Archive for the ‘Science’ Category

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Dolphins have unique whistle-names for each other

July 23, 2013
Mother and juvenile bottlenose dolphins head t...

Mother and juvenile bottlenose dolphins – Wikipedia

Dolphins it seems are not just self-aware but identify specific individuals with specific whistles. And that would mean not just having a sense of self-identity but also of having a “naming” convention and of communication. And if whistle-names exist then whistle-words and language are also already present or certainly not very far away. Researchers from the Sea Mammal Research Unit, School of Biology at the University of St. Andrews have just published a study of bottle-nosed dolphins.

Stephanie L. King and Vincent M. Janik, Bottlenose dolphins can use learned vocal labels to address each other, Published online before print July 22, 2013, doi:10.1073/pnas.1304459110 , PNAS July 22, 2013

Abstract: In animal communication research, vocal labeling refers to incidents in which an animal consistently uses a specific acoustic signal when presented with a specific object or class of objects. Labeling with learned signals is a foundation of human language but is notably rare in nonhuman communication systems. In natural animal systems, labeling often occurs with signals that are not influenced by learning, such as in alarm and food calling. There is a suggestion, however, that some species use learned signals to label conspecific individuals in their own communication system when mimicking individually distinctive calls. Bottlenose dolphins (Tursiops truncatus) are a promising animal for exploration in this area because they are capable of vocal production learning and can learn to use arbitrary signals to report the presence or absence of objects. Bottlenose dolphins develop their own unique identity signal, the signature whistle. This whistle encodes individual identity independently of voice features. The copying of signature whistles may therefore allow animals to label or address one another. Here, we show that wild bottlenose dolphins respond to hearing a copy of their own signature whistle by calling back. Animals did not respond to whistles that were not their own signature. This study provides compelling evidence that a dolphin’s learned identity signal is used as a label when addressing conspecifics. Bottlenose dolphins therefore appear to be unique as nonhuman mammals to use learned signals as individually specific labels for different social companions in their own natural communication system.

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Posted in Language, Science, Wildlife | Comments Off on Dolphins have unique whistle-names for each other

Fractal Explorer

July 23, 2013

The ultimate fractal explorer!

This could well be the tool that Slartibartfast used to design the Norwegian fjords and is using for the African fjords he is designing for the alternate Earth!

From unwrong.com

fractal explorer

Click on the image to explore.

Slartibartfast is a venerable Magrathean planetary designer. He specialises in Fjords, having won an award for Norway.

He was woken from a five million year sleep by a final order for a duplicate Earth. Its premature demolition caused a terrible hooha, and a new copy was ordered from the original blueprints.

Slartibartfast on life:

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Life on land four times older than previously thought

July 23, 2013

“Settled science” has had it that life on land dates from about 500 million years ago. But fossils of something rather simpler than plants or animals found in South Africa provide evidence that life on land could be 2.2 billion years old.

Gregory J. Retallack, Evelyn S. Krull, Glenn D. Thackray, Dula Parkinson. Problematic urn-shaped fossils from a Paleoproterozoic (2.2Ga) paleosol in South Africa. Precambrian Research, 2013; 235: 71

DOI:10.1016/j.precamres.2013.05.015

Science Daily: 

Conventional scientific wisdom has it that plants and other creatures have only lived on land for about 500 million years, and that landscapes of the early Earth were as barren as Mars.

A new study, led by geologist Gregory J. Retallack of the University of Oregon, now has presented evidence for life on land that is four times as old — at 2.2 billion years ago and almost half way back to the inception of the planet.

That evidence, which is detailed in the September issue of the journal Precambrian Research, involves fossils the size of match heads and connected into bunches by threads in the surface of an ancient soil from South Africa. They have been named Diskagma buttonii, meaning “disc-shaped fragments of Andy Button,” but it is unsure what the fossils were, the authors say.

“They certainly were not plants or animals, but something rather more simple,” said Retallack, professor of geological sciences and co-director of paleontological collections at the UO’s Museum of Natural and Cultural History. The fossils, he added, most resemble modern soil organisms called Geosiphon, a fungus with a central cavity filled with symbiotic cyanobacteria.

“There is independent evidence for cyanobacteria, but not fungi, of the same geological age, and these new fossils set a new and earlier benchmark for the greening of the land,” he said. “This gains added significance because fossil soils hosting the fossils have long been taken as evidence for a marked rise in the amount of oxygen in the atmosphere at about 2.4 billion to 2.2 billion years ago, widely called the Great Oxidation Event.”

By modern standards, in which Earth’s air is now 21 percent oxygen, this early rise was modest, to about 5 percent oxygen, but it represented a rise from vanishingly low oxygen levels earlier in geological time. …

Read the whole article

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Posted in Evolution, Geosciences, History, Life, Science | 1 Comment »

Animal studies biased to give “positive” results

July 18, 2013

It is not suggested that the bias is any form of deliberate misconduct but a new paper shows that animal studies are subject to an “excess significance bias”.

Tsilidis KK, Panagiotou OA, Sena ES, Aretouli E, Evangelou E, et al. (2013) Evaluation of Excess Significance Bias in Animal Studies of Neurological Diseases. PLoS Biol 11(7): e1001609. doi:10.1371/journal.pbio.1001609

Author Summary

Studies have shown that the results of animal biomedical experiments fail to translate into human clinical trials; this could be attributed either to real differences in the underlying biology between humans and animals, to shortcomings in the experimental design, or to bias in the reporting of results from the animal studies. We use a statistical technique to evaluate whether the number of published animal studies with “positive” (statistically significant) results is too large to be true. We assess 4,445 animal studies for 160 candidate treatments of neurological disorders, and observe that 1,719 of them have a “positive” result, whereas only 919 studies would a priori be expected to have such a result. According to our methodology, only eight of the 160 evaluated treatments should have been subsequently tested in humans. In summary, we judge that there are too many animal studies with “positive” results in the neurological disorder literature, and we discuss the reasons and potential remedies for this phenomenon.

Roli Roberts writes at the PLOS blog:

But a study just published in PLOS Biology by Konstantinos Tsilidis, John Ioannidis and colleagues at Stanford University shows that a meta-analysis is only as good as the scientific literature that it uses. That literature seems to be compromised by substantial bias in the reporting of animal studies and may be giving us a misleading picture of the chances that potential treatments will work in humans. ….

Rather than wilful fraud, the authors of the PLOS Biology study suggest that this excess significance comes from two main sources. The first is that scientists conducting an animal study might analyse their data in several different ways, but ultimately tend to pick the method that gives them the “better” result. The second arises because scientists usually want to publish in higher profile journals that tend to strongly prefer studies with positive, rather than negative, results. This can delay or even prevent publication, or relegate the study to a low-visibility journal, all of which reduce their chances of inclusion in a meta-analysis.

The new work raises important questions about the way in which the scientific literature works, and it’s possible that the types of bias reported in the PLOS Biology paper have been responsible for the inappropriate movement of treatments from animal studies into human clinical trials. What do we do about it? Here are the authors’ suggestions:

  1. Animal studies should adhere to strict guidelines (such as the ARRIVE guidelines) as to study design and analysis.
  2. Availability of methodological details and raw data would make it easier for other scientists to verify published studies.
  3. Animal studies (like human clinical trials) should be pre-registered so that publication of the outcome, however negative, is ensured.

 Well, these are all excellent, but most people would also say that there are problems elsewhere in the system – in the high-profile journals’ desire to a have a cute story with well-defined conclusions, and in the forces exerted on authors by institutions and funding bodies to publish in those high-profile journals.

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Further uncertainties in the Carbon cycle

July 4, 2013

The Carbon cycle is far from being fully understood or quantified. The absorption and release of carbon dioxide by the oceans and from biological plants and fungii – both on land and in the ocean – are a long way from being established. The amount of Carbon locked up in the earths crust is equally subject to great uncertainty.

A new paper shows that deep soils hold much higher levels of carbon than is usually assumed.

R. J. Harper, M. Tibbett, The hidden organic carbon in deep mineral soils, Plant and Soil, July 2013, Volume 368, Issue 1-2, pp 641-648

Abstract: Current estimates of soil organic carbon (SOC) are based largely on surficial measurements to depths of 0.3 to 1 m. Many of the world’s soils greatly exceed 1 m depth and there are numerous reports of biological activity to depths of many metres. Although SOC storage to depths of up to 8 m has been previously reported, the extent to which SOC is stored at deeper depths in soil profiles is currently unknown. This paper aims to provide the first detailed analysis of these previously unreported stores of SOC. ….. Mean SOC mass densities for each of the five locations varied from 21.8–37.5 kg C m−2, and were in toto two to five times greater than would be reported with sampling to a depth of 0.5 m.

PhysOrg reports: Current estimates of soil organic carbon are based largely on measurements to depths of 30 cm. This approach has evolved in North America and Europe, where soil is generally more shallow. 

However, many plant species have roots extending many metres deep, suggesting there is also carbon stored at such depth and inspiring researchers to explore the storage potential of deeper soils in older landscapes such as the Amazon or Australia. Researchers in the Amazon had previously sampled soils to 8 m. 

The researchers took soil measurements from samples taken to almost 40 metres deep at a range of sites in south-western Australia. They found that small amounts of carbon were present throughout the soils all the way to the bedrock, and that deep soils store up to five times more carbon than is normally reported.

Lead researcher Professor Richard Harper, an expert in water management and sustainability at Murdoch University said the findings extend our concept of the amounts and potential of carbon stored in soils.

“This carbon has been previously overlooked, and this opens up several lines of inquiry – for example, what happens to this carbon with land use change such as deforestation and reforestation?” Professor Harper said.

“There is likely more carbon stored in the world’s soils than previously considered. What will happen to this carbon – that is, will it be released as a result of either land-use change or climate change – is unknown. This is what we are working on now,” he said.

 

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On constraining the quality of climate science

July 3, 2013

I wrote this – following the words of the Bard – about something else

The quality of intelligence is not strain’d,
It may not be shaped or created or invented
to suit a man’s convenience. It is twice cursed:
It curses him who invents and curses the fool who believes.

and then realised it could easily be adapted to fit “hockey stick” climate science

The quality of climate science is not strain’d,
It may not be shaped or tricked into a hockey stick
to suit a Mann’s convenience. It is twice cursed:
It curses him who tricks and curses the fools who believe.

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Global warming theory lacks a falsifiable hypothesis and climate policy lacks Conditions of Success

June 21, 2013

In Science – to be considered a science – it is the formulation of the falsifiable hypothesis that is critical and ought to determine the subsequent collection or generation of data.

A fundamental requirement before setting out a new policy or embarking on any new course of action should be to define the Conditions of Success (CoS) prior to starting. This is usually so in industry and business – usually explicit but sometimes implicit – especially where investment is to be made or resources are to be used in implementing the new course of action:

  1. What are the objectives to be achieved, and
  2. how will we be able to measure if we are on track.

1. A Falsifiable Hypothesis:

The “global warming” hypothesis is that humans are impacting global climate and specifically that man-made carbon dioxide emissions are causing – through direct and indirect effects – the global climate to warm. But this formulation is virtually impossible either to prove or to falsify. With the many hundreds – if not thousands – of parameters which impact the chaotic system which makes up our climate, it is almost impossible to either collect or generate data which can isolate the effects of just this one parameter.

The prevailing “belief” that this hypothesis is correct is based on being able to say that observed warming is not inconsistent with climate models which include the warming due to anthropogenic emissions of carbon dioxide and that no better models exist. (The hiatus in temperature over the last 20 years is dismissed as being a “temporary” hiatus or due to some unknown effect – such as deep ocean take-up of heat – which is not included in the models). If no observation is permitted to falsify the hypothesis then this is merely a belief and a religion and not science.

However, the same global warming theory can easily be converted into a falsifiable hypothesis if it is formulated thus: “Increasing anthropogenic emissions of carbon dioxide have a significant warming effect on global climate”. This can then be subject to being proved false. The recent hiatus in global temperature then immediately leads to the conclusion that either

  1. the hypothesis is false, or
  2. the hypothesis must be modified to be
  3. “Increasing anthropogenic emissions of carbon dioxide may have a significant warming effect on global climate over long periods in excess of at least 50 years”

And then there is no longer any need for panic.

If the study of climate is ever to become science, the hypotheses will need to be revisited.

2. Conditions of Success

I am always somewhat perplexed that the global warming scare has led to the implementation of policies which – in not a single case – address the Conditions of Success. In no case of “decarbonisation” or carbon taxes or carbon credits or support for renewable energies is there any consideration of the measurements to be made to determine if the actions are having the desired effect.

It has been a blind rush into the support of solar and wind energy with no assessment of the increased electricity prices, the reduction of growth and the subsequent loss of jobs. In no country has there been a definition of the measurable results to be achieved along the way (except for measuring how much money was spent). Just the increase of the capacity of wind and solar power production has been taken to be a success though electricity prices have gone up sharply and no reduction of carbon dioxide concentration has been achieved. All the actions taken over the last 3 decades against the use of fossil fuels have had no impact whatsoever in reducing the rate of increase of carbon dioxide concentration in the atmosphere.

In the US the unexpected advent of shale gas has led to a reduction of carbon dioxide emissions though the global emissions are higher than ever before. And yet the global temperature has been at a standstill for almost 2 decades!

Of course for politicians carbon taxes and the like have become merely a source of revenue where the scare of “global warming” is used as a label merely to prevent resentment against a new tax. These taxes are invariably decoupled from any effects on the changes to carbon dioxide concentration and on global temperature to be achieved.

All these “climate” policies which have produced no reduction of carbon-dioxide concentration or even a reduction in the growth rate and where global temperatures have also failed to increase now seem needlessly self-destructive.

“Climate change policies” will never be credible or of any value until the Conditions of Success for such policies are defined in advance of such policies being implemented.

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Posted in Climate, Politics, Science | 1 Comment »

Carbon Cycle still has many uncertainties

June 20, 2013

How much of the increase in carbon dioxide concentration in the atmosphere is due to the use of fossil fuels is not as certain as many would like to believe. The role of the oceans both in the emission and the absorption of carbon dioxide is far from being understood or quantified. Emissions due to fossil fuel combustion are of the same magnitude as just the error band surrounding the emissions from the oceans and  from the emissions due to transpiration. The primary sources of carbon dioxide in the atmosphere are the oceans and transpiration. The assumption that these emissions are in balance with the absorption by the oceans and plant life is just an assumption based on an assumed equilibrium which is far from certain. I posted a few weeks ago

…. The general assumption is that about 40% of man-made carbon dioxide shows up as this increase with the remainder being absorbed by the enhanced action of sinks.

SOURCES AND SINKS OF CARBON DIOXIDE

The justification for this conclusion is supported by measurements of the falling proportion of  13C  in the atmosphere which is taken to signal the appearance of CO2 from fossil fuel emissions. …… 

The correlation of changes in δ13C with ENSO events and the comparison with a simple model of a series of cascades suggest that the changes in δ13C in the atmosphere have little to do with the input of CO2 emissions from the continuous use of fossil fuels.

Even though the combustion of fossil fuels only contributes less than 4% of total carbon dioxide production (about 26Gt/year of 800+GT/year), it is usually assumed that the sinks available balance the natural sources and that the carbon dioxide concentration – without the effects of man – would be largely in equilibrium.  (Why carbon dioxide concentration should not vary naturally escapes me!). It seems rather illogical to me to claim that sinks can somehow distinguish the source of carbon dioxide in the atmosphere and preferentially choose to absorb natural emissions and reject anthropogenic emissions! Also, there is no sink where the absorption rate would not increase with concentration.

Carbon dioxide emission sources (GT CO2/year)

  • Transpiration 440
  • Release from oceans 330
  • Fossil fuel combustion 26
  • Changing land use 6
  • Volcanoes and weathering 1

Carbon dioxide is accumulating in the atmosphere by about 15 GT CO2/ year. The accuracy of the amounts of carbon dioxide emitted by transpiration and by the oceans is no better than about 2 – 3% and that error band (+/- 20GT/year)  is itself almost as large as the total amount of emissions from fossil fuels. ….. 

Two new papers – in completely different fields – highlight the uncertainty in carbon dioxide emissions from the oceans and from plant and animal life:

1. Interannual variability in sea surface temperature and fCO2 changes in the Cariaco Basin,  Y.M. Astor et al, Deep-Sea Res. II (2013), http://dx.doi.org/10.1016/j.dsr2.2013.01.002i

The Hockey Schtick: A new paper published in Deep-Sea Research finds the ocean is a net source of CO2 to the atmosphere, the opposite of claims by climate alarmists that the ocean removes CO2 from the atmosphere. According to the authors, “At the [research] site, the ocean is primarily a source of CO2 to the atmosphere, except during strong upwelling events.” The paper also notes, “Astor et al.(2005) observed the interactions between physical and biochemical parameters that lead to temporal [over time] variations in fCO2 [CO2 flux from the] sea, finding that even during periods of high production, the CO2 flux between the ocean and the atmosphere decreased but remained positive, i.e. CO2 escaped from the ocean to the atmosphere.” 

The paper corroborates prior work by Salby, Humlum et al, Frölicher et al, Cho et al, Calder et al, Francey et al, Ahlbeck, Pettersson, and others demonstrating that man-made CO2 is not the driver of atmospheric CO2. This new work confirms the primary source of atmospheric CO2 is out-gassing from the oceans, which is due to decreased solubility with increased temperature.

2. Michael S. Strickland, Dror Hawlena, Aspen Reese, Mark A. Bradford, and Oswald J. Schmitz. Trophic cascade alters ecosystem carbon exchange. PNAS, 2013 DOI:10.1073/pnas.1305191110

EurekAlert: …. The study, conducted by researchers at the Yale School of Forestry & Environmental Studies, comes out this week in the Proceedings of the National Academy of Sciences. It looks at the relationship between grasshoppers and spiders—herbivores and predators in the study’s food chain—and how it affects the movement of carbon through a grassland ecosystem. Carbon, the basic building block of all organic tissue, moves through the food chain at varying speeds depending on whether it’s being consumed or being stored in the bodies of plants. However, this pathway is seldom looked at in terms of specific animal responses like fear from predation. …… 

….. The study found that the presence of spiders drove up the rate of carbon uptake by the plants by about 1.4 times more than when just grasshoppers were present and by 1.2 more times than when no animals were present. It was also revealed that the pattern of carbon storage in the plants changed when both herbivores and carnivores were present. The grasshoppers apparently were afraid of being eaten by the spiders and consumed less plant matter when the predators were around. The grasshoppers also shifted towards eating more herbs instead of grass under fearful scenarios.

At the same time, the grasses stored more carbon in their roots in a response to being disturbed at low levels when both herbivores and carnivores were present. In cases where only herbivores were present, the plants stored less carbon overall, likely due to the more intense eating habits of the herbivores that put pressure on plants to reduce their storage and breathe out carbon more. These stress impacts, then, caused both the plants and the herbivores to change their behaviors and change the composition of their local environment.

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Global cooling in the cretaceous shifted the global carbon cycle

June 17, 2013

A new paper in Nature Geoscience showing that global cooling is as significant as global warming.

‘Atlantic cooling associated with a marine biotic crisis during the mid-Cretaceous period’. A McAnena, S Flogel, P Hofmann, JO Herrle, A Griesand, J Pross, HM Talbot, J Rethemeyer, K Wallmann and T Wagner.  Nature Geoscience, DOI: 10.1038/NGEO1850, published on: 16th June 2013

From Newcastle Univeristy’s press release:

Global cooling as significant as global warming

A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to the ones witnessed in the past as a result of global warming, according to research published in Nature Geoscience.

The international study involving experts from the universities of Newcastle, UK, Cologne, Frankfurt and GEOMAR-Kiel, confirms the link between global cooling and a crash in the marine ecosystem during the mid-Cretaceous greenhouse period.

It also quantifies for the first time the amplitude and duration of the temperature change.  Analysing the geochemistry and micropaleontology of a marine sediment core taken from the North Atlantic Ocean, the team show that a global temperature drop of up to 5oC resulted in a major shift in the global carbon cycle over a period of 2.5 million years.

Occurring during a time of high tectonic activity that drove the breaking up of the super-continent Pangaea, the research explains how the opening and widening of new ocean basins around Africa, South America and Europe created additional space where large amounts of atmospheric CO2 was fixed by photosynthetic organisms like marine algae. The dead organisms were then buried in the sediments on the sea bed, producing organic, carbon rich shale in these new basins, locking away the carbon that was previously in the atmosphere.

The result of this massive carbon fixing mechanism was a drop in the levels of atmospheric CO2, reducing the greenhouse effect and lowering global temperature.

This period of global cooling came to an end after about 2 million years following the onset of a period of intense local volcanic activity in the Indian Ocean.  Producing huge volumes of volcanic gas, carbon that had been removed from the atmosphere when it was locked away in the shale was replaced with CO2 from the Earth’s interior, re-instating a greenhouse effect which led to warmer climate and an end to the “cold snap”.

The research team highlight in this study how global climate is intrinsically linked to processes taking place in the earth’s interior at million year time scales. These processes can modify ecospace for marine life, driving evolution.

Current research efforts tend to concentrate on global warming and the impact that a rise of a few degrees might have on past and present day ecosystems.  This study shows that if global temperatures swing the other way by a similar amount, the result can be just as severe, at least for marine life.

 

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Future human evolution will be selection by deselection

June 6, 2013

io9 carries  a look at how science fiction treats evolution :The most ludicrous depictions of evolution in science fiction history.

Of course this begs the question as to how humans are likely to evolve over the coming generations?

Humans and chimpanzees ancestors split some 7-8 million years ago and it took some 350,000 generations after that divergence for evolution by natural selection to produce anatomically modern humans (AMH). (This of course raises the question as to how chimpanzee evolution proceeded to reach modern chimpanzees while humans were developing into homo sapiens?).

It has been only about 10,000 generations since AMH appeared and only some 6,000 generations or so since modern humans left Africa. A very short time in evolutionary terms yet in this period humans have evolved to exhibit the various races of man that exist today. This differentiation is primarily superficial and all humans existing are capable of mating and producing viable offspring with each other. In theory humans existing today would also be compatible and – in the main – capable of mating with the humans of 6,000 generations ago. In practice a meeting of modern humans with those from 120,000 years ago would be an exaggerated replica of modern man meeting with isolated tribes in the 20th century. These isolated branches of humanity generally had lower levels of immunity to the bacteria carried by their distant cousins and were ravaged by disease after such encounters. The bacteria we carry are probably greatly different to those that humans carried at the dawn of anatomically modern humans. Probably no such meeting or mating would be very successful and one or both would probably succumb to disease brought on by the other’s bacteria. Nevertheless the genomes of the two – even after 6,000 generations – would  not be so very different and probably still be compatible. In any primate species a generational distance of over 20,000 between individuals will probably disqualify any theoretical possibility of successful mating.

(more…)

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