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.
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?
Weird Evolution Tales
July 27, 2011
Evolutionary theory leads to some fantastic tales. Since evolution is often presumed to be a fact that explains everything in biology, and is itself not subject to testing or doubt, everything in biology must be viewed through an evolutionary lens. This hard-core stance on evolution often leads to assertions and explanations that appear contrived, if not preposterous, to Darwin doubters. Here are some recent examples of weird evolution stories that made it past the logic inspectors simply because evolution is unquestioned.
Fossil Finds Feed Facile Fables
July 20, 2011
Remarkable fossils continue to come to science’s attention, yielding clues about past ecological conditions. Once in awhile, whole fossil specimens – even graveyards of many organisms – are uncovered, but most fossils are mere fragments. Placing fossils into interpretive stories requires knowledge of other fossils and comparisons with living species. Even then, the history of life is not directly observable. Fossils, being silent, can only show their current state; the lack of access to the past, combined with ignorance of all the clues, leaves room for alternative interpretations. Evolutionists, in their desire to fit fossils into a preconceived story, sometimes go far beyond what the actual fossil evidence is capable of saying – and some of their explanations border on the miraculous.
Body Language Says Design
July 17, 2011
Your body is speaking to scientists. Some of them hear it saying evolution. Others think it says intelligent design. What characteristics would each side expect? Most people intuitively know design when they see it. Here are three recent scientific papers that may help interpret body language.
Can evolutionary theory explain terrorism?
July 2, 2011
In military strategy, it is vital to know what the enemy is up to. Can evolutionary theory help? An interdisciplinary team at the University of Miami got their heads together and appealed to an evolutionary notion called the “Red Queen” hypothesis, and claimed it provides a “Pattern in Escalations in Insurgent and Terrorist Activity” that is neutral regarding the good guys and the bad guys. It resembles, they argue, how pedators and prey evolve in nature. They offer their model as a way military planners can have the ability “to estimate not only the number of fatalities but how often attacks that result in fatalities will take place.” They applied their pattern prediction to the wars in Iraq and Afghanistan. How robust is this notion, and should evolutionary theory take credit for it?
The Evolution of… Come Again?
July 1, 2011
Science news articles speak freely of the evolution of this or that, but the fine print often shows a disconnect with the evolution explanation. Can one speak of the evolution of something that has not changed for millions or years? The details in the following stories raise questions whether anything significant has evolved in the […]
Cells Have Dimmer Switches
June 30, 2011
A metaphor has been emerging among biophysicists: cells have rheostats or dimmer switches. The metaphor implies that some cellular regulatory processes are not just on or off; they have continuous ranges of values that can be finely tuned for the need of the organism. It's been years since our first report that gene expression is […]
Avoid Confusion: Disbelieve Paleoanthropologists
June 28, 2011
If you care about the true history of the human race, don’t believe paleoanthropologists. They are clueless and confused. Every solution they come up with creates new problems, and their boastful announcements are likely to be overturned. That’s the gist of a commentary in PNAS by Bernard Wood, who wrote, “The origin of our own genus remains frustratingly unclear.” He ought to know; he’s an eminent paleoanthropologist himself.
Follow the Leader: Nature
June 21, 2011
Ever since biomimetics (the imitation of nature) gradually emerged around 2002 and really took off in 2005, it has not slowed down. Over 90 previous entries in these pages have reported teams all over the world seeking out natural designs for ideas. The reports have accelerated in recent years to the point where there is only space for short summaries that give a taste of the wide variety of engineering work taking inspiration from plants, animals, and even cells. You yourself might inspire some inventor. Here are a few more highlights from recent adventures in biomimetics.
Stem Cell News
June 20, 2011
Stem cells continue to be hot subjects for research. They are divided into two basic “political” parties: embryonic stem cells (ES), which raise ethical issues about tampering with human life, and adult stem cells (AS), found throughout the body, which have no ethical issues and show the most progress for therapy. The latter include the induced pluripotent stem cells (iPS), coaxed from adult cells to recover the ability to differentiate into multiple tissue types. Even though AS is leading, some scientists are still demanding federal funding for ES.
Inner Ear Hair Cells Overcome Friction
June 19, 2011
The cochlea, that spiral-shaped structure in the inner ear, is filled with fluid. In this fluid, tiny hair cells called stereocilia are positioned in bundles along the length of the structure. These bundles sense vibrations transmitted into the fluid from the bony levers of the inner ear. The vibrations picked up by the hair cell bundles, each tuned to its own frequency, mechanically transduce the sound impulses by opening ion channels that set up electrical impulses in the auditory nerve, that travel to the brain. But motion in fluid creates friction known as viscous drag. How do the hair cell bundles overcome it? Scientists have figured out that the hair cells in the bundles are not only finely tuned to reduce viscous drag, but actually to employ it for even higher sensitivity to sound.
Evolution Against Intuition
June 7, 2011
As a general theory of life, evolution promises to explain everything. Not all observations fit neatly into that assumption. How do evolutionists respond when surprising or counter-intuitive observations require integration into the theory? Sometimes the only answer is that they evolved because they evolved. These 10 examples (with encore) can provide case studies for the discerning.
Appreciate Your Gifts
May 29, 2011
We like to showcase stories of amazing animals, but humans are special, too. What animal can boast some of the qualities that science has recently reported?
The Eyes Have It: Pro Software
May 5, 2011
You have a biological version of Photoshop in your eyes. That’s what Richard Robinson, a freelance science writer from Massachusetts, said in PLoS Biology.1 The eye is not a camera, and the retina is not a piece of film. Indeed, the retina might be better likened to a computer running Photoshop, given the extent of […]