Archaic Humans Are One With Us
August 12, 2011
According to the biological species concept, two varieties of anything are considered one species if they can interbreed and produce fertile offspring. Applied to humans, new evidence suggests that Neanderthals and the recently-discovered Denisovans were members of the human species. According to New Scientist, “On the western fringes of Siberia, the Stone Age Denisova cave has surrendered precious treasure: a toe bone that could shed light on early humans’ promiscuous relations with their hominin cousins.” Since one can only be promiscuous within the same species, this puts enormous pressure on evolutionary timelines that assume the Denisovans split from the Neanderthals 300,000 years ago.
Big Birds Lived with Dinosaurs
August 11, 2011
The largest flying bird is the California Condor with a wingspan of 2.9 meters. The largest flightless bird is the ostrich, up to 1.7 to 2.8 meters tall. These are shrimps compared to extinct birds that lived with dinosaurs. A fossil jaw from a Cretaceous bird has been found in Kazakhstan. The BBC News said, “If flightless, the bird would have been 2-3m tall; if it flew, it may have had a wingspan of 4m.” The find raises questions about what scientists know about the age of dinosaurs.
Playing Fast and Loose with Evolution
August 10, 2011
The word evolution gets used and misused often. Strictly speaking, neo-Darwinian evolution demands that mutations and natural selection operate with no foresight or oversight, no purpose or direction, no impetus toward a desired outcome. In actual practice, scientists and reporters play fast and loose with the term, making it into a designer substitute.
Is a Multiverse Detectable?
August 9, 2011
The idea of a multiverse (an ensemble of universes like our own visible one) has been criticized as unscientific because it would be unobservable, even in principle. Now, however, some theoretical physicists are claiming that bubble universes beyond ours could be detected in the cosmic microwave background radiation – provided they collide with our universe. Does this bring multiverse theory back into the realm of science?
Hobbits Were Brain Diseased Modern Humans
August 8, 2011
The discovery of fossils of miniature humans in Indonesia, designated Homo floresiensis but nicknamed Hobbits, was one of the most exciting and controversial announcements of 2004. Since then, interpretations of the fossils have fallen into two camps: those who think the skeletons represent normal humans with the brain-defective disease microcephaly, and those who think they represent evolutionary missing links. A new paper compared skulls of H. floresiensis with those of modern humans, Homo erectus, and humans with microcephaly. The result favors the interpretation that the Hobbits most likely were diseased modern humans.
When Science Gets Political
August 7, 2011
The classic view of the scientist as an unbiased observer of nature was shattered with the development of the atomic bomb. Suddenly, it became apparent to the physicists working out the equations of nuclear fission could not absolve themselves completely of responsibility for the political uses of their research. Yet since the days of the French Academy of Sciences in the 17th century, kings and other rulers have called on natural philosophers to inform their decisions. These days, scientific institutions state political opinions at will. Some recent news items show them inserting their opinions beyond what the data alone might indicate.
Cold Dinosaurs Resembled Warm Dinosaurs
August 6, 2011
Cold dinosaurs were just like warm dinosaurs, scientists have found. Species living in the Antarctic, with up to six months of winter darkness, show no major differences in bone structure than those who lived in temperate climates. This was a surprise that falsified earlier studies. Whatever adaptations the high-latitude dinosaurs had did not show up in their bone structure.
Pagan Gods Launched into Space
August 5, 2011
The latest Jupiter probe from NASA is named Juno, after the name of the wife of Jupiter, Roman chief of the gods. Launched today (August 5), the Juno spacecraft will use Earth for gravity assist in a complex path, to arrive at Jupiter in 2016, where it will study the largest planet from a polar orbit. As “part of a joint outreach and educational program developed as part of the partnership between NASA and the LEGO Group to inspire children to explore science, technology, engineering and mathematics,” according to a press release from the Jet Propulsion Lab, the spacecraft carries 1.5-inch likeness of three figures: Galileo Galileo, who discovered Jupiter’s moons, the Roman god Jupiter, and his wife Juno.
Another Crash in Lunar Tunes
August 4, 2011
Our moon has two faces. One is the familiar man-in-the-moon side that always faces Earth. The other side is mountainous and heavily cratered, possessing a thicker crust with almost none of the large impact basins we see as dark maria on the Earth-facing side. The giant impact theory for the origin of the moon – that a Mars-size object hit the Earth and the debris coalesced into our planetary companion – has been controversial since it was first proposed. Will adding another impact help? It all depends on what one means by “scientific progress.”
Poison Rat: Did It Evolve?
August 3, 2011
The African crested rat has a unique way of deterring predators. It licks the bark from a poisonous tree (the same one native hunters use to poison their darts), and licks it onto its fur. Any predator that tries to eat the rat becomes very sick, and quickly learns to keep its distance. This kind of defense has been seen in other animals, but is the first known case of a mammal using a substance from another organism to make itself toxic to predators. Is it a classic case of evolution?
Cell Chaperones Keep Proteins Properly Folded
August 2, 2011
Imagine linking together a chain of 300 plastic shapes, some with magnets at various places. Then let it go and see if you could get it to fold spontaneously into a teapot. This is the challenge that cells face every minute: folding long chains of amino acids (polypeptides) into molecular machines and structures for the cell’s numerous tasks required for life. DNA in the nucleus codes for these polypeptides. They are assembled in ribosomes in single-file order. How do they end up in complex folded shapes? Some polypeptides will spontaneously collapse into their native folds, like the magnetic chain in our analogy. Others, however, need help. Fortunately, the cell provides an army of assistants, called chaperones, to monitor, coax, and repair unfolded proteins, to achieve “proteostasis” – a stable, working set of proteins. That army is so well-organized and complex, scientists continue to try to figure out how it performs so well in the field.
Clue or Clueless on Plant Evolution
August 1, 2011
An article on The Scientist promised to provide “clues to plant evolution,” but the data seemed like clues to something else – namely, design. The article was about how plant proteins interact with one another – the “interactome” (another word to add to genome and proteome). Did the work actually fulfill evolutionary predictions? Even if they claim it did, did it really?
Brave New Chimeras
July 31, 2011
Tampering with human embryonic stem cells has been at the forefront of ethical debates for a decade. Behind it, though, lurks an even more alarming prospect: the creation of human-animal hybrids. As with embryos, the appeal has been to improve human health. But ethicists ask if there is any benefit worth blurring the line between humans and animals. Pro-chimera advocates admit there is a certain “disgust” factor that could arouse public anxiety, and agree that experimentation would need to be regulated. But who would regulate the regulators, and on what moral grounds?
Unique Mammal Senses
July 30, 2011
The ability to sense the environment is vital to all living things, and is a key characteristic that separates life from non-life. The senses are not limited to the five we learn as children – sight, hearing, touch, taste, and smell. In the animal kingdom there are more. Some of them repurpose existing organs; some detect other information from the world not detectable with the normal sense organs. In mammals, two very different animals – bats and dolphins – have expanded our understanding of sensation.
Earth Uniqueness Up; SETI Down
July 29, 2011
Our earth seems special – maybe because it is. Some astronomers are seriously considering that life might be rare or unique on our rare (or unique) planet. If so, hopes for finding sentient aliens on the celestial radio dial drop accordingly. The 50th anniversary of the first SETI search came, unfortunately for search enthusiasts, came at a time when funding is harder to get.