Group
Here are excerpts from recent web articles with my comments in square
brackets. I post these on other Lists I am on, so apologies if some of them
have already been posted here.
Steve
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http://dailynews.yahoo.com/h/nm/20001207/sc/feathers_dc_1.html Yahoo!
... December 7 ... Ancient Chinese 'Bird' Used Feathers to Fly Study ...
WASHINGTON (Reuters) - One of the earliest birds ever found used its
feathers to fly, Chinese scientists reported ... in a paper that other experts
said laid to rest any ideas that modern birds evolved from dinosaurs. But
scientists will probably continue to ruffle feathers over the origin-of- birds
debate, which heats up every few months as reports come out on fossils of
what look like birds ... Zhang and ... Zhou ... found a 120 million-year-old
bird that clearly had feathers and that clearly flew. ... the starling-sized bird
is called Protopteryx fengningensis. "The body of Protopteryx was
extensively covered by feathers, which were preserved as carbonized traces
or structured imprints," .... "The down feathers almost covered the whole
body." They said it had several features in common with modern flying
birds, such as a procoracoid process, a structure of the pelvis. "In modern
birds, the development of the procoracoid is an indicator of flight ability,"
they wrote. "Poor fliers such as pheasants have a reduced procoracoid.
True fliers, such as perching birds and hawks, have a well- developed
procoracoid." The feathers on the creature have many scale-like qualities,
which the researchers say show that feathers evolved from scales in distinct
stages. They propose that feathers evolved through four stages, in which
scales became elongated, developed a central shaft, sprouted strands called
barbs one each side, and finally developed a more complex network of
smaller strands called barbules. Protopteryx's feathers look like they come
from somewhere in the middle of this process. ... Alan Feduccia ... who has
led the argument that birds did not descend from dinosaurs, calls the paper
"extraordinarily important." "Here we have what could well be an
intermediate stage in the evolution of feathers and one of most intriguing
things about them is they are quite scale-like," ... "Beyond question it was a
flying bird," he added ... Feduccia said it helps show that feathered
dinosaurs, thought by some to have been the ancestors of modern birds,
were no such thing. "In a sense they really tell us that recent discoveries in
China, these dinosaurs with putative feathers, what they call dino-fuzz,
really could have nothing to do with the origin of feathers." He thinks the
structures found on some dinosaur fossils may represent collagen or some
other substance, not feathers, as some scientists have proposed. Feduccia
helped write a controversial report this past June on a 220- million-year-old
animal called Longisquama that he and colleagues said had feathers. Other
scientists have argued with the conclusion. Feduccia says Thursday's paper
supports his argument that birds descend from an ancestor that pre-dates
the dinosaur. "The true origin of birds is still up in the air," he said. ... [At
120 mya, this is ~25 myrs after Archaeopteryx (assuming the latter is not a
fake). These four stages of feathers sounds interesting (and un-Darwinian),
but bearing mind that Archaeopteryx had fully developed feathers ~25 mya
earlier, they could be just feathers in different stages of growth, or an
artifact of fossil preservation, or like Longisquama (see below), seeing
what one wants to be there.]
http://dailynews.yahoo.com/h/nm/20001206/sc/evolution_dc_1.html
Yahoo! ... December 6 ... Study: Human Evolutionary Tree Rooted in
Africa ... LONDON (Reuters) - The "Out of Africa" theory that modern
man evolved there and spread across the world got a boost ... with new
research tracing humans from diverse ethnic and geographical backgrounds
back to that continent. ... scientists used mitochondrial DNA -genetic
material in a cell that is passed unchanged from mother to child -from 53
people to show that the human evolutionary tree is firmly rooted in Africa.
"This is the first study in which the genome is being used in a sufficiently
large number of individuals to come up with very strong evidence, in this
case supporting the 'Out of Africa' theory," ... The biologist and geneticist
... said that even scientists who believe modern humans evolved
simultaneously in several parts of the globe would now have to
acknowledge that humans originate largely from Africa. ... The people
came from different continents and populations. Because mitochondrial
DNA is inherited only via the mother, it is a good way to trace genetic
lineage. The results ... show that all the people tested have origins in Africa
and that the migration from the continent began 52,000 years ago, not
100,000 years ago as was previously thought. "Our results point to
something around 52,000 years ago. Other estimates have pointed to
100,000 years ago but I think we have more accurate information," .... a
commentary ... described the Swedish research as the most thorough
analysis yet of divergences in human mitochondrial DNA. ... Hedges ...
added that ... some Africans are closer to Europeans and Asians than to
other Africans. ... See also:
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1058000/1058484.stm [I
broadly agree with the `Out-of-Africa'hypothesis (which is IMHO closer to
the Biblical picure-it was originally called the "Noah's Ark hypothesis"-and
was not the preferred evolutionary model). However, because the Near
East is so close to Africa and there is evidence of migration between the
two, I am still holding open the possibility of an eventual `Out-of-Israel'
hypothesis. This final migration ~52 kya is also conistent with my view of a
regional but anthropologically universal Noahic Flood.]
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1056000/1056040.stm
BBC ... 5 December, 2000 ... Domestic breeds head for extinction ... Many
breeds of domestic animal are threatened with extinction, according to the
United Nations Food and Agriculture Agency (FAO). ... FAO experts say
that 1,000 different breeds of domestic animal have become extinct during
the past century and a third of surviving breeds are endangered. ... The
problem is the success of breeders in the developed world in exporting
animals which have been bred to produce more and better meat or milk.
They go to developing countries where they may lack resistance to
unfamiliar diseases. ... Beata Sherf of the FAO explains: "We can't rely only
on a handful of animals, because animal breeds are adapted to their special
environments and if you transfer them to other environments they don't
produce as well as in the environment they have been adapted to. "You
may just imagine a racing car ... on rough gravel roads. The performance
would not be the same as on the racing circuit. "And the same applies to
animal breeds - if you transfer improved, highly productive breeds from
developed countries into developing countries, with big stresses in terms of
climate, disease and so on, these animals won't produce as in their country
of origin." ... [Another example of the limits of biological change, contrary
to Darwin's belief that there was "no limit to this power... of natural
selection" (see tagline for example of Darwin's use of rhetoric to carry this
crucial points in his theory.)]
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1058000/1058475.stm
BBC ... 6 December, 2000 ... Feathery fossil sheds light on flight origins ...
The fossil of a tiny, feathered dinosaur that lived 124 million years ago in
what is now China could reveal clues about the origins of bird flight. The
creature, named Microraptor, closes the gap in the fossil record between
large meat-eating dinosaurs and what is thought to be the earliest bird,
Archaeopteryx. The crow-sized dinosaur did not fly but had clawed feet
that it probably used to climb trees. The discovery adds weight to the
theory that small dinosaurs took to the branches to escape predators,
gradually developing flight. Many of the new animals are helping to plug
the gap between birds and dinosaurs once and for all ... Other scientists
argue that fast- running, bipedal dinosaurs evolved the wings, feathers and
muscle structure needed to take-off from the ground. ... The Microraptor
fossil came from a rock formation in western Liaoning, north-east China,
that has yielded more than 1,000 specimens of early birds and feathered
dinosaurs. ... Scientific scrutiny revealed an adult creature about the size of
a crow, with curved claws similar to those used by perching birds.
Microraptor has been classified as the smallest non-flying member of the
theropods, two-legged meat-eaters that walked the planet between 230
million and 66.4 million years ago. The find "further shortens the
morphological gaps between dinosaurs and birds," said Dr Xu. "It suggests
that the paleoecology ... of some bird-like dinosaurs is similar to that of
early birds," he added. ... The fossil is important because it could resolve a
scientific debate about the origins of bird flight. ... "The new animal shows
a number of modifications to the hips, tail and teeth which are in some
ways intermediate between those of advanced meat-eating dinosaurs and
birds. "There also appear to have been feathers, adding more evidence to
the view that feathers and feather-like structures predated the origin of
birds. "Finally, some of the anatomical specialisations of the feet hint at a
tree- dwelling habit - this runs contrary to what most scientists think
happened in the origin of birds. "The consensus has it that birds evolved
from the 'ground-up' from fast running animals that gradually took to the
air through becoming more efficient leapers. "This paper suggests that
there might be some currency in an older, less fashionable idea that birds
are descended from tree dwellers that evolved flight though a number of
intermediate gliding phases." ... See also:
http://www.nytimes.com/2000/12/07/science/07DINO.html [Again, at 124
mya, this is 20 myrs later than Archaeopteryx (assuming the latter is not a
fake-see next), so this Microraptor may just be a true bird on the way
`down' to becoming flightless. But that interpretation doesn't bring fame
and fortune!]
http://news.bbc.co.uk/hi/english/uk/wales/newsid_1059000/1059825.stm
BBC ... 7 December, 2000 ... Dinosaur exposed as fake The museum has
displayed the creature for 116 years A dinosaur on display at a Welsh
museum has been unmasked as an "elaborate fake". Officials at the
National Museum of Wales in Cardiff thought the fossilised creature which
has been on display for more than a century - was a perfect specimen of the
marine reptile Icthyosaurus. But when they decided the skeleton needed a
modern facelift it was discovered it was a forgery. Instead of being one
complete creature, the specimen is made up of two different sea creatures.
... The skull was that of an Icthyosaurus communis and embedded in a grey
rock. But the body was found to be that of a similar creature called
Leptonectes tenuirostris in a light brown rock. Other bones were made out
of plaster and stuck into the rock to make them look real while one flipper
was also a fake. "We have thought all along that it was a perfect specimen
of an Icthyosaurus," ... "But you have got to hand it to the Victorians for
pulling off such a trick and fooling us all these years." The skeleton is now
being cleaned up and will be put back on display as an example of how the
Victorians faked the exhibit. ... [If a museum can be fooled for 116 years,
then it seems reasonable to wonder how many other fossils are fakes?]
http://www.cnn.com/2000/TECH/space/11/30/inbrief.113000/index.html
CNN ... Quasar unseats galaxy as most distant object in universe
November 30, 2000 ... (CNN) -- A galaxy in the vicinity of the Big Dipper
has lost its title as most distant object known in the universe, NASA
scientists said ... The new king of cosmic distances ... is a quasar more than
10 billion light years way. Astronomers stripped the title from the faint
galaxy informally known as Sharon after using improved techniques to
estimate its distance. They determined it was much closer than originally
thought. Scientists ... first reported Sharon in 1999. They then calculated
its distance at about 12.5 billion light years, the equivalent to looking back
in time to some 600 million years after the Big Bang. ... new observations
indicate the galaxy is likely about 10 billion light years away. ... [Note the
shortening age of the universe at 13.1 bya. Since life on Earth is 3.9 byo
this makes it hard for cosmic panspermia theories because life would have
to originate elsewhere first, develop, and then travel to Earth before ~9
bya. More evidence for an intelligently directed origin of life on Earth!]
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1050000/1050258.stm
BBC ... 1 December, 2000 ... Black hole takes 'light snack' ... An animation
of the fast-moving stars at the centre of our galaxy shows up clearly the
location where a massive black hole is thought to reside. ... The centre of
our galaxy is a strange and dramatic place. Gigantic rotating gas rings can
be seen there, as well as stars travelling in excess of 1,000 kilometres per
second around a very massive central object. The presence of a black hole
there has been suspected for some time because of the nature of the faint
radiation coming from the location and the motion of the fast-moving stars.
Sustained observation has allowed astronomers to pinpoint with
unprecedented accuracy the hole's location, known as Sagittarius A* (Sgr
A*). It is about 26,000 light-years from Earth. ... Ghez ... has provided the
best estimate yet of the mass of the object - about 2.6 million times that of
the Sun. But her images, obtained using the 10-metre Keck telescope on
Hawaii, also give an eloquent demonstration of what is happening in this
extraordinary region of space. They indicate the black hole at Sgr A* is
going through what appears to be a new "feeding" phase, pulling in more
gas. "If we do think the black hole is going through a slightly larger feeding
phase at the moment, it is tiny compared to what other galaxies are doing,"
.... "In fact, this is still a very quiet black hole in spite of the fact that there
might be new emission from it." ... [Another design parameter for life on
Earth? A larger, more active central black hole might make life on Earth
unviable?]
http://www.cnn.com/2000/TECH/space/11/24/alien.microbe.claim/index.ht
ml CNN ... Scientists discover possible microbe from space ... November
24, 2000 ... (CNN) -- An international team of scientists has recovered
microorganisms in the upper reaches of the atmosphere that could have
originated from outer space, a participant in the study said Friday. The
living bacteria, plucked from an altitude of 10 miles (16 km) or higher by a
scientific balloon, could have been deposited in terrestrial airspace by a
passing comet, according to the researchers. The microorganisms are
unlike any known on Earth [false-see below], but the astrobiologists "want
to keep the details under wraps until they are absolutely convinced that
these are extraterrestrial," said ... Chandra Wickramasinghe ... NASA said
the finding is likely to meet considerable skepticism in the scientific
community. "Aerobiologists might argue that 10 miles is not too high for
Earth life to reside, a possibility that Wickramasinghe appears to accept,"
... However, NASA said, a compelling case can be made for the transport
of microorganisms through space aboard comets and meteors. "A recent
discovery indicates that microbes can remain dormant for millions of years
-- enough time to travel from planet to planet," ... Wickramasinghe ... does
acknowledge the possibility that terrestrial bacteria could be kicked up into
the stratosphere. Living fungal spores have been discovered at altitudes of
7 miles (11 km). But observations from this and a related study suggest the
presence of living bacteria far too high in the atmosphere to have originated
from the surface of the planet, according to Wickramasinghe. "What is
present in the upper atmosphere, critics will say it came from the ground.
That is a serious possibility at 15 kilometers, but at 40 or 85 kilometers,
you can forget about it," ... Wickramasinghe and colleague Sir Fred Hoyle
.... Looking at spectral data from the 1999 Leonid meteorite shower, they
detected a bacterial "fingerprint" as the tiny space rocks streaked across the
sky at a height of 51 miles (83 km) ... Along with Hoyle, Wickramasinghe
pioneered "panspermia," [false] the theory that outer space seeded Earth
with its first life forms about 4 billion years ago. Wickramasinghe holds
that primitive life could still be arriving from space. "If we find microbes at
great heights that are not contaminants from the ground, we have to
wonder where they came from. One hundred tons of comet and meteor
organic debris is deposited in the atmosphere every day." ... The location of
the microbe is what most impressed Wickramasinghe, not the composition.
It seems like a novel strain of a common bacteria genus on Earth, he said.
... [This sounds like clutching at straws. Even if these bacteria had been
arriving via comets, they would be now common on Earth. It is amazing that
H&W can believe that bacteria can blow millions of kms across interstellar
space, but not that they can blow 80 kms up in the atmosphere! Anyway,
this bacterium was only 16 kms high. And AFAIK spectrographic analysis
cannot differentiate between live bacteria and their separate, non-living
chemical constituents.]
http://www.cnn.com/2000/TECH/space/12/07/lunar.cataclysm/index.html
... December 7, 2000 ...(CNN) -- A new study of lunar meteorites strongly
suggests that the moon and Earth suffered a brief but cataclysmic
bombardment of asteroids almost 4 billion years ago at roughly the same
time that life formed on our planet. The flurry of killer space rocks could
have had major consequences on early Earth evolution, whether smashing
the building blocks of primordial life or delivering them to the planet in the
first place, researchers said. The burst of impacts lasted from 20 million and
200 million years, flanked in time by periods of relative calm. The rain of
meteorites or comets melted rocks, blasted out craters and reshaped the
surface across the entire moon ... The bombardment would have produced
the great basins that now shape the man in the moon. On Earth, the same
cataclysm would have affected the evolution of life, possibly forcing it to
begin anew ... "Earth would have been bombarded by at least 10 times as
many impact events as the moon, and these impact cratering processes are
immense," lunar geologist David Kring said ... The findings are based
studies of four lunar meteorites -- rocks that were ejected at random from
the moon's surface and landed on Earth after a million or so years in space.
The scientists applied a sophisticated dating technique to the meteorites to
determine when the lunar bombardment occurred. The Chixculub crater ...
"is puny by the scheme of we are talking about. Here we are talking about
impacts that are 10 times larger, impacts that blasted craters rim to rim the
size of continents on Earth today," ... The blasts would have vaporized the
oceans and filled the atmosphere with a life-choking fog, all but eliminating
terrestrial life if it existed. ... Unlike the lifeless moon, where the ancient
scarring remained easily visible, the Earth has blotted out signs of the
cataclysm through erosion and natural geologic changes over the eons.
Rather than death, ancient meteorites or comets could have brought life,
some scientists theorize. Proponents of a theory called "panspermia"
suggest that complex organic molecules or even primitive life forms seeded
the Earth after riding aboard rocky or icy cosmic debris. Previous analysis
on lunar rocks returned by the Apollo and Luna missions in the 1970s
suggested that the moon took a pounding near the equator where the
samples originated. But a sophisticated examination of lunar meteorites
now offers strong evidence that the maelstrom hammered the entire lunar
surface ... [More on this. The almost `instantaneous' origin of life on Earth
between the late heavy bombardment ~3.9 bya and the first trace fossils of
complex photosynthesing bacteria ~3.85 bya, is good evidence for an
intelligently directed origin of life or panspermia. However panspermia has
*huge* problems of its own. IMHO the best hypothesis that fits all the
facts and has the least difficulties is an intelligently directed origin of life
on Earth!]
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"If, then, animals and plants do vary, let it be ever so slightly or slowly,
why should not variations or individual differences, which are in any way
beneficial, be preserved and accumulated through natural selection, or the
survival of the fittest? If man can by patience select variations useful to
him, why, under changing and complex conditions of life, should not
variations useful to nature's living products often arise, and be preserved or
selected? What limit can be put to this power, acting during long ages and
rigidly scrutinising the whole constitution, structure, and habits of each
creature,-favouring the good and rejecting the bad? I can see no limit to
this power, in slowly and beautifully adapting each form to the most
complex relations of life. The theory of natural selection, even if we look
no farther than this, seems to be in the highest degree probable." (Darwin
C.R., "The Origin of Species by Means of Natural Selection," [1872],
Everyman's Library, J.M. Dent & Sons: London, 6th Edition, 1928, reprint,
pp.445-446)
Stephen E. Jones | Ph. +61 8 9448 7439 | http://www.iinet.net.au/~sejones
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