abriram agora...

Citação de: Geotecton em 03 de Dezembro de 2013, 17:20:00

Citação de: docdeoz em 03 de Dezembro de 2013, 17:08:28

http://geology.cr.usgs.gov/capabilities/gronemtrac/geochron/geochron.html

Não abriu....

Citação de: docdeoz em 03 de Dezembro de 2013, 17:13:43

http://www.talkorigins.org/indexcc/list.html

idem...

Verifique se o problema não está no seu browser.

Vivo banda lenta...

As antigas mensagens 463, 464, 465 e 466 foram postas no tópico "Fósseis Transicionais".

http://www.talkorigins.org/indexcc/list.html

Eu não vou ler tudo isso aí. Sejam mais específicos... Tipo esse debate.

http://www.nature.com/nature/debates/fossil/fossil_frameset.html

Esse debate está muito interessante...

Vou ser mais esperto do que no outro debate. Papers a serem utilizados:

http://mbe.oxfordjournals.org/content/23/10/1832.full.pdf+html
Testing the Molecular Clock: Molecular and Paleontological Estimates of
Divergence Times in the Echinoidea (Echinodermata)

http://mbe.oxfordjournals.org/content/29/2/707.full.pdf+html
Expansion Dating: Calibrating Molecular Clocks in Marine
Species from Expansions onto the Sunda Shelf Following the
Last Glacial Maximum

http://mbe.oxfordjournals.org/content/22/3/387.full.pdf+html?sid=efb9fccf-5eb4-4138-9a3a-c40731fdb337
Molecular Clocks Do Not Support the Cambrian Explosion

http://mbe.oxfordjournals.org/content/20/12/1947.full.pdf+html?sid=24287ee0-0d08-4840-9772-532df1a7f865
Bayesian Models of Episodic Evolution Support a Late Precambrian
Explosive Diversification of the Metazoa

http://mbe.oxfordjournals.org/content/23/1/212.full.pdf+html?sid=3d369ecd-8af3-4f6a-83da-d31f3ae83952
Bayesian Estimation of Species Divergence Times Under a Molecular Clock
Using Multiple Fossil Calibrations with Soft Bounds

http://mbe.oxfordjournals.org/content/24/1/90.full.pdf+html?sid=3d369ecd-8af3-4f6a-83da-d31f3ae83952
Fossil Calibration of Molecular Divergence Infers a Moderate Mutation Rate
and Recent Radiations for Pinus

http://rstb.royalsocietypublishing.org/content/359/1450/1477.long
Assessing the quality of molecular divergence time estimates
by fossil calibrations and fossil −based model selection

http://www.ncbi.nlm.nih.gov/pubmed/15729646
Avaliando a concordância de pontos de calibração fóssil em estudos relógio molecular: um exemplo usando tartarugas.

Silent mutation rate estimates for Pinus vary 50-fold, ranging from angiosperm-like to among the slowest reported for
plants. These differences either reflect extraordinary genomic processes or inconsistent fossil calibration, and they have
important consequences for population and biogeographical inferences

http://mbe.oxfordjournals.org/content/24/1/90.full.pdf+html?sid=3d369ecd-8af3-4f6a-83da-d31f3ae83952

É aqui que eu vou bater. Provavelmente não deve ter essa argumentação no Talkorigins. Sobre o assunto do outro tópico não tinha, com quase certeza, pois não foi citado...

Ughs! Vão ter de ler e pensar.... Eca...

Junto com o Debates Nature, fecho minha pequena resenha...

Syst Biol. 2011 Jul;60(4):519-27. doi: 10.1093/sysbio/syr019. Epub 2011 Mar 23.
Integrating fossil preservation biases in the selection of calibrations for molecular divergence time estimation.
Dornburg A, Beaulieu JM, Oliver JC, Near TJ.
http://sysbio.oxfordjournals.org/content/60/4/519.long

Assessing the quality of molecular divergence
time estimates by fossil calibrations and
fossil-based model selection
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1693436/pdf/15519966.pdf

Evaluating Fossil Calibrations for Dating Phylogenies in Light of Rates of Molecular Evolution: A Comparison of Three Approaches
http://sysbio.oxfordjournals.org/content/61/1/22.long

Expected Anomalies in the Fossil Record
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2614194/pdf/ebo-4-061.pdf

Abstract: The problem of intermediates in the fossil record has been frequently discussed ever since Darwin. The extent of
‘gaps’ (missing transitional stages) has been used to argue against gradual evolution from a common ancestor. Traditionally,
gaps have often been explained by the improbability of fossilization and the discontinuous selection of found fossils. Here
we take an analytical approach and demonstrate why, under certain sampling conditions, we may not expect intermediates to
be found. Using a simple null model, we show mathematically that the question of whether a taxon sampled from some time
in the past is likely to be morphologically intermediate to other samples (dated earlier and later) depends on the shape and
dimensions of the underlying phylogenetic tree that connects the taxa, and the times from which the fossils are sampled.

Please, I don´t understand english... Help me....

Citação de: docdeoz em 17 de Dezembro de 2013, 14:25:03

http://www.talkorigins.org/indexcc/list.html

Eu não vou ler tudo isso aí. Sejam mais específicos... Tipo esse debate.

http://www.nature.com/nature/debates/fossil/fossil_frameset.html

Esse debate está muito interessante...

Não há uma linha sequer neste ensaio que conteste a Geocronologia.

Citação de: docdeoz em 17 de Dezembro de 2013, 14:25:03

http://www.nature.com/nature/debates/fossil/fossil_frameset.html

Esse debate está muito interessante...

Citação de: docdeoz em 17 de Dezembro de 2013, 14:41:05

Vou ser mais esperto do que no outro debate. Papers a serem utilizados:

http://mbe.oxfordjournals.org/content/23/10/1832.full.pdf+html
Testing the Molecular Clock: Molecular and Paleontological Estimates of
Divergence Times in the Echinoidea (Echinodermata)

http://mbe.oxfordjournals.org/content/29/2/707.full.pdf+html
Expansion Dating: Calibrating Molecular Clocks in Marine
Species from Expansions onto the Sunda Shelf Following the
Last Glacial Maximum

http://mbe.oxfordjournals.org/content/22/3/387.full.pdf+html?sid=efb9fccf-5eb4-4138-9a3a-c40731fdb337
Molecular Clocks Do Not Support the Cambrian Explosion

http://mbe.oxfordjournals.org/content/20/12/1947.full.pdf+html?sid=24287ee0-0d08-4840-9772-532df1a7f865
Bayesian Models of Episodic Evolution Support a Late Precambrian
Explosive Diversification of the Metazoa

http://mbe.oxfordjournals.org/content/23/1/212.full.pdf+html?sid=3d369ecd-8af3-4f6a-83da-d31f3ae83952
Bayesian Estimation of Species Divergence Times Under a Molecular Clock
Using Multiple Fossil Calibrations with Soft Bounds

http://mbe.oxfordjournals.org/content/24/1/90.full.pdf+html?sid=3d369ecd-8af3-4f6a-83da-d31f3ae83952
Fossil Calibration of Molecular Divergence Infers a Moderate Mutation Rate
and Recent Radiations for Pinus

http://rstb.royalsocietypublishing.org/content/359/1450/1477.long
Assessing the quality of molecular divergence time estimates
by fossil calibrations and fossil −based model selection

http://www.ncbi.nlm.nih.gov/pubmed/15729646
Avaliando a concordância de pontos de calibração fóssil em estudos relógio molecular: um exemplo usando tartarugas.

Citação de: docdeoz em 17 de Dezembro de 2013, 14:45:16

Silent mutation rate estimates for Pinus vary 50-fold, ranging from angiosperm-like to among the slowest reported for
plants. These differences either reflect extraordinary genomic processes or inconsistent fossil calibration, and they have
important consequences for population and biogeographical inferences

http://mbe.oxfordjournals.org/content/24/1/90.full.pdf+html?sid=3d369ecd-8af3-4f6a-83da-d31f3ae83952

É aqui que eu vou bater. Provavelmente não deve ter essa argumentação no Talkorigins. Sobre o assunto do outro tópico não tinha, com quase certeza, pois não foi citado...

Ughs! Vão ter de ler e pensar.... Eca...

Citação de: docdeoz em 17 de Dezembro de 2013, 15:39:59

Junto com o Debates Nature, fecho minha pequena resenha...

Syst Biol. 2011 Jul;60(4):519-27. doi: 10.1093/sysbio/syr019. Epub 2011 Mar 23.
Integrating fossil preservation biases in the selection of calibrations for molecular divergence time estimation.
Dornburg A, Beaulieu JM, Oliver JC, Near TJ.
http://sysbio.oxfordjournals.org/content/60/4/519.long

Assessing the quality of molecular divergence
time estimates by fossil calibrations and
fossil-based model selection
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1693436/pdf/15519966.pdf

Evaluating Fossil Calibrations for Dating Phylogenies in Light of Rates of Molecular Evolution: A Comparison of Three Approaches
http://sysbio.oxfordjournals.org/content/61/1/22.long

Expected Anomalies in the Fossil Record
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2614194/pdf/ebo-4-061.pdf

Abstract: The problem of intermediates in the fossil record has been frequently discussed ever since Darwin. The extent of
‘gaps’ (missing transitional stages) has been used to argue against gradual evolution from a common ancestor. Traditionally,
gaps have often been explained by the improbability of fossilization and the discontinuous selection of found fossils. Here
we take an analytical approach and demonstrate why, under certain sampling conditions, we may not expect intermediates to
be found. Using a simple null model, we show mathematically that the question of whether a taxon sampled from some time
in the past is likely to be morphologically intermediate to other samples (dated earlier and later) depends on the shape and
dimensions of the underlying phylogenetic tree that connects the taxa, and the times from which the fossils are sampled.

Please, I don´t understand english... Help me....

Citação de: docdeoz em 17 de Dezembro de 2013, 14:25:03

http://www.talkorigins.org/indexcc/list.html

Eu não vou ler tudo isso aí. Sejam mais específicos... Tipo esse debate.

O senhor reclama que não quer ler o material indicado, posta um link com um ensaio que nenhuma relação tem com a sua assertiva ("datação radiométrica não é válida ou é limitadíssima") e ainda por cima lista uma quantidade enorme de links esperando que os foristas leiam ao mesmo tempo que o senhor recusa-se a ler o que lhe foi proposto.

E, dos ensaios e artigos que eu vi, nenhum contesta a Geocronologia e alguns deles afirmam que as conclusões baseadas apenas nos 'relógios moleculares' é que devem ser revistas.

Citação de: Blair, J.E.; Hedges, S.B., 2004

[...]
In contrast, when we treated fossil times as minimum constraints, the same data set recovered older dates, estimating the arthropod-deuterostome divergence as 777 to 851 MYA. The use of a local clock method (penalized likelihood) (Sanderson 2003) also showed discordance between those times estimated with fixed calibrations and those where the fossils were used as minimum constraints.

The use of maximum likelihood to estimate branch lengths resulted in older divergence times under a global clock and produced a similar pattern as distance-based branch lengths when fossils were treated either as fixed, resulting in younger time estimates, or as minimums, resulting in older time estimates. In addition, we estimated the divergence times for the calibration nodes when fossils were treated as minimum constraints (table 2); the resulting molecular times were, on average, 68.6% older than the fossil times.

Therefore, our reanalysis of the data of Peterson et al. (2004) shows that their main conclusion—young time estimates for divergences among animal phyla—was the result of incorrectly assuming that fossils provide maximum limits on calibration points. As we have shown, treating fossil times as minimum estimates for both global and local clock analyses recovers time estimates that are similar to previous molecular clock studies, indicating that arthropods and deuterostomes diverged 300 to 400 million years before the Cambrian explosion.

The viewpoint that the Cambrian explosion represented a time when many groups of animals evolved and diverged from one another is the same as the assumption that
the maximum limits of those Cambrian phyla correspond to their minimum limits in the fossil record. Therefore, if molecular clocks are to properly test this model, one should not include maximum limits on fossil calibrations unless the resulting time estimates are treated implicitly as minimums.

This was not the case with the Peterson et al. (2004) study, where they concluded that their results ‘‘support the view that the Cambrian explosion reflects, in part, the diversification of bilaterian phyla.’’
[...]

[...]
Conclusion

Here we have shown that two recent studies supporting the paleontological interpretation of the Cambrian explosion suffer from methodological problems that place into
question their results. In both cases, the reasons given by those authors for why their time estimates were younger than those of previous studies were incorrect. In the first case (Peterson et al. 2004), it was not a rate bias in the vertebrate fossil record, but rather the imposition (unjustified) of maximum time limits on fossil calibrations.

In the second case (Aris-Brosou and Yang 2003), it was not the Bayesian method of analysis, but rather the complex rate models and methods specific to their analysis. In addition, a third recent molecular clock study (Douzery et al. 2004) reported relatively young divergence times among animals (642 to 761 MYA) using a Bayesian Method of analysis. However, this study also violates the eukaryote fossil record by underestimating divergence times for red algae (;925 MYA versus 1,200 MYA fossil), stramenopiles (;800 MYA versus 1,000 MYA fossil), and cholorophytan green algae (;730MYA versus 1,000MYA fossil) (Woods, Knoll, and German 1998; Butterfield 2000; Kumar 2001).

Elsewhere (Hedges et al. 2004), we have analyzed larger sequence data sets with all available time estimation methods, including Bayesian, and found deep Precambrian divergences among animal phyla, consistent with clock studies over the past 3 decades. Specifically, those time estimates are 976 (786 to 1,166) MYA for arthropods versus deuterostomes, 1,351 (1,116 to 1,586) MYA for Porifera versus Eumetazoa, and 1,513 (1,384 to 1,642) MYA for animals versus fungi. Therefore, the viewpoint that the fossil record is missing a long period in the early.
[...]

Por favor aponte no caso supra em qual trecho os autores contestam a validade da Geocronologia?

http://www.talkorigins.org/indexcc/list.html

Seja mais específico...

No index tem de tudo e não é meu dever procurar. É o seu. Cite o que diz respeito ao assunto...