Jarn’s Journal Day 398

This is an excerpt from the (fictional) journal of a human-like alien stranded on Earth, in southern Africa, roughly 125,000 years ago. His journal will eventually become the Holy Book of many planets in the Jarnian Confederation, which is where my two science fiction novels, Homecoming and Tourist Trap, are set. The parts of the journal that have been blogged to date are on my author website.

The northern solstice has passed!

I have made a calendar of sorts, with Songbird’s aid. There is a particular flat rock I stand on, at the top of the rise where I have built my shelter. I can see the sunset move around the horizon from that point, and though the horizon is not flat, the hills are constant. Songbird goes out with me at sunset every day, and moves until the stake she holds is just lined up with the sun on the horizon. Then she drives it into the ground. If it will not go in (which sometimes happens) she holds it while I pile loose rocks around it.

The last few days the stakes have been almost in the same place, but this evening the position of the stake was definitely south of yesterday’s stake, if by only a fingerwidth.

I think the actual solstice was two days ago. At any rate that is what I will assume in figuring the year length, and in trying to estimate when the rains — and Songbird’s people – will be back.

Songbird was not very enthusiastic about helping me at first, though she was obedient enough to do as I said. More of this “god” stuff, I suppose. But when I explained that I wanted to use the sticks to help me know when to go look for her people’s return, she rapidly started reminding me when it was almost sunset. Her leg has healed without a trace of a limp, and I must admit that I feel rather proud of my skills as a doctor!

Of course I have not been here long enough yet to know exactly when the rains will start and the game and Songbird’s people will return. But both should occur as the sun’s course moves back south.

I want to see that shaman!

Jarn’s Journal day 390

Songbird has decided I need new clothes.

Not that I really need them for warmth, unless I go out at night. It cools off fast in the dry season. But there are an awfully lot of thorny plants, and while I don’t sunburn easily, I do sunburn. And the few clothes I had with me are falling to pieces.

That didn’t stop Songbird from close examination of my one-piece shipsuit (or what is left of it) and my woven tunic. Or my crude shoes, for that matter.

She herself is wearing a kind of tunic made of two gazelle skins, beautifully tanned, fastened together at the shoulders and sides. I am not sure whether the purpose is protection from thorns, a sunshade, or simply local cultural mores – I didn’t get a very close look at the females of her people. The men, at least when running down game, wear very little.

But this morning Songbird presented me with a new tunic. It is very coarse of weave, but it is woven – much like the baskets she has woven to hold foodstuffs. It seems to be woven all in one piece, like the baskets, but of softer fibers than grass. When I asked her what the fibers were, she showed me one of the plants she has asked me to gather for the seeds. She then explained that when allowed to soak in water, the fibers could be separated from the stems. Her people use it only rarely, because of the work involved, but she thought that since I am a god it would be appropriate for me.

I have given up on trying to convince her I am not a god.

The Place Where You Go to Listen

©Sue Ann Bowling

The music of the spheres–
A trite phrase, and one with little meaning
Since universal gravitation replaced crystalline spheres
And first man
And then the sun
And then a point in the center of the galaxy
And then everywhere and nowhere became our center.
We drift, uncentered.

But here
The music of the sun, the moon
The deep rumblings of the moving plates of the earth
The colors of our world–now gold below, blue above–
Make up a different music of the spheres.
Monotonous at first.  The heart of earth
Beats slowly by the beating of our hearts.
But change does come, bacteria
Gave way to jellyfish,
And dinosaurs to man.

These notes change slowly, night to day,
Season to season, the cycles of the sun.
Here we are centered once again.

What’s this about? There is a room at the UAF museum in which the rhythms of the earth — seismic tremors, sun, stars, aurorae — are expressed as musical tones and colors on the wall. This poem was inspired by that room.

Plate Tectonics: Part I

The important thing about science is that it has a built-in mechanism for corrections. It doesn’t always work as well as it should, because scientists are people and resist changing their beliefs. The fact remains that assumptions are always open to challenge.

I was reminded of this in watching a DVD on How the Earth was Made, which I’ll review soon. The point I want to make here is that the DVD presents examples as if the scientists involved were searching for pieces of a puzzle that they knew had missing pieces. More often the major breakthroughs – such as plate tectonics – are made when a gradually increasing number of people realize that the accepted theory just doesn’t explain something. Or many somethings. Essentially, that the puzzle pieces available have been put together wrongly, and the picture is in fact quite different.

This happened with plate tectonics.

I wasn’t involved directly, but I was at the Geophysical Institute when it happened, and had a chance to read many of the papers as they came out. And I was interested enough to do just that.

Even as early as grade school, I was unsatisfied with the encyclopedia’s explanation of mountain-building and geosynclines. What the encyclopedia said was that mountains were formed by the cooling and shrinking of the Earth, much as wrinkles are formed on the skin of a drying apple. Erosion wore the mountains down, depositing the sediments offshore, and the weight of those sediments pushed the ocean crust down so the mountains grew higher. It did not make sense to me, even then. These processes would have resulted in filling the oceans and leveling the mountains, not building them!

When I was a little older – high school age – I was given a book that gave some of the results of the International Geophysical Year – the IGY. The one that stuck in my mind as an unsolved mystery was the discovery of major east-west trending faults in the Pacific Ocean. Based on the offset of newly discovered magnetic stripes, these faults had large displacements – tens to hundreds of miles. But the displacements totally disappeared when the faults reached land! Not only could the east-west displacements not be found, in places such as the California coast there were well-known faults such as the San Andreas tending more nearly north-south.

At Harvard I took a basic geophysics class, hoping it would help me make sense of what seemed to be an increasingly frustrating puzzle. What I learned there – and it was the cutting-edge science of the early 60’s – left me as puzzled as ever.

Gravity measurements had proved that continents stood higher than oceans because continental rock was less dense than ocean rock. This was known as isostacy – the height of terrain essentially depended on how high it floated on the mantle.

Continental drift was nonsense – there was no way continents could plow through oceanic crust, and there were no traces of any such plowing through on the sea floor. The matching of rock formations on the opposite sides of the Atlantic was sheer coincidence.

Exchanges of plants and animals over  geological time were via land bridges.

The elephant in the room, from my point of view, was that isostacy did not allow sea floor to rise and form land bridges.

I went to the Geophysical Institute as a graduate student partly because of these mysteries, but I was sidetracked into atmospheric science and ice fog. Nevertheless, I stayed interested, and since many of the seminal papers in plate tectonics were published in the Journal of Geophysical Research (JGR) I watched the plate tectonics revolution happen. Next week I’ll talk about some of the breakthroughs that eventually led to the new paradigm of plate tectonics.

The Animal Connection: Review

Last month I blogged about an article in The New Scientist based on a book due to be released soon. The book, The Animal Connection by Pat Shipman, is now available and was one of the first I bought for my iPad.

This is a book anyone interested in animals, domestication or human evolution should read. Dr. Shipman points out that hunters must observe animals and learn to anticipate them in order to hunt successfully. She links tool-making to the hunting of animals, pointing out that we are unique as predators in using tools, not teeth or claws, to hunt. The addition of meat to our diet may well have been what made us able to support increasingly large brains, as brains have a very large energy cost.

The need to get “inside the skull” of another species may also be behind much of the empathy and imagination we share.

Later, the need to share information about animals may well be one of the driving forces behind our acquisition as a species of language. Language, although one of the traits that define us as a species, does not fossilize, so arguments here tend to have more than a little arm-waving about them. The fact remains that animals, rather than plants or other people, are the main subjects of Paleolithic art.

If animals were living tools, as the author argues, they are tools whose best use must be based on mutual understanding, not on force. There is nothing really new about this; Xenophon’s tretise on horsemanship said it over two thousand years ago.

The future? To quote the author, “The post-animal world, if we choose to live in it, is a fearsome place that threatens to destroy the very best qualities of humankind.”

I tend to believe most of the arguments in this book partly because they reflect my own conclusions. I wrote a short story over ten years ago suggesting that the connection between people and dogs may have shaped both into a new symbiosis, and I am glad to see that idea now accorded some degree of scientific acceptance.

Book: The Animal Connection, by Pat Shipman. Published by W.W. Norton,
ISBN 978-0-393-07054-5

Dinosaurs: Extreme Survivors (DVD Review)

This is a Discovery Channel DVD, and a very recent one – copyright 2011, so it should be up to date. I enjoyed it, though I raised my eyebrows now and then at the speculation produced as statements. In all fairness, the DVD did include segments of talking with the paleontologists who have often conflicting opinions on the interpretation of the fossil material.

The DVD has three programs of approximately an hour each. Clash of the Dinosaurs: Extreme Survivors, the title episode, goes over what made dinosaurs so successful for so long, and contrasts the strategies of producing huge numbers of young, very few of which will survive, and producing a few young and investing in their care.

Dino Gangs examines the possibility that Tyrannosaurus rex, the iconic big carnivore of the late Cretaceous, may have hunted in groups of mixed age. The young T. rex were apparently lightly built and capable of considerable speed. The older animals were much stronger but had to move more slowly to support their massive weight. In a mixed pack, the adolescents would have chased and turned back the prey for the adults to kill. Maybe. But it is not a world I’d like to visit!

The final program attempts to reconstruct the events when an asteroid struck the Earth 65 million years ago (not 165 million years; the narrator was mistaken there.) The cataclysm makes the events of this year look mild indeed, but I doubt the accuracy of some of what they have reconstructed. For instance, they have a secondary tsunami impacting the Pacific Northwest, but never mention that the initial impact would have caused a huge tidal wave in the Atlantic.

Overall a nice balance of computer generated dinosaurs and input from paleontologists, but it should be watched with full awareness that our understanding of dinosaurs is constantly evolving.

The Animal Connection

The Bargain
©Sue Ann Bowling

Long ago and far away
We made a bargain,
Your forefathers and ours.
One could find game, sharp-nosed, keen-eared, alert to every breeze.
One had spears to kill in safety.
One too often died beneath defending hooves
One too often found no target for his spears.
So we made the bargain:
One to find and one to kill, and the meat to share.

The years passed, and the bargain changed:
Tend our flocks.
Fight our wars.
Pull our sledges.
Guard our children,
Lead our blind.
Amuse us.
Love us, when all the world has abandoned us.

And on the other side, the same:
Share the food.
Share the fire.
Share our lives.

Wolf that was, how can I break the old bargain now?

I wrote that years ago, along with an apocalyptic short story, now posted on my website. But at the time, the idea that the domestication of the dog might have been two-way, that man as well as dog had been changed by the relationship, was scientific heresy. Now at last it seems it is being accepted.

In the May 28-June 3 issue of New Scientist there is a cover article titled “How Animals Shaped our Minds.” The article is based on a book, written by Pat Shipman, which is due to be published on June 13. I don’t want to say too much until I’ve read the book. But she argues that the mindset that made domestication possible, the knowledge of animal behavior gained through careful observation, may well have been a driving force behind our development of language. And the article, at least, makes the same points that I did in my story: our relationship with another species may be an important part of our humanity.

I am looking forward to reading the book, and will probably review it here. Meanwhile, read the article — and “Death of a Dog.”

DVD Review: Walking with Prehistoric Beasts

This is the third in the Walking With Dinosaurs series in terms of geologic time and the second in terms of release date. Like others in the series it is unclear what is imagination and what is fact, but the rendering of extinct animals is excellent. One comment on all the “Walking With” videos — animals make sounds for a reason. It may be to freeze or to scatter prey, to communicate with others, or to intimidate a rival — but an animal waiting for an opportunity to attack is silent.

The video is ten years old and some of the paleontology is out of date. So are some of the locations – the evidence for land-dwelling forerunners of the whales, for instance, comes mainly from Pakistan and it is somewhat questionable to put an Ambulocetis in Germany.

The first DVD has six episodes. The first “New Dawn,” is set in the early Eocene, when the earth had settled down from the K-T boundary event and the extinction of virtually all large animals. Mammals are still small, and the descendants of dinosaurs — the birds — are the dominant predators.

Later in the Eocene the mammals are beginning to take over, and the second segment, “Whale Killer,” focuses on marine and estuarine life. It also considers the climatic results of changing ocean currents due to plate tectonics.

The third episode, “Land of Giants,” is set in the Oligocene and focuses on a single type of animal, the indricothere, although others are shown as well. Imagine a rhinocerous the size of a giraffe! I’m not sure they gave their indricotheres the right environment, though.

The early evolution of our own species is covered in the fourth episode, “Next of Kin,” which centers on an australopithecine clan. Grass has now evolved, making backgrounds much easier for the filmmakers to find. This episode is relatively recent, only a little more than 3 million years ago.

The fifth episode. “Sabre Tooth,” is set in South America a million years after the Panamanian land bridge has opened, ending 30 million years of isolation. The old top predators were terror birds, much like those of the first episode. This episode focuses on the North American predator that has replaced them, the sabertooth cat.

The sixth episode, “Mammoth Journey,” takes place in Europe at the height of the last ice age, when two sub-species of humans shared the territory with a number of cold-adapted animals. Living in Alaska and knowing that mammoths did quite well here during the ice age, I am not so sure that the cold would have forced them to migrate out of the lush pastures of the North Sea, though.

Don’t forget the second DVD in the set. This has a good deal of information on how the episodes were made, interviews with the producers, model-makers and animators, and some behind the scenes information on the animals themselves and the evidence for their existence.

Walking With Dinosaurs (DVD Review)

In many ways this is a retrospective. Walking With Dinosaurs came out almost 12 years ago, in 1999. Last century stuff. But it set the stage for all the dino-documentaries that have come out since.

When it came out, realistic computer-generated dinosaurs were certainly a possibility in movies – Jurassic Park preceded and partly inspired Walking With Dinosaurs. But managing this quality of CGI on a television budget, treating the whole thing as a documentary and bringing in paleontologists not only as advisors but at times as collaborators, was new.

I do have some quibbles with the six episodes. First, there are a few places where the narration is just plain wrong. I’m not talking about things that were learned after the film was made or guesses that are presented as fact; I’m talking about things like the statement that carbon monoxide is heavier than air. In fact, it is almost exactly the same density as air. The suffocating, low-lying gas that is produced by volcanic action, and is heavier than air, is carbon dioxide.

Second, there are many things in the DVD that are pure guesswork. Some of these are pretty obvious, like the colors of extinct animals. No real problem there — they had to be some color, after all, and why not pattern them after existing reptiles? In some cases, such as pterosaurs getting around on the ground, even the paleontologists learned something from the animators’ efforts to get the animals to move. But flat statements such as the one that cynodonts paired for life, for instance, seem sheer guesswork.

Finally, this DVD has to be watched with recognition that a great deal has been learned about dinosaurs in the last 12 years. We now know, for instance, that a great many of the predatory dinosaurs had feathers, probably both for insulation and for display. Our ideas about the social life of dinosaurs are also undergoing a transition. The DVD shows Tyrannosaurs as solitary animals, guarding their territories jealously. There is increasing evidence that they may have hunted in packs, with a social life more like wolves.

Do look at the second DVD, the one that has “The making of” sequence. This points out things that are all too often ignored in later dino-documentaries, such as the fact that grass evolved quite recently, and was never present when the non-avian dinosaurs were alive.

This was the first made of the “trilogy of life” series, though it is the middle one in terms of geologic time. This trilogy is still probably the best of the dino-documentaries.

Where did the First Plants Come From?

How did plants invade the land?

Any living creature had to overcome a number of problems in moving from the water to the land. These include protection against desication, support, fluid and nutrient transport, gas exchange, ultraviolet radiation, and reproduction. The fin-to-limb post looked at how animals overcame those obstacles, but animals had to have something to provide an energy source before they could even begin to make the leap to land. That means that photosynthesizing organisms had to move onto land before animals could even get a start. So how and when did they do it?

Lots of natural and artificial selection between the earliest plants and these California Poppies.

Algae have been around for a long time – something like 2.1 billion years. Photosynthesizing bacteria are even older, and either could have formed thin mats where wave action or stream turbulence kept the ground wet. I’ve put photosynthesizing slimes in the wave zone on Mirror, one of the planets I imagined for Homecoming. Such thin mats or slimes, however, would be been dependent on being kept wet.

The first appearance of cuticle, the membrane that acts as a skin for plants and keeps them from drying out, was in the Ordovician, around 450 million years ago. Once you have a cuticle which prevents the interior of a cell mass from drying out, you also need some way of allowing carbon dioxide into the cells and oxygen out so stomata, the pores plants breathe through, are probably about the same age.

Early plants began to lift their fruiting bodies above the ground, but not far. They also had branching, cuticles, stomata, and photosynthesizing stems, but no leaves. Ultraviolet protection was probably a combination of pigments and enough oxygen in the atmosphere that an ozone layer formed. Gradually plants evolved mechanisms that transported nutrients and fluids via hollow cells that combined to form tubes (vascular system.) They also needed a system of roots to hold them upright.

The first plants did not have soil as we know it. A certain amount of mechanical weathering would have broken the rock down into silt or sand, but today’s soil is largely the result of chemical weathering (in which plants assist) and decayed plant matter.

Support systems developed slowly. The plants gradually began to show secondary growth (stems widening with age, instead of just getting longer) and the ability to synthesize cellulose from the sugars they produced via photosynthesis. By the time the first amphibians crawled out of the water, tall trees had developed. Why? Most likely competition for light.

Plants were not, however, a good food source. Even without the toxins that plants of today have evolved to avoid being eaten, neither cuticle nor cellulose is easy to digest. The herbivorous animals of today have a long history of adaptation to plant eating, but even so a large part of their (and our) digestion of plants is actually carried out by microorganisms.

The millipedes and other invertebrates that preceded the amphibians onto land were mostly detritus feeders, relying on bacteria and fungi to decompose the plant matter enough they could digest it, or carnivores that ate the detritus feeders. The fact that so many of the plants of the Carboniferous wound up as coal may even be due in part to the fact that few animals could eat them. Early amphibians may well have obtained most of their nourishment from insects and from the water.

Although many of the early plants reproduced by spores rather than seeds (as do mosses and ferns today) they had evolved seeds by the Devonian (around 380 million years ago.) Our amphibian ancestors would have found forests that included trees resembling today’s conifers and ginkgo. Flowers, however, came much later.

This is the last summary of the OLLI classes on major evolutionary transitions. Next Friday’s post will be on some other aspect of science.