Prevaricators' Paradise, or Victims' Vengeance?

kw: book reviews, nonfiction, logic, lying, critical thinking

I'm sure you've heard the old chestnut about public figures who lie, that some lie when they must, and some lie constantly to stay in practice. Or that for some, that the way to tell they are lying is that their lips are moving. And then we have Mark Twain remarking on "Lies, damned lies, and statistics", which he attributed to Disraeli, but he was mistaken (or, perhaps, lying!). And we occasionally hear a paraphrase of "To err is human" into "To lie is human". Ah, the great benefits we seem to attain by lying, at such a little cost!

Is it safe to say that nearly anyone trying to advance a viewpoint (or sell a product or win an argument) is lying? Usually, I suppose. It is your best, first assumption. But when you want to know "the truth", where do you turn? Now that the biggest news story closing out the year 2016 is "Fake News", where do you get "Real News"?

We have to take what we can get, and verify it the best we can. This is the primary reason for learning to think critically. It is why right, right now is a great time for a book to appear with the title A Field Guide to Lies: Critical Thinking in the Information Age. To quote the opening paragraph of author Daniel J. Levitin,

"This is a book about how to spot problems with the facts you encounter, problems that may lead you to draw the wrong conclusion. Sometimes the people giving you the facts are hoping you'll draw the wrong conclusion; sometimes they don't know the difference themselves. Today, information is available nearly instantaneously, but it is becoming increasingly hard to tell what's true and what's not, to sift through the various claims we hear and to recognize when they contain misinformation, pseudo-facts, distortions and outright lies."

Dr. Levitin jumps right over "lies and damned lies" to statistics in the first third of the book, "Evaluating Numbers". It is a great place to start because we are so damnably bad at evaluating numbers. The brain is an unbeatable pattern recognition machine. It excels at finding similarities, and it is over-tuned: it finds patterns where none exist. Thus we see all kinds of animals and scenery in clouds; a highly educated astronomer such as Percival Lowell spent much of his career mapping the canals on Mars; and to my recollection there are at least three pieces of burnt toast being carefully stored in freezers because they bear a mark that looks sort of like Jesus, so they have become objects of worship. But we are woefully deficient in discerning the meaning of numerical quantities.

It is curious: Recognizing a face reliably is something we do thousands of times daily, and we are very, very seldom mistaken. We almost never mistake a not-face for a face. What we do easily our computing machines do slowly and rather poorly. I have made heavy use of the Picasa face-tagging system for several years, for organizing my photos. It is really, really good, but will on occasion put a hopeful "Who is this?" tag on what I see as some random blob, or on a hubcap or the "face" of a clock. And it misses about a tenth of the genuine faces in an average scene, particularly when there is quite a range of sizes, that is, distances to the subjects. The computing power needed for Picasa's algorithms to work has only been available for about ten years. It takes a few billion computations to locate a face in a scene, and more billions to match it with a similar one in the database of recognized faces in your photo collection. Every one of us can recognize a person with great reliability in a tiny fraction of the time. But very few of us can determine the product 347x94 in less than several seconds, and probably not at all without the help of a calculator or a pencil and paper. Yet a computer can perform millions or billions of similar calculations every second, and does so whenever you recalculate an Excel spreadsheet. We must face the fact that our brain is tuned to see the tiger in the grass so we don't get eaten. Prior to the ascent of "civilization", we had no need to count the tiger's stripes, and if we were interested in doing so (unlikely!), it was only after we'd ganged up on the tiger to kill and skin it.

Part Two is "Evaluating Words", and in just under 60 pages, is the briefest of treatments of logical fallacies. There are numerous volumes written about the few dozen fallacies of formal logic that philosophers study, and further volumes that cover the fallacies of informal logic, the "everyday fallacies" such as "50,000 dentists agree" or "All the Kardashians (or celebrity of your choice) love product X" or "only a fool would pass up this offer". Pet Advertising Peeve of the year: any ad containing the phrase "don't want you to know" is fallacious. Period. Trust your uncle Polymath (but, then, this is possibly another fallacy!).

The third part of the book, "Evaluating the World", presents an excellent review of the Scientific Method, which is an armory containing our best weapons to discover error and falsity and correct them. The scientific method is collaborative; it cannot be practiced in isolation. The great difficulties we encounter using the scientific method glaringly illustrate just how prone we are to being deceived and to deceiving ourselves. Thus, if the brain is a pattern-recognition engine, the scientific method harnesses many brains to sharpen the focus and more properly set the boundary between "perceived facts" and "true facts".

I hesitate to go further. A book like this presents a quandary. While it exposes a few hundred ways you could be lied to, it is also a kind of prevaricator's textbook. I am reminded of the dilemma faced by missionaries to Hawaii, as described in James A. Michener's enormous novel Hawaii: They wanted to put up a sign with the Ten Commandments, but there was a problem. The Hawaiians didn't understand them, particularly "Thou shalt not commit adultery?" What was adultery? The missionaries argued thus: If we try to describe adultery in general terms, some people will say, "Oh, that isn't what I am doing." But if we list all the different things that are adultery, others will read the list and say about one item or another, "Wow, that sounds like fun. I'll try it!" They were further troubled by the cultural requirement that the king of Hawaii must marry his sister. It took the missionaries about two generations to change Hawaiian culture enough to eliminate "that kind of adultery". Thus there is a risk that some will read the book to get ideas.

I suppose Dr. Levitin has thought the matter through, and judged that putting weapons into our hands is worth the risk that a few liars might become better liars as a result. I agree. Caveat emptor is still the best policy, and always will be. Let this book full of caveats arm you.

Presenting CWWN v09 - The Present Testimony (2)

kw: book summaries, watchman nee, christian ministry

The present volume of the Collected Works of Watchman Nee contains Issues No. 19 – 36 of The Present Testimony, from the years 1931 and 1932. Issues 19 – 22 and a portion of Issue 23 concern a number of spiritual matters, and I find two of special note: "The Principle of the Second" (Issue 21) and "The Pattern on the Mountain" (Issue 22). The first shows how frequently God confers a better blessing on the second-born (Jacob over Esau) or the second-anointed (David over Saul). The second drives home the point that God does not permit human innovation regarding our carrying out of His service. Indeed, He must frequently hinder, stop, or even curse innovators. The great example of one whose service is pleasing to God is Moses, who "was faithful in all [God's] house" (Num 12:7; Heb 3:5). He oversaw production and construction of the tabernacle exactly according to the pattern he was shown on Mount Sinai. Those who have all kinds of "good ideas" for working for God are most likely to hear His rebuke at the Judgment Seat of Christ, "I didn't know [i.e. authorize] you; depart, you workers of iniquity".

From the tenth page of Issue 23 through the end of this volume we find the content of seven messages given at the Second Conference, which had been held in October, 1931, on the subject "The New Covenant". These 101 pages (as here printed) constitute the most thorough treatment to be found anywhere, of the meaning, purposes, contents, and consequences of God's new covenant.

Prior to becoming joined to a church that follows this ministry, I heard some preaching on the new covenant, and on the principles of God's covenants. I have heard preachers who claim to preach nothing but Covenant Theology. Some of what I heard was pretty good and quite encouraging. This volume could be a text for a doctoral-level course on the subject. The Covenant Theology preachers of my past are at best at grade school level by comparison.

From these messages I gleaned one item worth recalling (and I'll need to re-read to gain others equally precious): A covenant is not for God, it is for His people. He keeps the promises He makes, but we are weak and find it hard to consistently believe that He will do so. As He promised in foretelling the new covenant to Jeremiah (Jer 31:31-34), God writes His laws on the hearts and minds of His people, He becomes their God, and they become His people. Based on those three things are three more, that they will all know God and need no instruction to do so, that He will make propitiation for their unrighteousnesses, and that He will erase the record of their sins. By themselves these are promises. By making them a covenant, and even more, a testament (secured by the death of the testator, our savior Jesus), God has done all He can to ensure us that we need only claim the provisions of this covenant. We don't beg for forgiveness according to God's mercy; we claim forgiveness because, by believing Him, we fulfill the only requirement this covenant makes on us; all other provisions have been made by God and God guarantees them to us. We are saved by grace not according to mercy, but according to God's righteousness. When we see this, we will pray in a different way.

One may ask, why if I am presently partaking of ministry according to Watchman Nee and his co-workers, did I not already gain the point I make just above? These things are difficult to minister. Do not think the paragraph above is in any way a substitute for the several pages of Issues 35 and 36 where they are explained. Little by little over the years, much has been imparted to me. Reading this volume of CWWN is like taking a large and meaty meal. This is partly why it was so long since I wrote of the prior volume.

Those who wish to truly know the New Covenant must obtain this volume!

Figures kept in hiding no longer

kw: book reviews, nonfiction, biographies, space program, computers, human computers, civil rights

If the USSR had not launched Sputnik I in 1957, would the civil rights movement in the USA have gone as far as it did in the following decade? This event and the assassination of Dr. Martin Luther King, Jr just over ten years later bookended a sea change in American race relations, and we'll return briefly to that below.

The period 1955-1965 marked a great scientific change also. Prior to the mid-1950's a "computer" wore a skirt and performed calculations on paper forms, though assisted by calculating machines with names like Monroe and Smith-Corona-Marchant. They followed in the proud tradition of "Pickering's Harem", the women who performed astronomical calculations for the Harvard astronomer beginning in the 1880's. At Langley Air Force Base, from the beginning of World War II, women computers did the calculations required to design aircraft that changed how the war was fought, and later, how air frames in general could be made more durable, faster, and more nimble. By 1965 most numerical calculations had been turned over to automatic calculating machines such as the IBM 7090. And the skirted computers? Some had retired or moved on, and many others were dispersed into various engineering groups around Langley.

The existence of these women—these hundreds of computers—is practically unknown. Even more, without the work of Margot Lee Shetterly, hardly anyone of this generation would know, or could know, that about fifty of them were black. An executive order by President Roosevelt opened the door to government employment of black Americans in 1943, and, because Langley AFB was hiring people by the hundreds and thousands for the war effort, many blacks obtained employment there, including black women who were working as underpaid teachers, tutors of mathematics, and in other fields. As Ms Shetterly tells it, in her book Hidden Figures, by the end of the War, it wasn't unusual for a group of white, male engineers to find that the computer assigned to work among them for a time, that small, quiet and unassuming black woman, was the smartest person in the room.

Just over a decade after the War ended, when John Glenn was preparing for his orbital flight in the Mercury "Friendship 7", he didn't wholly trust the mechanical computing equipment and asked for the figures to be checked by "the girl". That "girl" was Katherine G. Johnson, who wasn't just a whiz computer; she had written the definitive report on the calculations needed to plan both easterly- and westerly-launched orbital spacecraft. Once she had verified the calculations, Glenn was satisfied he would be safe enough aloft, and would likely survive the splashdown. She just says she was in the right place at the right time, that it might have been any of "the girls", but we know better.

The Hampton Roads area in which Langley AFB resides is a core population area of eastern Virginia, and Virginia was the core of segregationist attitudes in the Jim Crow south. Racial segregation was like the smell of garlic in a kitchen; it was a part of the atmosphere, and hardly any white person gave it a moment's notice. Any employer other than the US government would have ignored any effort by non-whites to obtain employment outside the few menial areas "allowed" to blacks. But times were changing and the Air Force was hiring. However, segregation still ruled to a great extent. Langley's computing pool was divided into East Computing, where all the women were white, and West Computing, where they were all black.

Hidden Figures chronicles the lives of several of the Langley West computers during the war years, and then the fortunate circumstances that kept many of them employed during the crucial years 1946-1957. At least, I suppose you could call the Cold War "fortunate" for those whose employment depended on military expansion. The arms race with the USSR was not only in the nuclear arena. Fighter and bomber aircraft were getting better and better on both sides of the Iron Curtain. And in America this was largely due to the ex-computers, now engineering assistants and engineers. Several of them became ace programmers, learning FORTRAN almost overnight.

The quantum jump in American attitudes toward science arrived in October, 1957, when the Russians orbited Sputnik I. America was caught flat-footed. And a racial sea change was in the works simultaneously. During and after World War II, as one after another former colony of former European empires established themselves as independent countries, they looked at the world around them and saw America as a stronghold of racial discrimination, particularly as compared with nearly everywhere else. Folks, that right there is at the root of the mostly anti-American stance of the United Nations. To many nations, composed of non-whites, the racial tension that remains in this country besmirches every good-will effort we make.

Simply put, in order to jump-start technical education in America, we simply had to get rid of official segregation. We couldn't afford to waste any brains, of any "color". Hidebound reactionaries like Senator Byrd couldn't see that, but most national leaders could. Dr. King, Ralph Abernathy, and other black leaders took advantage of both the rapidly rising groundswell of black longings, and the growing sympathy for their cause among primarily northern-based political leaders (and a growing minority of southern ones also). The Civil Rights Act of 1964 was the end of a long and terrible struggle, and marked the beginning of another, one that is still going on.

Margot Lee Shetterly was, like Katherine Johnson, in the right place at the right time. When the time was ready, it happened that her father knew a few of the retired black computers, and put her in touch with them. They led her to others. She interviewed and researched and chronicled a truly astonishing story of the real brains behind many of the triumphs of American aviation in the 1940's and 50's, and in the space program ever since. It is still true that you can sometimes find yourself in the presence of a quiet black woman who is the smartest person in the room.

As I write this on Christmas Eve, 2016, a movie based on the book is to be released to theaters tomorrow, on Christmas Day. I hope it does the book justice. Even more, I hope the book is nominated for a Pulitzer Prize.

The Great Pond Snail

kw: species summaries, natural history, natural science, museums, research, photographs

This tray contains all but four of the lots of Lymnaea stagnalis (Linnaeus, 1758) that are currently in the collection of the Delaware Museum of Natural History. It is called the Great Pond Snail because it is the largest freshwater snail found in Great Britain ("Great" in this case meaning "large"). L. stagnalis is the type species of the genus Lymnaea, which is the type genus of the family Lymnaeidae. You'll notice one box contains only a pink label. That indicates the lot is a Topotype; it was collected in the location where Linnaeus's first-described specimen (the Holotype) was collected. The museum keeps types in a special cabinet. I'll get into more about types on another occasion.

The Latin prefix lymn- is equivalent to limn-, which refers to a lake. As a matter of fact, I am a bit puzzled that the family is not named Limnaeidae and the genus Limnaeus (but see below). The species was first named by Linnaeus as Helix stagnalis. He placed nearly all the spiral-shaped gastropods he knew of in the genus Helix, for obvious reasons. Later workers broke up the genus into quite a number of new genera so as to group the species more appropriately. For a time, subgenera had been created to group the species, and in fact, Lamarck renamed this species Lymnaea (Lymnaea) stagnalis in 1799, while placing several other former Helix species into that subgenus; the subgenus name is in parentheses. Later genus-splitters removed the subgenus designation. In 1875, Sandberg tried to rename the genus Limneus, considering it a justified spelling correction. Nearly everyone else disagreed because of priority rules, and so Lymnaea it remains.

Members of the family Lymnaeidae are lake snails almost exclusively, and some are also found in slow-moving streams, such as in deltas. This species in particular favors very quiet, shallow waters, even stagnant waters if the oxygen content is not too low. Thus the species name stagnalis.

I chose to photograph two of the lots. This first, catalog #60565, was collected in a shallow part of the Niagara River, on the New York side. These are the largest specimens of this species at DMNH. I neglected to put the scale in, but the museum label is 1" x 3", so the largest specimen's height is about 2.3" or 57 mm. The largest recorded specimen just exceeded 60 mm.

These shells, being nearly translucent and very light in weight, practically broadcast their environment: very quiet water and an absence of shell-crunching predators. However, they are hosts to several parasites, and intermediate hosts to at least six different flukes, including one that can severely affect humans. Thus, these are well studied because of their medical and economic impact.

They are "ubiquitously holarctic", meaning they are found throughout the Northern Hemisphere, particularly at higher latitudes, though south of the permafrost line. They apparently hunker into the mud to over-winter in England, Scotland, across northern Europe including Russia, and across the northern U.S. and Canada.

The second lot shown, #119635, contains some of the smallest adult specimens in this collection. The longest is just over 0.8", or 21 mm. Although these were collected in 1926, this indicates that the river where they were found, in or near Detroit, Michigan, must have already been heavily polluted.

Note that both of these lots have subspecies designations on the collectors' labels; one was jugularis and the other, expensa. These are now deprecated; so far as I have determined, no subspecies of L. stagnalis are recognized at present.

The labels of the second lot also show its history, or most of it. Originally collected by L. F. Merrill, it came into the hands of Grace M. Seymour, and then G. M. MacCoy, who donated it to DMNH. Sometimes, collections are accompanied by letters and other documents that tell more of the story. I haven't dug into the library records for the MacCoy collection to see if there is more to the tale.

Shell collectors who are dedicated enough to identify and index and label their specimens are dubbed Shellers. By contrast, the designation Conchologist is reserved for those who also devote time to studying shells, and perhaps living mollusks, and professional Conchologists are called Malacologists. Mollusk enthusiasts and dealers Guido and Philippe Poppe have gathered information about more than 41,000 Shellers in their site Conchology Inc., from which they sell and trade shells, and curate a kind of online museum. It is one of a handful of online resources that I have found very useful to determine the full name of someone. Interestingly, however, none of these three Shellers is included. Neither is Esley Doremus, the donor of the lot from New York.

At least we have the initials for two of them and full names for the other two. In many cases I find a label that says nothing more than a species name, a location, and a surname followed by "leg." or "legit.", the usual Latin designations for a collector. The abbreviation "col." is also sometimes used, but "coll." usually means "from the collection of"; Shellers trade and buy shells so much that for many large collections, only a small percentage of the holdings were actually self-collected by the owner.

The 78 lots of this species held at DMNH allow researchers to study areal extent, presence through time at locations or in areas that were visited more than once, and changes in animal health. I occasionally find a note among the labels that specimens were collected from the bed of a dried-up pond, indicating at least local extinction. Rather poignant, that.

Multiple gulping spiders

kw: blogging, blogs, spider scanning

Nearly two months ago I posted about what appeared to be a periodic internet spider that seemed to be grabbing about 30 posts at a time in this blog, roughly every 4 hours. A few weeks later, such activity increased. Today I find that it has increased again. Have a look:

These are hourly hits for the past week. The prior increase was to roughly one 30-hit session each two hours. I think now there are several spiders at work, and it is hard to tell how many posts each one is getting. There is also a shift in the source of the activity. Prior to the past couple of weeks, most activity was based in the US. Now:

In this pair, the left side shows one day's activity (nearly 900 hits total), and the right side shows one week, the week shown above. Clearly, the US activity has held steady at around 210-220 daily hits, while Russia has ramped up to dominate my "audience" just in the past two or three days.

Does it strike you, as it strikes me, that the sudden boost in activity starting late on Dec. 16 coincides with the threats against Russia made by President Obama in his latest news conference? It looks like they are targeting a whole lot more than just political operatives! I mean, I am probably one of the lowest-rated bloggers out there, and I write at most one politically "interesting" post every year or two.

Thus, I wonder just who in all that immense country called Russia is really Hoovering up data from my blog. Fellow bloggers, if any of you happen across this post, check your stats, and their pattern since mid-year. I am sure I am not the only one. And I'd like to hear from you.

This activity doesn't concern me much. It isn't hacking. I have about 80 to 100 legitimate daily readers. Most of them stumble across the blog and seldom return; I have no more than a handful of followers. The only annoyance to me is, I don't any longer have a good handle on how many actual readers come to this blog. The spider activity swamps that signal almost out of existence. Oh, well. Maybe they'll get bored and go away.

I find it amusing to think that, just perhaps, the KGB has some poor analyst reading my posts (at the rate of a couple of hundred per day?) to find out what is interesting. Or maybe they have a really smart AI doing relevance searches. Has anything been passed along to Wikileaks? If any human is at the other end of one of these spiders' pipeline, I counsel you to get a more interesting hobby! It can't be my stellar writing style.

Valuable Volunteers at the Museum

kw: natural history, museums, volunteers

At least a few days per week, from my desk along the side wall of the mollusk collections room of the Delaware Museum of Natural History, when I look to my left, I see something like this. This day there are three volunteers on duty.

No museum—indeed, no nonprofit organization—can function without volunteers. I think museum volunteers have some of the best "jobs" going (but I am a science geek; what do I know?).

The Collections Manager at DMNH is also the Volunteer Manager. Of the daunting variety of tasks needed to care for a large seashell collection, he must prioritize and assign them, and also perform many himself (a couple of years ago there was a "herself"). At the moment, much work is being done on shells from a couple of new donations, and updating some existing material.

Here the woman sitting nearest me is labeling specimens. That little Coffee Bean Cowrie is just about the smallest shell that can be practically written on with a "00" nib India Ink pen. The first four digits of 121472 are already there, and she graciously paused long enough for a photo. (The number indicates this is some re-work on older material. New material is getting numbers above 240,000.)

The policy is, if a lot has 30 shells or fewer, and the shells are large enough, they are each numbered. Considering that the average size of a lot is seven shells, and that most shells are indeed larger than a fingernail, that comes to a lot of inking! Where they are too small or too numerous to number individually the shells are not put in an open box but into a lidded plastic container or vial.

This man is identifying shells, as is the other. We don't expect volunteers to be experts, but nearly anyone with good eyesight (and a magnifier or microscope if needed, and this fellow has one within arms' reach) and a good reference book can match a shell with a picture.

Online references are improving all the time, including WoRMS, the World Register of Marine Species, which he and the other man have up on their screens.

Most preliminary identification can be done by volunteers, and then the Collections Manager can verify their work. Sometimes, the species cannot be fully discerned at first, and the volunteer reports only the genus. In all cases, to make sure an identification is up to date, the literature is searched to see if a specialist has renamed a species or lumped it into another species. Then the identification (now called a determination once it is verified) is recorded for that lot.

The third volunteer of the day was working on a different donation, shells from Papua New Guinea, collected by a former ambassador. The standard reference to shells from that huge island's seas can be seen next to the specimen tray. Tropical shells are the most fun to work with. They are beautiful, incredibly varied, and species are usually easier to distinguish from one another, compared to the mud snails with which I have spent the past year!

Few museum volunteers work more than a day or two per week, and those are frequently short days of 4-5 hours. But their work adds up. The time spent by these three volunteers amounts to about 3/4 of a full-time person; and there are a few more volunteers who work on other days. Even more, as our lunchtime banter attests, having a few volunteers around makes the work a lot less lonely, compared to a couple of folks sharing a huge room with two million seashells.

No bridge yet discovered

kw: book reviews, nonfiction, science, evolution, human origins

One popular conception of evolution is the giant leap: A rabbit wakes up one morning to find that it is a deer; a monkey goes to bed a monkey and wakes up an ape, or maybe a human. This was a popular view in the early Twentieth Century, and the occasional story appeared in which someone used radiation to "evolve" into a higher being with massive intelligence and penetrating wisdom. It lingers in genres such as the Fantastic Four or X-Men, and even Spider Man, in which some mysterious energy or chemical influence suddenly "evolves" ordinary folks into super beings. I don't pay as much attention to these stories as most folks, but it seems to me that the only "superhero" story that doesn't depend primarily on some kind of magical transformation of this type is Batman.

We do like our catastrophes, and we do like the solutions to disastrous problems to be simple, complete, and in particular, FAST. Need I belabor our addiction to the 30- and 60-minute TV episode formats, or two-hour (more or less) films? Emotionally, we need fast solutions, because if we don't solve the problem of "one death per person, no exceptions", in a matter of a few decades, we are all to be thrust into eternity, not even knowing if there is an eternity. Of course, as a Christian, I have a spiritual answer for that. But as a Humanist, I know that most folks don't really believe in an afterlife; instead they hope against hope that there really is one, and that it isn't Hell.

Humans are the longest-lived of the mammals, although perhaps some species of baleen whale might live longer. A few slower-living critters are known: A turtle that was collected while Darwin was living died last year; some species of clam were recently shown to have individuals aged as much as 500 years. But among animals that can recognize themselves in a mirror, only humans routinely live more than 60 years. But compared to evolutionary time or geologic time, this is very short and inevitably forces our mind into rather short-term thinking.

Can any of us, without great effort and practice, comprehend time spans much greater than 50 years? Aficionados of genealogy gradually come to comprehend spans of a few hundred years, perhaps a thousand or so: a few Europeans and Euro-Americans can trace their family tree to Charlemagne, some 1,200 years ago. A few cities (Damascus comes to mind) have been occupied more-or-less continuously for 3,000 years or more. How can any of us comprehend a million years or more? The "young earth" Evangelicals, who allow no more than 6,000 to 10,000 years for the entire age of the Earth, are onto something. That is the limit most people's minds can reach, and a span of 10,000 years is practically meaningless; how much more unfathomable a million or a billion?

The basic unit of the evolution of vertebrate species is one million years. That seems to be on the shorter side of the survival of a species of mammal, bird, or reptile. The longer side is three to five million years (I may discuss marine invertebrate species, some of which appear to survive for tens to hundreds of millions of years, on some another occasion). Interestingly, the survival of primate species seems to be inversely correlated with body size. Species of monkeys and small apes weighing less than around ten kilograms may go on for five to ten million years. Larger apes seem to speciate more frequently and vanish sooner. The human ancestral apes and proto-human species of genera such as Homo, Australopithecus, Ardipithecus and so forth seem to stay around between 100,000 and 500,000 years. Of course, the fierce competition among paleoantrhopologists to be remembered for naming new species and genera has resulted in some over-splitting, so future scientists will most likely lump together many putative species .

I also wonder: If there were equally huge prestige associated with naming each new species of fly or snail or nematode, would the number of named species multiply, and the duration of fossil species accordingly shorten? A side note: I spent the last year taking inventory of a few thousand specimen lots of river-and-pond snails of the family Pleuroceridae, at the Delaware Museum of Natural History. The collection includes about 300 names species in a dozen genera. This is a winnowing (i.e., lumping together) from about 1,000 named species described prior to 1980 or so, and more recent work using DNA methods is finding that many "species" are regional variations of more widespread species. A specialist in the field told me recently that there may actually be no more than five or six actual species in this family! To the point, though, evolution makes no sense in time frames much shorter than a million years, and significant levels of change can take much longer.

Well, to come to the matter in hand. About 20 fossil species have so far been named in the Hominid line—those creatures purportedly descended, on the human side of the tree, from the common ancestor of Homo sapiens (us) and the two Chimpanzee species of the genus Pan. There were most likely many more. The species that we find today in every genus or family represent, in metaphor, the tips of the twigs of a dense bush. In the case of the little branch that began with the proto-Chimp-Human, only three twig tips remain. In the six or seven million years that have elapsed since that primeval split, who knows how many twigs on the Chimp side, and how many on the Human side, really existed? Several proto-Chimps are known (or suspected), and, as I said, about 20 proto-Humans.

In a book published in 1998, Becoming Human: Evolution and Human Uniqueness, author Ian Tattersall describes what is known of the major changes that arose among the five or six of those proto-Human species that are actually ancestral to Cro-Magnon, the earliest expression of Homo sapiens, which arose between 150,000 and 200,000 years ago. Dr. Tattersall set himself two challenges: to explain to a popular audience the actual bushiness of pre-Human evolution, and to describe and account for the qualitative differences between humans and the rest of the apes.

It has become fashionable in the past generation or so to "demote" humanity from the pedestal on which our cultural habits have placed us. In the author's mind, these demotions have gone too far (Am I becoming a curmudgeon? It seems to me that "going too far" is what people do best, and most frequently, and almost without exception!). Thus, he skates a careful line in this book. The origin of humanity has not been some unrelenting upward march. On the other hand, something very striking has indeed happened, that produced a species that isn't just a big-brained ape, but something new.

To cut to the chase (I'll leave it to you to read this very well written and thoroughly fascinating book), the Cro-Magnons and their cousins the Neanderthals had brains of about equal size. They co-existed, usually not in the same areas, for a few tens of thousands of years. Here is a point that struck me with particular force: Many, but not all, Neanderthal skulls have an arch in the skull base atop the vocal tract, something that is necessary for articulate speech. All Cro-Magnon skulls have it. Yet prior to about 40,000 or perhaps 50,000 years ago, neither species left fossil or archaeological remains that indicate they used symbolic thought. The Cro-Magnon remains of this period are usually termed "anatomically modern". Then, almost overnight, a dramatic cultural shift occurred. Some time in the "thirties" (a little before 30,000 years ago), art of all kinds began to be produced. Cave paintings are rightly famous, but personal artifacts became much more artful, both decorations on useful items and items that are purposely artistic but otherwise (probably) useless. In this period, the term used is "culturally modern."

It is hard to draw conclusions about what actually happened when we can't go back and interview them. We don't even have really good DNA from anybody who lived 30- to 50,000 years ago. Yes, we have enough Neanderthal DNA—all discovered since the book was written—to allow us to determine that various human populations carry between 1% and 6% of Neanderthal DNA. But, as the author describes, skills such as language arose only after the physical (including to the brain) changes needed had arisen for other reasons. These are called exaptations, a kind of adaptation that gets co-opted for another use. Personally, I find it hard to think that Broca's and Wernicke's areas in our left brain hemisphere could have arisen for purposes that we can't discern, and were then found to be just what was needed to support language. In any case, positing pre-existing exaptations, the further changes needed to produce language, symbolic reasoning, and art seem to have taken place quickly, without making any discernible changes in fossil remains. And that is where Dr. Tattersall has to leave it. We still don't know enough to say how such a significant cultural shift occurred.

In the last few pages, he allows himself to speculate on future evolution of Homo sapiens. He thinks not much will happen. I intended earlier to write of the tension between uniformitarianism and catastrophism, both in geology and in biology, but the writing took a life of its own. Let me instead briefly say, a mix of uniformitarian periods and catastrophic events have happened to mold the Earth we see today, and the styles of living species we discover all around us. He points out that species don't evolve much. They go on for millions of years unchanged. But when some circumstance isolates a smallish population of a species, the narrower gene pool available among them is more prone to genetic drift and to the fixation of new, beneficial (even though small) mutations that would be swamped and eliminated from a larger gene pool. Given enough time, usually at least tens to hundreds of thousands of years in the case of large primates, the small "drifted" population will have changed enough that interbreeding is no possible with the larger population from which they arose, should they come back into contact. They are a new species. If they are viable, and even more, better able to thrive in the same environment, they original species may die out in their favor.

Today, what opportunity is there for some small but viable population of humans—say, a few thousand—to remain isolated for 100 or 1,000 centuries? Zero, Zip, Nil, Nada. Small evolutionary changes will continue: maybe our descendants will have fewer back problems; maybe few or none will have wisdom teeth. Our inefficient retina will probably never be replaced with the more efficient squid retina, unless genetic engineering really, really takes off (but would there somehow be a tendency for these engineered folks to spit ink?). We are the first truly global species. That will last as long as we do, or until we experience, or even cause, a catastrophe that reduces humanity to a scattering of small tribes, no more than 100,000 people in groups seldom exceeding a few hundred. Then speciation is possible. Not before. You don't like catastrophes? Then take care of the things that remain. Also, look around. The sorts of people we see today are about what we can expect for the next thousand centuries or so.