettisoned prematurely and that the landing rockets shut off just a few seconds after igniting. Engineers with ESA’s ExoMars mission are still analyzing that data to understand what went wrong.
Global emissions of carbon dioxide won’t increase much in 2016 despite overall economic growth, newly released bookkeeping suggests. The result marks a three-year-long plateau in the amount of CO2 released by human activities, scientists from the Global Carbon Project report November 14 in Earth System Science Data.
The group’s projected rise in CO2 emissions of 0.2 percent for 2016 is far lower than the rapid emissions growth of around 2.3 percent annually on average from 2004 through 2013. Emissions increased by about 0.7 percent in 2014 over the previous year and remained largely flat in 2015.
China is largely responsible for the emissions slowdown, the researchers write. The country is the world’s largest carbon dioxide emitter and is projected to reduce its CO2 emissions by 0.5 percent this year.
SAN ANTONIO — The world’s earliest alphabet, inscribed on stone slabs at several Egyptian sites, was an early form of Hebrew, a controversial new analysis concludes.
Israelites living in Egypt transformed that civilization’s hieroglyphics into Hebrew 1.0 more than 3,800 years ago, at a time when the Old Testament describes Jews living in Egypt, says archaeologist and epigrapher Douglas Petrovich of Wilfrid Laurier University in Waterloo, Canada. Hebrew speakers seeking a way to communicate in writing with other Egyptian Jews simplified the pharaohs’ complex hieroglyphic writing system into 22 alphabetic letters, Petrovich proposed on November 17 at the annual meeting of the American Schools of Oriental Research. “There is a connection between ancient Egyptian texts and preserved alphabets,” Petrovich said.
That’s a highly controversial contention among scholars of the Bible and ancient civilizations. Many argue, despite what’s recounted in the Old Testament, that Israelites did not live in Egypt as long ago as proposed by Petrovich. Biblical dates for the Israelites’ stay in Egypt are unreliable, they say. Scholars have also generally assumed for more than 150 years that the oldest alphabetic script Petrovich studied could be based on any of a group of ancient Semitic languages. But not enough is known about those tongues to specify one language in particular. Petrovich’s Hebrew identification for the ancient inscriptions is starved for evidence, said biblical scholar and Semitic language specialist Christopher Rollston of George Washington University in Washington, D.C. There is no way to tell which of many Semitic languages are represented by the early alphabetic system, Rollston contended.
The origins of writing in different parts of the world — including that of the alphabet carved into the Egyptian slabs — have long stimulated scholarly debates (SN: 3/6/93, p. 152). A German scholar identified the ancient Egyptian writing as Hebrew in the 1920s. But he failed to identify many letters in the alphabet, leading to implausible translations that were rejected by researchers.
Petrovich says his big break came in January 2012. While conducting research at the Egyptian Museum in Cairo, he came across the word “Hebrews” in a text from 1874 B.C. that includes the earliest known alphabetic letter. According to the Old Testament, Israelites spent 434 years in Egypt, from 1876 B.C. to 1442 B.C. Petrovich then combined previous identifications of some letters in the ancient alphabet with his own identifications of disputed letters to peg the script as Hebrew. Armed with the entire fledgling alphabet, he translated 18 Hebrew inscriptions from three Egyptian sites.
Several biblical figures turn up in the translated inscriptions, including Joseph, who was sold into slavery by his half-brothers and then became a powerful political figure in Egypt, Joseph’s wife Asenath and Joseph’s son Manasseh, a leading figure in a turquoise-mining business that involved yearly trips to Egypt’s Sinai Peninsula. Moses, who led the Israelites out of Egypt, is also mentioned, Petrovich says.
One inscription, dated to 1834 B.C., translates as “Wine is more abundant than the daylight, than the baker, than a nobleman.” This statement probably meant that, at that time or shortly before, drink was plentiful, but food was scarce, Petrovich suspects. Israelites, including Joseph and his family, likely moved to Egypt during a time of famine, when Egyptians were building silos to store food, he suggests.
A book by Petrovich detailing his analyses of the ancient inscriptions will be published within the next few months. Petrovich says the book definitively shows that only an early version of Hebrew can make sense of the Egyptian inscriptions.
SAN ANTONIO — A roughly 3,000-year-old cemetery on Israel’s coast is providing an unprecedented look at burial practices of the Philistines, a mysterious population known from the Old Testament for having battled the Israelites.
Work at the Ashkelon cemetery from 2013 to 2016 has uncovered remains of at least 227 individuals, ranging from infants to older adults. Only a small section of the cemetery has been explored. Archaeologist and excavation director Adam Aja of the Harvard Semitic Museum estimates that approximately 1,200 people were interred there over a span of about 100 years. “For the first time, we have found a formal Philistine cemetery,” Aja said November 18 at the annual meeting of the American Schools of Oriental Research. Aja and his colleagues first announced having found the Philistine graveyard on July 10. He was among several researchers to present their latest findings about the cemetery at the meeting.
Despite the new discoveries, the geographic origins of the Philistines remain unknown, Aja said. It’s also unclear how early Philistines reached the Middle East or how much their culture changed by the time they started burying their dead at Ashkelon.
Philistine burial practices have been discussed and debated for about a century. Other ancient Philistine sites in Israel, also identified in ancient texts, have yielded individual graves and small-scale burial grounds.
At Ashkelon, the dead were interred in several ways. Most individuals were placed in shallow pits, often with pairs of jugs or storage containers near the bodies. Some pits contained a person’s remains that had been buried on top of one or more previously interred bodies. Bronze earrings, bracelets, rings and other jewelry adorn most skeletons of children and women. Several pit graves of male skeletons include ornamental beads or engraved stones.
One grave holds a set of iron arrows near a man’s hip. A quiver probably once held the arrows at the man’s side, Aja suggested. Researchers also uncovered ashes and bone fragments from six human cremations in sealed jars placed in pit graves.
At least eight stone burial chambers capped with stone slabs were also found. The largest chamber held skeletons of 23 individuals. These burial chambers were aligned in three rows that ran parallel to the coast, Aja said.
Tapered storage jars found in pit graves and burial chambers were influenced by pottery of the Canaanites, a nearby population along the Mediterranean coast, said team member Janling Fu of Harvard University.
Fu suspects the excavation is located at the cemetery’s edge. Considerable space between some burials suggests denser clusters of grave sites lie nearby, he proposed, raising the prospect of learning much more about how the Philistines treated their dead.
Although the excavation is in its early stages, it’s clear that Philistines buried at Ashkelon show signs of physiological stress, reported bioarchaeologist and team member Sherry Fox of Eastern Michigan University in Ypsilanti. Many individuals’ teeth have signs of growth interruptions caused by fever, malnutrition or a range of possible biological disorders, she said.
Relatively short average heights for people buried at Ashkelon — about 5 feet, 1 inch for men and 4 feet, 10 inches for women — also fit a scenario of biological stress, Fox said. Short stature and minimal height differences between men and women occur with population-wide stresses such as malnutrition, she said.
The Philistines were a famously combative crowd. Archaeologist Eric Meyers of Duke University, who was not a member of the Ashkelon team, wondered if at least some of those buried at Ashkelon had been killed in battles or fights. But no head injuries or other skeletal signs of violent encounters appeared among the dead at Ashkelon, Fox said. Neither did any skeletons contain evidence of tumors or cancers.
If DNA can be extracted from the Ashkelon skeletons, scientists may get a glimpse of where the Philistines originally came from. Evolutionary geneticist Johannes Krause of the Max Planck Institute for the Science of Human History in Jena, Germany, is currently directing efforts to retrieve genetic sequences from the Ashkelon bones.
