Springtime collision

I've written here before about the rather sobering topic of mass extinctions, and from what reading I've done on the topic, it always leaves me thinking about how fragile Earth's ecosystems are.  Most of the biggest extinctions were not due to a single cause, though; for example, the Ordovician-Silurian extinction of about 445 million years ago seems to have been touched off by plate tectonics -- the massive southern continent of Gondwana meandered across the south pole, leading to ice cap formation, massive glaciation, and a drop in sea level.  However, there followed a huge drop in atmospheric oxygen and spike in sulfur, leading to worldwide oceanic anoxia.  The result: an estimate 60% mortality rate in species all over the Earth.

Anoxia is also thought to have played a role in the largest mass extinction ever, the Permian-Triassic extinction of 252 million years ago.  This one, however, seems to have begun with a catastrophic volcanic eruption that boosted the carbon dioxide in the atmosphere, and thus the temperature.  Temperature is inversely related to oxygen solubility, so as the oceans warmed, what oxygen was left in the air didn't dissolve as well, and nearly everything in the oceans died (a mortality rate estimated at an almost unimaginable 95%).  This caused an explosive growth in anaerobic bacteria, pumping both carbon dioxide and methane into the atmosphere.  The average temperature skyrocketed by as much as ten degrees Celsius.

Even the smaller extinctions seldom come from one cause.  I wrote recently about the Eocene-Oligocene extinction, which wiped out a good many of Africa's mammal species (our ancestors survived, fortunately for us), and was apparently an evil confluence of three unrelated events -- rapid cooling of the climate after the Paleocene-Eocene Thermal Maximum, a massive meteorite collision near what is now Chesapeake Bay, and explosive volcanism in Ethiopia.

The exception to the rule seems to be the most famous extinction of all, the Cretaceous-Tertiary extinction of 66 million years ago.  The one that ended the hegemony of the dinosaurs.  I always find it wryly amusing when the dinosaurs are described as some kind of evolutionary dead-end, as if their failure to survive to today is indicative that they were inferior or maladapted.  In fact, the dinosaurs as such were the dominant group of terrestrial animals for almost two hundred million years -- from the late Permian to the end of the Cretaceous -- and that's not counting birds, which are (frankly) dinosaurs, too.  That means if you consider the earliest modern humans to have lived in Africa on the order of three hundred thousand years ago, the dinosaurs kind of ran the planet for over six hundred times longer than we've even existed.

And in the blink of an eye, everything changed.  Far from being an evolutionary cul-de-sac, the dinosaurs were doing just fine, when a meteor ten kilometers in diameter slammed into the Earth near what is now the Yucatán Peninsula of Mexico.  And now scientists have been able to pinpoint not only where the collision happened, but what time of year -- the middle of the Northern Hemisphere's spring.

The Chicxulub Impact, as visualized by artist Donald E. Davis [image is in the Public Domain courtesy of NASA]

Paleontologists working in North Dakota have found a rich fossil site that was created on that fateful day.  Pre-collision, the area was a wet lowland forest with a shallow river.  The slow-moving water was the home of paddlefish and sturgeon, swimming slowly and nosing around in the mud for food.  Then, three thousand kilometers away, the meteor struck.  The shock wave ejected a sheet of superheated steam and molten rock skyward; the impact, which occurred in what was (and still is) a shallow marine region, generated a tsunami the likes of which I can't even imagine.  The southern part of North America got flash-fried by the heat generated by the strike; only a few minutes later, it was followed by a wall of water the height of a skyscraper that swept across the land at an estimated five hundred kilometers an hour.

The first thing the fish would have noticed, though, is a rain of tiny globs of molten glass that sizzled as they hit the water and settled out, coating the riverbed and clogging their gills.  Then the tsunami hit, burying the site under thick layers of sediment.  By the time things calmed down, most of the living things in North America were dead, their fossils left behind as a near-instantaneous photograph of one of the worst days the Earth has ever seen.

It's the quickness of the event that allowed scientists to figure out when it happened.  Paddlefish bones form growth layers -- a little like the rings inside a tree trunk -- and all of the paddlefish fossils from the site show an increasing rate of growth, but not yet at its annual peak (which occurs in the warmest parts of summer).  The Chicxulub meteorite seems to have struck the Earth in April or May.

This may be another reason why the Northern Hemisphere flora and fauna took a much bigger hit than the ones in the Southern Hemisphere.  The initial explanation was that the meteor struck the Earth at an angle, on with a trajectory on the order of forty-five degrees south of vertical, so the shower of molten debris mostly got blasted northward.  (This may well be true; the current research doesn't contradict that assessment.)  But if the strike occurred in the Northern Hemisphere's spring, when plants are leafing out and flowering, and animals increasing in activity, it would have been catastrophic.  The ones in the Southern Hemisphere, heading into fall and winter, would have been in the process of powering down and moving toward dormancy and hibernation, and may have been more insulated from the effects.

Besides the obvious fascination of an event so cataclysmic, it's just stupendous that we can analyze the evidence so finely that we can determine what time of year it occurred, 66 million years later.  It also highlights how suddenly things can change.  The dinosaurs had been around for two hundred million years, surviving not only the colossal Permian-Triassic extinction but the smaller (but still huge) end-Triassic extinction, that took out thirty percent of the species on Earth.  In one particular April of 66 million years ago, a quick look around would have led you to believe that everything was fine, and that the dinosaurs and other Mesozoic critters weren't going anywhere.

A day later, the entire face of the Earth had changed forever.

**************************************

"Gotcha" proselytizing

A frequent reader and commenter on Skeptophilia sent me a note a few days ago, with a link and the cryptic comment, "Gordon, I think you need to take a look at this."  At first, I thought the link was to my own website -- but underneath the link was an explanation that the individual had discovered the link by accidentally mistyping the website address as skeptophilia.blogpsot.com.  (Bet it took you a while to figure out the misspelling, didn't it?  It did me.)

So, anyway, I clicked on the link, and was brought here.

To say that I found this a little alarming was an understatement.  Had someone gone to the lengths of purchasing a website name one letter off from mine, to catch off guard the unwary (and possibly uneasy) skeptics and agnostics who thought they were going to visit a site devoted to rationalism?  I've been the target of negative comments before, from angry believers in everything from homeopathy to hauntings, and certainly have gotten my share of hate mail from the vehemently religious contingent who are bothered by the fact that I am an atheist who is completely, and confidently, "out," and am an unapologetic defender of the evolutionary model, Big Bang cosmology, and so on.  But this seemed kind of out there even for those folks.

Fortunately, my wife, who is blessed with a better-than-her-fair-share amount of common sense and a good grounding in technology, suggested that I try to type in SomethingElse.blogpsot.com.  So I did.  I first tried the address for a friend's blog, but put in the deliberate misspelling for "blogspot."  It brought me to the same place.  Then I tried "CreationismIsNonsense.blogpsot.com."  Same thing.

So apparently, the owner of this ultra-fundamentalist website, with its babble about the Rapture and Armageddon and the literal truth of the Bible, had just bought the domain name "blogpsot.com," so that any time anyone makes that particular misspelling in heading to their favorite blog, it takes them to that site.  I was relieved, actually; the thought that someone would go to all that trouble to target me in particular was a little unnerving.  (And evidently the fact that on the homepage of the "blogpsot" site, there is a link for "The World's Biggest Skeptic" is just a coincidence.)

However, you have to wonder if the person who owns the site really is laboring under the mistaken impression that this is an effective proselytizing tool.  Can you really imagine someone who is trying to check out the latest post on his/her favorite blog on, say, sewing, and lands here -- and then suddenly goes all glassy-eyed, and says, "Good heavens. I get it now.  The Bible is true, the Rapture is coming, and I'd better repent right now."

No, neither can I.

And when you think about it, the door-to-door religion salesmen that periodically show up in our neighborhoods are the same kind of thing, aren't they?  A little less covert and sneaky, that's all.  But they're trying to accomplish the same goal -- catching you off guard, getting a foot in the door, spreading the message.

Of course, that approach sometimes backfires.  A couple of years ago a pair of missionaries (Jehovah's Witnesses, if I recall correctly) came up to my front door.  They were both women, the older maybe forty and the younger looking like she was in her twenties.  Both of them were immaculately attired in modest dresses and starched white blouses.  They didn't see that I was working in the garden; I was kind of hidden behind a bush I was pruning.  It was a blistering hot day, and when I heard the knock I walked over to them -- shirtless, covered in grime and sweat.  I acted completely nonchalant, but they were clearly uncomfortable.  The usual spiel was seriously truncated, and they made an excuse to leave after five minutes or so despite my rather over-the-top friendliness.

I gave them a big wave when they left and told them to drop in any time.

Never saw them again.  I guess God's only interested in converts who are clean and fully clothed.

Franciscan missionaries in California (woodcut from Zephyrin Engelhardt's Mission San Juan Capistrano: A Pocket Guide, 1922) [Image is in the Public Domain]

In any case, my previous comment about this sort of thing being an ineffective proselytizing tool is irrelevant, really.  It's like spam emails.  If you send out a million emails, and your success rate is 0.1%, you've still made money, because of the extremely low overhead.  Same here; you get volunteers (in the case of the door-to-door folks) or unsuspecting drop-ins (in the case of the website).  Most of the target individuals say no, or hit the "Back" button -- but the fraction of a percent that don't are your payoff.

The whole thing pisses me off, frankly, because it's so sneaky.  Even if it wasn't targeted at me specifically, it just seems like a skeevy way to get converts.  But to a lot of these folks, how you convert people is unimportant.  The essential thing is to convert them in the first place.  If you can grab people when their rational faculties are not expecting it, all the better -- because, after all, rationality is the last thing they want to engage.

**************************************

Unity in diversity

It was in my evolutionary biology class in college that I ran into a concept that blew my mind, and in many ways still does.

It was the idea that race is primarily a cultural feature, not a biological or genetic one.  There is more genetic diversity amongst the people of sub-Saharan Africa -- people who many of us would lump together as "Black" -- than there is in the rest of the world combined.  A typical person of western European descent is, our professor told us, closer genetically to a person from Japan than a Tswana man is to the !Kung woman he lives right next door to in Botswana, even though both have dark skin and generally "African features."

To reiterate: I'm not saying race doesn't exist.  It certainly does, and the social, cultural, and political ramifications are abundantly clear.  It's just that what we often think of as race has very close to zero genetic support; we base our racial classifications on a handful of characteristics like skin and eye color, the shape of the nose and mouth, and the color and texture of the hair, all of which can so easily undergo convergent evolution that it triggers us to lump together very distantly-related groups and split ones that lie much closer together on the family tree.

The reason this comes up today is a couple of bits of recent research highlighting the fact that the subject is way more complicated than it seems at first.  The first looks at the fragmentation that happened in Africa, on the order of twenty thousand years ago, that resulted in the enormous genetic diversity still to be found in sub-Saharan Africa today.  By analyzing DNA from both living individuals and the remains of people from long ago, researchers at Harvard University found that this was about the time that our ancestors stopped (for the most part) making extended walkabouts to find mates, and settled into being homebodies.  What triggered this is a matter of conjecture; one possibility is that this was in the middle of the last ice age, it could be that the colder and drier conditions (even in equatorial regions) made food scarcer, so long trips into unknown territory were fraught with more danger than usual.

Whatever the cause, the isolation led to genetic drift.  A general rule of evolutionary biology is that if you prevent genetic mixing, populations will diverge because of the accrual of random mutations, and that seems to be what happened here.  The fact that a Tswana person and a !Kung person (to use my earlier example) are so distinct is because they've been genetically isolated for a very long time -- something facilitated by a tendency to stay at home and partner with the people you've known all your life.

Interestingly, some research last year suggested that there are "ghost lineages" in the human ancestry -- groups that are ancestral to at least some modern humans, but are as yet unidentified from the fossil record.  The one studied in last year's paper were ancestral to the Yoruba and Mende people of west Africa, in which between two and nineteen percent of the genomes come from this ghost lineage -- but the phenomenon isn't limited to them.  The authors found analogous (but different) traces of ghost lineages in people of northern and western European and Han Chinese descent, and the guess is that all human groups have mysterious, unidentified ancestral groups.

The other bit of research that was published last week was an exhaustive study of the genetics of people around the world, with an ambitious goal -- coming up with a genetic family tree for every group of people on Earth. "We have basically built a huge family tree, a genealogy for all of humanity that models as exactly as we can the history that generated all the genetic variation we find in humans today," said Yan Wong of the University of Oxford, who co-authored the study.  "This genealogy allows us to see how every person's genetic sequence relates to every other, along all the points of the genome."

The researchers analyzed 3,609 individual DNA samples representing 215 different ethnic groups, and used software to compare various stretches of the DNA and assemble them using the technique called parsimony -- basically, creating a family tree that requires the fewest random coincidences and ad hoc assumptions.  The result was an enormous genealogy containing 27 million reconstructed common ancestors.  They then linked location data to the DNA samples -- and the program identified not only when the common ancestors probably lived, but where they lived.

I find this absolutely amazing.  Using modern genetic analysis techniques, we can assemble our own family tree, with roots extending backwards tens of thousands of years and encompassing lineages for which we have no archaeological or paleontological records.  With the number of connections the research generated, I have no doubt we'll be studying it for years to come, and have only started to uncover the surprises it contains.

But all part of living up to the maxim inscribed in the Temple of Apollo at Delphi -- γνῶθι σεαυτόν.

"Know thyself."

**************************************

Out of sight, out of mind

Humans have amazingly short memories.

I suppose that there's at least some benefit to this.  Unpleasant events in our lives would be far, far worse if the distress we experienced over them was as fresh every single day as it was the moment it happened.  That's the horror of PTSD; the trauma gets locked in, triggered by anything that is even remotely similar, and is re-experienced over and over again.

So it's probably better that negative emotions lose their punch over time, that we simply don't remember a lot of what happens to us.  But even so, I kind of wish people would keep important stuff more in mind, so we don't repeat the same idiotic mistakes.  Santayana's quote has almost become a cliché -- "Those who don't remember the past are doomed to repeat it" -- but part of the saying's sticking power is its tragic accuracy.

The reason this comes up is because of some research out of Oxford University that appeared in the journal Trends in Ecology and Evolution this week.  A team led by Ivan Jarić looked at the phenomenon of extinction -- but framed it a bit differently than you may have seen it, and in doing so, turned the spotlight on our own unfortunate capacity for forgetting.

There are various kinds of extinction.  Extirpation is when a species is lost from a region, but still exists elsewhere; mountain lions, for example, used to live here in the northeastern United States, but were eradicated in the late nineteenth and early twentieth century (the last confirmed sighting was in Maine in 1938).  They're still holding their own in western North America, however.  Functional extinction is when the population is reduced so much that it either no longer has much impact on the ecosystem, or else would not survive in the wild without signification conservation measures, or both.  Sadly, the northern white rhinoceros, the northern right whale, and the south China tiger are all considered functionally extinct.  

Extinct in the wild is exactly what it sounds like; relict populations may exist in captivity, but it's gone from its original range.  Examples include the beautiful scimitar oryx, the Hawaiian crow, and the franklinia tree (collected in the Altamaha River basin in Georgia in 1803 and never seen in the wild since).  Such species may be reintroduced from captive breeding, but it tends to be difficult, expensive, and is often unsuccessful.

Then there's global extinction.  Gone forever.  There has been some talk about trying to resuscitate species for which we have remains that have intact DNA, Jurassic Park-style, but the hurdles to overcome before that could be a reality are enormous -- and there's an ongoing debate about the ethics of bringing back an extinct species into a changed modern world.

The new research, however, considers yet another form of extinction: societal extinction.  This occurs when a population is reduced to the point that people basically forget it ever existed.  It's amazing both how fast, and how completely, this can happen.  Consider two bird species from North America -- the passenger pigeon (Ectopistes migratorius) and the Carolina parakeet (Conuropsis carolinensis) -- both of which were common in the wild, and both of which went completely extinct, in 1914 and 1918 respectively.

Illustration of the passenger pigeon by naturalist Mark Catesby (1731) [Image is in the Public Domain]

Actually, "common" is a significant understatement.  Up until the mid-nineteenth century, passenger pigeons were the most common bird in North America, with an estimated population of five billion individuals.  Flocks were so huge that a single migratory group could take hours to pass overhead.  Carolina parakeets, though not quite that common, were abundant enough to earn the ire of fruit-growers because of their taste for ripe fruit of various kinds.  Both species were hunted to extinction, something that only fifty years earlier would have been considered inconceivable -- as absurd-sounding as if someone told you that fifty years from now, gray squirrels, robins, house sparrows, and white-tailed deer were going to be gone completely.

What is even more astounding, though, is how quickly those ubiquitous species were almost entirely forgotten.  In my biology classes, a few (very few) students had heard of passenger pigeons; just about no one knew that only 150 years ago, there was a species of parrot that lived from the Gulf of Mexico north to southern New England, and west into the eastern part of Colorado.  As a species, we're amazingly good at living the "out of sight, out of mind" principle.

The scariest part of this collective amnesia is that it makes us unaware of how much things have changed -- and are continuing to change.  Efforts to conserve the biodiversity we still have sometimes don't even get off the ground if when the species is named, the average layperson just shrugs and says, "What's that?"  Consider the snail darter (Percina tanasi), a drab little fish found in freshwater streams in the eastern United States, that became the center of a firestorm of controversy when ecologists found that its survival was jeopardized by the Tellico Dam Hydroelectric Project.  No one but the zoologists seemed to be able to work up much sympathy for it -- the fact that it wasn't wiped out is due only to the fact that a population of the fish was moved to neighboring streams that weren't at risk from the dam, and survived.  (It's currently considered "threatened but stable.")

"It is important to note that the majority of species actually cannot become societally extinct, simply because they never had a societal presence to begin with," said study lead author Ivan Jarić, in an interview with Science Daily.  "This is common in uncharismatic, small, cryptic, or inaccessible species, especially among invertebrates, plants, fungi and microorganisms -- many of which are not yet formally described by scientists or known by humankind.  Their declines and extinctions remain silent and unseen by the people and societies."

Which is honestly kind of terrifying.  It's bad enough to lose species that are, as it were, right in front of our eyes; how many more are we losing that are familiar names only to biologists, or aren't even yet known to science?  And keep in mind that little-known doesn't mean unimportant.  There are plenty of "uncharismatic, small, cryptic, or inaccessible species" that are pretty damn critical.  One that springs to mind immediately are mycorrhizae, a group of underground fungi that form a symbiotic relationship with plant roots.  The relationship is mutually beneficial; the plant has its capacity to absorb minerals and water greatly increased, and the fungus gets a home and a source of food.  By some estimates, 95% of plant species have a mycorrhizal partner, and some -- notably orchids -- are completely dependent on it, and die if they are separated from their fungal symbiont.  Even plants that aren't entirely reliant on them benefit from the relationship; there is increasing evidence that adding mycorrhizal spores to an ordinary vegetable garden can decrease dependence on chemical fertilizers, improve drought resistance, and increase crop yield (some experiments have seen it as much as double).

Incredibly cool.  But not what most of us would consider "charismatic."  I doubt, for example, that micrographs of mycorrhizae will ever usurp the wolves and eagles and elephants on the pages of the calendars we hang on our walls.  I mean, I would buy one, but I suspect I'm in the minority.

What this highlights to me is that we need to fight this tendency to overlook or forget about the organisms in our world that aren't obvious -- the rare, the small, the hidden.  The fact that their plight is not as obvious as the whales and the elephants and the tigers doesn't mean they're unimportant.  We need to become conscious of what's around us, and committed to protecting it.  Another comparison that's become almost a cliché is comparing biodiversity to a tapestry, but the symbolism is apt.

Pull out enough threads, and the entire thing comes to pieces.

**************************************

Continental mashup

Today's topic comes to us not because it's some earthshattering discovery that overturns what we've understood, but solely because it's really cool.

You probably know the general rule that isolated ecosystems -- islands, especially -- tend to evolve in their own direction, resulting in a flora and fauna that is completely unique.  Two of the most common places cited as illustrations of this general rule are Australia and Madagascar, home to two of the oddest collections of species on Earth.  Australia's species are so different from the (relatively) nearby biomes in southeast Asia that it was noticed over 150 years ago by British naturalist Alfred Russel Wallace, and the boundary was named "Wallace's Line" in his honor.  It's an amazingly sharp edge.  Wallace's Line runs between Borneo (to the west) and Sulawesi (to the east), and between Bali (to the west) and Lombok (to the east); the distance between Bali and Lombok is only 35 kilometers, but their flora and fauna are so different it was apparent to Wallace immediately.  North and west of Wallace's Line, the animals and plants are the typical assemblage you see in all of southeast Asia.  South and east of it, you get the families you find in Australia.

Another case of this was the linkup of North and South America, forming the Isthmus of Panama three million years ago.  Prior to this, South America had been isolated for 150 million years, resulting in the evolution of a completely unique group of living things, including the giant ground sloth (Megatherium) and the armored-tank glyptodons.  When the connection formed, this allowed the North American carnivores (especially dogs, cats, and weasels) to migrate south.  Humans eventually followed.  The result -- extinction of most of the South American megafauna.  (One of the only species to make the return trip successfully is the armadillo.)

The research that brings this topic up is a study showing that this kind of thing has been going on throughout the Earth's history.  In this case, a team of paleontologists and geologists has shown that a similar scenario unfolded forty million years ago, during the Eocene Epoch, when three land masses collided -- what are now Europe and western Asia, and a low-lying island in between that has been named Balkanatolia (because what's left of it now forms the Balkans and Anatolia).  Here is the layout prior to the collision, and where those land masses are today:

So here, we have not two but three assemblages of species suddenly finding themselves being stirred together.  The result has been named the Grande Coupure (the "great break"), when most of the endemic European fauna -- groups like the paleotheres, distantly related to horses, and the European primate family Omomyidae -- vanished completely.  The winners were the ancestors of who you see now, pretty much across the entire region; canids, true perissodactyls and artiodactyls (for example, horses and pigs respectively), squirrels, hamsters, beavers, and hedgehogs.

Sometimes, who wins and who loses is due as much to luck as it is to fitness.  The species that became extinct in these continental fusion events were doing just fine before the land masses linked together; had North and South America not joined, we might well have giant ground sloths and glyptodons today.  (Of course, those kinds of counterfactual speculation are probably pointless.  Any number of things besides predation by North American mammals could have led to the extinctions.  After all, there have been a lot of changes, climatic and otherwise, since then, and megafauna always seem to get hit hardest by rapidly-shifting conditions.)

But it's cool to find another example of this effect.  And it also gives us a hint of what's to come.  The Australian Plate is moving generally northward at about seven centimeters per year, and will inevitably collide with Asia in a hundred million years or so.  This fusion will erase Wallace's Line and allow for mixing of the two faunal and floral assemblages.

Who will win?  No way to tell, but considering how badass some of the Australian animals are (saltwater crocodiles, cassowaries, brown snakes and taipans, and funnel-web spiders, to name just a few), I'm putting my money on the Land Down Under.

**************************************

Yanking open the closet door

If you needed another reason to be outraged at the direction the United States is going, a bill currently moving through the state congress of Florida -- and 100% supported by Governor DeSantis -- would not only prohibit teachers from mentioning anything about sexual orientation (their own or anyone else's), but would require them to out LGBTQ students to their parents.

Further support of journalist Adam Serwer's statement that with the GOP, the cruelty is the point.

Nicknamed the "Don't Say Gay" bill, Florida's House Bill 1557 initially was intended to prevent any discussion of queerness in the classroom -- up to and including teachers revealing, even in passing, that they are queer themselves.  So this would, in effect, prevent a gay teacher (for example) from mentioning his partner's name, or even having a photograph of the two of them on his desk.  So what happens when he's seen holding hands with his partner in public, and a student asks him point-blank, "Are you gay?"  Is he supposed to say, "I can't answer that?"  Or "None of your business?"

Joe Harding, a Republican (surprise!) in the state House of Representatives, proposed an amendment on Friday to the bill that made it even worse.  If the bill passes -- and it looks like it will -- teachers who find out a student is LGBTQ are required to tell the parents.  Schools would be compelled to "develop a plan, using all available governmental resources" to out children to their parents "through an open dialogue in a safe, supportive, and judgment-free environment that respects the parent-child relationship and protects the mental, emotional, and physical well-being of the student."

Originally there was a clause providing an exemption "if a reasonably prudent person would believe" that outing the student might cause "abuse, abandonment, or neglect," but Harding took that bit out.

The cruelty is the point.

I'm going to say this as plainly as I know how.  I doubt any Florida Republicans are listening, and even if they are, I doubt even more that they'd care,  but despite that:

No one ever, ever, ever has the right to out a person to anyone, except the person him/herself.  Ever.

[Image licensed under the Creative Commons Benson Kua, Rainbow flag breeze, CC BY-SA 2.0]

While I often have wished that I'd had the courage to come out as bisexual much earlier in my life, I can't even imagine what my life would have been like if one of my high school teachers had outed me to my parents without my consent.  I wouldn't have been physically abused; neither of my parents ever laid a hand on me.  However, I was already enduring so much emotional abuse that now, almost fifty years later, I'm still dealing with the damage.  I shudder to think of what my life would have been like if my conservative, traditional Roman Catholic parents had found out I was bi when I figured it out myself at age fifteen.

Even without this, I was already told enough times what a crashing disappointment I was.  Add this on...  Well, to put things in perspective, as it was I attempted suicide twice, ages seventeen and twenty.  That I didn't succeed was honestly just dumb luck.

Had someone told my parents I was bi?  I have little doubt that I wouldn't be here today.

Oh, and the clause that outs the kid in a "safe, supportive, and judgment-free environment that respects the parent-child relationship and protects the mental, emotional, and physical well-being of the student" is unadulterated bullshit.  I can vouch for this from my own experience.  No one -- no one -- knew about my suicide attempts.  Not family members, not friends, not teachers.  From the outside, my parents looked like they were straight out of The Brady Bunch.  My mom, especially, was very good at being a chameleon, and the way she treated me in public was 180 degrees from the way she treated me at home.  There is no way that anyone would have known that I wasn't in an environment that supported my mental, emotional, and physical well-being.

Once again, let me put this plainly: teachers don't know what students' home life is like.  Not even if they've met the parents, not even if they've talked to the student.  And I can say with complete assurance that if I were a teacher in Florida, they would have to fire me, because no way in hell would I comply with the proposed law.  Putting teachers -- even well-meaning ones -- in charge of revealing a student's sexual orientation isn't just irresponsible, it's actively dangerous.  Queer teenagers already have a four times higher risk of self-harm or suicide than straight teens do; this bill, if it passes, will make it much, much worse.

But I suspect that won't make a difference.

The cruelty is the point.

The only thing that might stop this is if people in Florida contact their representatives and senators and say, "No.  This is unacceptable."  It's all well and good to say, "The blood of every queer teen in Florida who comes to harm after this is on your hands," but by that time, it's too fucking late.  This bill needs to be stopped, and it needs to be stopped now.  Somehow, the most unfeeling, unkind, bigoted people have become the ones who are making the laws, and while there's no easy way to get them out of office until the next election, they sure as hell can get buried by angry letters and emails.

Please.  Do it now.

Lives are at stake, here.

**************************************

Splitting the difference

One of the most misunderstood pieces of the evolutionary model is that natural selection is almost always a compromise.

Very few changes that could occur an organism's genes (and thus in its physical makeup) are unequivocally good.  (Plenty of them are unequivocally bad, of course.)  Take, for example, our upright posture, which is usually explained as having been selected for by (1) allowing us to see farther over tall grass and thus spot predators, (2) leaving our hands free for tool use, (3) making it easier to carry our offspring before they can walk on their own, or (4) all of the above.  At the same time, remodeling our spines to accommodate walking upright -- basically, taking a vertebral column that evolved in an animal that supported itself on all fours, and just kind of bending it upwards -- has given us a proneness to lower back injury unmatched in the natural world.  The weakening of the rotator cuff, due to the upper body no longer having to support part of our weight, has predisposed us to shoulder dislocations.

Then there are the bad changes that have beneficial features.  One common question I was asked when teaching evolutionary biology is if selection favors beneficial traits and weeds out maladaptive ones, why do negative traits hang around in populations?  One answer is that a lot of maladaptive gene changes are recessive -- you can carry them without showing an effect, and if you and your partner are both carriers, your child can inherit both copies (and thus the ill effect).  But it's even more interesting than that.  It was recently discovered that being a carrier for the gene for the devastating disease cystic fibrosis gives you resistance to one of the biggest killers of babies in places without medical care -- cholera.  It's well known that being heterozygous for the gene for sickle-cell anemia makes you resistant to malaria.  Weirdest of all, the (dominant) gene for the horrible neurodegenerative disorder Huntington's disease gives you an eighty percent lower likelihood of developing cancer -- offset, of course, by the fact that all it takes is one copy of the gene to doom you by age 55 or so to progressive debility, coma, and death.

So the idea of "selective advantage" is more complex than it seems at first.  The simplest way to put it is that if an inheritable change on balance gives you a greater chance of survival and reproduction, it will be selected for even if it gives you disadvantages in other respects, even some serious ones.

The reason the topic comes up is because of a cool piece of research out of the University of California - Santa Barbara into a curious genetic change in the charming little Colorado blue columbine (Aquilegia caerulea), familiar to anyone who's spent much time in the Rocky Mountains.

Colorado blue columbine (Aquilegia caerulea) [Image licensed under the Creative Commons Rob Duval, Heavycolumbinebloom, CC BY-SA 3.0]

Both the common name and scientific name have to do with birds; columba is Latin for dove, aquila Latin for eagle.  The reason is the graceful, backwards-curved tubular petals, which (viewed from the side) look a little like a bird's foot.  The tubes end in nectar glands, and are there to lure in pollinators -- mostly hummingbirds and butterflies -- whose mouthparts can fit all the way down the long, narrow tubes.

Well, the researchers found that not all of them have these.  In fact, there's a group of them that don't have the central petals and nectar spurs at all.  The loss is due to a single gene, APETALA3-3, which simply halts complete flower development.  So far, nothing too odd; there are a lot of cases where some defective gene or another causes the individual to be missing a structure.  What is more puzzling is that in the study region (an alpine meadow in central Colorado), a quarter of the plants have the defective flowers.

You would think that a plant without its prime method of attracting pollinators would be at a serious disadvantage.  How could this gene be selected strongly enough to result in 25% of the plants having the change?  The answer turned out to be entirely unexpected.  The plants with the defective gene don't get visited by butterflies and hummingbirds as much -- but they are also, for some reason, much less attractive to herbivores, including aphids, caterpillars, rabbits, and deer.  So it may be that the flowers don't get pollinated as readily as those of their petal-ful kin, but they are much less likely to sustain energy-depleting damage to the plant itself (in the case of deer, sometimes chomping the entire plant down to ground level). 

If fewer flowers get pollinated, but the ones that do come from plants that are undamaged and vigorous and able to throw all their energy into seed production, on balance the trait is still advantageous.

Even cooler is that the two different morphs rely on different pollinators.  Species of butterfly with a shorter proboscis tend to favor the spurless variant, while the original spurred morph attracts butterflies and hummingbirds with the ability to reach all the way down into the spur.  What the researchers found is that there is much less cross-pollination between the two morphs than there is between plants of the same morph.

For speciation to occur, there needs to be two things at work: (1) a genetic change that acts as a selecting mechanism, and (2) reproductive isolation between the two different morphs.  This trait checks both boxes.

So it looks like the Colorado blue columbine may be on the way to splitting into two species.

Once again, we have an example from the real world demonstrating the power and depth of the evolutionary model -- and one that's kind of hard to explain if you don't buy it.  This time, it's a pretty little flower that has vindicated Darwin, and shown that right in front of our eyes, evolution is still "creating many forms most beautiful and most wonderful."

**************************************