The Amazing Pigeon Techno-Beak

first_imgHow do homing pigeons find home?  Scientists at University of Frankfurt may have found the answer: magnetic minerals in their beaks.  A press release from Springer Publications describes the amazing pigeon techno-beak:In histological and physicochemical examinations in collaboration with HASYLAB, the synchrotron laboratories based in Hamburg, Germany, iron-containing subcellular particles of maghemite and magnetite were found in sensory dendrites of the skin lining the upper beak of homing pigeons.  This research project found that these dendrites are arranged in a complex three-dimensional pattern with different spatial orientation designed to analyze the three components of the magnetic field vector separately.  They react to the Earth’s external magnetic field in a very sensitive and specific manner, thus acting as a three-axis magnetometer.    The study suggests that the birds sense the magnetic field independent of their motion and posture and thus can identify their geographical position.This mechanism is probably not unique to homing pigeons, the article states.  It might be found in all birds – and even in other animals that excel at navigation.  Indeed, “many animals display behavior that is modified or controlled by the Earth’s magnetic field.”  These include animals as diverse as sea turtles, lobsters and butterflies.    A spin-off of this discovery is the human desire to imitate it.  Will similar nanotechnology someday help doctors target drugs in the body?  Will it spur inventions into new data storage devices?  Will it reduce the size of magnetometers on aircraft and spacecraft?  Too early to say.  First, inventors must find ways to synthesize these sensors.  One of the scientists at the University of Frankfurt commented, “Even though birds have been producing these particles for millions of years, the main problem for scientists who want to find benefits from their use will be the technical production of these particles.”Millions of years would not help pigeons develop techno-beaks.  Aside from that bit of Darwinian flatulence, this is an astonishing announcement.  It goes to show that no skill in nature just happens; there must be structure adequate for each function.  Homing pigeons have been known for a long time.  People have marveled at pigeon navigational abilities since antiquity, but only now do we begin to understand what machinery is involved.  The iron-containing structure in the beak is just one aspect of a system.  As with eyes and ears, a brain must be adequate to process the continuous information flow and make quick decisions.  Would that Charles Darwin, that famous pigeon-breeder, had known about this.  Things might have been different in 1859.(Visited 14 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Bacteria to the Future

first_imgBacteria used to be considered so boring, they were passed over by scientists eager to look where the action was: eukaryotic cells.  That was then.  Now, Nature reported,1 the little rods and spheres and spirals have lots of tricks up their sleeves worth investigating.  “Long dismissed as featureless, disorganized sacks, bacteria are now revealing a multitude of elegant internal structures.”  These include spiral skeletons (“sophisticated internal structures that give them shape, and help them grow and divide”) and actin-like motors that control magnetosomes (iron-containing structures) that give bacteria a sense of direction.    Until recently, bacteria appeared to have featureless interiors, even when viewed through electron microscopes.  New techniques, particularly cryo-electron tomography, are disclosing wonders that were previously invisible.  The discovery by Jeff Errington in 2001 that bacteria do indeed have a cytoskeleton was “one of those few times in a scientific career when you do an experiment that completely changes your way of thinking.”  Errington imaged filaments of tubulin wrapped around the inner wall of the cell like the stripes on a barber pole.  One theory is that the scaffolding “tells the cell wall’s enzyme contractors outside the cytoplasm where to lay new bricks” (see 01/16/2003).  The filaments and associated proteins are also involved in quality control during cell division, and help organize the magnetosomes into sensory organs.    Eukaryotic cells themselves were assumed by 19th century biologists to be featureless blobs of protoplasm.  That view, of course, changed dramatically throughout the second half of the 20th century.  History seems to be repeating itself with respect to the tinier cells that comprise the most numerous life forms on earth: “For more than a century, cell biology had been practised on ‘proper’ cells – those of the eukaryotes (a category that includes animals, plants, protists and fungi),” Ewen Callaway wrote.  “….Hundreds to thousands of times smaller than their eukaryotic cousins, and seemingly featureless, bacteria were rarely invited to the cell biology party.”  These discoveries about “simple” bacteria are helping to change that.  “We know very little,” said Dyche Mullins [UC San Francisco].  The discovery of the cytoskeleton proved that “There was a lot of organization in bacterial cells we were just missing.”  The field is just now opening up after decades of neglect.  “There’s a lot of unexplored biology,” he said – and this article didn’t even touch on the subject of the bacterial flagellum.1.  Ewen Callaway, “Cell biology: Bacteria’s new bones,” Nature 9 January 2008 | Nature 451, 124-126 (2008) | doi:10.1038/451124a.  Also published on [email protected] cognitive dissonance in this article was worth noting.  Throughout the text, scientists were admitting how little they know about bacteria – and this is with millions of the little cells right under their noses, in real time, in the present.  But then, right in the middle of the article, a just-so story was inserted about a mythical past that would be unobservable even in principle:As cytoskeletons evolved, they took on new chores and snowballed in complexity.  At some stage after eukaryotes branched off from bacteria, the eukaryote cytoskeleton seems to have frozen in time.  From yeast through to people, its proteins do many of the same jobs, such as towing sister chromosomes to opposite ends of a dividing cell or making sure the endoplasmic reticulum nestles up against the nucleus.  More complex eukaryotes might use actin to flex muscles and keratin to make hair, but those tasks are variations on a theme.    Not so with bacteria, says Mullins.  Actins that determine cell shape work differently across the bacterial world, and some rod-shaped bacteria, such as tuberculosis, don’t even have them.  Due to their vast numbers and unicellular lifestyle, “bacteria can play around with fundamental mechanisms for doing things in a way that eukaryotes can’t”, he says.This is how the Darwinians get away with calling evolution a “fact” (see next entry).  They simply declare it a fact and treat it as if it were a fact.  Those only makes sense if f.a.c.t. stands for Fictional Account Creatively Told.  It doesn’t have to actually be a fact in the old-fashioned sense.  As long as everyone is trained to think it is a fact, the Darwin Party can remain in power, the trains run on time and there is peace in the streets.    The downside is that people’s minds are enslaved to a myth and science suffers.  Did Darwinian assumptions hold back progress in bacterial biology?  Arguably so.  According to the Darwinian mindset, bacteria were just primitive, featureless blobs, till new techniques revealed what is really going on.    A design-theoretic biology might have motivated a different approach.  For an organism to be this small yet maintain all the functions necessary for life, there must be incredible nano-engineering and miniaturization going on inside those cells.  Let’s find out.  Maybe we can even learn some principles that can help us with our micro-engineering questions.  The evolutionary paradigm is revolting.  Time for a design revolution.(Visited 21 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Life Crams Stuff on the Long Road

first_imgThis quote from UC Berkeley wins Stupid Evolution Quote of the Week: In the long evolutionary road from bacteria to humans, a major milestone occurred some 1.5 billion years ago when microbes started building closets for all their stuff, storing DNA inside a nucleus, for example, or cramming all the energy machinery inside mitochondria.Any questions?  Science Daily repeated it without laughing.    The occasion for the comment is research on a microbe that can switch between an amoeba-like form and a flagellated form.  Naegleria gruberi, when stressed, can switch on genes that grow two flagella.  A Berkeley bioinformaticist commented that “It is a very rare process to go from amoeba to flagellate like this.”  It has two completely different modes of motility.    The flagellum is a poster child of intelligent design.  It would seem the ability to switch between two completely different modes of motility is even more complex.  Nevertheless, to these scientists, this germ is “shedding light on the set of perhaps 4,000 genes that may have been part of the first, most primitive eukaryotes” and will “shed light on how cells move, how they signal one another and how they metabolize nutrients.”  Presumably, discoveries about this living microbe “will help in understanding the evolution of more complicated organisms” hundreds of millions of years ago.  It “can help scientists understand the origins of these parallel systems during the evolution of eukaryotes.”    Wow, there’s light and understanding all over the place.  According to one team member, “By comparing diverse organisms like Naegleria from all over the family tree of eukaryotes we can begin to understand where we come from.”  Apparently we are to understand this: we are amoebas, just a few million years down the long evolutionary road, but we have learned one thing: how to cram our machinery in closets.It is said that the difference between stuff and junk is that junk is the stuff you throw away, but stuff is the junk you keep.  How many of you cram your irreducibly complex machinery in a closet when moving down the road and keep it there for 1.5 billion years?  How many of you like to mix metaphors while doing it?    The long evolutionary road from bacteria to humans… (sigh).  What can you say to such people.  Where do you start.  Is it even worth trying.  They don’t call it UC Berserkeley for nothing.  Prevention is the only intervention with hope in such cases.  Reach the inmates before they get into the asylum.(Visited 13 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Safer opioids needed to stem epidemic of overdoses top publichealth doctor

first_imgOTTAWA — Canada’s chief public health officer says the need to increase access to a “safer supply” of opioids is being reviewed with provinces and territories — a move encouraged by a number of public health experts.Tam’s comments come as the Public Health Agency of Canada releases data that says in the first half of 2018, opioid drugs were a factor in more than 2,000 deaths. That’s a higher death rate than the previous year.Tam says a toxic drug supply is causing a key part of this epidemic.Fentanyl, a drug more powerful than heroin, is often mixed into opioids sold on the street, meaning users can’t know the potency of the drugs they take.Tam says the country must “double down” on its efforts to address the opioid crisis, stressing the need for escalated treatment.The health agency found more than 9,000 lives were lost in Canada between January 2016 and June 2018, suggesting the country has not been able to turn the tide on the crisis. The Canadian Presslast_img read more