An active area of research in the earth sciences concerns oscillating trends in the composition and mineralogy of Phanerozoic carbonates and halites – trends that have been correlated with changes in seawater chemistry and rates of sea floor spreading. A paper about to be published in Science (Coggon et al. 2010) reports efforts to reconstruct past seawater Mg/Ca and Sr/Ca ratios from calcium carbonate veins formed when seawater interacts with basalts on the flanks of mid-ocean ridges. The abstract says:

Proxies for past seawater chemistry such as Mg/Ca and Sr/Ca ratios provide a record of the dynamic exchanges of elements between the solid Earth, atmosphere and hydrosphere, and the evolving influence of life. Here, we estimate past oceanic Mg/Ca and Sr/Ca ratios from suites of 1.6 to 170-million-year-old calcium carbonate veins precipitated from seawater-derived fluids in ocean ridge flank basalts. Our data indicate that prior to the Neogene, oceanic Mg/Ca and Sr/Ca were lower than in the modern ocean. Decreased ocean spreading since the Cretaceous and the resulting slow reduction in ocean crustal hydrothermal exchange throughout the early Tertiary may explain the recent rise in these ratios.

Data like these provide important clues into what was happening to ocean water chemistry both during and after the flood, and have significant implications for our understanding of how carbonates and precipitites formed. Note also the implied slowing of sea floor spreading since the Cretaceous – evidenced by the apparent reduction in chemical exchange between crust and seawater – another interesting trend from a creationist perspective.

Reference

Coggon, R. M., Teagle, D. A. H., Smith-Duque, C. E., Alt, J. C., Cooper, M. J. 2010. Reconstructing past seawater Mg/Ca and Sr/Ca from mid-ocean ridge flank calcium carbonate veins. Science, DOI: 10.1126/science.1182252

Further to the recent announcement about Dr Todd Wood’s visit to the UK in March 2010, full details of his itinerary are now available on the Biblical Creation Ministries diary page. I have also taken the liberty of listing the details at the end of this post.

Todd will be speaking at venues in Salford (11 March), Coventry (13 March), Cambridge (14 March) and Elsenham (16 March). The meetings are open to the public and all are very welcome to attend.

At three of these meetings, Todd will be speaking on Science and the Supernatural and will address the question of what it means to be both a scientist and a creationist. Modern scientists commonly claim that true science cannot consider supernatural causes, since they are outside the realm of observation. Todd will review the reasons for this and propose a way to allow the supernatural realm to inform and enrich scientific research. This talk is suitable for all audiences.

At the meeting in Coventry, Todd’s theme will be a somewhat more technical presentation entitled The Challenge of Darwin. Throughout Origin of Species, Charles Darwin makes the case that a wide variety of biological data is “inexplicable” on the view of creation. Twentieth century evolutionary biologist Theodosius Dobzhansky went further with his claim that “nothing in biology makes sense except in the light of evolution.” But Todd will review and evaluate an emerging model of biological origins that explicitly denies the ancestry of all living things.

If you would like further details about any of these meetings, please contact the tour co-ordinators, Stephen and Joan Bazlinton, by telephone (01371 856495) or email (s.j.bazlinton@googlemail.com), or the listed contact person at each venue.

Thursday 11 March 2010, 8.00 pm,
“Science and the Supernatural”, Elmwood Church, Eccles Old Road, Salford, Manchester M6 8AG. Further information from Duncan Bottrill (0161 7892963; Church website).

Saturday 13 March 2010, 6.30 pm,
“The Challenge of Darwin”, Genesis Agendum Public Lecture, Lower Ford Street Baptist Church, Coventry CV1 5QJ. Further information from Jeff Lowe (0116 2707421; Genesis Agendum website).

Sunday 14 March 2010, 7.30 pm,
“Science and the Supernatural”, After-church meeting, Cambridge Presbyterian Church, meeting in Resurrection Lutheran Church, Westfield Lane (just off Huntingdon Road and opposite New Hall College), Cambridge. Further information from Rev. Ian Hamilton (01223 212370; Church website).

Tuesday 16 March 2010, 8.00 pm,
“Science and the Supernatural”, Elsenham Village Hall (Primary School), High Street, Elsenham, near Bishops Stortford CM22 6DD. Further information from Stephen and Joan Bazlinton (01371 856495).

In the light of Wise and Croxton’s proposal that rafting on floating vegetation played a major role in post-Flood biogeographic dispersal, this advance Nature publication caught my eye. In 1940, George Gaylord Simpson proposed that the ancestors of the present-day mammals of Madagascar had rafted to the island from the African mainland. But there was a problem with his idea: the observed ocean currents didn’t fit the theory. Others argued that the mammals got there across a long-vanished land bridge – but that didn’t explain why only smaller mammals (e.g. lemurs, tenrecs, rodents) apparently made the journey.

New modelling work reported by Ali and Huber (2010) may have solved the problem. Their study suggests that during the Palaeogene (when the mammals in question were arriving) the ocean currents would have been in just the right position to allow rafting from the mainland. That’s because Africa and Madagascar were 15 degrees further south and the Mozambique Channel separating them was in a different ocean gyre than today. As plate tectonics moved Africa and Madagascar northwards, the current system evolved towards its present configuration and the delivery of species eventually stopped. So Ali and Huber conclude that Simpson was probably right all along.

Neat study.

References

Ali J. R. and Huber M. 2010. Mammalian biodiversity on Madagascar controlled by ocean currents. Nature advance online publication, 20 January 2010. doi:10.1038/nature08706.

Wise K. P. and Croxton M. 2003. Rafting: a post-Flood biogeographic dispersal mechanism, in: Ivey R. L., Jr. (editor), Proceedings of the Fifth International Conference on Creationism, Creation Science Fellowship, Pittsburgh, pp.465-477.

Hurray! It’s finally arrived! What am I talking about? Andrew Snelling’s new book, that’s what. All 1102-pages of it landed on my doormat this morning. Earth’s Catastrophic Past: Geology, Creation and the Flood is a two-volume overview of the creationist model of earth history written by one of the world’s leading creation geologists. It’s being described on the ICR website as the long-awaited update to Whitcomb and Morris’ seminal The Genesis Flood. Of course, I’ve only briefly thumbed through these volumes, but they are handsome hardbacks and the production values look high. No doubt I’ll be blogging about the book’s contents in due course (along with Oard and Reed’s Rock Solid Answers: The Biblical Truth Behind 14 Geological Questions and Young and Stearley’s The Bible, Rocks and Time: Geological Evidence for the Age of the Earth, both of which I’d also like to review). In the meantime, you can buy your copy of Earth’s Catastrophic Past from ICR’s bookstore, and follow the links above for the other books mentioned.

Okay, I know what I said just before Christmas. But can the snow please now stop? Pleeeaassse?

Another couple of papers caught my eye this week, both from the latest issue of Nature Geoscience:

First up is a paper by Vry et al. (2010) which indicates that the rapid exhumation of metasediments in orogenic belts might provide a rich and hitherto unrecognized source of hydrous fluids. They applied mineral-equilibria modelling to show that the rapid uplift and erosion of greywackes in an orogenic belt such as the Southern Alps of New Zealand could generate a constant supply of fluids, especially at temperatures below about 500 degrees C. This has significant implications because such fluids have the potential to enhance earthquake activity by weakening the rocks through which they migrate, as well as generating mineral deposits of various kinds.

In the second paper, van der Meer et al. (2010) used seismic tomography to identify 28 remnants of oceanic plates that were subducted into the lower mantle. Making the assumption that they sank vertically, they were then able to reconstruct the longitudinal position at which they were subducted. What they discovered was that the estimated locations of these palaeo-subduction zones were offset by about 18-20 degrees compared with accepted plate tectonic reconstructions. Interestingly, they found that all the slab remnants in the lower mantle were Permo-Triassic in age; none was Carboniferous or older. The authors interpreted that to mean that slab remnants only remain visible to seismic tomography for about 300 million years before assimilation. However, some creationists think that the phase of plate motions during the Palaeozoic may have been the result of an initial decoupling of the earth’s crust from the underlying mantle, rather than an episode of true plate tectonics. If so, that might also explain the apparent absence of pre-Permian slab remnants in the lower mantle.

References

Van der Meer D. G., Spakman W., van Hinsbergen D. J. J., Amaru M. L., Torsvik T. H. 2010. Towards absolute plate motions constrained by lower-mantle slab remnants. Nature Geoscience 3(1):36-40.

Vry J., Powell R., Golden K. M., Petersen K. 2010. The role of exhumation in metamorphic dehydration and fluid production. Nature Geoscience 3(1):31-35.

The science blogs have been abuzz with news of the Middle Devonian tetrapod tracks from Zachełmie, Poland, which apparently pre-date the first tetrapod body fossils by 18 million years (conventionally speaking) and even elpistostegids such as Panderichthys and Tiktaalik by 10 million years (Niedźwiedzki et al. 2010). This is certainly a discovery with “wow factor”. There have been previous claims of tetrapod tracks pre-dating the body fossils, but this is the first with really secure stratigraphic constraints. Brian Switek sounds a cautionary note, wondering whether the Polish tracks might be impressions made by fins with digit-like extensions, but Ed Yong notes that Jenny Clack, who has seen the tracks at firsthand, seems pretty convinced of their tetrapod origin. It’s also interesting, I think, that these tracks are in marine sediments. If the bizarre ‘fishapods’ of the Devonian were really semi-aquatic denizens of floating forests that extended out over the pre-Flood oceans, as Kurt Wise (2003, 2008) has proposed, this association with the marine environment is significant.

In other news, the speed at which the Mediterranean Basin was filled with water following the Messinian salinity crisis is being re-evaluated. Subsurface erosion features, previously attributed to the action of rivers, have been reinterpreted by Garcia-Castellanos et al. (2009) as the product of catastrophic flooding. This research suggests that 90% of the basin might have been filled in a short period ranging from a few months to two years, and that sea level rise during the event might have peaked at >10 metres per day. This adds to a growing list of large-scale overspill floods during the Cenozoic, including those associated with the Ebro Basin, Lake Agassiz, Lake Missoula, Lake Bonneville, and the English Channel.

Finally, Todd Wood has posted brief responses to some of the comments on my post concerning the recurrent laryngeal nerve. You can check out what he has to say here.

References

Garcia-Castellanos D., Estrada F., Jiménez-Munt I., Gorini C., Fernàndez M., Vergés J., De Vicente R. (2009). Catastrophic flood of the Mediterranean after the Messinian salinity crisis. Nature 462:778-781.

Niedźwiedzki G., Szrek P., Narkiewicz K., Narkiewicz M., Ahlberg, P. E. 2010. Tetrapod trackways from the early Middle Devonian period of Poland. Nature 463:43-48.

Wise K. P. 2003. The pre-Flood floating forest: a study in paleontological pattern recognition, in: Ivey R. L. Jr. (editor), Proceedings of the Fifth International Conference on Creationism, Creation Science Fellowship, Pittsburgh, pp.371-381.

Wise K. P. 2008. Sinking a floating forest. Answers 3(4):40-45.

One of the most intriguing arguments in support of evolution comes from biological features or structures that are suggestive of historical contingency. Since evolution involves the modification of pre-existing structures to give rise to new ones, certain constraints are imposed on the possible evolutionary pathways that may be taken. Some structures are said to retain a legacy of these constraints in their current form or configuration, and are thus understood as ‘accidents of history’ or ’suboptimal improvisations’. For example, Richard Dawkins has been making much recently about the route taken by the recurrent laryngeal nerve in giraffes (Giraffa camelopardalis). The laryngeal nerve, which serves the larynx, originates as a branch of the vagus nerve in the neck. However, it then passes down into the chest, loops under the posterior side of the aorta, and then travels back up to the larynx – in the giraffe, a diversion of some 3 to 5 metres. Dawkins’ argument is that the laryngeal nerve takes this much-longer-than-necessary route because the giraffe evolved from short-necked ancestors.

Now as I thought about this, it occurred to me that the same hypothesis might apply even from a creationist perspective. Assuming, as many creationists do, that the created kind (or baramin) is approximately equivalent to the taxonomic rank of family, i.e. encompassing all the Giraffidae, and hypothesising, as many creationists do, that the Cenozoic sediments which contain giraffid fossils were laid down in depositional events after the global Flood, we might conclude that the fossil record of giraffids represents post-Flood intrabaraminic (‘within-kind’) diversification. Furthermore, recognising that the earliest known Cenozoic giraffids (as well as the only other living member of that family, the okapi) possess short necks, we might well infer that the ancestral giraffe on the ark was short-necked and subsequently diversified into longer-necked forms, thus giving rise to a historically contingent pathway of the laryngeal nerve.

Of course, that still leaves the question of why the recurrent laryngeal nerve takes a slightly circuitous route even in mammals with short necks, including presumably the ancestral giraffid. Perhaps there’s a functional reason, but, if so, it’s not obvious what it is (ideas on a postcard, please). Some might attribute it to the inscrutability of God’s will, but that doesn’t seem very satisfying. However, the point here is that, unless we assume species fixity, the route taken by the recurrent laryngeal nerve does not help us to discriminate between creationist and evolutionist explanations of the origin of the modern giraffe as Dawkins seems to have assumed.

We have snow! In fact, it stopped me getting to my final lecture of 2009 this morning, so that’ll have to be rescheduled to the New Year. But I’m not really complaining – it’s somewhat magical for the young at heart if not very helpful to commuting creationists. Snow in mid December is a little unusual for this part of the UK but we may even get a white Christmas if the Arctic weatherfront prevails over the milder air coming up from the south.

So as I gaze out from my study window at the white stuff blanketing our driveway, may I take this opportunity to wish all my readers a very merry Christmas and a prosperous New Year. And if you’re currently snowed in, why not take a look at this topical article by Larry Vardiman on the extraordinary beauty and design of snowflakes. Happy sledging.

The New Creationism has been reviewed in the latest edition of Grace Magazine (December 2009, p.21). The reviewer is Dr J. H. John Peet. Grace Magazine’s editor, Colin Grimwood, has kindly given me permission to post the review here. You can find out more about Grace Magazine, including subscription details, on its website.

Paul Garner is well known amongst the Grace Baptist constituency as an able creationist speaker. This book will be welcomed by those who have heard him and appreciated by even more.

This year has been noted as the anniversary of Darwin’s birth and of the publication of his book ‘On the Origin of Species.’ This has caused a spate of new books and this one will probably head the booklists of those interested in the subject. The title may surprise some: what is new about creationism? It reflects the fact that the creationist position has come of age. It is not simply an anti-evolution approach. It has a positive biblical position and, as this book shows, a mature approach to the scientific data.

The book is marked by its readability: the reader does not need to be a scientist in order to understand the subject. On the other hand, the scientifically-minded will find it satisfying and a basis for further study. The end-notes (30 pages) and bibliography will provide [sic] valuable for research. It divides into four parts. In the first, Paul explores the origin and nature of the universe, showing the clear signs of its divine creation and maintenance. The Earth stands out as a unique planet, made specifically for mankind.

But what of the time element? This occupies several chapters in Part 2. Firstly, Paul looks at the biblical evidence for a young universe/young Earth. He goes on to examine the geological evidence for a catastrophic history. This leaves the ‘problem’ of claims that radiometric dating methods establish unambiguously that the world is very old. Paul describes some outstanding creationist research of the last decade which demonstrates an alternative interpretation favouring a short geological history. In the last chapter of this section, he describes other processes (cosmological, earthly and human) that suggest the beginning of all these things must be relatively recent. Readers will appreciate the caution that Paul introduces into his arguments showing their limitations.

The third part deals with the biological evidence which supports the creationist position. Paul tackles the underlying issues arising in the debate about the miraculous creation claimed by the Scriptures: the origin of life itself, diversity by design, biological classification (first developed by creationists!), defects and degeneration and embryology. A section full of fascinating facts presented again in a very readable format.

Finally, the Flood and its consequences. This is the field in which Paul is active in his research; this is reflected in the thoroughness of his account. He acknowledges views other than his own held within the creationist community. He begins, rightly, with a careful look at the biblical record of the Flood and then demonstrates how the evidence accords with this. The formation of fossils is not recorded in the Scriptures and so we have to examine Scripture and the fossil record carefully to see where they fit in. Evolutionists see the fossils as a record of appearance of different plant and animal types; the evidence points to their disappearance – in biblical terms, judgment.

The Ice Age is an area where creationist studies have a strong lead over the uniformitarian (evolutionary) approaches. The chapter on this makes very interesting and exciting reading. This leads directly into the concluding chapter on Stone Age Man and where he fits into the biblical record.

Paul closes his book with a brief gospel message. This is appropriate as many of us will be pleased to pass a copy of this book to non-Christian friends. But, in any case, read it yourself and be blessed.