Saturday, February 20, 2010

MORALITY RESEARCH SHEDS LIGHT ON THE ORIGINS OF RELIGION

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The details surrounding the emergence and evolution of religion have not been clearly established and remain a source of much debate among scholars. Now, an article published by Cell Press in the journal Trends in Cognitive Sciences on February 8 brings a new understanding to this long-standing discussion by exploring the fascinating link between morality and religion.

There is no doubt that spiritual experiences and religion, which are ubiquitous across cultures and time and associated exclusively with humans, are ultimately based in the brain. However, there are many unanswered questions about how and why these behaviors originated and how they may have been shaped during evolution.

"Some scholars claim that religion evolved as an adaptation to solve the problem of cooperation among genetically unrelated individuals, while others propose that religion emerged as a by-product of pre-existing cognitive capacities," explains study co-author Dr. Ilkka Pyysiainen from the Helsinki Collegium for Advanced Studies. Although there is some support for both, these alternative proposals have been difficult to investigate.

Dr. Pyysiainen and co-author Dr. Marc Hauser, from the Departments of Psychology and Human Evolutionary Biology at Harvard University, used a fresh perspective based in experimental moral psychology to review these two competing theories. "We were interested in making use of this perspective because religion is linked to morality in different ways," says Dr. Hauser. "For some, there is no morality without religion, while others see religion as merely one way of expressing one's moral intuitions."

Citing several studies in moral psychology, the authors highlight the finding that despite differences in, or even an absence of, religious backgrounds, individuals show no difference in moral judgments for unfamiliar moral dilemmas. The research suggests that intuitive judgments of right and wrong seem to operate independently of explicit religious commitments.

"This supports the theory that religion did not originally emerge as a biological adaptation for cooperation, but evolved as a separate by-product of pre-existing cognitive functions that evolved from non-religious functions," says Dr. Pyysiainen. "However, although it appears as if cooperation is made possible by mental mechanisms that are not specific to religion, religion can play a role in facilitating and stabilizing cooperation between groups."

Perhaps this may help to explain the complex association between morality and religion. "It seems that in many cultures religious concepts and beliefs have become the standard way of conceptualizing moral intuitions. Although, as we discuss in our paper, this link is not a necessary one, many people have become so accustomed to using it, that criticism targeted at religion is experienced as a fundamental threat to our moral existence," concludes Dr. Hauser.

Cell Press

CARBONATE VEINS REVEAL CHEMISTRY OF ANCIENT SEAWATER

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The chemical composition of our oceans is not constant but has varied significantly over geological time. In a study published in Science, researchers describe a novel method for reconstructing past ocean chemistry using calcium carbonate veins that precipitate from seawater-derived fluids in rocks beneath the seafloor. The research was led by scientists from the University of Southampton's School of Ocean and Earth Science (SOES) hosted at the National Oceanography Centre, Southampton (NOCS).

"Records of ancient seawater chemistry allow us to unravel past changes in climate, plate tectonics and evolution of life in the oceans. These processes affect ocean chemistry and have shaped our planet over millions of years," said Dr Rosalind Coggon, formerly of NOCS now at Imperial College London.

"Reconstructing past ocean chemistry remains a major challenge for Earth scientists, but small calcium carbonate veins formed from warm seawater when it reacts with basalts from the oceanic crust provide a unique opportunity to develop such records," added co-author Professor Damon Teagle from SOES.

Calcium carbonate veins record the chemical evolution of seawater as it flows through the ocean crust and reacts with the rock. The composition of past seawater can therefore be determined from suites of calcium carbonate veins that precipitated millions of years ago in ancient ocean crust.

The researchers reconstructed records of the ratios of strontium to calcium (Sr/Ca) and magnesium to calcium (Mg/Ca) over the last 170 million years. To do this, they analysed calcium carbonate veins from basaltic rocks recovered by several decades of scientific deep-ocean drilling by the Integrated Ocean Drilling Program (IODP) and its predecessors.

"The carbonate veins indicate that both the Sr/Ca and Mg/Ca ratios of seawater were significantly lower than at present prior to about 25 million years ago. We attribute the increases in seawater Sr/Ca and Mg/Ca since then to the long-term effects of decreased seafloor volcanism and the consequent reduction in chemical exchange between seawater and the ocean crust," said Professor Teagle.

(Photo: NOCS)

National Oceanography Centre, Southampton (NOCS)

HOW THE BUTTERFLIES GOT THEIR SPOTS

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How two butterfly species have evolved exactly the same striking wing colour and pattern has intrigued biologists since Darwin's day. Now, scientists at Cambridge have found "hotspots" in the butterflies' genes that they believe will explain one of the most extraordinary examples of mimicry in the natural world.

Heliconius, or passion-vine butterflies, live in the Americas – from the southern United States to southern South America. Although they cannot interbreed, H. melpomene and H. erato have evolved to mimic one another perfectly.

These delicate butterflies have splashes of red and yellow on their black wings, signaling to birds that they contain toxins and are extremely unpalatable. They mimic one another's colour and pattern to reinforce these warning signals.

Scientists have studied these butterflies since the 1860s as a classic case of evolution in action, but only now is modern sequencing technology unlocking the underlying genetics.

The Cambridge-led team of researchers from UK and US universities, which has been breeding the butterflies in Panama for the past decade, has been searching for the genes responsible for the butterflies' wing patterns and the answer to the question of whether the same genes in two different species are responsible for the mimicry.

According to Dr Chris Jiggins of the Department of Zoology at the University of Cambridge, one of the authors of the study: "The mimicry is remarkable. The two species that we study – erato and melpomene – are quite distantly related, yet you can't tell them apart until you get them in your hand. The similarity is incredible – even down to the spots on the body and the minute details of the wing pattern."

That the two species have evolved to look exactly the same is due to predation by birds. "The birds will try anything that looks different in the hope that it's good, so they learn that certain wing patterns are unpalatable and avoid them, but anything that deviates slightly from what they've experienced before is more likely to be attacked," he explains.

These butterflies have been studied since Darwin's day because they are such a striking example of adaptation. For years, scientists have pondered whether when different species evolve to look the same, they share a common genetic mechanism.

According to Jiggins: "It's interesting because it tells us how flexible evolution is. If you get the same wing pattern evolving independently in different populations, do you expect the same genes to be involved?"

Because there are thousands of genes in the butterflies' genome, most scientists felt it was unlikely that the same genes should be involved. But the results of this study suggest that this is, in fact, the case.

The new results – published today in two parallel papers in the journal PLoS Genetics – show that the regions of the genome associated with the wing patterns are very small – akin to genetic "hotspots".

"This tells us something about the limitations on evolution, and how predictable it is. Our results imply that despite the many thousands of genes in the genome there are only one or two that are useful for changing this colour pattern. It seems like evolution might be concentrated in quite small regions of the genome – or hotspots – while the rest of it does not change very much," says Jiggins.

This is not the only unexpected element of the study. The team was also surprised that the obvious candidate genes – such as those involved in colour or wing pattern in other species – do not seem to be involved in the passion-vine butterflies' mimicry.

According to Jiggins: "We think it's more likely to be some novel method of cellular signaling, which is quite intriguing and could be important in many other insect species."

The next stage of the research is to look at other traits, such as behaviour, because the butterflies have preferences for particular colours and use wing patterns to select mates. "It seems the same regions of the genome control this behaviour as well as the wing pattern. We'd like to understand this," he says.

(Photo: Copyright Chris Jiggins, University of Cambridge)

University of Cambridge

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