Little cat man

It's amazing how many attempts it took for primates to successfully colonize North America.

There's only one primate species currently in the continent.  Us.  Other mammalian groups -- carnivores, rodents, ungulates, insectivores, bats, and so on -- have done fine here, flourishing and diversifying and lasting for tens of millions of years.

Primates haven't been so successful.

The first primates -- well, proto-primates -- in North America were the plesiadapiformes, which first appear in the fossil record in the early Paleocene Epoch, right after the Chicxulub Impact pretty well wiped out all the big animal species (most notably, the non-avian dinosaurs).  To modern eyes, they would have looked a bit like squirrels:

[Image licensed under the Creative Commons Nobu Tamura (http://spinops.blogspot.com), Plesiadapis NT, CC BY-SA 3.0]

Despite the superficially squirrelly appearance, their skulls, and especially their teeth, show clear affinities with primates, not with rodents.

These guys were widespread, living throughout North America, Europe, and Asia.  All of those continents were still connected at this point -- what had been Pangaea had broken into a northern continent (Laurasia) and a southern continent (Gondwanaland, made up of what are now South America, Australia, and Antarctica).  But things were changing, as they are wont to do.  The Central Atlantic Magmatic Province had kicked into high gear, rifting Laurasia and splitting what would become North America from the rest of the continent, opening up the North Atlantic Ocean.  At that point, the primate species (and everyone else) in North America were pretty well stuck there.

And they lasted a while.  But at the end of the Eocene Epoch, around 34 million years ago, the North American continent got significantly cooler and drier.  This drove all the warmth-loving native primates to extinction.

[Nota bene: South American monkeys come from a different lineage.  Recall that at this point, North and South America were pretty far apart, and there was a lot of ocean in between.  South America was a great deal closer to Africa, though -- and was colonized by primates from Africa, probably by monkeys and other species clinging to rafts of plant roots and brush torn loose during storms.  They seem to have made this amazing journey in several pulses, starting about thirty million years ago.  In any case -- the genetic and structural evidence is clear that South American monkeys are related to primates from Africa, not the extinct groups in North America.]

In any case, North America was primateless for about four million years.  Then, suddenly, a primate appeared in what is now Nebraska.  This species, named Ekgmowechashala (the name is Sioux for "little cat man"), weighed about three kilograms, and looked a bit like a lemur.  But where the hell did it come from?

The whole topic came up in the first place because of new research into this odd creature, which appeared in the Journal of Human Evolution last week.  A thorough analysis of Ekgmowechashala fossils dating from around thirty million years ago found that they most closely resemble primate species in China and eastern Siberia.  Apparently, the ancestors of Ekgmowechashala did what the ancestors of the Native Americans would do, millions of years later.  They took advantage of the fact that the cooler conditions locked up more sea water in the form of ice, lowering sea levels.  Among other things, this turned what is now the Bering Sea into a broad valley with rolling hills (nicknamed Beringia), allowing them to cross into North America.

"The 'Lazarus effect' in paleontology is when we find evidence in the fossil record of animals apparently going extinct -- only to reappear after a long hiatus, seemingly out of nowhere," said Chris Beard, of the University of Kansas, who was senior author of the paper.  "This is the grand pattern of evolution that we see in the fossil record of North American primates. The first primates came to North America about 56 million years ago at the beginning of the Eocene, and they flourished on this continent for more than 20 million years.  But they went extinct when climate became cooler and drier near the Eocene-Oligocene boundary, about 34 million years ago.  Several million years later Ekgmowechashala shows up like a drifting gunslinger in a Western movie, only to be a flash in the pan as far as the long trajectory of evolution is concerned.  After Ekgmowechashala is gone for more than 25 million years, Clovis people come to North America, marking the third chapter of primates on this continent. Like Ekgmowechashala, humans in North America are a prime example of the Lazarus effect."

So the "little cat man" didn't last very long -- the continual cooling of the climate, peaking with the repeated continental glaciations of the "Ice Ages," was more than primates could cope with.  But as Beard points out, that didn't stop our own species from doing the very same thing, eventually colonizing all of North America, and more inhospitable places yet.

But it's odd to think that thirty million years ago, there was something very like a lemur living near what is now Omaha.

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The swamps of Canada

Ellesmere Island would be high on the list of the Earth's most inhospitable places.

It's huge, only slightly smaller in area than Britain, and is part of the territory of Nunavut in Canada.  It is entirely above the Arctic Circle.  The record high temperature there was 15.6 C (60 F); the average high is 7 C (45 F).  The record low, on the other hand, is -47 C (-52.6 F).  It's also exceedingly dry, averaging a little over six inches of total precipitation a year.  It's no wonder that although the Inuit use some of it as summer hunting grounds, the permanent resident population stands at 144 brave souls.

Honestly, I'm a bit mystified as to why anyone lives there.

It wasn't always that way, though.  As hard as it is to fathom, Ellesmere Island used to be a swamp, back during the Paleocene-Eocene Thermal Maximum, a period about fifty-five million years ago during which the global average temperature was about eight degrees hotter than it is now.  The reasons it occurred are still a matter of discussion amongst climatologists, but from the chemistry and deposition of sedimentary rocks, it clearly came from a massive increase in the levels of atmospheric carbon dioxide, and was accompanied by the sea levels reaching levels between three hundred and four hundred meters higher than they are today.

If that happened now, where I'm currently sitting in upstate New York would be beachfront property.

What's most interesting about the climate of Ellesmere back then is that even though it was a warm swamp, it was pretty much located where it is today (i.e. above the Arctic Circle).  But even though for a couple of months of the year it was plunged into darkness, there were still trees -- fossils of the conifers Metasequoia and Glyptostrobus have been found in regions that now host little else besides mosses and lichens.

And a paper in PLOS-One this week showed that it isn't just subtropical trees that used to live on Ellesmere -- so did some long-lost cousins of primates.

We usually think of primates as being tropical, and for good reason; most of the primate species in the world live in areas not too far from the equator.  We originated there, too, of course; the ancestral home of Homo sapiens is Kenya and Tanzania (that's all humans -- sorry, racists).  We've since expanded our territory a little, but our relative hairlessness is a good indicator that we originally came from warmer climes.

But back during the PETM, Ellesmere was a warmer clime, and paleontologists have found in sedimentary rock strata the fossils of two proto-primates, Ignacius mckennai and Ignacius dawsonae.  The genus Ignacius is part of a much larger group called the plesiadapiforms, who are all extinct but whose closest living relatives are modern primates.  Ignacius was a genus confined to the northern half of North America, and when the temperatures warmed up and the forests spread north, Ignacius followed them.

This makes these remains the northernmost primate fossils ever found.

A reconstruction of Ignacius dawsonae [Image is licensed under the Creative Commons Kristen Miller/Biodiversity Institute/University of Kansas (CC-BY 4.0)]

What is amazing to me about this is... well... everything.  That trees could flourish in a swampy environment well above the Arctic Circle.  That non-human primates ever got this far north.  And most especially, that the Earth's climate was this drastically different, only fifty-five million years ago -- a long time ago on our usual timeline, but pretty much day before yesterday on the geological scale.

Of course, this should be a cautionary tale for us cocky humans, and probably won't be.  Things can change drastically.  Have changed drastically, and will again.  What we're doing right now is spiking the atmospheric carbon dioxide levels, and thus the temperature, at a far faster rate than just about anything in the geological record -- perhaps even exceeding the carbon dioxide pulse that set off the Permian-Triassic Mass Extinction.

And that cataclysm killed an estimated ninety percent of life on Earth.

All I can say is, we damn well better start paying attention, or else we'll find out that Santayana's famous quote about not learning from history also applies to not learning from prehistory.  Or, put more succinctly, that the best strategy is not "fuck around and find out."

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Switching on humanity

Humans, chimps, and bonobos share a little over 99% of their DNA.

That remaining just-under-one-percent accounts for every physical difference between you and our nearest ape relatives.  It's natural enough to be surprised by this; we look and act pretty different from them most of the time.  (Although if you've read Desmond Morris's classic study The Naked Ape, you'll find there's a lot more overlap between humans and apes behaviorally than you might have realized.)

[Image licensed under the Creative Commons Greg Hume, Bonobo-04, CC BY-SA 3.0]

Part of that sense of differentness is from the cultural context most of us grew up in -- that "human" and "animal" are two separate categories.  In a lot of places that comes from religion, specifically the idea that the Creator fashioned humans separately from the rest of the species on Earth, and that separation persists in our worldviews even for many of us who no longer believe in a supreme deity.  The truth is we're just another branch of Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Primata, albeit a good bit more intelligent and technologically capable than most of the other branches.

It's that last bit that has captured the curiosity of evolutionary geneticists for decades.  The similarities between ourselves and apes are obvious; but where did the differences come from?  How could less than one percent of our DNA be responsible for all the things that do set us apart -- our larger brains, capacity for language, upright posture, and so on?

Just last week, a paper in the journal Cell, written by a team out of Duke University, may have provided us with some answers.

The researchers found that the most striking differences between the genomes of humans and those of chimps and bonobos lay in a set of switches they dubbed Human Ancestor Quickly-Evolved Regions (HAQERs -- pronounced, as you might have guessed, like "hackers").  HAQERs are genetic regulatory switches, that control when and how long other genes are active.  The HAQER sequences the team discovered seem to mostly affect two sets of developmental genes -- the ones that influence brain complexity and the ones involved in the production of the gastrointestinal tract.

"We see lots of regulatory elements that are turning on in these tissues," said Craig Lowe, who co-authored the paper, in an interview with Science Daily.  "These are the tissues where humans are refining which genes are expressed and at what level...  Today, our brains are larger than other apes, and our guts are shorter.  People have hypothesized that those two are even linked, because they are two really expensive metabolic tissues to have around.  I think what we're seeing is that there wasn't really one mutation that gave you a large brain and one mutation that really struck the gut, it was probably many of these small changes over time."

What's most interesting of all is that the HAQER sequences provide another example of how evolution is so frequently a trade-off.  Consider, for example, our upright posture; our vertebral column evolved in animals that walked on all fours, and when we switched to being bipedal it gave us the advantage of freeing up our hands and being able to see farther, but it bequeathed a legacy of lower back problems most other mammals never have to worry about.  Here, the HAQERs that seem to be responsible for our larger and more complex brains also correlate to a variety of disorder susceptibilities.  Particular variants of HAQER sequences are associated with a higher risk of hypertension, neuroblastoma, depression, bipolar disorder, and schizophrenia.

It's just the way genetic change works.  Sometimes you can't improve one thing without screwing something else up.  And if, on balance, the change improves survival and reproductive likelihood, it's still selected for despite the disadvantages.

So we seem to finally be making some inroads into the question of why such a tiny slice of our genome creates all the differences between ourselves and our nearest relatives.  It's worth a reminder, though, that we aren't substantially different than the other species we share the planet it.  It reminds me of the famous quote from Chief Seattle: "We did not weave the web of life, we are merely one strand in it.  Whatever we do to the web, we do to ourselves."

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Analysis of a triple-whammy

I always find it wryly amusing when I hear someone talk about the Strong Anthropic Principle -- the idea that the universe was fine-tuned by a creator to be hospitable to life, particularly human life -- because it doesn't take much of a close look to become aware of exactly how inhospitable the universe actually is.

Even here on Earth, the situation is kind of dicey.  Our planet's history is really one cataclysm after another; that our own particular lineage survived is probably more a matter of luck than anything else.  In fact, only 74,000 years ago, climate havoc caused by the eruption of the Indonesian volcano Toba is thought by some scientists to have nearly wiped out our species -- they estimate the "Toba bottleneck event" to have reduced the entire population of Homo sapiens to under ten thousand individuals.  (For reference, that means that the human population of the whole planet was about as many people as currently live in Sitka, Alaska.)  Besides major volcanic eruptions, add in earthquakes and tsunamis, global marine anoxia events, and meteor strikes, and you can see that where we live isn't nearly as hospitable as it might look at first.

So the truth lies closer to the Weak Anthropic Principle -- of course the universe, and the Earth in particular, have the conditions necessary for life to exist, because if they didn't, we wouldn't be here to consider the question.

The reason all this catastrophic stuff comes up is a paper that came out a couple of weeks ago in Nature Communications Biology.  Entitled, "Widespread Loss of Mammalian Lineage and Dietary Diversity in the Early Oligocene of Afro-Arabia," by Dorien de Vries (of the University of Salford), Steven Heritage (of Stony Brook University), and Matthew Borths, Hesham Sallam, and Erik Seiffert (of the Duke University Museum of Natural History), it looks at a little-known extinction event that was apparently the result of a one-two-three punch that nearly halted the mammalian species in Africa in their tracks.

Which, of course, also includes our own ancestors.

Some of the Eocene animal groups affected by the extinction -- the left two are primates, the upper right a hyaenodont, and the lower right a prehistoric rodent.  [Photo by Matthew Borths]

The researchers had their first clues about the magnitude of the event, which occurred on the order of thirty-three million years ago, from looking at fossilized mammal teeth from East Africa, and found that right on the boundary of the Eocene and Oligocene, the number of mammal species dropped drastically.

"In our anthropoid ancestors, diversity bottoms out to almost nothing around thirty million years ago, leaving them with a single tooth type,” said Erik Seiffert, senior co-author of the paper, in an interview with EurekAlert.  "That ancestral tooth shape determined what was possible in terms of later dietary diversification...  There's an interesting story about the role of that bottleneck in our own early evolutionary history.  We came pretty close to never existing, if our monkey-like ancestors had gone extinct thirty million years ago.  Luckily they didn’t."

What seems to have driven the extinction was a triple-whammy -- rapid cooling of the climate after the equally catastrophic Paleocene-Eocene Thermal Maximum (during which the global average temperature was eight degrees warmer than it is now), followed by the huge Chesapeake Bay meteorite collision and a near-simultaneous massive eruption of flood basalts in Ethiopia.

Diversity plummeted.  More interestingly, the extinction preferentially spared generalists -- mammals which, from their tooth morphology, apparently could eat a variety of different kinds of food.  Specialists got hit the hardest, once again reinforcing the general evolutionary concept that if the ecosystem is stable, specialization is a good thing, but during periods of rapid change, it's the generalists who come out on top.

This -- as Seiffert says, luckily for us -- left our own distant ancestors to continue loping about on the African savanna, and also knocked out a lot of the competition.  The shape and structure of our own teeth reflect that event.  "We lost a lot of diversity at the Eocene-Oligocene boundary," said study co-author Matthew Borths.  "But the species that survived apparently had enough of a toolkit to persist through this fluctuating climate."

This should be yet another cautionary note about the fragility of the Earth's suitability for humanity, not to mention our current heedless messing-about with the planetary climate and ecosystems.  It's unlikely to, of course.  We don't have a very good record of listening to scientists, even when our own survival is at stake.  Part of this is that in recent memory we haven't had to deal with planet-wide natural disasters -- it's made us cocky.

"We've always been fine before," is the general attitude.

All it takes is reading the de Vries et al. paper to realize that "always" is singularly inapt.

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My master's degree is in historical linguistics, with a focus on Scandinavia and Great Britain (and the interactions between them) -- so it was with great interest that I read Cat Jarman's book River Kings: A New History of Vikings from Scandinavia to the Silk Road.

Jarman, who is an archaeologist working for the University of Bristol and the Scandinavian Museum of Cultural History of the University of Oslo, is one of the world's experts on the Viking Age.  She does a great job of de-mythologizing these wide-traveling raiders, explorers, and merchants, taking them out of the caricature depictions of guys with blond braids and horned helmets into the reality of a complex, dynamic culture that impacted lands and people from Labrador to China.

River Kings is a brilliantly-written analysis of an often-misunderstood group -- beginning with the fact that "Viking" isn't an ethnic designation, but an occupation -- and tracing artifacts they left behind traveling between their homeland in Sweden, Norway, and Denmark to Iceland, the Hebrides, Normandy, the Silk Road, and Russia.  (In fact, the Rus -- the people who founded, and gave their name to, Russia -- were Scandinavian explorers who settled in what is now the Ukraine and western Russia, intermarrying with the Slavic population there and eventually forming a unique melded culture.)

If you are interested in the Vikings or in European history in general, you should put Jarman's book in your to-read list.  It goes a long way toward replacing the legendary status of these fierce, sea-going people with a historically-accurate reality that is just as fascinating.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Chewing gum and talking about talking

Earlier this week I looked at three cool archaeological discoveries -- cave art in Indonesia, and two finds in Egypt, one of a bone from someone killed in the battle recorded on the Rosetta stone, and the other about a researcher who found that the practice of tattooing has been around for a very long time.

But we're not done with mind-blowing archaeological stories, apparently, because there are two more that I just found out about, and which (if anything) are even cooler than the ones I wrote about Monday.

I learned of the first one from my friend, novelist and blogger Andrew Butters, whose blog Potato Chip Math is a must-read.  In this one, we find out that a team of geneticists have sequenced the DNA of a girl who lived in Denmark 5,700 years ago...

... from a wad of chewing gum.

Well, technically, it was birch sap, but same idea.  They were able to extract her DNA from the gum and sequence her entire genome, which allowed them not only to figure out what ethnic group she was from, but to make a good shot at her appearance.  She had dark skin and hair, they found, and blue eyes.  Here's an artist's reconstruction of what she might have looked like:

[Reconstruction by Tom Björklund]

The authors write:

Analysis of the human reads revealed that the individual whose genome we recovered was female and that she likely had dark skin, dark brown hair and blue eyes.  This combination of physical traits has been previously noted in other European hunter-gatherers, suggesting that this phenotype was widespread in Mesolithic Europe and that the adaptive spread of light skin pigmentation in European populations only occurred later in prehistory.  We also find that she had the alleles associated with lactase non-persistence, which fits with the notion that lactase persistence in adults only evolved fairly recently in Europe, after the introduction of dairy farming with the Neolithic revolution.

The period she lived in was when northern Europe was taken over by people known as the "Funnel Beaker Culture," so named because of their characteristic narrow-based, highly-ornamented pottery:

The 5,200 year old Skarpsalling vessel [Image is licensed under the Creative Commons Nationalmuseet, Skarpsallingkarret DO-9665 original, CC BY-SA 3.0]

"It is amazing to have gotten a complete ancient human genome from anything other than bone,'' said study lead author, evolutionary geneticist Hannes Schroeder, of the University of Copenhagen, in an interview with Science Alert.  "The DNA is so exceptionally well preserved that we were able to recover a complete ancient human genome from the sample… which is particularly significant since, so far, no human remains have been recovered from the site."

The second story goes back a great deal further in time than the little Neolithic Danish girl, though.  In fact, it kind of crosses the line from archaeology into paleontology, because in a paper in Science Advances we find out that the ability to speak might have been around in primates for twenty million years.

The study, led by Louis-Jean Boë of the University of Grenoble, analyzes the mechanics of human speech, in particular how the morphology of the mouth, trachea, and larynx allow for the production of meaningful sound.  It's been thought for years that the advent of speech occurred when our ancestors' larynxes (voice boxes) gradually moved downward, pulling the back of the tongue backward and downward as well and giving the tongue more mobility to shape sounds.  But what Boë's team found was that even if you accept that as the hallmark of speech, it goes a long way further back than we'd realized.

"First, even among primates, laryngeal descent is not uniquely human," Boë and his team write.  "Second, laryngeal descent is not required to produce contrasting patterns in vocalizations.  Third, living non-human primates produce vocalizations with contrasting patterns.  Thus, evidence now overwhelmingly refutes the long-standing laryngeal descent theory, which pushes back 'the dawn of speech' beyond ~200 ka ago to over ~20 Ma ago, a difference of two orders of magnitude."

So that means that at least from a mechanical standpoint, our distant ancestors had the capacity for speech.  Whether their brains were developed enough to say anything particularly interesting is still a matter of conjecture.  But evolution is all about minuscule gains.  Once the upper respiratory tract becomes capable of modulating sounds in a meaningful way, this puts selective pressure on the brain to refine its ability to understand and convey meaning with those sounds -- which puts pressure on the vocal apparatus to become better at producing subtle differences in sounds, and so on and so forth.  Which, as comedian Paula Poundstone notes, may not be entirely a good thing:

Be that as it may, it's a pretty cool discovery.  As I pointed out in Monday's post, it's incredible how much we can infer about our distant ancestors' appearance, culture, and abilities from evidence that would have been a closed book only ten years ago.  Our techniques for carrying out this research are only going to improve, so keep watching the journals -- my sense is that the amazing discoveries in this field have only just begun.

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This week's Skeptophilia book recommendation is pure fun, and a perfect holiday gift for anyone you know who (1) is a science buff, and (2) has a sense of humor.  What If?, by Randall Munroe (creator of the brilliant comic strip xkcd) gives scientifically-sound answers to some very interesting hypothetical questions.  What if everyone aimed a laser pointer simultaneously at the same spot on the Moon?  Could you make a jetpack using a bunch of downward-pointing machine guns?  What would happen if everyone on the Earth jumped simultaneously?

Munroe's answers make for fascinating, and often hilarious, reading.  His scientific acumen, which shines through in xkcd, is on full display here, as is his sharp-edged and absurd sense of humor.  It's great reading for anyone who has sat up at night wondering... "what if?"

[Note:  if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

A new twig on the family tree

My long-ago professor of evolutionary biology, Dr. Andrew Collins, once said, "The only reason humans came up with the concept of species as little air-tight boxes is that we have no near relatives still alive."  After a pause, he added, "And it's also the reason why evolution isn't completely self-evident to everyone."

I've always remembered that -- the word "species" is an artificial construct, and is the hardest concept in biology to come up with a consistent definition for.  No matter how you define it, you come up with exceptions and qualifications (something I dealt with a while back in my post "Grass, gulls, mosquitoes, and mice"), and it's only our determination that nature should be pigeonholeable (to coin a word) that keeps it in the textbooks.

We had a lovely example of that announced this week, when we learned that a stunningly well-preserved 3.8-million-year-old skull from Ethiopia had been identified as Australopithecus anamensis.  This species had been thought ancestral to A. afarensis (the species to which the famous Lucy belonged), but the Ethiopian skull (nicknamed MRD after Miro Dora, the site where it was discovered) is the same age as the earliest clearly A. afarensis remains.

So it looks like the two coexisted at least for a while, which is actually a much more common thing than the textbook one-species-slowly-morphing-into-another model.  Take, for example, our own (much more recent) ancestry, when only fifty thousand years ago there was enough interbreeding between Neanderthals, Denisovans, and anatomically-modern humans that we still find significant traces of each of those lineages in our own DNA.  (When I had my own DNA sequenced, I was proud to find out that I had 284 clearly Neanderthal markers, putting me in the 60th percentile and possibly explaining why I eat my t-bone steaks rare and like running around with little to no clothing on.)

The current discovery, though, is awfully cool.  Here's the skull itself, and a reconstruction of what its owner might have looked like, by the amazing John Gurche:

[Images courtesy of Jennifer Taylor, Dale Mori, and Liz Russell (right); and John Gurche and Matt Crow (left)] 

As an aside, John Gurche lives in the same little upstate New York village that I do, and I was privileged to teach all three of his kids.  His son, Loren, is now a paleontologist in his own right, and even when he was an eleventh grader in my AP Biology class he so clearly knew more about extinct animals than I did that I gladly asked him to contribute every time the topic came up in class.

Anyhow, the whole thing is wicked cool.  Picture it; an African savanna with not just one, but several different kinds of proto-hominins running around, some of them quite human-like and others more similar to our ape ancestors.  I'm always a little astonished at people who find the idea of our non-human ancestry demeaning -- I think it's grand that we're connected, in a series of unbroken links extending back three billion years, to every other life form on Earth.

And the whole thing took place, for the most part, in a smooth set of small changes, almost indistinguishable without the advantage of a huge time scale.  As Charles Darwin put it in The Descent of Man, "In a series of forms graduating insensibly from some apelike creature to man as he now exists, it would be impossible to fix on any definite point where the term 'man' ought to be used."

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This week's Skeptophilia book recommendation is about a subject near and dear to my heart; the possibility of intelligent extraterrestrial life.  In The Three-Body Problem, Chinese science fiction writer Cixin Liu takes an interesting angle on this question; if intelligent life were discovered in the universe -- maybe if it even gave us a visit -- how would humans react?

Liu examines the impact of finding we're not alone in the cosmos from political, social, and religious perspectives, and doesn't engage in any pollyanna-ish assumptions that we'll all be hunky-dory and ascend to the next plane of existence.  What he does think might happen, though, makes for fascinating reading, and leaves you pondering our place in the universe for days after you turn over the last page.

[Note: if you purchase this book from the image/link below, part of the proceeds goes to support Skeptophilia!]

The Beast of Tunbridge Wells

Following on the heels of yesterday's post about Dr. Melba Ketchum and the maybe-perhaps-sort-of confirmation of Sasquatch DNA from a hair sample, we now have a story wherein the Brits (not to be outdone by a bunch of upstart Americans) are claiming their own Bigfoot-clone.  [Source]

Nicknamed "The Beast of Tunbridge Wells," this cryptid is described as an eight-foot-tall beast, human-shaped but covered with hair, with "long arms" and "demonic red eyes."  Some locals are afraid to go outside at night because there have been so many sightings in the past six months; but the story claims that the thing has been seen for seventy or more years, and describe a sighting that occurred in 1942 and was told to a "man named Graham S."

Well, far be it from me to doubt any anecdotal reports from "a man named Graham S.," but let me just interject a bit of a science lesson that may raise some questions in your mind.

There's a concept in ecology called "minimum viable population."  This is the number of organisms needed in a population to assure that (assuming nothing changes) the birth rate equals or exceeds the death rate.  It is quite difficult to estimate, and depends on a great many factors, including the number of offspring per mating, mortality in the young, dependency on available resources, size of the territory, and so on.  To give two extreme examples that will illustrate this:  the MVP for mosquitoes is probably pretty damn close to two, as long as one was male and one was female, and they were near enough to find each other and had a source of food and water.  Mosquitoes can produce so many young from one mating that it's likely you could rebuild a sizable population in short order from those two survivors.  Elephants, on the other hand, reproduce very slowly, and the young are slow to reach sexual maturity; in order to have a population large enough for the birth rate to equal or exceed the death rate (from natural causes, predators, poaching, and so on), you would need hundreds, perhaps thousands, of individuals in the population.

Get it?  Now, let's consider how many Britsquatches we'd need to have a viable, sustainable population.

To get a handle on this, I referred to the paper "Estimates of Minimum Viable Population Sizes for Vertebrates and Factors Influencing Those Estimates," by David Reed, Julian O'Grady, Barry Brook, Jonathan Ballou, and Richard Frankham, which appeared in the Journal of Biological Conservation in 2003.  The paper is lucidly written but relies on some rather specialized models and technical mathematics; if you want to give it a go, you can access it here.  The main thing of interest for our purposes is in the Appendix, wherein Reed et al. use their techniques to make an upper and lower bound estimate for MVP; the lower bound is just using raw birth and death rates, the upper bound generated from a mathematical formula that estimates the number of individuals required to give a 99% likelihood of the population sustaining for forty generations.  Interestingly, there is a large primate species listed -- the Mountain Gorilla (Gorilla gorilla beringei).  And Reed et al. place the lower bound for MVP for the Mountain Gorilla at 849, and the upper bound at somewhat over 11,000 individuals.

So assuming the Tunbridge Britsquatch (Sasquatchius anglicus kentei) has a similar MVP, and has been wandering about the highways and byways of southeastern England since time immemorial (or at least since 1942), you can't just claim that there are two, or four, or even a dozen of them... you have to believe that there are thousands.

Maybe some of my readers live in southeastern England, and might be able to explain how there could be a thousand (or more) eight-foot-tall hairy hominids hiding out down there, doing all the things animals do -- feeding (and an animal that size would need a lot of food), making noise, sleeping, mating, dying, and so on -- and they've only been seen a handful of times near Tunbridge Wells.  That such a thing could happen in the trackless woods of the Pacific Northwest, or the icy reaches of the Himalayas, I might be able to believe.

But Kent?  Really?

I'm sorry, but this just sounds preposterous to me.  As much as I'd love to see some cryptid discovered, and confirmed by science, I'm betting this won't be the one.  In fact, I think what we should be doing is looking for some prankster in Tunbridge Wells with a gorilla suit.