Showing posts with label birds. Show all posts
Showing posts with label birds. Show all posts

Saturday, November 28, 2020

Evolution of the Larynx

Primates already had bigger and more diverse larynxes, before humans came on the scene.

While oxygen was originally a photosynthetic waste product and toxic to all life forms, we gradually got used to it. Some, especially the eukaryotes, made a virtue of oxygen's great electronegativity to adopt a new and more efficient metabolism with oxygen as the final electron acceptor. This allowed the evolution of large animals, which breathe oxygen. All this happened in the oceans. But it turns out that it is far easier to get oxygen from air than from water, leading air breathing to evolve independently dozens of times among fishes of all sorts of lineages. Lungs developed from many tissues, but rarely from the swim bladder, which had critical roles revolving around constant and controllable pressure, pretty much the opposite of what one needs in a lung. So in our lineage, the lung developed as an adjunct to the digestive system, where the fish could gulp air when gill breathing didn't cut it. 


Overview of the atmosphere of earth. Lungs were only possible when the level of oxygen in air rose sufficiently, and respiration of any kind only when oxygen had vanquished the originally reducing chemical environment.

This in turn naturally led to the need to keep food from going into the nascent lung, (air going into the stomach is less of a problem.. we still do that part), thus the primitive larynx, which just a bit of muscle constricting the passage to the lung. As this breathing system became more important, regulating access to the lung became more important as well, and the larynx developed more muscles to open as well as close the air passage, then a progessively more stable and complex surrounding structure made of cartilage to anchor all these muscles. 

But that was not the end of the story, since animals decided that they wanted to express themselves. Birds developed an entirely different organ, the syrinx, separate from the larynx and positioned at the first tracheal branch, which allows them to sing with great power and sometimes two different notes at once. But mammals developed vocal cords right in the center of the larynx, making use of the cartilaginous structure and the passing air to send one fluttering note out to the world. The tension with which these cords are held, the air velocity going past them, and the shapes used in the upper amplifying structures of the throat, mouth, and sinuses all affect the final sound, giving mammals their expressive range, such as it is.

So why are humans the only animals to fully develop these capacities, into music and speech? Virtually all other mammals have communicative abilities, often quite rich, like purrs, barks, squealing, mewling, rasping, and the like. But none of this approaches the facility we have evolved. A lot can be laid to the evolution of our brains and cognitive capacities, but some involves evolution of the larynx itself. A recent paper discussed its trajectory in the primate lineages.

Comparison of representative larynxes, showing a typical size difference.

The authors accumulate a large database of larynx anatomy and function- sizes, frequency patterns, evolutionary divergence times- and use this to show that on average, the primate lineage has larger larynxes than other mammals, and has experienced faster larynx evolution, to a larger spread of sizes and functions, than other mammals. The largest larynxes of all belong to black howler monkeys, who are notorious for their loudness. "The call can be heard up to 5 km away." They also claim that among primates, larynx size is less closely related to body size than it is among other mammals, suggesting again that there has been more direct selection for larynx characteristics in this lineage.

Primates (blue) show greater larynx size and variability than other carnivores.

This all indicates that in the runup to human evolution, there had already been a lot of evolutionary development of the larynx among primates, probably due to their social complexity and tendency to live in dense forested areas where communication is difficult by other means. Yet do primates have vocal languages, in any respect? No- their vocalizations are hardly more complex than those of birds. Their increased evolutionary flexibility at most laid the physical groundwork for the rapid development of human speech, which included a permanently descended larynx and more importantly, cognitive and motor changes to enable fine voluntary control in line with a more powerful conceptual apparatus.

  • Is there a liar in your life?
  • Against climate change, we need much more... action.
  • 2020, auto-tuned.
  • Turns out, there was a war on Christmas.

Saturday, June 6, 2020

Eating the Wild Things

Despite humanity's long tradition of eating wildlife, it is high time to rethink it as a practice. 

The coronavirus outbreak certainly gives one pause, and time to think about what we are doing to the biosphere and to ourselves. It also makes one wonder about the wisdom of killing and eating wildlife. I have been reading a book about a different disaster, the struggles of the crew of the ship Essex, back in 1820. This Nantucket-based factory ship was hunting whales in the middle of the Pacific when, in an ironic, yet all too-rare turn of events, a huge male sperm whale rammed and sank the mother ship as the smaller whaleboats were out killing its relatives. Months of drama, extremity, and cannibalism ensue, (for the humans), after which a fraction of the crew survive to tell the tale. It seems to us now bizarre, and beyond wasteful, that street lights in Nantucket were lit with whale oil, and that people would sail all over the world's oceans just to kill whales for the oil in their heads and blubber. Humans have an instinct for survival, and for the most concentrated source of various goods, and, whether under the colors of capitalism or simple greed, think little of externalizing costs, no matter how brutal and far-reaching, whether eating each other, "fishing out" some rich source of food, causing extinctions, or setting Charles island of the Galapagos ablaze in an inferno (another episode that occurs in this ill-starred history). One must be "hard" in this business of living, after all.

Well, we can do better. Now, two centuries on, we are still abusing the biosphere. Some ways are new, (climate change, plastics, insecticides), but others are old, such as over-fishing. Factory ships are still plying the great oceans of the world, vacuuming up wild animals so that we can eat them. And not just do they derange whole ecosystems and litter the oceans with their waste, but they also kill a lot of innocent bystanders, euphemistically called "bycatch"- sea turtles, albatrosses, dolphins, whales, etc. Albatross populations are in steady decline, from very low levels and heading towards extinction, for one main reason, which is the fishing industry.


This simply has to stop. It is a tragedy of the commons, on a collossal scale, all for the atavistic desire to eat wild animals. Human overpopulation, coupled with technology, means that no wild animals stand a chance in an unregulated environment- not in Africa, not in Brazil, and not in the international oceans. We are killing them by a thousand cuts, but do we also have to eat them, as the final indignity and form of waste?

If we want to save the biosphere from utter impoverishment, humanity needs a change of heart- an ethic for keeping the wild biosphere wild, rather than running it like so much farmland, or so much "resource" to be pillaged, whether "sustainably" or not. Obviously, eating meat at all is a fraught issue- ethically, and environmentally. But surely we can agree that wild animals, and wild ecosystems, deserve a break? Conversely, where we have so screwed up ecosystems by eliminating natural predators or introducing invasive species, we may have to kill (and yes, perhaps eat) wild animals in systematic fashion, to bring back a functional balance. Go to town on feral hogs, boa constrictors, Asian carp, etc. (But try to do so without poisoning yourselves and the evironment with lead.) The point is that we are stewards of this Earth now, like it or not, and ensuing generations over the next hundreds and thousands of years deserve an Earth with a functioning biosphere, with some semblance of its original richness.

  • Lying is a weapon of war.
  • It's the same old Pakistan.
  • Astronomers take a whack at the virus.
  • What to do after the protests. And then prohibit public employee unions from corrupting political campaigns. And then prohibit all other special interests from corrupting campaigns as well, for good measure.

Saturday, September 16, 2017

Bullets of Poison

Lead, condors, and the toxic legacy of right-wing politics.

Of the many ways we have ravaged our environment, some of the most heartbreaking are the silent killers- DDT, other insecticides, PCBs, trash, CFCs, CO2, PFOA, and lead. The same technologies that have conjured out of our environment the many wonders of modernity have also unlocked demons, like plutonium and other radioactive poisons, which we struggle to control and dispose of.

But our thoughtless dumping of pesticides and other poisons doesn't even rate that kind of drama. It took an especially gifted writer, Rachel Carson, to bring the ravages of DDT to light 50 years ago, and we have since slipped into an amnesia through which other poisons like the neonicotinoids have seeped into astonishingly widespread use, making arthropod wastelands of our most fertile country.

One of the more insidious poisons is lead. Through the Flint water crisis, we have learned once again that lead is pervasive, and an enormous health threat. Why have we tolerated it for so long? It has taken painstaking public efforts to get lead out of gasoline, out of paint, and out of new water pipes. Yet it is still common in old pipes, and in coal ash, killing and impairing Americans continuously. And it is common in firearm ammunition.

Poisoning oneself and one's family by hunting with lead is one thing, and tragic enough. But it turns out that other animals can be even more strongly affected, particularly the California Condor. This magnificent bird, North America's largest, is, naturally, attracted to carcasses and viscera left by hunters, and is not a picky eater when it comes to lead. But even if they were, it would be impossible to avoid lead from such carcasses, since lead bullets leave a wide swath of fragments and contamination in the victim. Condors also have particularly strong digestive juices that mobilize more of the lead they ingest than do those of other predators and scavangers, making lead the leading cause of death among the painstakingly re-established and tiny wild population. Indeed, that population can not grow until lead is eliminated from its food supply.


California has, with great political effort, established a ban on hunting with lead ammunition, to take effect within a couple of years. The Obama administration likewise set up a ban on use of lead ammunition in federal wildlife refuges. But the new administration, in line with the rest of its immoral and mindless policies, reinstated the use of lead ammunition. It is one more example of the sheer meanness and spitefulness that seems to pervade this sector of American politics- a segment of the elite and the electorate that could not care less about nature, about justice, and about the future in general. As long as they are "winning" over their perceived enemies, in a zero sum spiral of death, scientists, truth, justice, and the future of humanity, not to mention the biosphere, can be damned. Even the US Army has recognized that the costs of creating enormous toxic waste dumps out of their firing ranges and conflict zones (not to mention the manufacturing stream) is too high a price to pay, and has switched to unleaded ammunition. (Though uranium- that is a different story!).

A similar story has played out tragically in India, where an antibiotic used in cattle turned out to kill vultures, wiping out the population, and causing some very unpleasant ecological consequences in a country in dire need of efficient trash and carcass collection. While we should not stifle all progress with overly cautious regulation, once a tragic consequence from some technological innovation (or ancient practice) becomes apparent, we should recognize our own power in the role of the government to set rules for the good of our long-term collective interests- interests which surely include preservation of our own health and that of wild animals.

  • Defenseless animals are next.
  • Krugman: it isn't just science at stake, but civilization.
  • The irony of Texas.
  • Silencers- as American as apple pie.
  • Bias in the biomedical literature.
  • Incentives only go so far. Character counts for a lot as well- about half.
  • Problems with the upcoming Vietnam War.

Saturday, May 16, 2015

Death of a Species

Callous indifference and business-as-usual greed dooms the delta, and the delta smelt.

As ecological icons go, the delta smelt isn't much. A small silver fish, like a zillion others. But it lives in the way of dredgers, bulldozers, farmers, shippers, and a thirsty multitude. It was put on the endangered species list in 1993, and has kept right on dwindling, until in the most recent count, a single smelt was found. One.



The San Joaquin / Sacramento / San Francisco Bay delta used to be a very large estuary of marshes, reeds, rivers, and islands that gradually fed the great rivers of the Sierras into the Bay and thence through the Golden Gate the Pacific ocean. Fresh water met briny in constant tidal and rain-fed flows. Smelt were obviously not the only beneficiary of this rich ecosystem, but countless shellfish, mammals such as beavers, insects by the billion, and birds by the million. The delta was a major stop on the Pacific flyway for migrating birds. And it was the conduit for several species of now-endangered salmon.

Comparison of the delta as it was, and as it is now. Virtually all its marshland and most of its complex river habitat is gone.

Despite the popular image of California as a state of nature and natural wonders, it has been pillaged in the name of greed from the beginning. The Spanish mission system started the ball rolling by enslaving and decimating the native peoples. Then the gold rush led to thorough destruction and pollution of the rivers, while working its way upwards into the hardrock mines of the Sierra. Next was agriculture, which in California became a rapacious and short-sighted industry, well-illustrated in the now-obscure novel by Frank Norris, The Octopus. Then it was onwards to a thorough re-plumbing of the state by the water lords of Southern California. The latest incarnation of this get-rich quick ethic was the dot-com bubble, by which Silicon Valley took investors all over the world to the cleaners.



The little smelt and all the natural riches it stands for had little chance, of course, when there was free, fertile land to be had by diking, draining, and dredging. A state which had some inclination to protect the spectacular, yet conveniently remote and barren, high Sierras, had no appreciation for the ecological values of wilderness in the bottomlands, even for flood control, which is increasingly difficult as so much of the "reclaimed" land is under sea level, protected by primitive, flimsy dikes. With the extended drought and the vast rerouting of fresh water, the delta has begun to flow backwards, introducing salt as well. But the state, being owned by its commercial interests, leaves public and ecological policy to die a quiet death, along with the smelt.

The planetary climate and biosphere face similar forces of corruption, greed, inertia, and neglect, which will just as soon see it die with a whimper than plan in a public and morally forward thinking spirit for future generations of all species.


  • Notes on our friends the Saudis.
  • Secularization hypothesis finds new support.
  • Further notes from the religion of peace.
  • The odd history of US fundamentalism.
  • Bruce Bartlett just can't take the corruption any more.
  • Even if corruption is quite natural.
  • Notes on real estate redlining.
  • Economics is not yet a science.
  • Silence on fiscal policy is dereliction by central banks.
  • Bill Mitchell on the Australian budget process. A cartoon.
  • Aetna raises its minimum wage: "The pay raise and benefit program for low-wage workers will cost Aetna only $26 million, while the CEO alone made $15.6 million last year, though most of it in stock options."
  • Some problems with TPP.
  • Class and money beats performance.
  • Essay on the new frontiers of brain science, and its changing nature.
  • 110 year old infrastructure for trains? We can do better.
  • Two banks find a judge with a spine, after they lied to convince Fannie and Freddie to go subprime.
  • Economic graph of the week: Stiglitz on inequality.

Saturday, October 4, 2014

Environmentalism is anti-American

Book Review of the biography of Rachel Carson, "On a farther shore".

Are we part of nature, or above it? Did god give it to us for our domination, or did we wriggle from its bosom to the condition of (bare) consciousness and power that threatens to undo the patient work of millions of years of evolution? Thousands of years ago, we had already killed off all our immediate ancestors in the hominid line and countless other species of megafauna. Now we have taken over most of the arable land of earth, comandeered much of the fresh water, polluted the rest of it, as well as the oceans, killed off many more species, doubled the concentration of CO2 in the atmosphere and the fixed nitrogen in the biosphere, and are facing ocean acidification and dramatic climate heating as an irreversible future fate.

But two generations ago humanity (and that would be the US) created the most immediately alarming and noxious dangers of all- nuclear weapons with their attendent radioactivity, and a fusilade of biocides and other poisons emerging from the postwar chemical industry- pesticides, herbicides, plastics, drugs, "food" additives, cleaners, etc. After a cavalier start to the era, when Las Vegas visitors turned out with their sunglasses to watch nuclear tests, the far-reaching dangers came increasingly to public consciousness, resulting in the above-ground nuclear test ban treaty of 1963, and the establishment of the EPA in 1970 and banning of DDT in 1972.

The reduction of nuclear radiation has been enormously successful, with negligible impact from current uses. The Chernobyl and Fukushima nuclear disasters have been the sole, and very large, blots on a very good record of radiation control (negligible amounts were released in the Three Mile Island disaster). Whether we want to use more nuclear power or not for the sake of climate change is a reasonable question.

Our record on control of biocides and other environmentally harmful chemicals, on the other hand, is far less impressive. Their use is less individually dramatic than that of nuclear technology, but their scale is mind-boggling. Every home and garden center hosts a biocide department that reeks to high heaven. DDT may have been banned, but an endless supply of other biocides have been concocted that are applied over the best land to kill all insects on it. The holocaust is ongoing.
"In 2006 and 2007, the world used approximately 5.2 billion pounds of pesticides"

Rachel Carson played a large role in our budding environmental awareness, both in her early work in books like "The Sea Around Us" that celebrated the beauty and interest of the natural environment, and in her last prophetic work on the dangers of the new pesticides, "Silent Spring". This biography is a worthy testament to her drive and talent which formed out of very unlikely materials (being a self-made professional woman in the 1950's) an earth-shaking message.

Indeed she could even be regarded as a significant religious leader, inspiring love for the world, and issuing prophetic warnings about its mistreatment at the hands of humanity, due in part to a lack of spiritual awareness, or misdirection. Humans have an innate religious sensibility about nature, and all the old religions treat it with reverence. The Celts had their sacred groves, worship of trees, and custom of bringing holly and mistletoe to their dwellings at the winter solstice. Unfortunately, the monotheisms, with their worship of a blown-up self-image, put nature into the shade as something to be dominated, something lost anyhow (Eden), even dirty and unclean. The unholy mix with post-war technologies allowed the dream to become a reality ... to "purify" the world of insects, vermin, disease, and all kinds of uncleanliness.

Obviously there is a great deal of good in cleanliness. But we learn that even our own health benefits from some amount of infection and dirt, lest our immune system idly turn its attention on our own tissues by mistake. Which is not to mention the wider ecological benefits of moderation and species diversity, and particularly in less wanton destruction of insects and other unheralded organisms that may not be the "stars" of our nature shows.

While we have banned the most noxious chemicals, (thalidomide, DDT, aldrin, lead arsinate, etc.), our systems and policies are simply not up to the task of protecting ourselves or the environment in a more comprehensive way. They are not precautionary, but rather wait for some dramatic harm to come to light before starting studies and investigations that take forever. The neonicotinoid insecticides are still being applied by the ton, despite their clear harm to bees (not to mention to all other insects).

Why? Principally, it is the agricultural and chemical interests, and their conservative allies, that fight chemical control policies every step of the way. There was once a time, when the EPA was founded, when conservatives were true to their name and cared about conservation, not only of their power, but of the environment as well. Those times are long gone, as the interests of the 1% diverge increasingly from those of the rest of society, indeed of humanity in general. Their loud patriotism tells us that government is bad, taxes always too high, scientists are all lying, and corporations always tell the truth. The worship of self has turned from a projected image of god to the even worse god of Mammon.
"It had only taken a few short centuries to move from a time when we gazed out at the ocean and wondered what was over the horizon. Now, she said, "our whole earth has become only another shore from which we look out across the dark ocean of space, uncertain what we shall find when we sail out among the stars." Based on the experience of her own generation- which had brought the world to such a dangerous crossroads- Carson said it was now time for the inheritors of earth and it many difficulties to finally prove human mastery not of nature, but of itself. "Your generation," she said, "must come to terms with the environment."

  • Wildlife is in dramatic decline.
  • Bees are in especially dramatic decline ... collapse.
  • Fly less to fight climate change.
  • On the psychology of evil, corruption, ideology, contradiction, hypocrisy, and other forms of humanity.
  • In the new economy, nice guys finish last.
  • Cute kids ... these days.
  • The recent US military campaign has little immediate effect. ISIS keeps gaining ground, and "One estimate puts the number of overall desertions for the Iraqi Army at over 90,000."
  • How and why the Fed shores up the global dollar system.
  • But banks run the Fed, so of course ... the Fed serves Goldman.
  • Goldman, Lehman, Enron.
  • AIG as a money-laundering bailout. "Alternatively, maybe Mr. Geithner simply felt that Goldman and the like had a more legitimate claim to billions of dollars in funds than the taxpayers who were footing the bill."
  • Bonanza gets one in against the bankers (Episode 284, The Trackers)
  • Pray our way, or the highway.
  • To screw workers, employers talk out of both sides of their mouths.
  • This week in the WSJ, annals of irony: "But does anybody in the government feel it is necessary to be truthful about anything anymore?"   
  • Economic graph of the week.. just how dramatically our economy has changed over the last 60 years. We've already had a class war, and we lost.

Saturday, April 11, 2009

Mimus polyglottus

Spring means birds singing. But at 2 AM?

We've been serenaded by a mockingbird for the last week, at all hours, at top volume, mixing samples collected from all over the western hemisphere to create a crazy-wild DJ scene on the premises. The bird is awe-inspiring to say the least, giving pitch-perfect renditions of titmice, crows, blue jays, and frogs, as well as a few call-and-response numbers, among many other turntable classics.

Why? What is the origin of this bird and its behaviors? A recent article in science laid out the DNA-based phylogeny of birds, of which there are over 10,000 species. It upset quite a few previous classifications, and definitively, since sequence-based phylogenies have greater resolution than character-based ones. Mockingbirds reside in the largest group, the passeriformes, along with other songbirds. I had assumed, from its shape, size, flight style, wing bars, and aggressive behavior that they are closely related to jays, which are related to corvids/crows. But not true! Mockingbirds are cousins of starlings, showing that vocal facility, which starlings share in spades, is also a crucial diagnostic trait. Indeed, an incredibly charming book, now out of print, relates how one starling was taught to speak (and sing) passable English.

The study of birds continues to fascinate the evolutionary community, with new specimens of Archaeopteryx being lovingly studied as it becomes common knowledge that birds are our only living connection to the dinosaur lineage. The fossil record in this case, as is true for whales and other organisms, is filling out to give us an ever-fuller account of complexity and gradualism in the history of life. Additionally, studies of bird memory were the first to demonstrate the birth of new neurons in adult brains, concomitant with the memorization of new songs. Subsequent work found the same phenomenon in humans- an important focus of contemporary neurobiology and even stem cell-associated hopes.

Archaeopteryx from the Jurassic (~150 to 200 million years ago).
Note the claws at the end of the wing/fingers.

Mockingbirds have upwards of 150 song samples at their command, and change their repertoires between spring and fall. The function of their singing, other than attracting mates, is not clear. But one could speculate that the high volume and enormous fund of mimicked songs functions to keep other species at bay, creating better-quality territories for the omnivorous mockingbird. The utility of this trait would in turn create a sexual selection rationale for females (who also sing, just not a 2 AM) to select mates with larger repertoires, more accurate reproduction, and higher volume.

As our culture gradually transitions away from the Christian fetishes of false hope, blood, and death at this time of year to the much more ancient themes of life, fertility, and birth, it is wonderous to participate (if unwillingly!) in the rituals of birds who are so diligently and flamboyantly engaged in the tasks of life.

  • Subscription site at Cornell is the leading resource for general bird knowledge.