By Azadeh Ansari, CNN
Everyone knows dinosaurs were gigantic, but they grew from tiny embryos just like birds do. What were these extinct reptiles like at this early stage of development?
Scientists have found some new clues that could shed light on this age-old mystery.
In a study published Wednesday in the journal Nature, scientists said they have discovered the oldest known collection of fossilized dinosaur embryos.
"In a way, I think we have set a new standard for dinosaur embryology," said paleontologist Robert Reisz, the lead study author.
Brazilian health authorities have taken the lead in the fight against dengue fever not with vaccines but rather with mosquitoes. At the start of this week they expanded their program and opened a large-scale mosquito farm in the northeast state of Bahia.
Now, these are not the garden-variety mosquitoes, they are an army of genetically modified male mosquitoes being used to combat, rather than spread, disease. In the laboratory, male mosquitoes are genetically modified to carry a lethal gene against the dengue virus. They are then released into the wild to mate with female mosquitoes (who are actually the ones who bite humans – since they need the blood for their eggs) and once the lethal gene is passed on to the offspring they die in the larvae stage and never make it to adulthood.
The target is dengue fever, for which there currently is no vaccine, and prevention largely has failed.
The first modern humans in Europe perhaps did more than hunt and gather. They may have been artistically inclined, according to a new study.
Scientists involved in the research, to be released Friday in the journal Science, found cave art that dates back thousands of years earlier than previously thought. The team of researchers said the findings imply the paintings were created either by the first anatomically modern humans in Europe or, perhaps, by Neanderthals.
"This currently is Europe's oldest dated art by at least 4,000 years," said archaeologist and lead author of the study Alistair Pike in a press conference to reporters.
The Caribbean islands are more than a tourist hot spot; they are also breeding grounds for some of the most diverse species of lizards, many of which are also on the verge of extinction, scientists say.
Twenty-four species of lizards, known as skinks and never before identified, slithered into the scientific textbooks this week.
“For all these years working in the Caribbean, I just assumed that these skinks had not evolved very much in this specific region. It’s a real surprise to find this diverse fauna of lizards,” said Blair Hedges, a Penn State University evolutionary biologist and lead author of the study identifying these previously unknown species of skinks.
Skinks have snakelike bodies with small, smooth and round scales, but they are different than most other reptiles because they have a lengthy gestational period like humans.
“There are other lizards that give live birth, but only skinks make a placenta and carry their offspring for up to one year,” Hedges said.
The discovery of a partial foot fossil in Ethiopia suggests that our human ancestors were possibly an occasional tree-climber and an occasional upright walker.
In a search for additional clues on how and when our ancestors stopped climbing trees and started walking on two feet, scientists went to the central Afar region in Ethiopia. It’s home to some of the world's richest fossil and artifact sites, including the famous Hadar site. “Lucy,” the partial ape-human skeleton, was excavated at Hadar in 1974.
About 30 miles north of Hadar in 2009, scientists excavated a surprising set of foot bones at the Burtele palaeontological site. Scientists spent the next three years analyzing their findings before reaching a moment of eureka.
“For the first time, we have good evidence that there is indeed another hominin lineage that lived at the same time as Lucy’s species,” study co-author Bruce Latimer said in a scientific news briefing. He is an anthropologist at Case Western Reserve University in Cleveland.
Newly identified partial skeletons of "mysterious humans" excavated at two caves in southwest China display an unique mix of primitive and modern anatomical features, scientists say.
"Their skulls are anatomically unique. They look very different to all modern humans, whether alive today or in Africa 150,000 years ago," said evolutionary biologist Darren Curnoe, the lead author of the study, from the University of New South Wales in Australia.
The fossils found at excavation sites in Longlin Cave, in Guangxi Province, and the Maludong Cave, in Yunnan Province, indicate that the stone-aged people had short, flat faces and lacked a modern chin. They had thick skull bones, a rounded brain case, prominent brow ridges and a moderate-size brain.
The oldest and largest crater in the solar system - The South Pole-Aitken basin - sheds new light on understanding how the Earth-Moon system possibly formed and evolved, scientists say.
The first measurement of magnetic fields on the moon's surface was done in 1969 during the Apollo 12 mission. Since lunar rocks are not very magnetic, scientists say the discovery of the strong, localized magnetic fields did not correlate with any geologic structures or known processes.
For decades, scientists have scratched their heads trying to pinpoint the origin of the moon's magnetic fields. They quite literally became "moonstruck" with the idea.
Experiments on naked mole-rats may lead to better treatments with fewer side effects for humans suffering from painful inflammatory arthritis, according to a new study published Friday in the journal Science.
The partially blind, hairless, wrinkly, cold-blooded mammals were good candidates for the study because of their unique insensitivity to acid-induced pain.
Native to sub-Saharan Africa, the naked mole-rat makes its home burrowed deep in huge colonies in underground tunnels, with access to very little oxygen and high levels of carbon dioxide.
“Exposure to high levels of carbon dioxide in turn would evoke acidosis, but the naked mole-rat has evolved in a way to manage this acid load and to be able to live in acidic environments, which for most other rodents in the world would be uninhabitable,” said neuroscientist Ewan St. John Smith, the lead author of the study.
Scientists say in most mammals - including humans - exposure to acid stimulates special channels at the tips of sensory neurons, called nociceptors. Once these nociceptors are activated, they transmit a signal along the spinal cord to the brain.
But among naked mole-rats, although acid triggers the nociceptors, their pain-sensing neurons contain proteins with genetic mutations that prevent neurons from firing off pain signals in response to acid.
Inflammatory disorders, such as arthritis, are normally associated with acidosis, scientists say.
“If a drug could now be developed which acts on these particular proteins on the sensory neurons, you could limit the ability of acid to cause pain in patients with arthritis and other inflammatory disorders,” Smith said.
According to the Centers for Disease Control and Prevention, an estimated 50 million U.S. adults (about 1 in 5) report doctor-diagnosed arthritis. That number is projected to increase to 67 million by 2030.
“We can learn a lot from comparative physiology. By understanding how an animal adapts to its environment, this will teach us a lot of our own biological system,” said neuroscientists Gary R. Lewin, one of the authors of the study, conducted by the Max Delbrück Center for Molecular Medicine in Germany.
The naked mole-rat has been the subject of other groundbreaking studies. The buck-tooth rodent has been found to have an unusually long life span; it can live three years longer than other rodents and is resistant to cancer.
Most recently, scientists sequenced and analyzed the entire genome, which Smith and his colleagues hope to be able to use for their next phase of research.
"It’s cool to know how things work, especially when things don’t work as you expect them to,” Smith said.
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Scientists said Tuesday that they’re a little bit closer to answering one of the biggest questions of particle physics: Does the so-called God particle exist?
Gathering in Geneva, Switzerland, experts from around the world revealed results of their search for the particle – known officially as the Higgs boson - using the Large Hadron Collider, the world’s largest atom smasher.
The Higgs boson, which has been theorized but never glimpsed, plays a fundamental role in the workings of our universe. One expert called it the “missing piece of the jigsaw.”
Scientists at Tuesday's event said they had made strides in their search for the Higgs boson but did not have strong enough conclusions to claim a discovery.
“The first important results are that we have been able to restrict the most likely mass region over the last months to a very narrow range,” Fabiola Gianotti said Tuesday at the European Organization for Nuclear Research, known as CERN. “In this mass region, we see some excessive events. It’s too early to tell if this excess is due to a fluctuation in the background or something more interesting.”
The collider fires together protons, which are positively charged particles that make up all atoms that can interact in many different ways. Scientists are looking very closely for a "Higgs bump," which is "literally a bump in a graph which will pop up and say, 'that's it!' " said physicist Martin Archer of the Imperial College of London.
Related: Higgs coming into focus
"It is too early to draw a definite conclusion. More studies and more data are needed. We have built solid foundations for the exciting months to come," Gianotti added. “We are discussing something, which is the last chapter we hope for a story which lasts since 47 years.”
Two groups of scientists worked independently on different parts of the hydrogen collider to watch and analyze the particle collisions.
Scientists say Higgs boson particles won’t be discovered by actually observing the particles themselves. They will be discovered by observing how other particles react to them.
"As of today, what we see is consistent either with a background fluctuation or with the presence of the boson,” said Guido Tonelli, another scientist who participated in the research. “Refined analyses and additional data delivered in 2012 by this magnificent machine will definitely give an answer.”
The Standard Model is the theory physicists use to describe the behavior of fundamental particles and the forces that act between them. It describes the ordinary matter from which we, and everything visible in the universe, are made and does it extremely well. Nevertheless, the Standard Model does not describe the 96% of the universe that is invisible: so-called Dark Matter. One of the main goals of the collider's research program is to go beyond the Standard Model, and the Higgs boson could be the key, CERN scientists explained.
“The very good news that we know from today that in the next year, it’s very likely we might get an answer that we could consider solid,” Tonelli said.
New clues about early star formation are putting a twinkle in astronomers’ eyes this week.
Researchers have discovered clouds of primordial gas from 2 billion years after the Big Bang that confirm what had only been theorized: that early star formations consisted only of the three lightest elements on the periodic table. The study is published in the journal Science.