Why work on a Sunday? Playing, I find there is a new theory onthe
origin of Dinosaur flight, discussed at
This brings the theory count to three: that flight evolved from using feathered forelimbs to 1) run faster, 2) run up steep slopes/hills, or 3) to aid in leaping from tree to tree.
I am unequivocally on the side of the third hypothesis. In fact, I press the point beyond hypothesis, into the realm of speculation:
Dinosaur flight with its precursor, feathers, evolved with the archosaur/dinosaur line itself. And this happened much earlier than has thus far been suggested by any experts I know of, nearly simultaneously (in terms of geological time) with the emergence of reptiles as a distinct line of terrestrial tetrapods. This would have occurred between the end of the Devonian and the beginning of the Mesozoic, during Carboniferous and Permian time.I am a bit of a dinosaur myself, and it has been eons since I really studied these things. If anyone current on the topics touched on happens to read this, and has comments, please write me at email@example.com. I hope to do a more thorough revie of the evolution of the tetrapods, synapsids, archosaur/dinosaurs, and birds with appropriate links, and will include a P.S. here linking to it if I do.
It occurred as small reptiles, newly evolved as land animals, moved into the arboreal habitat to take advantage of insect and other food sources there, and to escape predation by their larger reptilian and proto-mammalian competitors (such as Dimetrodon) on the ground. Once in this habitat, there emerged the changes in skeletal, reproductive, and behavioral characteristics which make the archosaur/dinosaur line so unique. The first structural change would have been the evolution of forelimb aided bipedality and claw like nails. But the most important of these changes was the evolution of feathers and physiological (heart/circualtory) and skeletal (light, hollow bones and modified skull, pelvic and shoulder arrangements) features adapted to speed -that insect prey, remember?
When the dominant forms of life in the late Paleozoic became extinct (for reasons still not resolved but possibly involving glaciation and climate change) the proto-archosaur/dinosaur lines were able to respond to the new conditions, and begin their reign over Mesozoic time. For some, this meant descending from the trees, changing diet, and growing larger. Some would eventually assume a quadrapedal gait, as well. The light bone structure, and the skeletal evidence of a once bipedal gait remained for all dinosaurs, however.
One branch of the archosaur/dinosaur family remained in the trees, except for a few phylogenetic offshoots over geologic time. Those are the birds, and their latest large terrestrial offshoots are the Ostrich, Moa, and Emu.
(Note: The birds may also have evolved from a flightless dinosaur line, but by re-exploitation or expression of a "conserved developmental pathway" from much earlier in archosaur/dinosaur evolution. I believe that evidence of the exploitation of flight and gliding capabilities inherent, through such conserved developmental pathways, in the archosaur/dinosaur line is already available, and I think more will be found if sought for. The fact that the "four winged dinosaur" of the dromeosaur line referenced below is some 25 million years younger than the first known true bird, Archeopteryx, is itself possible evidence of the repeated expression of pre-existing developmental pathways for feather and flight. For an example of conservation of developmental pathways for flight from the insects, see "Loss and recovery of wings in stick insects".)
The other archosaurs radiated into virtually every terrestrial, and even oceanic ecological niche.
What evidence, in addition to the preservation of the bipedal gait relicts in skeletal structure and the light bone structure, is there for such speculation?
Why is there little or no fossil evidence of this? The fact that no one has been looking, may be one reason. Reexamination of existing fossil evidence might support this speculation. But such evidence may be very scarce, as the environmental conditions of late Paleozoic time were unfriendly to preservation of small, fragile remains, particularly of arboreal creatures. (The dominant animals of the late Paleozoic, including the most famous, Dimetrodon, were Diapsids - actually more closely related to the mammals - and were not the ancestors of the Synapsid archosaur/dinosaurs.) An interested paleontologist might start searching for anomalous bone fragments in the locations and formations where insect remains have been preserved, or in areas where forests have been preserved by sudden events.
- There is much evidence for "nesting" behavior and herd or flock behavior among dinosaurs, even early dinosaurs.
- The discovery of "bird dinosaur" fossils, clearly dinosaur in physical characteristics but with unmistakable feathers, and early in the history of their race, adds weight.
- There is even preliminary evidence that neonate T. rex's may have had "chick down".
- There is the "logic" that it is near inconceivable that an ecological niche of the richness of the arboreal realm in the Carboniferous and Permian would have gone unexploited by emerging terrestrial tetrapods for 200 million years or more; compounded by the clear compatibility between archosaur/dinosaur skeletal characteristics and an arboreal evolutionary past.
(Note: The other Geologist in the family has referred me to:
http://news.nationalgeographic.com/news/2003/01/0121_030122_dromaeosaur.html which discusses the "Four winged dinosaur" recently discovered in China.)
The truth about global warming!
has been one looong cold spell.
The present concentration of greenhouse gases is 30% above the benchmark pre industrial content, rising to that level in only a century, and is likely to be the highest for the past 20 million years. According to the 'warmest scenario' projections of the Intergovernmental Panel on Climate Change, the projected doubling of CO2 concentration by the end of this century is expected to result in a climate that the planet last experienced about 70 million years ago (Fig. 1). http://www.nature.com/nature/journal/v421/n6920/fig_tab/421221a_F1.htmlWeblog 2003-01-18
(Note that the time scale above the zero (present time) point is in hundreds of years, that below is in millions of years.)
In today's email...
You travel to the distant corners:
Ladakh, Tierra Del Fuego, Timor,
seeking you know not what, only
that it's far from where you are.
You hunger after revelations in the planes
of dark faces, sounds of strange languages,
come away instead with a carving
nervously haggled for from someone
whose name you did not bother to ask.
And in exchange for pretty postcards;
boxes of neatly labeled slides,
you leave beggars, whores, plastic
wrappers, impossible hopes.
With what Godlike ease you tear
the tissues of ancient cultures,
seeking you know not what, only
that it's far from where you are.
copyright, Jerry Bass
One of the very most important anniversaries of my life is today; of one who has always and continues to make me so proud and happy.
I have been sending out invitations to be added to my small list of friends to whom I occasionally email news items and commentaries - with a sample of the kinds of things which I include in the mailings. The "sample" is three items and a link from a "Guardian Unlimited" Special report: Israel and the Middle East. Busy with that and some other things (including a brief and mild flu) I have not actually done much other reading, writing, or sending.
If I were, here is what I would send:
The Times, UK - January 15, 2003: America has entered one of its periods of historical madness, but this is the worst I can remember: worse than McCarthyism, worse than the Bay of Pigs and in the long term potentially more disastrous than the Vietnam War. . . .
http://www.timesonline.co.uk/article/0,,482-543296,00.html (There is a copy in the "Unpublished" directory if the "Times Online" site does not work for you.)
"You can subscribe
now to Semiconductor Innovation Letter (sample
issue) for the introductory price of only $795."
(From email received! Whoopdeedoo, as they say. Of course it
IS tax deductible business/professional expense.)
I have been away for several several weeks, but am back, as the great spirit provides.
MOTS (More of the Same)
I fear not much has changed, and certainly not for the better, since I was last able to post an entry in this log. Which is to say to anyone who reads this, nothing of significance is missing due to my having been. Kind of sad, isn't it? On the other hand, the way things go in the world, no news really is good news.
The tragically poisonous influence of what passes for 'conservatism' and is more properly known as radical fundamentalism within humanity's dominant (to avoid the term 'great') religious traditions is as apparent today as at the end of October, when these notes were first posted: Darbyism (Dispensationalism) and Israel and Armageddon!
I hope you'll have a look at them.
Also at the end of October it was apparent that the threat of BioWarfare in the Middle East was being actively planned for by Israel, England, and the US. I'll post on that again soon, in the meanwhile the weblog for October 30 or thereabouts has information which is increasingly relevant to our future or lack thereof.
Gresham's Law of Economic Policy
Originally applied to relationships among currencies, Gresham's law states that "bad money drives out good". It applies equally to economic policy, and we see now the Shrubbyist government's overt effort to use bad economic policy in the US to drive out good policies elsewhere in the world. America's deficit, the world's problem remains official us policy, notwithstanding the change of leadership at the Treasury Department. Check the weblog for October 22 for my original comment, I expect to have more soon.
The financial and stock market situation generally has not changed much either - the penultimate "More of the Same" item forwarded from October 2002 to January 2003. In October I looked at the possibility of a round of 'stagflation', since then there has been discussion among talk show pundits of the possibility of deflation, based on supposed pricing plans by business. That might be plausible, if the information about those plans were plausible. Based on my careful review of prices in the groceries, and of housing and automobile costs, I just do not believe it. I think price inflation, at the consumer level, is occurring now, and is significant.
Maybe this consumer price jump will be a temporary spike. I have my doubts. I still fear that consumer prices are increasing at a time employment opportunities and wage parities are decreasing. And I believe that the planned acceleration in tax reductions and increases in the budget deficit will or would result in increased interest costs, a 'credit crunch', reduced business investment and capital purchases, reduced profitability of durable goods producers, an erosion in stock prices, and an erosion in the value of personal savings. Reduced value of personal savings, coupled with higher prices, high unemployment and wage stagnation will reduce consumption and the profitability of consumer goods companies, which will further depress the financial markets, employment, and consumption.
Yeah, we may yet get to deflation... but not by the scenic route!!
Mortgages - how low can they go?
The potential uptick in mortgage rates I speculated on in October has not occurred save for a couple of spikes, as the 30 year rate has moved to 5.85%, only 83 basis points above the 20 year Treasury, 48 basis points above the 30 year Treasury. Due to the nature of mortgage instruments today, and the increasing use of mortgage based derivatives, 10 year Treasuries are a better indicator. Here the spread between Treasuries and Mortgages has dropped 61 points from a premium of 241 basis points on October 9 to only 180 basis points on January 3! This is in line with the spread of 177 basis points on July 3, 2002, before the sharp move down in the Treasury rate. It might be safe to infer that mortgage rates track the 10 year Treasuries, but lag behind sharp changes in them. That would mean they are very near as low as they will go. See http://www.bankrate.com/elink/news/bank/20021025a.asp for background.
The uptick in Treasury rates after the late September lows has held stable since. 10 year Treasuries are at 1963 levels, 4.0%. The next year the VietNam deficit precipitated an interest rate inflation that took that rate to 15.5% by 1981; a generation of high interest rates, stagflation, increasing income inequality and social dislocation that dramatically changed our society and national character. If the Shrubbyist plan for us goes unchecked we are in for another, even worse round of the same kind.
See http://www.jimpivonka.com/pages/financestats.html for sources for these and other financial stats.
Of restating financial reports: O' bitter reality.
My November 2nd entry concluded with my shock at having to account for some expenses I had previously ignored in tracking my finances. That has prompted me to look more closely at my bookkeeping. Yecch! This year is the 20th in which I have used basically the same tool set, and each year made improvements based on the errors and inadequacies of the previous year. My efforts to be responsible have been diligent and consistent, to the extent of my ability to make them so. Yet I continue to find adjustments are needed to reflect the "truth of the matter", and these never improve the picture.
Well, at least they give me a better fix on reality - which always seems to involve absorbing the impact of bad news, a measure of an apparent lifelong capacity for financial self delusion and deferred recognition of bad news. The only antidote seems to be careful attention to detailed, objective, and near daily review of actual and accruing expenses versus income.
Why do expenses always whip income so badly? If they were sports teams, they'd not be in the same league. If I were a Seinfeld I could do a routine on that, but there is no comedy here now, and certainly no comedian.
Everyone should try tracking the real cost of their transportation arrangements
for a while, be it automobile ownership and operation or any other.
I must say, though, that I am happy with my selection of Bridgestone "Touranza"
H tires. Nice feel so far, possibly some improvement in handling,
still too early to know if mileage is better or not. I hated
to part with the cachet of the Michelin name, but the $110 price difference
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