Synthetic Fossils Show Organic Films Can Preserve Quickly

first_img2. Statements regarding controversies about preservation potential that the scientists wished to test:The discovery that melanosomes preserve commonly inexceptional fossils (Vinther et al. 2008; Colleary et al.2015) has opened new avenues of palaeontologicalresearch, but their study has not been without controversy.These structures have alternatively been identifiedas fossil bacteria (Wuttke 1983; Davis & Briggs 1995), aposition still maintained by some (Moyer et al. 2014;Lindgren et al. 2015; Schweitzer et al. 2015). However,this stance has been countered by the fact that microbodiescommonly found in fossil skin, hair and feathersconform to melanosomes in distribution, size and organization(Vinther et al. 2008; Vinther 2015, 2016). Furthermore,chemical analyses show that these structurescontain melanin (Glass et al. 2012, 2013; Lindgren et al.2012, 2014; Colleary et al. 2015; Clements et al. 2016;Gabbott et al. 2016; Brown et al. 2017).In addition, it has been suggested that keratin proteincan preserve organically in fossils (Schweitzer et al. 1999,2015; Edwards et al. 2011; Moyer et al. 2016a, b) and,thus, melanosomes might be obscured by a keratin proteinmatrix (Zhang et al. 2010; Moyer et al. 2014; Panet al. 2016). However, studies have described melanosomesas being exposed on the sediment while nonpigmentedregions yield only rock matrix (Vinther et al.2008; Colleary et al. 2015; Vinther 2015). More recently,studies have argued that the only constituents of keratinoustissues preserved deep in the geological record arecalcium phosphate and pigments (Mayr et al. 2016;Vinther et al. 2016; Saitta et al. 2017a).Experimental taphonomy supports the poor preservationpotential of keratin protein. Previous, non-sedimentencasedmaturation experiments turned keratin into avolatile-rich, water-soluble fluid (Saitta et al. 2017a) whileextracted melanosomes survived largely intact (Collearyet al. 2015). This contrasting behaviour between keratinprotein and melanin during maturation suggests that diageneticdegradation and loss of keratin protein is to beexpected in fossils, leaving behind melanosomes. However,this keratin–melanin dynamic has yet to be experimentallyobserved simultaneously.Similarly, decay-resistant collagenous tissue (Sansomet al. 2010a, b, 2013) is expected to be diageneticallyunstable (Parry et al. 2018), like other proteinaceousorganics (Bada et al. 1999). However, epidermal collagenprotein has been proposed in Mesozoic fossils (Lingham-Soliar et al. 2007), although such claims are debated(Smith et al. 2015; Smithwick et al. 2017).Regarding the specific experiments described here, wehypothesize that tissues containing diagenetically-unstableorganics such as proteins and labile lipids (e.g. keratinous,collagenous, muscle and adipose tissues) will largelybecome degraded and lost into the sediment, while diagenetically-stable organics such as melanin (i.e. melanosomes)will tend to remain with the specimen. If thehypothesized filtering effect of porous sediment on diagenetically-altered organic materials is correct, then experimentalresults from sediment-encased maturation shouldbe expected to resemble fossils such that preserved organicstains consist largely of exposed melanosomes resting onthe sediment with a loss of surrounding tissues. In an attempt to learn about the fossilization process, scientists have found that exceptional fossils don’t require millions of years.Scientists at the University of Bristol are old-earth evolutionists, but what they found by experiment mimicked what can be seen in fossils. How long did it take? One day.Exceptionally-preserved fossils, like those of dinosaur bones and birds with soft-tissue remains in the form of carbon films, have been in the news for the last 20 to 30 years. Mary Schweitzer, in particular, created a stir with her fossils of what looked like intact blood vessels in a T. rex bone. The evidence of elastic tissue under a microscope elicited gasps by host Leslie Stahl of 60 Minutes in 2010 (YouTube). Numerous reports have come in since, showing intact collagen and melanosomes in bird feathers and carbon films thought to be residues of organs and tissues (see footnote 2). Despite their astonishment at these finds, no one in the secular journals or mainstream media ever questions that these fossils really did form many tens of millions of years ago. Creationist radio host Bob Enyart keeps a running list of fossils with soft-tissue remains as evidence against the assumed long ages.Can the conditions that created these exceptional fossils be reproduced in the lab? Researchers have created “synthetic fossils” (artificial taphonomy) in order to test what conditions can reproduce the observed remains. They tried to speed up the fossilization process by applying heat and pressure. These “maturation” experiments have been a staple for organic geochemists, says a press release from the University of Bristol, to help geochemists understand the formation of fossil fuels, or to produce synthetic diamonds.More recently, maturation has been used to study the formation of exceptional fossils that preserve soft tissues as dark, organic films in addition to mineralised tissues like bone, including fossil dinosaurs from China with organically preserved feathers.New work at the University of Bristol by grad student Evan Saitta has mimicked these types of fossils. His team gathered chicken feathers and living birds and lizards, then performed “humane euthanasia” on them by gassing them with CO2 (see footnote 1). When he used the standard maturation processes on his specimens, however, all he got was a “foul-smelling fluid.” He altered the technique by placing the specimens in compressible bentonite clay. This provided an outlet for fluids during the compaction step:Saitta explained: “The sediment acts as a filter allowing unstable molecules to escape from the sample, revealing browned, flattened bones surrounded by dark, organic films where soft tissues once were.“These results closely resemble exceptional fossils, not just visually, but also microscopically as revealed using a scanning electron microscope.”Microscopic, pigment-bearing structures called melanosomes reside within the organic films in feathers and lizards treated with the new method while unstable protein and fatty tissues degrade and are lost, just as in exceptional fossils which have been used by scientists such as Vinther to reconstruct the original colours of dinosaurs.The methods described in the paper in Palaeontology say that the experiment ran for 12 to 23 hours – less than one day (see footnote 1).The researchers say the new method of sediment filtration represents an improvement upon earlier maturation experiments and will allow for the testing of many hypotheses regarding organic preservation in fossils and sediments.The findings did not change the team’s views about long ages. They still believe fossils like Schweitzer’s fossils formed 60 to 80 million years ago (see footnote 2). But on what basis?One commonly employed experimental approach is known as ‘artificial maturation’, where high heat and pressure accelerate the chemical degradation reactions that normally occur over millions of years when a fossil is buried deep underground and exposed to geothermal heat and pressure from overlying sediment.And yet scientifically speaking, no scientist ever observed the presumed millions of years. What they observed, tested and found only took 23 hours.To back up their claim, the team should repeat the setup without applying heat and pressure, and then wait 68 million years. Then their conclusions might be scientifically supportable.Source paperSediment‐encased maturation: a novel method for simulating diagenesis in organic fossil preservationEvan T. Saitta, Thomas G. Kaye, and Jakob VintherFirst published: 25 July 2018 in Palaeontology archiving statement: Data for this study are available in the Dryad Digital Repository: from the Method section of the paper:Fresh feathers (Gallus gallus and Meleagris gallopavo fromUK farms) and lizards (Anolis captured from the wild inArizona, USA) were matured shortly after acquisition/humaneeuthanasia via CO2 asphyxiation with their fullrange of tissue composition present (see Saitta et al.(2018) for additional, preliminary results on non-vertebrates).Specimens were buried in easily-compacted bentoniticclay (purchased from Clay Terra; inside a metal piston and compacted using a hydraulicpress (9–18 tonnes over 126.7 mm2), producing a consolidatedtablet (Fig. 1A). Previous attempts with loosesediment did not produce results macrostructurally comparableto fossils, or amenable to easy structural analysis,indicating that compaction is important in establishingthe desired pore space filtration. Tablets were loaded intoa welded metal tube (19 mm inner diameter), forming anairtight chamber tapped for a high-pressure airline, withthe goal of providing space for the escape of maturationproducts from the sediment (Fig. 1B). The chamberresided inside a ceramic-lined laboratory oven. The airlineexited a hole in the oven and connected a pressure-regulatedair compressor. Experiments ran at 210–250°C/225–300 bars/12–23 h (Saitta et al. 2018) consistent with othermaturation studies of fossilization. (Visited 653 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

China deal: a new day for Africa

first_imgJohn BattersbyThe recent acquisition by China’s largest bank of 20% of South Africa’s Standard Bank is a watershed event in the growing relationship between China and the development of the African continent.The symbolism is overwhelming.China is an emerging global power and the sheer scale of its economy is already beginning to dwarf anything that has come before it.The Industrial and Commercial Bank of China (ICBC), which made the move on Standard Bank, recently overtook Citigroup as the world’s largest bank, with a market capitalisation of US$254-billion (R1.4-trillion).Its $5.5-billion (R36.7-billion) stake in Standard Bank, the bank with the largest presence in Africa, is the largest ever inward investment in South Africa, as well as the biggest Chinese financial acquisition ever.It further consolidates the uniquely strategic relationship between China and South Africa, its major partner on the African continent, and marks the moment at which South Africa can look to the new “BRIC” global economic powers – Brazil, Russia, India and China – as the source of foreign direct investment which has fallen short of expectations in the case of traditional trading partners Britain, France, the United States and Japan.China moves on AfricaChina has in the past decade or so become the fastest growing investor in African infrastructure, one of the major source of soft loans to African states, one of the largest consumers of African oil and steel and the largest exporter of cheap manufactured goods to the continent.Bilateral trade between China and African nations has increased a staggering tenfold to $55.5-billion (R350-billion) in less than a decade. In the six years from 2000 to 2006, China pumped $6.6-billion (R43-billion) in foreign direct investment into Africa.China’s state financial institutions – such as the Chinese Export-Import Bank – are advancing soft loans for developing African infrastructure, which run into $25-billion (R152-billion) over the next three years or so in four countries alone: Nigeria, Angola, Ethiopia and the Democratic Republic of Congo (DRC).China’s strategic approach in building a long-term relationship with Africa to serve its own economic interests has opened up opportunities for African countries which were unthinkable even a decade ago.The Chinese approach of doing business without preconditions based on human rights and good governance has presented the continent’s traditional trading partners – and multilateral bodies such as the World Bank – with a major challenge.Beyond aid and debt reliefThe stark reality is that Western aid to Africa has not worked. It is estimated that since 1960 more than $655-billion in Western aid has been pumped into Africa, with little to show for it.That is six times more than the $111-billion (at today’s prices) invested by the United States in the Marshall Plan for the reconstruction of Europe after World War II, according to Richard Dowden, director of the Royal Africa Society.It is only in the past five years or so that the G8 and the European Union have started to recast the relationship with Africa in terms of a partnership in which aid could be jointly monitored and managed and sustainable joint ventures could come into being.The call for a Marshall Plan for African development – which has been made at various times by Nobel peace laureate Archbishop Desmond Tutu and British Prime Minister Gordon Brown during his term as Chancellor of the Exchequer – is an analogy which can only be taken so far.Clearly, what Africa needs, more than aid and debt relief – although it needs these interventions too – is trade and investment, and partnerships which will ensure a transfer of skills and technology that will enable Africans increasingly to become the architects of their own renaissance.African interventionsIn that sense, there has been much progress through the interventions of South Africa President Thabo Mbeki and other African leaders is setting new standards of political and economic governance through the reformation of the African Union, and the creation of the New Partnership for Africa’s Development (Nepad) and the African Peer Review Mechanism (APRM).Mbeki has also been at the forefront of positioning Africa – which has contributed least to climate change but stands to suffer most from its impact – as a potentially key broker in the quest for a global deal on climate change.Then there are the interventions of homegrown African role models such as Mohammed Ibrahim, the former chair of Celtel, who set up a foundation to encourage African leaders to leave a legacy of development for their people and to monitor governance throughout the continent.Former Mozambican President Joaquim Chissano recently became the first recipient of the Mo Ibrahim Foundation’s $5-million (R33-million) award for his wise leadership and contribution to development. Mozambique is growing impressively from a low base.Neighbouring Tanzania’s former president, Benjamin Mkapa, is Reuters chairman Niall FitzGerald’s co-chair as head of the Investment Climate Facility, which seeks to remove impediments to investment and streamline registration and customs clearance procedures.African success storiesAngola, mainly beyond the scrutiny of Western correspondents, is undergoing an extraordinary economic revival and is set to become a regional power in the years ahead.Botswana, long a role model of good governance and economic efficiency, was described recently by Barclays Chief John Varley, at a symposium at the CASS Business School attached to London’s City University, as “one of greatest undeclared miracles of growth and economic management”.Nigeria, which is projected to be one of the word’s 10 largest economies by 2020, is moving on a trajectory of growth and accountability, and countries like Ghana, Senegal, Tanzania, Mozambique and Zambia have become relative havens of peace and development.The advent of the mobile phone has given entrepreneurism a major boost throughout the continent, and the most pressing needs lie with infrastructure development – particularly in energy and transport – financial inclusion and access to capital, the revival of the continent’s universities, and a sound education and health infrastructure.Most pressing – and this is where the Western countries could deliver, but vested interests in the US and the EU prevent it – is the need for a levelling of the rules for global trade, in particular through scrapping agricultural subsidies.Seeing Africa in a different lightBut one can already begin to feel the difference in Africa. Investors are looking at Africa in a new light and increasingly seeing the need to have a foothold there, much as was the case with China 20 years ago. Banks talk excitedly about the opportunities, and venture capital is engaging increasingly in the once marginalised continent.“To be successful in Africa, business leaders must reject the image of a continent in constant crisis,” said FitzGerald, Britain’s most credible and passionate Afro-optimist. “Challenges remain but, in a continent of almost a billion people, so do huge opportunities. The potential dividends for businesses which are bold and forward-looking are huge.”China’s involvement in Africa is strategic and long-term. There are already signs of a shift in China’s terms for business in Darfur and Zimbabwe, and similar shifts are evident in China’s growing attention to intellectual property rights and anti-corruption measures.Western countries have long tended to dismiss China’s interest as inimical to human rights and sustainable development, but they might not be able to do so for much longer.“China is lining up its entrepreneurs behind a vision which is based on securing mineral supplies and building future markets,” said Fitzgerald. “This is very powerful and we ignore it at our peril.”The marriage of China’s largest bank and South Africa’s Standard Bank is the clearest sign yet that the global economic order is in the midst of fundamental change. Its centre of gravity is moving eastwards and southwards, and the trend is gaining momentum rapidly.As a strategic partner of China and closely allied to Brazil and India, South Africa is strategically placed to make the best of the new day that is coming … just around the bend. John Battersby is the UK country manager of the International Marketing Council of South Africa. He is based in London. This article was first published in South Africa magazine. Useful linksStandard Bank of South AfricaIndustrial and Commercial Bank of ChinaChinese Embassy in South AfricaAsia Pacific South Africa Chamber of CommerceChinese Export-Import BankRoyal African SocietyNew Partnership for Africa’s DevelopmentAfrican Peer Review MechanismMo Ibrahim FoundationInvestment Climate Facility for Africalast_img read more