Science at Atheist Universe
PLUG OF THE WEEK: The NAKED APE Video Thread. We are collecting here great videos from scientists and other experts, on the science and cultural evolution of human psychology, behavior, cognition, language, memory, intelligence, emotion, and consciousness. Here is one such video to whet your appetite; please check the whole discussion out, and post interesting stuff you find around the web!
Two very interesting discussion posts on animals using “language”!
ANIMAL BEHAVIOR: Parrots call each other using individual "names" in the wild. Parrots are known for their intelligence and of course, their unique ability to imitate all kinds of sounds, including human speech. Their capacity to imitate serves a purpose in the wild too. Scientists have now determined that parrot parents pass on vocal signatures to their offspring, similar to us human parents giving names to our kids. By imitating the vocal signature of a specific parrot, the parrot who is calling out the "name" gets the other bird's attention. Although the specific signature call was given by parents to the offspring, it is not biological, but rather, social, learned, since adoptive parents passed on their signature calls to foster baby parrots.
Chimp recognizes synthetic speech. A female chimpanzee called Panzee can recognize distorted and incomplete words spoken by a computer, just like humans can. The finding suggests that the common ancestor of humans and chimps may have possessed the ability to perceive spoken sounds. It also refutes the hypothesis that humans are the only animals with brains specifically and uniquely evolved to process speech. Panzee was raised by humans and treated as if she was human. She was taught to use symbols called lexigrams to communicate. She can understand approximately 130 English words. Graduate student Lisa Heimbauer, an author in the study, explained that many scientists believe humans have a unique ability to produce and perceive speech, and that this is due to a specialized cognitive module that processes speech. The fact that humans can understand human speech even when distorted (as in spoken by a machine, or with an altered frequency), is taken as evidence of this uniquely human ability to process language. But, Heimbauer explains, an alternative view is that auditory processing is very important for most mammals, and that therefore t is fundamentally similar across mammals. Heimbauer and colleagues were able to test Panzee’s ability to recognize distorted or incomplete spoken words because she had been previously trained to use lexigrams. They used noise-vocoded speech, which alters the frequencies of the spoken words and results in a sound similar to what people with cochlear implants hear. They also played for her sine-wave speech, which is synthesized from just three tones. Humans can understand both types of distorted speech. Although her recognition was not 100%, Panzee recognized the distorted spoken words far more often than she should by chance. Naturally, her upbringing and training from an early age appears to have given her enough experience of hearing and understanding spoken words to allow her to recognize them when they are distorted. The scientists think this highlights the importance of early experience in shaping speech perception.
EVOLUTION: Fish fins and mouse feet controlled by the same ancient genetic switch. Great post by Ed Yong on homeobox genes, i.e. those genes that regulate body patterns. Unsurprisingly, but still very, very cool to have experimental evidence, the genetic switch that controls the homeobox (Hox) genes that make a fish's fin can also make a mouse's paw, if introduced in mice, and vice versa: the mouse genetic switch for the Hox gene, when introduced in the fish, can make a fin. Voilà, it is this simple. The genetic controls for making a limb are interchangeable in vertebrates that have been separated by hundreds of millions of years of evolution. Yes: that switch was present way before vertebrates ventured out on land. Evolution, baby. You can't beat that.
ASTRONOMY: White dwarfs caught in a fatalistic dance. Via PHYSORG: White dwarfs are believed to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star, over 97% of the stars in our galaxy, including our Sun are candidate white dwarfs. Astronomers have discovered a pair of white dwarfs spiraling into one another at very high speeds. Today, these white dwarfs make a complete orbit in just 13 minutes, and they are gradually slipping closer together. About 900,000 years from now, a blink of an eye in astronomical time, they will merge and possibly explode as a supernova. But we don’t have 900,000 years learn from these white dwarfs that are dancing to their own demise and rebirth as a supernova: in the meantime, by studying how they are converging, astrophysicists will gather data to test both Einstein's theory of general relativity and the origin of some peculiar supernovae, called underluminous supernovae (faint stellar explosions). General relativity predicts that moving objects will create ripples in space-time, called gravitational waves. Measuring the change in the separation of these two stars can test the existence of these waves. This first test will take place in ~ 2 months, when the dancing stars emerges from behind the Sun.
MATHEMATHICS: Playing games with infinity. As a kid, I was fascinated by the number infinity. It is hard for us humans to wrap our minds around the concept of infinity. But mathematics makes it possible of course. And fun. I found this great article on the "Hilbert Hotel"; I hope you enjoy it too. Here’s the deal: the Hilbert Hotel is always booked solid, yet there’s always a vacancy, because the Hilbert Hotel has an infinite number of them. Whenever a new guest arrives, the manager shifts the occupant of room 1 to room 2, room 2 to room 3, and so on. That frees up room 1 for the newcomer, and accommodates everyone else as well. Now suppose infinitely many new guests arrive; the unflappable manager moves the occupant of room 1 to room 2, room 2 to room 4, room 3 to room 6, and so on. This doubling trick opens up all the odd-numbered rooms, infinitely many of them, for the new guests. Later that night, an endless convoy of buses rumbles up to reception. There are infinitely many buses, and worse still, each one is loaded with an infinite number of crabby people demanding that the hotel live up to its motto, “There’s always room at the Hilbert Hotel.” What should be done? Don’t miss the conclusion! Hint: some infinities are bigger than others. Happy math headache!
LAST, BUT NOT LEAST: Category: “Science politics”: Genomics for the entire world: it's time to study non-Europeans, too. Nature has a very good article, written by three top genomic scientists, from Stanford and UCSF (Carlos Bustamante, Esteban González Burchard and Francisco de la Vega), highlighting how 96% of the human genomes being sequenced belong to people of European descent. This may not be that relevant if science had shown that the difference in allele frequencies for rare variants was not that big between people with different geographic ancestry. However, it is big enough that most of the rare variants identified in Europeans are not found in Han Chinese or Yoruba people, as an example. Why are rare variants important? Rare variants are a sought after group for medical genomics: rare variants in different combinations may explain the genetic risk for complex diseases such as cardiovascular disease and diabetes. The way to find these associations with risk is to sequence groups of diseased and healthy individuals and see what "pops out" in terms of rare variants found in one group vs. the other. But if we don't even know which are the rare variants in non-Europeans, the vast majority of the population of our planet will simply miss out on the medical genomics revolution and its implications for worldwide health. The three scientists exhort those agencies that grant funds for genomic research to demand that a variety of people from different geographic backgrounds are included in sequencing efforts. I could not agree more.
Science bits and news from other sites:
What’s new about new synthetic organs? The world’s first synthetic organ transplant. Everyone knows how difficult it is to find available donated organs for patients in need of transplantation. Biomedical engineers have been investigating the possibility of growing organs in the lab for quite some time. Last month, the world’s first transplantation of a biosynthetic organ, a trachea, took place in Barcelona. This week it was reported that the recipient, Andemariam Teklesenbet Beyene, who had cancer, is doing great one month after the surgery and is cancer-free. The surgeon was Dr Paolo Macchiarini, from the University of Barcelona. Alex Seifalian’s team at University College London built the trachea in the lab. The scientists first built a scaffold specially fitted for the patient, made of a special nanocomposite material, with millions of tiny holes. The scaffold was incubated with adult stem cells from the patient (therefore eliminating the risk of rejection). The cells seeded the scaffold, thanks to the large surface area provided by the microscopic holes. Tracheas grown in the lab had been transplanted before, but the scaffold used was a trachea from a donor who had died. The biggest breakthrough here is that the scaffold was generated from scratch from a nanomaterial; this allows the new organ to be made to order, and no wait time is necessary. The next challenge will be to grown organs that are not tubes in the lab. Hollow organs are “easier” because they can be grown around a mold. More complex organs are a bigger challenge in terms of designing a synthetic scaffold.
Whales and Fish Adapt to Climate-Induced Changes in the Pacific Ocean Climate change is affecting the ecology of the world’s oceans, but at least this week there was some good news regarding the Pacific Ocean. Scientists recently found that gray whales can feed at both seafloor and surface levels. This flexibility has allowed them to survive fluctuations in food supply during a series of glacial periods, over the past 120,000 years. The ability of this cetacean to survive major ecological shifts in the past suggests they will be able to deal with changes in the climate in the future as well. The study was published in the journal PLoS ONE. Most gray whales are bottom feeders and migrate annually from Mexico to Alaska. The scientists found that gray whales off the coast of Vancouver Island, become resident in the location, do not migrate feed on krill and herring nearer to the ocean surface when necessary. This means the whales have retained their ancestors’ ability to feed on the surface. In another study, to be published soon, scientists found that a number of fish species are adapting to climate change by moving further north to cooler waters. A Canadian and U.S. team of scientists examined the distributional changes of 28 species of fish including salmon, herring, certain species of sharks, anchovies, sardines and more northern fish like pollock, and found they all moved north by about 25 miles a decade. The danger here is that some of these species some will move into waters which could contain less food. But the more drastic adjustments, he said, could involve those living on land along the West Coast. These changes in the distribution of fish population will have a very big impact on fishermen, who will have to travel further north and spend more fuel in order to reach the fish.
A rare half-male half female butterfly is born in London. This amazing butterfly hatched at the Museum of Natural history in London. As you can see, a longitudinal line down the insect's body, exactly in the middle, marks the division between its male side and its female side (the female side is the beautifully colored side). The insect is a rare chimera, a gynandromorph in technical terms, resulting from failure of the butterfly's sex chromosomes to separate during fertilization. The double-sexed butterfly is Papilio memnon, an Asian species. After its natural life of one month, the butterfly will be preserved in the museum’s collection. The split is not only superficial, its sexual organs are half and half, and even its antennae are different lengths. Though rare (0.01% occurrence), gynandromorphy isn't unique to butterflies; it has been described in other arthropods, such as crabs and lobsters, as well as in chickens.
Once thought extinct, rainbow toad is spotted after 87 years. This is the most beautiful amphibian I’ve ever seen. I did not even know it existed! The striking Bornean rainbow toad (Ansonia latidisca) has been seen for the first time since the 1920s and finally caught on camera. Previously, the only image of the toad was a black and white drawing, but we can now see that the toad clearly deserves its title. The spectacular species was one of Conservation International’s ‘ten most wanted amphibians’ and was rediscovered in Malaysia by a team led by Indraneil Das from Malaysia Sarawak University (UNIMAS). The discovery comes as part of a CI search for lost amphibian species launched in August 2010, which, in its first five months, supported expeditions by 126 researchers in 21 different countries. The search mission is targeting 100 amphibians not seen for more than 10 years and aims to update the conservation status of these elusive species.