Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Wednesday, December 5, 2018

Send in the clones

I'm not sure if it's heartening or discouraging to find out that the United States hasn't cornered the market on counterfactual lunacy.

I mean, that's the way it seems lately.  All I have to do is read the news -- something I've been trying not to do often, because it was having horrible effects on my mood -- and I see dozens of examples of people from my country who fervently believe stuff despite, or in some cases because of, there being no evidence whatsoever.

Or sometimes, even if there's powerful evidence supporting the opposing claim.  Amazing how squalling "fake news" has allowed people to resist even looking at opinions that they'd very much like not to be true.

But I guess people fall for loony claims the world over.  If I had any doubts of that, they were eradicated by a story sent to me by a friend and long-time loyal reader of Skeptophilia, which tells about how apparently there are a large number of people in Nigeria who think their president is an evil clone.

I'm not making this up.  President Muhammadu Buhari, who has been the leader of Nigeria since 2015, is gearing up for re-election in 2019, and this seems to have kicked into high gear a claim that Buhari isn't Buhari.  The fact that he was in London for treatment for an undisclosed illness last year was enough to convince a significant number of people that while he was overseas, Buhari was killed and swapped out for either a Sudanese lookalike named Jubril, or an evil laboratory-created clone who has nothing but wicked intent for the people of Nigeria.

President Muhammadu Buhari, or at least so he says [Image is in the Public Domain]

Of course, Buhari claims it's all nonsense.  Also of course, it's had no effect whatsoever.  "It’s the real me, I assure you,” Buhari said in a press conference last Sunday in Poland, where he was attending a United Nations climate conference.  "I will soon celebrate my 76th birthday and I will still go strong."

Which, you have to admit, is exactly what either a Sudanese duplicate or an evil superintelligent clone would say.

The flames were then fueled by Buhari's enemies, who had nothing to lose and a lot to gain by trashing Buhari's credibility.  Nnamdi Kanu, who belongs to a group called Indigenous People of Biafra, has trumpeted the claim on his pirate radio station, Radio Biafra.  And the more Kanu and Buhari's other rivals spread the rumor around, the harder it is for Buhari to say, "Oh, for fuck's sake, are you people serious?" and have anyone listen.

He's still in there swinging, though.  At his news conference, he said, "One of the questions that came up today in my meeting with Nigerians in Poland was on the issue of whether I’ve been cloned or not.  The ignorant rumors are not surprising — when I was away on medical vacation last year a lot of people hoped I was dead."

Well, hoping someone's dead is not really the same thing as thinking he's a laboratory-created clone.  But the fact is, Buhari hasn't really been all that popular, and he's been accused of giving favors to people of his own ethnic group (the Fulani) and ignoring the plight of other groups, especially Christian ones.  Worse, his detractors say he's turned a blind eye to the depredations of Boko Haram, which is still terrorizing the northern part of the country.  The economy has pretty much tanked, with estimates of the ranks of the unemployed up around the ten million mark.

So it's not like Buhari's rivals don't have ammunition enough for criticizing his rule.  Which is probably why there are no fewer than 79 people running in the election, which even exceeds the electoral chaos we typically have here in the United States.  The problem is, it's not like his opponents are squeaky-clean, either; one of the favorites in the election is former vice president Atiku Abubakar, whose motto seems to be "help people when it's expedient and kick 'em in the balls when it isn't."  Abubakar's reputation for the carrot-and-stick approach is evident in the fact that Olosegun Obasanjo, who was himself president of Nigeria from 1999 to 2007, went from saying "If I support Atiku for anything, God will not forgive me" in August and singing his praises last week.

Which makes perfect sense, considering Abubakar's likelihood of winning the election and his penchant for taking revenge on people who criticize him.

So the whole thing is a mess, and is not being helped by the wacky claims about Buhari, or Evil Clone of Buhari, or Jubril of Sudan, depending on which version you went for earlier.

And you know, maybe that would explain a lot about our own political mess.  These elected officials aren't really human beings.  They're holograms that have been sent in by a race of aliens determined to bring down our civilization by making our leaders appear to have lost their marbles.  The problem -- from the aliens' point of view, anyhow -- is that it doesn't seem to be working.  Every time some person in government says something completely outlandish, or idiotic, or outright false, a good third of Americans say, "Exactly right!  You tell 'em!"

So maybe it's my fellow citizens who are holograms.  I just don't know any more.  At this point, I'm ready to throw in the towel and welcome our Alien Overlords.  Can't be any worse that what we've been enduring.

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

This week's Skeptophilia book recommendation is a classic: Richard Dawkins's The Blind Watchmaker.  This book is, in my opinion, the most lucid and readable exposition of the evolutionary model ever written, and along the way takes down the arguments for Intelligent Design a piece at a time.  I realize Dawkins is a controversial figure, given his no-quarter-given approach to religious claims, but even if you don't accept the scientific model yourself, you owe it to yourself to see what the evolutionary biologists are actually saying.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]




Tuesday, December 4, 2018

Medical care, serial dilution, and mathematical horses

It's been a while since we've seen a new salvo from the homeopaths, but I knew this did not mean they'd retreated in disarray.  After all, a belief in pseudoscientific woo-woo quackery means never having to say you're sorry.

The most recent news from the world of homeopathy comes from an online magazine called Clever H.  This is in many ways an unfortunate choice of names.  It immediately reminded me of "Clever Hans," a horse back in 1907 whose owner claimed he could do arithmetic.  Of course, the horse could do no such thing, but was shown by German psychologist Oskar Pfungst to be receiving cues from its owner.  Once the owner was taken off stage, suddenly Clever Hans lost his phenomenal ability to do calculations.

Clever Hans and his owner [Image is in the Public Domain]

So calling the magazine a name that recalls a debunked false claim isn't so much unflattering as it is ironic.  Apparently unaware of this, the writers are boundless in their enthusiasm, subtitling Clever H as "The Mag by Homeopaths, for Homeopaths, With the Patient in Mind!"  The article that caught my attention was called "The Anti-Aging of Homeopathic Cell Salts," which I at first thought meant they'd discovered a way to keep salt from aging.

Which, as far as I've heard, is not really a big problem.

But that isn't what the article's about.  It claims that they've discovered some chemicals ("cell salts") that can prevent, or even reverse, aging.  The authors write:
Tissue Salts are an off shoot of homeopathy and are vital elements that correspond to the same minerals our cells are made of.  These “vital elements” will nourish and rebuild your cells...   [A] homeopathic treatment that can be helpful in slowing the aging process and reducing the early signs of aging is a homeopathic detox of the liver, kidney and lymphatic system.  This will stimulate your body to function better.  A noticeable difference will be seen on the skin’s appearance and even aches and pains will improve.  When the lymphatic system is functioning at its best, weight loss and cellulite will be in control and the immune system will be functioning optimally.

Equipped with such homeopathic anti-aging secrets, the aging process can be slowed and life can be lived to the fullest beyond the days of youth.
Now, at the age of 58, no one would be happier than me to find there was a way to reverse aging.  (Physical aging, I mean.  My emotional age kind of plateaued around age 13, which is why I still laugh at fart jokes.)  On the other hand, I'm not so fond of the gray hair, wrinkles, and miscellaneous aches and pains, and would thrilled if I could return to the physique I had when I was 25.

What Clever H says we should do is take the homeopathic concoctions "calc fluor," "calc phos," and "kali phos," because all of these are valuable "cell salts" that will have the effect of restoring your youth.  Oh, and also "nat mur," which is a "water distributor."  Which, I suppose, is better than having water pool in our feet, or something.

So I did some research -- if you can dignify it by that name -- and found out that "calc fluor" is useful for treating hemorrhoids, "calc phos" restores health after an injury, "kali phos" is good for stress, and "nat mur" keeps you from drying out.  "Nat mur," I also found out, was made from plain old salt, so I was curious as to why they were making such a big deal about it.  In searching for an answer I stumbled upon a page about "nat mur" on the site of the British Homeopathic Organization, which had some information that was puzzling, to say the least:
The higher organisms, the mammals, require sodium chloride in comparatively large amounts.  It is clear that as life evolves to higher forms, and the faculties of perception and feeling unfold, the role of sodium chloride in psychological and biological functions becomes increasingly important.  The active secretion of salt through the urine, sweat and tears appeared in parallel with the development of feeling and the tender emotions.
So I'm supposed to develop tender emotions when I'm taking a piss?  Or am I missing some vital piece of the argument, here?

We also find out there are "nat mur" personalities, which are characterized by harshness, resentment, and lack of demonstrative emotions.  Because of the ocean or something.

 But back to the Clever H page, wherein we find that the recommended concentrations of all of these "remedies" are between "6x" and "30x."  For those of you who don't know how homeopathic "remedies" are produced, allow me to explain that each "x" represents a 1-in-10 dilution.  So a 6x dilution would have 1 part of the original substance dissolved in 1,000,000 parts of some inert substance like water or a sugar pill.  So that's pretty dilute, but it's nothing like a 30x dilution, which is 1 part of the original substance dissolved in 1,000,000,000,000,000,000,000,000,000,000 parts of inert substance.

Which for most of us qualifies as "really fucking dilute," but those of you who know some chemistry might recognize that this dilution far surpasses Avogadro's Limit -- because once you have done a 1-in-10 serial dilution 23 times, you have (on average) one molecule of the original substance left.  Any further dilution, and you essentially have nothing there but the inert carrier.

Not that the original substance does what the homeopaths say it does in the first place.  But considering that they claim that the more dilute a substance is, the stronger it is, I'm not sure we should be splitting scientific hairs, here.

If you paw around the Clever H site, you find the following disclaimer:
All content on this website is intended as an adjunct to, not a substitute for professional homeopathic and/or medical care. 
No publication of Clever H. or its sub-pages should be interpreted as a means of diagnosis or treatment for any disease or condition, and the articles published at Clever H. by no means claim completeness of information. 
For a medical diagnosis or treatment a licensed medical professional should be consulted. Homeopathic treatments should only be undertaken under direct guidance and care of a professionally trained Health Care Professional specialized in the services described.
Maybe it's just me, but "A noticeable difference will be seen on the skin’s appearance and even aches and pains will improve.  When the lymphatic system is functioning at its best, weight loss and cellulite will be in control and the immune system will be functioning optimally" sure sounds like a recommendation for a "treatment of [a] disease or condition."

I keep hoping that the homeopaths and other purveyors of pseudo-medical quackery will be so widely known for what they are that they'll go out of business, but (much as it pains me to admit it) homeopathic "remedies" are still on the shelves of our local pharmacy.  Including some that are 30x dilutions (or even more dilute, and therefore stronger).  This means that people are buying them, and using them in the hopes of treating conditions for which they should be seeking out legitimate medical care.  Bringing me back once again to the site What's the Harm -- wherein you will find that a lack of critical thinking skills, with regards to your own health, can be very, very dangerous.

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

This week's Skeptophilia book recommendation is a classic: Richard Dawkins's The Blind Watchmaker.  This book is, in my opinion, the most lucid and readable exposition of the evolutionary model ever written, and along the way takes down the arguments for Intelligent Design a piece at a time.  I realize Dawkins is a controversial figure, given his no-quarter-given approach to religious claims, but even if you don't accept the scientific model yourself, you owe it to yourself to see what the evolutionary biologists are actually saying.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]




Monday, December 3, 2018

Fruits and vegetables

What is the fascination creationists have for the produce aisle?

First we had Ray Comfort claiming that bananas were "the atheists' worst nightmare" because we for some reason were supposedly befuddled by the fact that bananas are "perfectly shaped to fit into the human hand" and had a "non-slip surface," so they must have been created that way by an intelligent deity.  After Comfort was subjected to ridicule on social media at a level that would induce most of us to change our names and have our faces surgically altered before being willing to go out into public again -- I'll leave it to your imagination as to what other objects people informed Comfort were "perfectly shaped to fit into the human hand" -- you'd think the creationists would say, "Okay, maybe that's not the best argument we have."

But no.  Creationists, as a whole, seem to think that if at first you fail miserably, you don't just try try again, you beat the idea unto death with a blunt instrument.  And no one is better at that strategy than Kent Hovind, who is famous not only for specious arguments for young-Earth creationism but for spending ten years in federal prison for tax evasion.

Hovind seems to think that the way to support Ray Comfort's argument is to find other fruits and vegetables that are "the atheists' worst nightmare."  First, we had lettuce:
How could lettuce evolve slowly by chance and from what?  How many trillions of intermediate steps would there have to be to go from a dot of nothing to a living lettuce plant?  Is there any scientific evidence besides lines on paper?
Yes, there is.  Thanks for asking.

How could a grapevine… evolve slowly by chance and from what?  Wait till you see what they teach on the internet that the grapes evolve from.  You won’t believe it… 
How could it happen by chance and from what?  How many trillions of intermediate steps would there have to be to turn a dot of nothing into a grape?  Isn’t that what they teach?
No, it isn't.  Thanks for asking.

Because that was such a wildly successful line of reasoning, Hovind turned to celery:
How could celery have evolved slowly by chance, and from what?…  I would like some hard scientific evidence.  What is the ancestor of celery if it wasn’t celery?  What was it?  And if it was something other than celery, please tell me how it changed. 
How many trillions of intermediate steps would there have to be to go from an amoeba to celery?  I would say it would take a lot.  I would like to see what’s the evidence is for that…
That is going to be problematic, because celery didn't evolve from amoebas.  But once again, thanks for asking.

So what about... broccoli?
Broccoli.  How could broccoli have evolved slowly by chance?  I would like an answer to that.  A very simple answer.  How many trillions of intermediate steps would there have to be to change from an amoeba... to broccoli?  Is there any scientific evidence for these supposed changes that you guys believe in — capital B, believe? 
Evolution is a religion.  Is it more logical to believe that maybe broccoli was created by a really smart Creator?
Hovind seems to like amoebas almost as much as fruits and vegetables.  Maybe he doesn't know about any other life forms, so that's why he keeps coming back to those.

To wit, last week's installment, wherein we hear about oranges.  And you'll never guess what his argument is:
You think all those oranges, and those trees that are producing it, and the dirt that’s holding it all came from a dot of nothing that exploded 13.7 billion years ago?  Whodathunkit.  That’s a new word I made up. 
How many trillions of intermediate steps would there have to be to go from a dot of nothing to an orange tree, and where is the evidence?  Is there any scientific evidence for all these supposed changes you guys talk about?…  Could it be more logical to believe, maybe, the orange tree was created by a really smart Creator?…  That’s the most logical conclusion.
 Of course, what all this boils down to is the argument from ignorance; "I can't imagine how this could happen" = "this didn't happen."  Evolutionary biologists and geneticists have a very good idea about how all of these organisms evolved (in most of these examples, with significant help from artificial selection by humans), and Hovind is only claiming this because he hasn't bothered to read any of the scientific papers explaining in great detail the answers to all of these questions.

[Image is in the Public Domain]

And I swear, if I hear one more time that the Big Bang Model says that "a dot of nothing exploded and made everything," I'm going to punch a wall.  For fuck's sake, if you're going to blather on about something, at least read the Wikipedia article first, if more technical treatments are above your head.  If you can't be bothered to do at least that much, allow me to direct you to the definition of "straw man argument."

Oh, and Kent?  You did not make up "whodathunkit."  I can remember my dad saying that back in the mid-1970s when I was in high school.  But given your determination to misrepresent and play fast and loose with scientific claims (not to mention your IRS return), I don't suppose there's any reason to expect you'd be more honest about other stuff.

But you have to wonder where he's going to go now.  Artichokes?  Mangoes?  Okra?  Pomegranates?  Bok choi?  The possibilities are endless.  It'd be nice, though, if he could change the rest of the argument, because it's getting tiresome to read, "So, consider _____.  Could that have come from a dot of nothing 13.7 billion years ago?  What's the evidence?" etc. etc. etc.  He's rung the changes on this one enough, don't you think?

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

This week's Skeptophilia book recommendation is a classic: Richard Dawkins's The Blind Watchmaker.  This book is, in my opinion, the most lucid and readable exposition of the evolutionary model ever written, and along the way takes down the arguments for Intelligent Design a piece at a time.  I realize Dawkins is a controversial figure, given his no-quarter-given approach to religious claims, but even if you don't accept the scientific model yourself, you owe it to yourself to see what the evolutionary biologists are actually saying.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]




Saturday, December 1, 2018

CRISPR babies

One of my problems with resolving ethical questions is that I so often have a hard time deciding the difference between moral, ethical, reasonable, and justifiable, and figuring out where an issue lies on the spectrum thereof.

I've always had this problem.  There are things that in my view are always wrong -- harming or endangering a child comes to mind -- but the vast majority of issues lie in that immense field of gray areas.

Which is why I'm having a hard time deciding what to make of the bombshell announcement last week that a Chinese geneticist, He Jiankui, claims to have genetically altered a pair of human embryos -- and it resulted in the birth of twin girls who, if the gene editing was successful, will be resistant to HIV.

The technique involved was CRISPR-Cas9, a protein complex that allows for what amounts to cut-and-paste for your DNA.  What He did was to use CRISPR-Cas9 to selectively delete a gene for a  receptor called CCR5 that allows HIV to attach to cells.  Without that receptor -- He hopes -- the children will be genetically immune.

[Image is in the Public Domain]

When He made his announcement, the scientific community had a collective meltdown.  "The underlying purpose of doing the experiment was obviously to show that they could do gene editing on an embryo, but the purpose for the party involved does not make any sense," said Anthony Fauci, an HIV/AIDS researcher and head of the U.S. National Institute of Allergy and Infectious Diseases in Bethesda, Maryland.  "There are so many ways to adequately, efficiently, and definitively protect yourself against HIV that the thought of editing the genes of an embryo to get to an effect that you could easily do in so many other ways in my mind is unethical."

Okay, I'm not defending He.  The real issue here, in my opinion, is risk.  "Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer," said Julian Savulescu, an ethicist at the Oxford University.  "This experiment exposes healthy normal children to risks of gene editing for no real necessary benefit."

But the problem is that at some point, scientists were going to have to take the leap and do something like this.  Ever since Jennifer Doudna of UC-Berkeley developed CRISPR-Cas9 as a gene editing protocol in 2012, it's only been a matter of time.  Once a technique like this becomes possible, it becomes inevitable.

So sooner or later, someone was going to have to accept the risk of trying it on human embryos.  Animal models only get you so far.  The potential for eradicating genetic diseases is nothing short of astonishing; think of a world without cystic fibrosis, Huntington's disease, Tay-Sachs disease, sickle-cell anemia, hemophilia.  All of that is well within the realm of possibility now.

But.  Once you've started down that road, what's to stop people from altering other traits?  Appearance, personality, behavior... for me, this gets out onto some very thin ice.  When this Pandora's box is opened, there's no telling what dubiously ethical practices will escape.

There's also the problem that if such a technique really becomes capable of (relatively) risk-free editing out of deleterious genes, it's almost certain that it would be available only to the rich, further widening the gap between the privileged and the non-privileged.  The brilliant (and prescient) 1997 film Gattaca dealt with this very issue -- how genetic engineering of children could result in a new lower class, people conceived the old-fashioned way who didn't have the same opportunities for jobs, education, health care, and health insurance as the smarter, stronger, healthier "Valids."

So I'm of two, or more, minds about all of this.  First, the potential of the therapy is mind-boggling.  And the idea that once developed, researchers were going to hold off trying it out on human embryos, is naively optimistic about human nature.

But it comes back once again to the quote from scientist Alan Grant in Jurassic Park -- "You were so busy trying to figure out if you could, you never gave any thought to whether you should."  The thorny ethical issues this technique brings up go way beyond the potential risk to two baby girls in China.

All of which makes me glad that I'm not on the scientific regulatory boards who are wrestling with how to respond to He's announcement.

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

Ever wonder why we evolved to have muscles that can only pull, not push?  How about why the proportions of an animals' legs change as you look at progressively larger and larger species -- why, in other words, insects can get by with skinny little legs, while elephants need the equivalent of Grecian marble columns?  Why there are dozens of different takes on locomotion in the animal world, but no animal has ever evolved wheels?

If so, you need to read Steven Vogel's brilliant book Cats' Paws and Catapults.  Vogel is a bioengineer -- he looks at the mechanical engineering of animals, analyzing how things move, support their weight, and resist such catastrophes as cracking, buckling, crumbling, or breaking.  It's a delightful read, only skirting some of the more technical details (almost no math needed to understand his main points), and will give you a new perspective on the various solutions that natural selection has happened upon in the 4-billion-odd years life's been around on planet Earth.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]






Friday, November 30, 2018

Escapees from Siberia

As you might expect from someone who is passionately interested in both genealogy and evolutionary genetics, when there's a study that combines both, it's a source of great joy to me.

This week, Nature published a study on the evolutionary history of humans in northern Europe, specifically the Finns.  Entitled, "Ancient Fennoscandian Genomes Reveal Origin and Spread of Siberian Ancestry in Europe," it was authored by no less than seventeen researchers (including Svante Pääbo, a Swedish biologist who is widely credited as founding the entire science of paleogenetics) from the Max Planck Institute, the University of Helsinki, the Russian Academy of Sciences, the Vavilov Institute for General Genetics, and the University of Turku.

Quite a collaborative effort.

It's been known for a while that Europe was populated in three broad waves of settlement.  First, there were hunter-gatherers who came in as early as 40,000 years ago, and proceeded not only to hunt and gather but to have lots of hot caveperson-on-caveperson sex with the pre-existing Neanderthals, whose genetic traces can be discerned in their descendants unto this very day.  Then, there was an agricultural society that came into Europe from what is now Turkey starting around 8,000 years ago.  Finally, some nomadic groups -- believed to be the ancestors of both the Scythians and the Celts -- swept across Europe around 4,500 years ago.

Anyone with European ancestry has all three.  Despite the genetic distinctness of different ethnic groups -- without which 23 & Me genetic analysis wouldn't work at all -- there's been enough time, mixture, and cross-breeding between the groups that no one has ancestry purely from one population or another.

Which, as an aside, is one of the many reasons that the whole "racial purity" crowd is so ridiculous.  We're all mixtures, however uniform you think your ethnic heritage is.  Besides, racial purity wouldn't a good thing even if it were possible; that's called inbreeding, and causes a high rate of homozygosity (put simply, you're likely to inherit the same alleles from both your mother and father).  This causes lethal recessives to rear their ugly heads; heterozygous individuals are protected from these because the presence of the recessive allele is masked by the other, dominant (working) copy.  It's why genetic disorders can be localized to different groups; cystic fibrosis in northern Europeans, Huntington's disease in people whose ancestry comes from eastern England, sickle-cell anemia from sub-Saharan Africa, Tay-Sachs disease in Ashkenazic Jews, and so on.

So mixed-ethnic relationships are more likely to produce genetically healthy children.  Take that, neo-Nazis.

Map of ethnic groups in Europe, ca. 1899 [Image is in the Public Domain]

In any case, the current paper looks at the subset of Europeans who have a fourth ancestral population -- people in northeastern Europe, including Finns, the Saami, Russians, the Chuvash, Estonians, and Hungarians.  And they found that the origin of this additional group of ancestors is all the way from Siberia!

The authors write:
[T]he genetic makeup of northern Europe was shaped by migrations from Siberia that began at least 3500 years ago.  This Siberian ancestry was subsequently admixed into many modern populations in the region, particularly into populations speaking Uralic languages today.  Additionally... [the] ancestors of modern Saami inhabited a larger territory during the Iron Age.
The coolest part is that this lines up brilliantly with what we know about languages spoken in the area:
The Finno-Ugric branch of the Uralic language family, to which both Saami and Finnish languages belong, has diverged from other Uralic languages no earlier than 4000–5000 years ago, when Finland was already inhabited by speakers of a language today unknown.  Linguistic evidence shows that Saami languages were spoken in Finland prior to the arrival of the early Finnish language and have dominated the whole of the Finnish region before 1000 CE.  Particularly, southern Ostrobothnia, where Levänluhta is located, has been suggested through place names to harbour a southern Saami dialect until the late first millennium, when early Finnish took over as the dominant language.  Historical sources note Lapps living in the parishes of central Finland still in the 1500s.  It is, however, unclear whether all of them spoke Saami, or if some of them were Finns who had changed their subsistence strategy from agriculture to hunting and fishing.  There are also documents of intermarriage, although many of the indigenous people retreated to the north...  Ancestors of present-day Finnish speakers possibly migrated from northern Estonia, to which Finns still remain linguistically close, and displaced but also admixed with the local population of Finland, the likely ancestors of today’s Saami speakers.
Which I think is pretty damn cool.  The idea that we can use the genetics and linguistics of people today, and use it to infer migratory patterns back 40,000 years, is nothing short of stunning.

Unfortunately, however, I have zero ancestry in Finland or any of the other areas the researchers were studying.  According to 23 & Me, my presumed French, Scottish, Dutch, German, and English ancestry was shown to be... French, Scottish, Dutch, German, and English.  No surprise admixtures of genetic information from some infidelity by my great-great-grandmother with a guy from Japan, or anything.

On the other hand, I did have 284 markers associated with Neanderthal ancestry.  Probably explaining why I like my steaks medium-rare and run around more or less naked when the weather's warm.  Which I suppose makes up for my lack of unexpected ethnic heritage.

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

Ever wonder why we evolved to have muscles that can only pull, not push?  How about why the proportions of an animals' legs change as you look at progressively larger and larger species -- why, in other words, insects can get by with skinny little legs, while elephants need the equivalent of Grecian marble columns?  Why there are dozens of different takes on locomotion in the animal world, but no animal has ever evolved wheels?

If so, you need to read Steven Vogel's brilliant book Cats' Paws and Catapults.  Vogel is a bioengineer -- he looks at the mechanical engineering of animals, analyzing how things move, support their weight, and resist such catastrophes as cracking, buckling, crumbling, or breaking.  It's a delightful read, only skirting some of the more technical details (almost no math needed to understand his main points), and will give you a new perspective on the various solutions that natural selection has happened upon in the 4-billion-odd years life's been around on planet Earth.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]






Thursday, November 29, 2018

The origin of oxygen

One of the (many) things I love about science is the fact that for every discovery made, a slew of new questions open up.

Sometimes, "a slew" doesn't even cover it.  There have been discoveries that have revolutionized entire fields.  For example, when J. Tuzo Wilson, Harry Hess, and others developed the plate tectonics model in the early 1960s, to explain the magnetic mapping of the Atlantic Ocean, it explained a whole lot of other things -- why there are always volcanoes near oceanic trenches, why the coastline of North and South America fits together with Europe and Africa as if they were puzzle pieces, why the Himalayas are not volcanic, but are an earthquake zone (and are, in fact, still rising).  But it opened up a huge number of other questions -- why volcanoes in different spots have different characteristics (for example, the hot, fluid lava of Kilauea as compared to the monstrous explosions of Mount St. Helens and Vesuvius), why coastal California is made up of dozens of unrelated chunks of rock (which go by the delightful name of "suspect terranes"), and -- most importantly -- what force is driving the entire process.

Geologists are still devoting their careers to understanding the outfall from that one discovery.

A study published earlier this month in Geobiology has that characteristic of good science -- of solving one question and in the process opening up lots of others.  Called, "The Early Archean Origin of Photosystem II," by Tanai Cardona and A. William Rutherford of Imperial College of London, Patricia Sánchez‐Baracaldo of the University of Bristol, and Anthony W. Larkum of the University of Sydney, at first seems as if it would only be of interest to people who are fascinated with the gruesome biochemical details of photosynthesis.  Photosystem II is an array of proteins and pigment molecules that forms one of the two "light traps" in chloroplasts (the other, unsurprisingly, is called "photosystem I").  So who, other than botanists, really cares when it evolved?

Well, it turns out that the timing of this event is mighty peculiar -- because apparently photosystem II, central to the glucose-production system of all plants, arose around 3.4 billion years ago -- 700 million years before the earliest known autotrophs, the cyanobacteria (commonly called "blue-green algae").

The way this was discovered was a technique called a molecular clock -- using a known mutation rate for a specific gene to estimate when related genes in different organisms had a common ancestor.  (As a wildly oversimplified example, if you know that the rate of mutation in a particular gene cluster is 1 base pair change per million years, and that gene cluster in species A has 23 differences from the related gene cluster in species B, you can infer that the most recent common ancestor between A and B occurred 23 million years ago.)

Here, the researchers looked not at genes in two different organisms, but two different proteins in the same organism -- photosystem I and photosystem II, the genes for which were once a single piece of DNA that diverged in two directions.  And if you use the molecular clock technique to estimate when the common ancestor of those two genes was, you get a number way bigger than anyone expected.

The cyanobacteria Tolypothrix [Image licensed under the Creative Commons Matthewjparker, Tolypothrix (Cyanobacteria), CC BY-SA 3.0]

This is strange.  The geological evidence is pretty clear that earlier than 2.7 billion years ago, the atmosphere had no free oxygen.  So if photosynthesis -- the major oxygen-producing activity on Earth -- evolved 700 million years before significant quantities of oxygen accumulated in the atmosphere, it raises two awkward questions:
  1. Who was doing it?
  2. Where did all the oxygen go in the interim?
I'm sure these questions have perfectly rational answers.  It's possible cyanobacteria evolved a lot earlier than we'd thought -- after all, they're not common as fossils.  It could be that at first some biological or geological process was locking up the oxygen as soon as it was released, so it took a long time for it to start building up to levels that would leave a discernible fingerprint in the rocks.  It could be that something's confounding the molecular clock data and causing it to give an inaccurate result -- although in reading the paper, to my only moderately-trained eye, this doesn't look at all likely.  The analysis was careful, thorough, and painstaking.

It could also be that the earliest photosystems were simply much less efficient than today's, so their ability to oxidize water was insufficient to lead to an oxygen buildup in the atmosphere.  Or that the ancestral gene/protein for today's photosystems had a different purpose for the organisms that had them, and only afterwards was co-opted to store energy and synthesize food -- a phenomenon called preadaptation.

Or maybe something else.  The point is, it's a peculiar and fascinating discovery.  And like many peculiar and fascinating discoveries, I'm sure it will lead to further questions -- and, with hard work, insight, and a grain of luck, a whole host of further answers.

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

Ever wonder why we evolved to have muscles that can only pull, not push?  How about why the proportions of an animals' legs change as you look at progressively larger and larger species -- why, in other words, insects can get by with skinny little legs, while elephants need the equivalent of Grecian marble columns?  Why there are dozens of different takes on locomotion in the animal world, but no animal has ever evolved wheels?

If so, you need to read Steven Vogel's brilliant book Cats' Paws and Catapults.  Vogel is a bioengineer -- he looks at the mechanical engineering of animals, analyzing how things move, support their weight, and resist such catastrophes as cracking, buckling, crumbling, or breaking.  It's a delightful read, only skirting some of the more technical details (almost no math needed to understand his main points), and will give you a new perspective on the various solutions that natural selection has happened upon in the 4-billion-odd years life's been around on planet Earth.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]






Wednesday, November 28, 2018

Kite flying

A few years ago, I wrote a post here at Skeptophilia called "Grass, gulls, mosquitoes, and mice," in which I laid out the argument that while evolution is usually slow, sometimes it's so fast we can see it happening before our very eyes.  And when that happens, the anti-evolutionists amongst us have some explaining to do.

It's always nice to have another arrow in your quiver, and that came in a recent paper in Nature called, "Rapid Morphological Change of a Top Predator With the Invasion of a Novel Prey," by Christopher E. Cattau, Robert J. Fletcher Jr, Rebecca T. Kimball, Christine W. Miller, and Wiley M. Kitchens, all biologists at the University of Florida, who have been studying Snail Kites, a rare bird of prey found in the Everglades (and, as you'll see, in a few other places).

The Snail Kite, as you might expect from the name, is a specialist predator that feeds only on apple snails, a large species of freshwater gastropod found in the Everglades.  They have hooked beaks for removing the meat from the snail, and taloned feet for holding onto the shell -- well adapted for their niche.

The problem started with the accidental introduction into Florida of the island apple snail (Pomacea maculata), a larger, heavier species native to Argentina.  The native species, the Florida apple snail (Pomacea paludosa), was quickly outcompeted in areas where they both occurred, which concerned not only fans of the Snail Kite but rice farmers, as the island apple snail is a voracious pest on rice crops.

[Image licensed under the Creative Commons, photograph by Andy Morffew]

When an exotic species replaces a native species upon which other animals depend for food, the usual result is a drastic blow to the pre-existing food chain.  Here, though, we have a different result -- an eye-opening response by the Snail Kites that recalls evolutionary biologist Alan Grant's comment in Jurassic Park that "nature finds a way."

As is, the Snail Kites in Florida were not equipped to prey upon the island apple snails -- their feet were too small to hold onto the shells, not surprising as the snails are five times larger than the native Florida apple snails.  But the expected drop in the bird's numbers didn't happen.  Instead, in only a couple of generations, selection was so powerful on the population that the average talon size and bill size increased measurably, and the alterations were reflected by changes in their DNA.

"Nobody would believe me," said Robert Fletcher, co-author of the study, when the findings were announced. "They said, 'No, that cannot be. It's too quick.'"  But even the naysayers were convinced when the introduced snail species showed up in huge numbers in one part of the Snail Kite's range, and instead of leaving the premises, nearly all of the nearby kites converged on the spot.

I guess birds like an all-you-can-eat buffet as much as the rest of us do.

The authors write:
[T]rends in predicted breeding values emphasize that recent morphological changes have been driven primarily by phenotypic plasticity rather than micro-evolutionary change.  Our findings suggest that evolutionary change may be imminent and underscore that even long-lived vertebrates can respond quickly to invasive species.  Furthermore, these results highlight that phenotypic plasticity may provide a crucial role for predators experiencing rapid environmental change.
It's good news for the kites, but it bears mention that a lot of times, the introduction of an exotic species can spell disaster for native ones.  The kites were lucky in that there was already a range of bill sizes because of spontaneous mutations, and the new prey acted as a selecting agent, favoring the largest-billed and largest-footed individuals.

The most interesting part is that once you set this in motion, it ultimately will split the population from related populations elsewhere.  I first saw Snail Kites in Belize, where there are no island apple snails, so the pressure to cope with bigger prey doesn't exist.  Given time -- and, apparently, less time than anyone thought -- the population in Belize and the one in Florida will diverge genetically to the point that they will be, by anyone's definition, different species.

So there you have it: another example of evolution in action.  Cool enough for anyone to appreciate, but for evolutionary biologists, this is nothing short of spectacular.  We can add this to the list of times we've actually observed species evolving quickly enough to see it happen -- which is one more nail in the coffin of strict creationism, not that we particularly needed another one.

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

Ever wonder why we evolved to have muscles that can only pull, not push?  How about why the proportions of an animals' legs change as you look at progressively larger and larger species -- why, in other words, insects can get by with skinny little legs, while elephants need the equivalent of Grecian marble columns?  Why there are dozens of different takes on locomotion in the animal world, but no animal has ever evolved wheels?

If so, you need to read Steven Vogel's brilliant book Cats' Paws and Catapults.  Vogel is a bioengineer -- he looks at the mechanical engineering of animals, analyzing how things move, support their weight, and resist such catastrophes as cracking, buckling, crumbling, or breaking.  It's a delightful read, only skirting some of the more technical details (almost no math needed to understand his main points), and will give you a new perspective on the various solutions that natural selection has happened upon in the 4-billion-odd years life's been around on planet Earth.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]