mellowtigger: (food)
Scientists may have finally discovered why red meat is bad for humans.  Vegetarians score a big win with this new discovery, because the consequence is inescapable for any of us. Given that this genetic change appeared 2-3 million years ago as the Homo genus made its appearance in the world, it seems that we (unlike modern apes) are designed specifically not to eat red meat.

We already know that red meat is associated with poor health in humans, linked to conditions as varied as arthritis, heart disease, and different cancers.  Nobody, though, had a clear and concise explanation for these associations. I figured it was mostly our modern livestock production system (antibiotics, chemical-laced foods, inhumane conditions, etc.) that was to blame, but it turns out that humans evolved a unique biological difference from other mammals... and it leaves those other mammals noxious to us as food sources.

Most other mammals (including other apes) produce a kind of sugar whose long name is N-Glycolylneuraminic acid and whose shortened name is Neu5Gc. This simple sugar ends up in their meat and their milk. Humans, however, are incapable of producing this molecule. It is thought that we evolved this deficit because it made us immune to a form of malaria while other mammals are still susceptible to infection. Neu5Gc is a natural substance and non-cancerous in itself, but it is now foreign to us. When we eat this food, our immune systems develop an antibody response to it. That antibody reaction then produces inflammation, and the chronic inflammation from daily exposure leads to cancers and other ills.

Researchers created mice with the same Neu5Gc deficiency that humans have, then they fed them with Neu5Gc.

When such mice were challenged with anti-Neu5Gc antibodies, they developed evidence of systemic inflammation. Long-term exposure to this combination resulted in a significantly higher incidence of carcinomas (five-fold increase) and an association with Neu5Gc accumulation in the tumors. Similar mechanisms may contribute to the association of red meat consumption with other diseases, such as atherosclerosis and type 2 diabetes, which are also exacerbated by inflammation.

Chronic exposure with antibodies caused tumor development, and those tumors were rich in Neu5Gc deposits even though the mouse cells could not produce the substance. It appears that they discovered the "smoking gun" that explains why red meat is bad for human health.  I look forward to the human trials that can conclusively show the same link.

I've been semi-vegetarian for many years already. I have many meatless days by happenstance. I did not choose this lifestyle for humanitarian concerns. I am the only person responsible for my food, and I simply don't trust myself to store and cook meat properly for safe consumption. Instead, I eat meat when I go out to restaurants. It's not clear at this point what amount of Neu5Gc exposure is safe (unlikely to trigger antibodies), if any at all.

Like the Whos down in Whoville, maybe it's time that we switched to a healthy (but humane) roast beast?
mellowtigger: (Terry 2010)
dogs domesticated in 8 secondsNo modern human population lacks dogs in its culture. Our long, intertwined history leads to the co-evolution theory that humans and canines evolved together through mutual dependence.

Sure, humans have domesticated lots of animals, but those are typically done as shepherds. The animals feed themselves, or we collect their natural food for them. We use them as tools and eventually as meat. In the case of dogs, however, their bodies evolved with ours to adapt to new sources of food as we developed agriculture. Basically, we had good garbage that was rich in starch, and they scavenged our scraps.

We shouldn't take credit for the process, though. It's not that we were controlling their mating behavior to select our own choice of breeds; it's the wolves who adapted to us. Independent of humans, canines are quite versatile with their social bonding. After all, we aren't the only primates who integrate canines as tools in their society. Watch these baboons do it too... by force.

Nevertheless, the idea of humans and dogs evolving in mutual symbiosis is an interesting idea. It leads to questions about the genetic lineage of "village dogs", a term that refers to integrated canines who still mate by their own choice. One idea is that our mutual benefit is so strong, that adaptation may have happened independently many times. UCLA Today quotes Mark Derr:

"Wherever there are wolves and humans, you end up with dogs.

I donated $100 to this crowdfunding project that is sampling village dog DNA from areas throughout Africa. They barely achieved their fundraising goal, but at least they made it. They're hoping to find genes favored by natural selection (rather than human-directed artificial selection) in canines. Those genes might help us better understand our own health. They sent me this photo as a souvenir of their travel in Africa. Notice how their appearance favors a tan-and-white coat and a longer, pointed snout than we typically see in cultivated breeds. (Click to see the photo in much larger version.)

Village Dog Project 2012

All that fascinating history, and I haven't even scratched the surface of "interesting" with the abandoned dogs of Moscow who are evolving into 4 distinct groups: guard dogs, scavengers, wild dogs, and beggars. The beggars who specialize in brains rather than brawn have developed enough intelligence to master riding the subway on their own.
mellowtigger: (brain)
I've been talking for nearly a decade about how some autistics live with an older form of emotional brain that has been awakened from slumber for another "test drive" of suitability in this test lab that is our global industrial civilization.

I count some emotions as just another kind of sensory experience. Sensations require an effort to establish a link between the perception and the actual cause in the external world. It's not easy to establish these links. Cringing is useful because the action takes you away from the source of harm without any need to understand the source. Anger and fear, however, require understanding the source, otherwise actions are taken "wildly" that often fling harm in all directions equally. Connecting internal sensation with the external world is very important.

Today is the first day I've seen some rather specific evidence in favor of this subjective experience as a complicated process. Scientific American published "Decoding the Body Watcher", an article that explains a few key points that echo my own assertions:
  • "While the prefrontal cortex may indeed be specialized for attending to external information, older and more buried parts of the brain including the “insula” and “posterior cingulate cortex” appear to be specialized in observing our internal landscape."
  • "Contrary to the conventional assumption that all attention relies upon the frontal lobe of the brain, the researchers found that this was true of only exteroceptive attention; interoceptive attention used evolutionarily older parts of the brain more associated with sensation and integration of physical experience."
  • "By recruiting “limbic-bridge” areas like the insula and posterior cingulate, a person using interoceptive attention may bypass the pre-frontal neocortex, directly tapping into bodily awareness that is free from social judgment or conceptual self-evaluation."
So when autistics like me self-report that some physical (and some emotional) sensations overwhelm our sense of self with their intensity, now there may be a good and objective reason to accept our account.  There are a host of articles that link these same two brain regions with autistic minds.
mellowtigger: (brain)
I learned today that humans (perhaps all vertebrates) have a second brain in their body. It's diffuse, primitive, and limited to concerns of the gut, but it's definitely there. It's called the "enteric nervous system". It forms from the same early cells as the brain, it has more neurons than the spinal cord, and it can work independently.

"This is indeed the picture seen by developmental biologists. A clump of tissue called the neural crest forms early in embryogenesis, Dr. Gershon said. One section turns into the central nervous system. Another piece migrates to become the enteric nervous system. Only later are the two nervous systems connected via a cable called the vagus nerve."

So it is literally a fragment of brain material that matures into a separate integration center, where it receiving incoming signals and reacts by directing appropriate responses. It's the area responsible for "stomach butterflies" during emotional stress. It is associated through neurotransmitters to our emotional state, and it may play a large part in emotional responses.

"The enteric nervous system uses more than 30 neurotransmitters, just like the brain, and in fact 95 percent of the body's serotonin is found in the bowels. Because antidepressant medications called selective serotonin reuptake inhibitors (SSRIs) increase serotonin levels, it's little wonder that meds meant to cause chemical changes in the mind often provoke GI issues as a side effect. Irritable bowel syndrome—which afflicts more than two million Americans—also arises in part from too much serotonin in our entrails, and could perhaps be regarded as a "mental illness" of the second brain."

I've been talking for years about emotion as a primary sensory issue for autistics (overwhelmed by bloodstream "emotional chemicals").

"I have argued previously that I think some emotions are actually sensations. I suspect that there are cells in the brain that "sense" chemicals in the blood and produce a perception of emotion the same way that we have cells that "sense" chemicals in the air we breathe and then produce a perception of odor."
- Terry Walker, 2005 February 06, ANI-L@LISTSERV.SYR.EDU, Autism Network International Listserv

This new information fits very well with my personal observations. It might eventually lead to hard evidence explaining why so many autistics use diet as a means of symptom and behavior control.
mellowtigger: (dna mouse)
I haven't seen it mentioned elsewhere yet, but researchers have boosted the "intelligence" of mice by increasing the growth of their hippocampus. These engineered mice made better choices by improving their discrimination between similar situations, in effect "learning" more effectively.
mellowtigger: (dna mouse)
I mentioned last year the theory of recapitulation. It explains why a developing embryo goes through different stages that represent the evolutionary history of its ancestors. Most people, for example, are familiar with the gill slits (reminiscent of a fish) that a human embryo briefly grows.

1892 drawingNot explicity stated in the theory, however, is that this historical time warp is not completed for humans by the time of their birth. Human newborns are still partially pre-human in their body configuration. Their historic shape-changing continues well past their first gasps of air. My previous post mentions the chimpanzee trachea, for instance, that does not drop into its human position until a few months after birth.

I have previously claimed (without evidence) that we should expect to see even later changes in the development of the newborn human brain. Since those evolutionary changes that distinguish Homo sapiens from our other ape cousins are the most recent to be added to the human lineage, their chemical signaling should occur very late in human development. They should occur even after the trachea descent.

Now there's evidence to support the idea.

Baby brain growth mirrors changes from apes to humans

"Through comparisons between humans and macaque monkeys, my lab previously showed that many of these high-growth regions are expanded in humans as a result of recent evolutionary changes that made the human brain much larger than that of any other primate," says Van Essen. "The correlation isn't perfect, but it's much too good to put down to chance."

The high-growth regions are areas linked to advanced mental functions such as language, reasoning, and what Van Essen calls "the abilities that make us uniquely human." He speculates that the full physical growth of these regions may be delayed somewhat to allow them to be shaped by early life experiences.


The article summary does not specify the ages which were studied. I expect further research to pinpoint the "final growth" stage of human brain development to occur at exactly that point where many autistic children diverge from the standard population: 30 months of age, give or take a few months.

I think it is no coincidence that parents "lose their child to autism" at age 2-3 years.  Humans still contain the genetic baggage of their ancient ancestors.  Epigenetics keeps the unnecessary bits turned off until needed.  Suppose the final bits that are supposed to turn on to achieve a "human" brain don't get activated?  Suppose a Homo infant keeps its original, older brain configuration?  Even more interesting, suppose it gets something new at age 30 months, something different from what Homo sapiens infants get?

When its time to experiment, cells are able to start turning on bits and pieces of older genetic code to see what produces a useful and successful combination.  Scientists are still working out the chemical signals that encourage (and inhibit) this experimentation.  So far, it sounds like the gender war begins at the cellular level, with male and female parent chemicals warring for control over developing embryonic genetic machinery.

There's already a theory that epigenetic changes precede genetic ones.  As the turn-on/turn-off war continues, different combinations of codes produce new kinds of creatures. They're still the same species as the parent, so far, as new stable combinations are produced. The genes haven't changed yet, only the epigenetic signals.

Combinations that succeed, however, may then develop over time into a new genetic lineage.  Additional gene changes are accumulated to help stabilize the combination, and then it may be fairly represented as a new species. I still claim that autism is exactly one of these changes, one of Mother Nature's attempts to rearrange sentient apes into a form that I call Homo solus.

I eagerly await more research reports.  :)
mellowtigger: (hypercube)
A new study casts doubt on the whole "mirror neuron" theory of autism.  I think that I've never commented in my blog regarding the mirror neuron theory.  It certainly sounded interesting, but I had my doubts about its influence.  Now there is objective reason to question it, rather than just relying upon my subjective musings.

This autism study used 13 autistics and 10 control subjects.  That's too small an example to make for a compelling overthrow of existing theory.  Their results seem detailed to me (however little I'm understanding them at the moment), and they offer more than one evaluation that contradicts the mirror neuron theory.

"... we show that individuals with autism exhibited not only normal fMRI responses in mirror system areas during observation and execution of hand movements but also exhibited typical movement-selective adaptation (repetition suppression) when observing or executing the same movement repeatedly... as such, these findings argue against a mirror system dysfunction in autism."

That link includes a nice 5-minute video (mp4 download) that explains mirror neurons and shows examples of what movements they had people perform inside the MRI ring.  The actual paper (pdf download) includes more charts and graphs than I know what to make of them.  Blah, blah, blah, very convincing, yes?   (Ugh, I need sleep.  *laugh*)

Perhaps-not-unrelated, another study shows that humans are horny apes that have a long history of "pollinating" (to quote the fictional alien time lord, Doctor Who) their way across the frontier with any species willing and able.  Besides recent stories about genetic evidence of Homo sapiens interbreeding with Homo neanderthalensis, there is new evidence of interbreeding with another lineage of extinct hominids.  Scientists are still working out the details.  The likely candidate at this point is Homo erectus, but they haven't yet ruled out the possibility of Homo floresiensis.

I have previously described my two theories of autism.
  1. Autism represents not a new way of thinking but in fact a very old way of thinking based in sensory experience rather than in verbal constructions, and it is now making an unexpected comeback in newborn humans, triggered by environmental cues similar to some period of our ancient past.
  2. Autism is a new feature resulting from epigenetic changes in our species intended to improve our data evaluation capability in response to our redesign of society into a gender-equal information processing culture.
If such neural experimentation by Mother Nature that leads to autism happened to coincide with genetic clusters of markers from "older" hominids (most recently introduced to Homo sapiens), I think it would actually boost both of my theories.  I think that Mother Nature is "turning back the clock" of human evolution, reevaluating recent modifications to our genetics and redirecting them (blindly, randomly) in order to find alternative branches of development that are more suitable to our current environment.

Or so I'm willing to argue while in a sleep-deprived stupor.  Homo solus for the win.
mellowtigger: (hypercube)
It's only been 2 weeks since I posted my new autism theory, and I already have some confirming evidence of my prediction.  :)

A new California study has found autism "clusters" within the state, mostly within the urban areas of San Francisco and Los Angeles.  The researchers studied the California records of the 2.5 million babies born there between 1996 and 2000.  Within these clusters, autism rates are twice what they are outside of the clusters.  What is the sole unifying feature that they identified among these groups?

The 10 clusters were found mostly among children with highly educated parents...
My goodness, but that was some quick confirmation of my idea.  *laugh*

The scientists go on to explore various explanations for why this association could be found.  They mention that richer people have better access to doctors who can diagnose.  They also say that richer people may have different household items that are causing an environmental (chemical) exposure.  Both of these possibilities are reasonable and should be explored.

They fail to mention, however, that the bodies of these parents have changed (epigenetically) because of their lifestyle, and that change might be triggering differences in their offspring.  I hope somebody is planning studies on the effects of meta-cognition (thinking about thinking) on the epigenetic landscape within human bodies (including the germline).

I still like my theory.  :)
mellowtigger: (dna)
Embryonic humans have features like gills and tail, and humans at birth have the trachea of chimpanzees. Embryonic great whales have teeth, but great whales at birth have baleen (keratin plates) instead.

The field of Evolutionary Development takes advantage of the observation that a developing embryo undergoes a mini-movie (but fast-forwarded) history of the evolutionary development of that particular species. The animal's oldest history appears in the youngest embryo and then progresses from there. In the case of humans, such developmental change occurs even past birth. So significant are the developmental milestones that appear in an embryo that Darwin himself advocated using these features to help identify on what branch in the Tree Of Life (YouTube video) an animal is placed.
We can see why characters derived from the embryo should be of equal importance with those derived from the adult, for a natural classification of course includes all ages.
This relationship is not reliable enough to be regarded as a law of biology.  Recapitulation theory is discredited.  Still, these curious observations persist.

I think my favorite biological anachronism is the "chimpanzee throat" that humans are born with, because it shows that we are not fully human creatures even after that significant milestone of birth.  It entices me to think that perhaps we have failed to notice even more subtle changes that distinguish us from our primate relatives and our pre-human ancestors when they occur even after our trachea migrates into its "proper" modern human location.

What is your favorite evolutionary development?
mellowtigger: (Default)
global warming predictionsIn addition to the financial meltdown that I'm expecting, there's also that old stand-by of disasters... global warming.  NASA has released an image (produced elsewhere) that shows the temperature changes expected over the next century.  The arctic changes the most, but South America gets a big hit too.

Another interesting point is that the center of the North American continent gets a higher boost in temperature than neighboring regions.  I've been in Minnesota for more than a decade, and I've noticed that each winter seems milder than the one before.  Apparently that trend is expected to continue.  As some Minnesotans are wont to say, "Global warming?  Bring it on!"

Warming is not so welcome in most areas.  Changing sea temperatures have a large impact on some animals that live there.  As was noticed almost a year ago, "A third of reef-building corals face extinction."  *sigh*  Of course, it's a little more complicated than just the temperature.  According to a related BBC article, there's also the matter of water pollution and overfishing to consider.

Changing temperature and rainfall patterns are taken into account when predicting extinction effects on land species.  Someone realized last summer, though, that the "species extinction threat underestimated due to math glitch", and that the danger is about 100x greater than previously reported.

Thank you for listening.  We now return you to your global financial meltdown.
mellowtigger: (Default)
I've lived for the past decade in Minnesota. One of the state's well known nicknames is "The land of 10,000 lakes." But the locals enjoy adding, "... and ten billion mosquitoes."  I've gone camping out here and regretted it. Mosquitoes and horseflies during only two days left my body covered in more than 70 bloody itchy mounds.

That was bad enough. But who knew that bloodsucking pests could grow so huge?!

mellowtigger: (Default)
I'll start with the photo. Lecture afterward. :)

Back in October 2003, I think it was, I picked some leaves from plants around the parking lot where I worked at the time. I put them in a flatbed scanner and created this photo. It's available in 1600x1200 pixels, if you keep clicking links to the original photo.

It's made a nice autumn desktop for my pc for a few years. Maybe someone else will enjoy it too.  Now time for the lecture....

I've long read that leaves turn color in the fall because the tree works to prevent moisture loss. As the air changes temperature, it cannot hold as much water per cubic meter when the air is cold versus when it is warm. To keep from drying out (getting freezer burned, essentially), a tree loses its leaves during the cold season. Before it drops the leaves, it tries to recover some of the nutrients, nitrogen, and chlorophyll (?). As the chlorophyll breaks down, other pigments (which had been there all along) show their colors.

But why these particular colors? Is one dying leaf the same as any other dying leaf?

Maybe not. Some researchers think that plants may develop a red leaf as a way to further conceal (even after the green chlorophyll is gone) the underlying yellow color that would remain. Yellow, apparently, is very enticing to some insects that are harmful to trees. The scientists tested their theory by creating a color test for aphids, giving them opportunity to mate and lay eggs on backgrounds of 70 different colors.
After two weeks, they found that traps appearing green to humans caught on average more than three times as many aphids as the red traps, but yellow traps attracted even more, around four times as many as the green ones.
So even as the leaves "die", they may still be working to play a part in the health of their tree.  Although the theory is not accepted yet, it already has people thinking about pest control possibilities.  Maybe growing a red-leafed variety alone would help reduce pest problems.
mellowtigger: (Default)
Remember the tv show Hercules that presented tales of the adventures of Hercules and Iolaus? Well, they had more interesting adventures than even that good series was capable of showing. According to Plutarch, the fidelity of Iolaus to Hercules (but not vice versa) was so famed that male couples would use him as an example and profess their fidelity to each other at the tomb of Iolaus.
"And as to the loves of Hercules, it is difficult to record them because of their number; but those who think that Iolaus was one of them do to this day worship and honor him, and make their loved ones swear fidelity at his tomb."
- Plutarch, "Eroticus", par. 17

"It is a tradition likewise that Iolaus, who assisted Hercules in his labors and fought at his side, was beloved of him; and Aristotle observes that even in his time lovers plighted their faith at Iolaus' tomb."
- Plutarch, "Life of Pelopidas", Clough translation
Sexual fidelity, however, is such a rare thing. Not just among humans but also other animals. Rare, though, is not the same thing as absent. According to a PubMed article:
"The Wandering Albatross provides a striking exception to partner infidelity. This albatross is one of the most remarkable animals in the world (Figure 13). These enormous birds, with a wingspan that measures 11 feet, the longest of any bird (one wing is as long as your outstretched arms), mate for life, which is often 6 decades or longer."
I had originally thought that maybe "til death do us part" would have made a lot more sense for humans back when we only lived to our 30s, but this albatross proves that it is natural (for them) even across long lifetimes. A few days ago, news broke about a study that found what seems to be an infidelity gene that was linked statistically to the strength of the bond that a male (human) feels to his partner. Men without the gene had higher fidelity and higher relationship satisfaction (as reported by their partner).  Men with one copy of the gene had lower scores on those attributes.  Men with two copies of the gene had even lower scores.  The researchers looked at this gene after it was previously found to play a role in the fidelity of male voles (a small rodent).

When talking about the feature in humans, it's much too easy to get caught up in political maneuvering instead of rational inquiry.  Since that article, though, I've been pondering what sexual reproductive strategy would be "best" for a species (any species) given a few starting conditions:
  1. males and females have comparable abilities (no significant disparity in survival skills individually)
  2. long lifespan (>60 years)
  3. long child development (>15 years)
  4. one adult is designated primary caregiver for each child born
  5. permanent sexual fertility (not annual/seasonal like many animals) across lifespan
  6. pathogens that can kill "quickly" (<2 years)
Given those simplistic terms, what reproductive strategy yields the highest number of healthy children?

I find that #3 takes precedence.  Since child rearing takes so very long, it requires more resources than can reasonably be expected from only one adult.  (Let's call that Corollary 3a.)  I see some kind of fidelity involved in arranging for these long relationships.  Why?  If sexual attraction is responsible for creating children, then anyone who creates a child will want to ensure that another adult can be relied upon to continue providing resources.  If sexual attraction produced one child, then it can produce another with a different sexual partner, leading to loss of resources to the first child's primary caregiver.

At first, I kept thinking that some form of group fidelity would be an excellent arrangement.  If the group remains small, then problems introduced by #6 can still be minimized.  Even if one particular partner dies, then the cost of child rearing can still be shared amongst the other available (and committed) adults.  Sounds great.  But then I realized the complication that appears across generations.  The group must continually bring in new members to avoid inbreeding.  In return, it must continuously shed old members to other groups.  So the pathogen issue comes up again.  Unless (cruelty alert) newcomers are quarantined for the 2 years during which pathogens can make their presence apparent.

So I was back to shrinking the group down to only a couple.  Pathogen involvement is limited (with fidelity).  Except, of course, when one partner dies and the remaining partner looks for a new caregiver to share in child rearing.  But at least risk affects only one adult and their children rather than an entire group.

Promiscuity is excellent at avoiding the inbreeding problem (thereby introducing necessary genetic variety) but loses its luster when faced with the pathogen problem.  The only way I can get it to "work" is if transmission of genetic material (mating) happens only once and then the receiving partner maintains the genetic material to use slowly across time.  Some animals can do that for short periods of time.  In this scenario, pathogen exposure (sexually transmitted, anyway) happens only once.  If the receiving partner survives, then they can continuously produce offspring from that one encounter.  No additional risk necessary.  Then finding someone to share resources during child development would likely occur in groups only with other surviving child-producers (since they have proven themselves free of deadly pathogen).  It could be the females (like mammals) or the males (like the seahorse), whichever protects the fetus during development.

So that's the best that I can come up with, examining things without involving religious tradition or political propaganda.  My 6 starting rules seem to yield 3 possible outcomes that are very good for the stated goal of producing lots of healthy children.
  1. binary couples with fidelity
  2. group structure with fidelity and newcomer sequestration
  3. random promiscuity during sole lifetime encounter, followed by parent-group association
Did I miss something?
mellowtigger: (Default)
That landing against the tree seems to require more repair than I had initially figured. I've been very tired and sleepy since then, seeming to rest up so my body can spend its energy on undoing some unseen damage. My lower back still hurts, but it's getting better. I have spackled skin where the tree bark roughed my back, but I see no sign of any serious harm. Still, I've slept 1.5 times as much as usual, and I blame my energy level for today's pessimism.

We're changing the content of our biosphere in so many ways:
  • atmosphere (through combustion vehicle exhaust and factory exhaust)
  • soil (though mass ranching, and with pesticides through mass farming, maybe even with electricity)
  • water (with chemicals carried by rain runoff from our cities, and with pharmaceuticals from our sewers, noise from our sonar)
  • biodiversity (simply by carrying macro/micro living organisms across every spot of land on the globe every day, or by mechanizing the destruction of one local ecology to replace it with a new local ecology)
I'm not surprised that a fungal disease is ravaging the world's frog population, or that the north pole may be ice-free this summer for the first time in recorded human history, or that bees (whose species outnumber mammals and birds combined) are suffering colony collapse disorder apparently as a result of a viral infection and their loss will cause even more food shortage for humans.

No, all of that I could believe without getting depressed.

But now even NASA is getting desperate to ring the alarms, primarily as a result of the efforts of Dr. James Hansen, the director of the Goddard Institute of Space Sciences. This man has his own collection of worrying notes, but the pertinent one today is his look back at his last 20 years (pdf) working on just the issue of climate change. Part of me wishes that Homo sapiens would be included in the list of casualties in this now-unfolding 6th occurence of mass extinction in earth's history, as it would seem the only just outcome of our own influence. Or, at the very least, that we evolve into a less-intelligent (and less influential) species, as described by Kurt Vonnegut in his story, Galapagos.

If we ascribe agency to the anthropomorphic Mother Nature... maybe that's what She's preparing for.  One can hope.  (In such a pessimistic mood.)
mellowtigger: (Default)
Well, a new study shows that there is actually a link of some kind between autism diagnosis and proximity to environmental mercury exposure. Not only that, but it shows a statistically significant link between risk level and distance from the mercury source such that "... community autism prevalence is reduced by 1 percent to 2 percent with each 10 miles of distance from the pollution source."

The study was done on data from Texas, where I grew up. They looked at influence from coal-fired power plants and other industrial facilities. They did not consider mercury contamination from the water supply, where decades of defoliant use on cotton crops has made the groundwater into a known health hazard during dry seasons.  Thankfully, the author is apparently aware of another issue (individual response to mercury) and stated plainly that, “This study was not designed to understand which individuals in the population are at risk due to mercury exposure."

I'm a bit of an agnostic in this debate. I do not believe that autism is just another word for mercury poisoning. I do not believe that autistics respond the same way to mercury as the rest of the population. I could fairly be called a fence sitter, just waiting for more information. That's fine. My own thoughts are more specific but just harder to classify in the usual dichotomy.

My pet theory: Autism results when an environmental factor (edit: mercury? zinc?) triggers an awakening (via epigenetic influence) of long-dormant genes, specifically genes related to the metabolism of metals (mercury and others) that were never quite "completed" successfully whenever they were last being worked on by evolutionary pressures. How soon and how fully the old genetic machinery awakens may influence the constellation of symptoms experienced by the individual.

Shorter translation: Mother Nature is experimenting again with an old, previously shelved model of human, and we call the results autism.

*goes back to sitting on the fence, waiting for more information, mulling more thoughts about my quack theory*
mellowtigger: (Default)
Researchers managed to create a system that directs evolutionary changes in molecules. Essentially, they ran a chemical soup in a petri dish for 70 hours, slowly starved it for energy, then watched the molecules evolve into forms 90x more efficient than the starting molecules. Estimated cost for the device: $8.

Yes, order increases spontanously without direction, and it changes as a reaction to its environment. This is the central idea behind the title of the book, Darwin's Dangerous Idea. The author, philosopher Daniel C Dennett, argues that after more than a century people are still unable to grasp that concept and so that's why they still haven't come to terms with evolution as a reality. It's not that evolution contradicts religion, it's that it makes creationism an unnecessary complexity. The only thing it helps to contradict is the notion of a 6000-year-old earth. Evolution is real, it works, but it needs a lot more time than that.
The Scripps Research investigators who designed the device note that the findings provide an example of the Darwinian principle of selective pressure at work, seen in real time. "This is evolution at the level of molecules as a fact, not a theory,"...

These steps were repeated automatically for 500 iterations of 10-fold growth followed by 10-fold dilution. "The competition between the RNA enzymes to scrape up the few substrates became progressively stiffer, and the variants of RNA enzymes that could bind fastest and tightest to the substrate fuel molecules won out," Paegel says.

"We starved these enzymes, pushing them to become better and faster at forming a bond so they could reproduce themselves," Joyce says. "This is like the evolution of animals that can survive food famines. Only here we can see it happen in 70 hours and we know why the mutations that constitute evolution in these molecules occurred. We witnessed the entire story."
Very interesting. Coincidentally, the news arrives as "Expelled: No Intelligence Allowed" arrives in movie theaters. I don't understand the subtitle to that movie. It seems to insult the people meant to watch it, those wanting intelligent design?


mellowtigger: (Default)

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