Real Science Friday: What Museums Aren't Showing You

[Alate_One]

I've never seen a whale (modern or otherwise) with legs. I've seen a dolphin with an extra pair of flippers, but it didn't look like they were going anywhere to me.

And? Do you think Dorudon's legs were "going anywhere"?

What's a walrus? What's a manatee? It's just another aquatic mammal that isn't a whale.

Do we really need to play this game again? A walrus is clearly not related to whales, same thing with a manatee. Anyone can look at the skeleton and see that. But when you look at basilosaurus and dorudon, it's obvious where they belong.

I haven't contradicted myself at all. Nor am I the one claiming that whales are born with legs and lose them as they grow.

What are the leg buds doing on the dolphin embryo then?

 

[Stripe]

I really don't see why you think this is a big deal.

Of course you don't.

You may not have noticed but soil, sediment and rock are pretty heavy.

Depends how much you've got.

It really won't take much of any of them to crush small animals, which is all we have talked about thus far.

Yeah? How much?

And which came first, the fossilisation or the crushing?

And would you mind not posting such massive images. Thanks. :up:

 

[Jukia]

I get the impression you two did not download the show. You would not have made the idiotic comment about the sabor tooth tiger.

I listened to as much of the show as I could stomach.
I neither listened to nor commented on sabor (or saber, or sabre or any)
tooth tigers. I never got that far.

Enyart should be ashamed of taking advantage of children. It was about as miserable a show as he has ever put out.

 

[Jukia]

Wow, Alate and I compared to Pinky and the Brain. Thanks, but Alate's posts are usually much brainier than mine, Alate should be the Brain. I tend to lose my self control when dealing with some of you fundys and try to limit my comments.

Although, I suspect that between the two of us, I would much rather control the whole world than Alate would.

If you are going for comic characters, not sure any one is as dense as Stripe. Maybe Wile E. Coyote. Doomed to failure based on a misunderstanding of basic science. Well perhaps he spends too much time getting his education from Pastor Bob and Walt Brown.

 

[Alate_One]

Wow, Alate and I compared to Pinky and the Brain. Thanks, but Alate's posts are usually much brainier than mine, Alate should be the Brain. I tend to lose my self control when dealing with some of you fundys and try to limit my comments.

But I do like to say "Narf" on occasion. I think the real explanation is Nick has an inverse relationship with anything complex. The more complex and detailed something is the "dumber" he thinks it is. You're usually more concise in your posts than I am so . . . :chuckle:

:think:Although, I suspect that between the two of us, I would much rather control the whole world than Alate would.

Oh, I don't know about that. :think:
Plants are the dominant organisms on the planet already. All you have to do is control *them*, and who better to do that than a botanist. . . . .

If you are going for comic characters, not sure any one is as dense as Stripe. Maybe Wile E. Coyote. Doomed to failure based on a misunderstanding of basic science. Well perhaps he spends too much time getting his education from Pastor Bob and Walt Brown.

So you're saying Walt Brown and Pastor Bob are really the founders of the ACME gadget company?

 

[voltaire]

Said evidence is consistent with a several billion year old earth.

It is also consistent with a much younger earth... like 300,000 years, depending on your starting assumptions.

The age of the universe or the earth isn't calculated from the geologic column for obvious reasons.

The age of the universe is calculated by measuring the number of light years away the furtherest stars are and making a number of assumptions that are no better than assumptions i can make regarding the issue. The age of the earth can be determined using the geologic column alongside other evidence like sedimentation rates. I dont mean an exact age can be determined, but a range of values certainly can.

The evidence from the Grand Canyon alone does show a succession of creatures beginning from simplest to more complex. The geological column as a whole shows a much clearer picture of related organisms. However, I think the common descent argument is best supported by DNA evidence.

It only shows an increase in morphological complexity. It would take knowing the size of the genomes of said fossils to know if there truly was an increase in complexity. The geologic column shows relatedness only in very narrow sections of the column... like fossils that are only seperated by less than 2 million years on a radiometric timescale. The rest is pure speculation and I could make up a list of relatedness radically different than yours and yours would be no more likely than mine. Common descent of the next in line on the phylogenetic tree is supported by DNA evidence,but common descent of all organisms from one common ancestor is certainly no more supported by the DNA evidence than common descent from thousands of common ancestors is supported by the DNA evidence. DNA evidence is consistent with both and is actually more consistent with thousands of common ancestors. Really, my point is that your evidence may consistent with your conclusions, but it is also consistent with other equally valid conclusions. I said show why your conclusions are the only valid ones that could be made , and you failed to show that this time around.

​

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[voltaire]

No biologist would call evolution simply "random". Undirected yes, but you can't actually disprove or prove supernatural direction of evolution, since the supernatural isn't truly subject to falsification.

Evolution is random in that the genome is modified in an ad hoc manner. The mutations do not occur in order to adjust to a changing environment; they occur at random without regard to the environment. So an intelligence that programmed the genomes of animals to respond to the environment in a directed manner is supernatural? How do you know such an intelligence does not exist? Why does this intelligence have to be God or supernatural at all? An alien simply could have come to the earth and seeded it with a small population of a few thousand different kinds of animals, each programmed to recolonize an earth that was utterly destroyed during the late heavy bombardment. This would not be supernatural and plenty of evidence could be garnered to show that the each evolutionary advance was made at the same time or shortly after certain ecological niches opened up. .... nothing supernatural there.

The evidence I posted was in answer to an assertion that evidence that the earth is young is everywhere

. Yes evidence that is consistent with a young earth is everywhere. They were correct. You are also correct in you assertions that your conclusions are consistent with the evidence, but the opposing conclusions each depend on starting assumptions that have not been substantially supported. I can show you where everytime you say such and such evidence is consistent with your conclusions, that you are depending on certain starting assumptions.

 

[DavisBJ]

It is also consistent with a much younger earth... like 300,000 years, depending on your starting assumptions.
…
The age of the universe is calculated by measuring the number of light years away the furtherest stars are and making a number of assumptions that are no better than assumptions i can make regarding the issue.

It would help if, instead of these amorphous generalized claims, you would supply some specifics. What are the starting assumptions that you use to say the earth is 300k years old? What assumptions do you use that are as good as the ones cosmologists us to compute the age of the universe? It’s kinda hard to evaluate your claims without some clearer details being supplied.

 

[voltaire]

DavisBJ. I don't have it all in front of me right now. I was stating this from memory. I read an enormous amount of material and it is not always easy to go back and find the exact details on a moments notice. The 300,000 year figure? First there is not reason to believe the earth is 4.5 billions years old other than radiometric dating and an assumption that mutation with selection pressure can produce the complex life forms we see today. Based on that assumption, they take known mutation rates and extrapolate back in time to get like 600,000 years for the first multicellular animals of the ediacaran period. That age is first determined by radiometric dating and then it is seen if known mutation rates are compatible with that age. They assume that it took about 2.5 billion years to get from the first microbes of the archean to the multicellular edicaran period. This took longer they assume because the same mechanisms were not in play during this period as they were during the phanerozoic period.
All of what i just stated is to show that , other than radiometric dating, there is no good reason to believe in a 4.5 billion year old earth.
I arrive at 300,000 because it allows for 200,000 years for mitochondrial eve. She is the same species as we are and even if you assume the other hominid fossils are human ancestors, they are not far removed from homo sapiens in the fossil record.....2 million radiometric years. That is not much time on the radiometric scale. My point is that the all hominids are not far apart and we have actual molecular evidence that our own species is as old as 200,000 years. If radiometric dating is off by orders of magnitude as i claim it is, then the other hominids are not much older than 200,000 years. You may protest that this time only includes hominids, but all the other fossils are not necessarily ancestors of each other in a tree of life , and therefore, there is no reason to assume any significant time elapsed during the deposition of all these fossils. They could simply be a record of recolonization of life on earth after all life had been destroyed before. Other than radiometric dating, there is no reason to assume all the sedimentary layers took billions of years to form either. I can show you that they can form in less than a million years.
With all that said, why couldn't the earth be only 300,000 years old? Radiometric dating is really the only evidence that goes against it. There are several lines of evidence that this dating is grossly exaggerated. Sedimentation rates of the cretaceous for instance show only 4,000 years of accumulation for instance.

 

[DavisBJ]

DavisBJ. I don't have it all in front of me right now. I was stating this from memory. I read an enormous amount of material and it is not always easy to go back and find the exact details on a moments notice.

I know it takes some legwork to dig out the supporting data, but if you don’t we are left with nothing more than an unsupported claim that, as far as we know, is made up out of thin air.

The 300,000 year figure? First there is not reason to believe the earth is 4.5 billions years old other than radiometric dating and an assumption that mutation with selection pressure can produce the complex life forms we see today.

The timeline for evolution did not drive the age-of-the earth figure.

Based on that assumption, they take known mutation rates and extrapolate back in time to get like 600,000 years for the first multicellular animals of the ediacaran period. That age is first determined by radiometric dating and then it is seen if known mutation rates are compatible with that age.

Be consistent. Your first sentence says 600,000 years was derived from extrapolating mutation rates into the past. Then you turn around and say it was radiometrically derived, and mutation rates were compared against that figure. I am not a molecular biologist, but I would be surprised if mutation rates would be considered a reliable clock that far back.

All of what i just stated is to show that , other than radiometric dating, there is no good reason to believe in a 4.5 billion year old earth.

If you have something more reliable, then out with it.

I arrive at 300,000 because it allows for 200,000 years for mitochondrial eve. She is the same species as we are and even if you assume the other hominid fossils are human ancestors, they are not far removed from homo sapiens in the fossil record.....2 million radiometric years. That is not much time on the radiometric scale. My point is that the all hominids are not far apart and we have actual molecular evidence that our own species is as old as 200,000 years.

Evolutionarily speaking, Mitochondrial Eve was a very recent lady.

If radiometric dating is off by orders of magnitude as I claim it is, then the other hominids are not much older than 200,000 years. You may protest that this time only includes hominids, but all the other fossils are not necessarily ancestors of each other in a tree of life , and therefore, there is no reason to assume any significant time elapsed during the deposition of all these fossils. They could simply be a record of recolonization of life on earth after all life had been destroyed before. Other than radiometric dating, there is no reason to assume all the sedimentary layers took billions of years to form either. I can show you that they can form in less than a million years.

Lacking specifics, I lump this into your “generalized claim” bucket.

With all that said, why couldn't the earth be only 300,000 years old? Radiometric dating is really the only evidence that goes against it. There are several lines of evidence that this dating is grossly exaggerated. Sedimentation rates of the cretaceous for instance show only 4,000 years of accumulation for instance.

Specifics supporting the 4,000 year figure?

 

[voltaire]

Support for 4,000 year cretaceous coming up. Don't bite my head off that it is a cut and paste. Trying to summarize it would not show exactly how the figure is arrived at.

 

[voltaire]

The three cycles of
precession, obliquity and
eccentricity are known as
Milankovitch cycles, after
the scientist who proposed
that these long-term
variations have a noticeable
effect on climate. Milutin
Milankovitch published his
theory in 1941, but it was
not until the 1980s that
geologists began applying
it to sedimentary
sequences. These – for
example chalk sequences –
seemed to bear him out.
Where deposits were
stratified in couplets and
sedimentation seemed to
have been fairly
continuous, one couplet
could often be interpreted
as indicating a warm
climate and the other a cool
climate.

 

[voltaire]

Chalk consists
predominantly of
microscopic plates from
warm-water algae known as
coccolithophores. Although
from a distance it can
appear a monotonous mass
of white or grey, on closer
inspection it proves to be
bedded. In some places,
beds of relatively pure chalk
alternate with beds of marl
– chalk mixed with clay. In
others, compact and
densely burrowed beds
alternate with those that
that are not so compact or
densely burrowed. Often
the tops of beds are marked
by nodules of flint.

 

[voltaire]

The interpretation offered
is that the couplets reflect
the precession cycle, with
the chalk accumulating
when the climate was
warmer and the marl when
the climate was colder and
wetter. Clay erodes from the
land more quickly when the
weather is rainy.
Oscillations in oxygen
isotope ratios (δ18O)
appear to confirm the
interpretation, since they
follow oscillations in
temperature and trace a
similar pattern. Climate
change thus provides an
explanation for the
occurrence of bedding in
chalk.

 

[voltaire]

If the Milankovitch theory
is correct, such cyclicity can
be used to test radioisotope
dating. For example, if the
system attributes 3 million
years to a continuous
sequence and the
precession cycle was 20,000
years, the sequence should
comprise 150 such
couplets. Substantially
more or fewer than 150
would be evidence that the
timescale was in error. In
practice, the two
chronological systems
rarely give the same result.
Sometimes even
approximate agreement is
achieved only on the
premise that the couplets
reflect obliquity rather than
precession – or a mixture.
Some studies claim to have
detected cyclicity
corresponding to all three
Milankovitch cycles. In such
instances the smallest
cycle is visible as repeating
couplets and the larger
cycles as ‘bundles’ of
couplets – a bundle of four
or five being seen as
evidence of the eccentricity
cycle. Thus, in relation to
the Biancone Formation, in
the Alps, Mayer and Appel
(1999) report:

 

[voltaire]

Cycle periods of 45 cm, 80
cm and 180 cm likely
correspond to dominant
precession, obliquity and
eccentricity cycles. Owing to
the inaccuracy of the
Cretaceous time scale,
periods cannot be matched
exactly, but cycle ratios are
extremely close to expected
ratios so that Milankovitch
climate cycles could be
positively identified in this
Early Cretaceous section.
Sin

 

[voltaire]

Astronomical tuning is a
rash move, for if the only
criterion for determining
whether a sedi- mentary
sequence reflects
Milankovitch cycles is the
degree of closeness to the
radioisotope timescale,
there is no independent
control on either method.
The Milankovitch
interpretation is upheld by
producing a result
approximately consistent
with the radioisotope dates,
and the radioisotope
timescale is then adjusted
to it. The reasoning
remains circular.

 

[voltaire]

If the danger is not clear
enough from the Biancone
Formation, it is well
illustrated by the debate
over a succession in the
western Dolomites, where
470 metres encompass
around 600 bedding cycles.
After making allowance for
variable rates of
sedimentation, researchers
thought they could detect
signals relating to both
precession and eccentricity.
According to Preto and
Hinnov (2003):

 

[voltaire]

All of the principal
periodicities related to the
precession index and
eccentricity … are present:
P1 (21.9 ky); P2 (17.8 ky);
E1 (400 ky), E2 (95 ky), and
E3 (125 ky), along with a
peak at a frequency double
that of the precession,
which is a predicted feature
of orbitally forced
insolation at the equator.
Components possibly
related to Earth ’s obliquity
at ca. 35 ky and ca. 46 ky
are present as well.

 

[voltaire]

(P1 and P2 designate the
different precession cycles,
E1-E3 the different
eccentricity cycles, ‘Ma’ is
millions of years ago and
‘ ky’ is a thousand years.)
This Triassic succession
preserved ‘the oldest
pristine Milankovitch
signature yet observed in
the geologic record ’. Other
workers rejected the
interpretation, finding that
radioisotope ages from
interspersed volcanic-ash
layers indicated a much
shorter interval. The
procedures involved in
analysing cyclical bedding
could generate
Milankovitch-like
periodicities (once
calibrated to the
radioisotope timescale)
that were nothing of the
sort: the appearance of a
close fit with the
astronomical cycles was
illusory.