ScienceWeek

SCIENCEWEEK

April 20, 2007

Vol. 11 - Number 15

--------------------------------

To receive the complete text of ScienceWeek each week by Email via the Science and Politics discussion list, send Email to contents@scienceweek.com with subject line "CONTENTS", and we will subscribe you and add your name to the distribution list.

You can make relevant comments or queries to the entire distribution list of ScienceWeek and the Science and Politics discussion list simply by sending Email to scipol@googlegroups.com with an appropriate subject line. Please do not make any posts not relevant to science or the interface between science and politics. Announcements of conferences, symposia, new books, etc. are acceptable.

--------------------------------

But he who has been earnest in the love of knowledge and of true wisdom, and has exercised his intellect more than any other part of him, must have thoughts immortal and divine, if he attain truth, and in so far as human nature is capable of sharing in immortality, he must altogether be immortal.

-- Plato (428-348 B.C.)

--------------------------------

Contents (full text below):

1. Evolution: Aging and Sexual Conflict

2. Planetary Science: A New Spin on Saturn's Rotation

3. Book Review: Coming to Life: How Genes Drive Development

4. Book Review: Baby at Risk: The Uncertain Legacies of Medical Miracles for Babies, Families, and Society

5. Neurobiology: Feeling Right About Doing Right

6. Quantum Mechanics: To Be or Not To Be Local

7. Book Review: The Curious History of Relativity: How Einstein's Theory of Gravity was Lost and Found Again

8. Book Review: Science Business: The Promise, the Reality, and the Future of Biotech

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

1.

Science 20 April 2007: Vol. 316. no. 5823, pp. 383 - 384 DOI: 10.1126/science.1142201

Evolution: Aging and Sexual Conflict

Rebecca Dean, Michael B. Bonsall, Tommaso Pizzari

In many human societies, men are becoming fathers increasingly late in life, and it is estimated that fertility problems experienced by one-third of couples can be attributed to male factors, including aging (1). Aging can affect male reproductive success through two processes, each with distinct evolutionary implications: the age of the male and the age of his sperm. Recent empirical studies demonstrate that both male aging and sperm aging may have a dramatic impact on fertility, embryo viability, and ultimately on the evolutionary conflict between sexual partners, known as sexual conflict.

Male fertilizing efficiency is especially important in species where females mate with multiple males and the ejaculates of different males compete for fertilization, a process called sperm competition. One recent study of the hide beetle (Dermestes maculates) (2) reveals that male aging may be an important determinant of the outcome of sperm competition. The study analyzed fertilization success in two scenarios: when the ejaculates of two males were inseminated into a female (sperm competition), and when the ejaculate of only one male was inseminated (absence of sperm competition). The study demonstrates that the fertilizing ability of an ejaculate peaks at an intermediate male age. Most young males copulated with females but only 36% of them had developed mature sperm, indicating that most young males were not sexually mature. Similarly, although all old males produced mature sperm, some of them failed to transfer sperm during mating (aspermic copulation). Males in their prime (intermediate age), on the other hand, never failed to inseminate a female. Moreover, in sperm competition, their ejaculates outcompeted those of old and young males in fertilizing the eggs of a female. These results confirm earlier work on this species showing that a female incurs fertility costs when she mates with either a young or an old male (3).

This recent hide beetle study also indicates that the propensity of a female to mate with a particular male will depend on his age. The age-dependent risk of aspermic copulation and associated fertility costs thus favor female preference for partners of intermediate age to ensure fertilization. Similarly, we would expect a female to be more likely to re-mate after copulation with either a young or an old male. Whereas the ejaculates of intermediate-age males thrive in sperm competition, it would be particularly advantageous for young and old males, who produce less competitive ejaculates, to defend paternity by preventing females from re-mating with other males, thus imposing fertility costs on females. A cheap way to inhibit female propensity to re-mate may be precisely to perform aspermic copulations (4), which could explain why sperm-depleted young and old males still copulate with females. Therefore, the effect of male aging on fertilizing efficiency may be a critical factor underlying female partner choice and re-mating strategies. Ultimately, male aging sets the scene for evolutionary conflict over mating between two prospective partners.

In addition to male age effect on fertility rates, the impact of male age on gamete health also factors into reproductive costs. The DNA carried by sperm cells produced by old males may accumulate deleterious genetic mutations and thus cause developmental defects and reduced viability of the embryo. For instance, strong links have been revealed between male age and frequencies of sperm with DNA fragmentation and gene mutations associated with achondroplasia (5), a genetic disorder leading to drastically shortened bones. Therefore, in addition to fertility costs, inseminations by old males--when they do result in fertilization--may also reduce offspring quality, creating another source of conflict: sexual conflict over fertilization.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

2.

Science 20 April 2007: Vol. 316. no. 5823, pp. 380 - 381 DOI: 10.1126/science.1142329

Planetary Science: A New Spin on Saturn's Rotation

Fran Bagenal

The rotation rate of a planet is among its most important properties. For solid planets, simple observation of the surface tells us how fast the object is spinning. On gas planets such as Saturn or Jupiter, however, the visible outer layers move differently from the interior. So how do we know how fast the interior of a gas planet is spinning? The usual trick is to measure the periodicity of radio emissions that are modulated by the planet's internal magnetic field. This method assumes that the magnetic field is tilted and that the dynamo region where the field is generated spins at a rate representative of the bulk of the planet. But on page 442 of this issue, Gurnett et al. (1) argue that recent data from NASA's Cassini spacecraft indicate that apparent changes in Saturn's spin could be caused by processes external to the planet. This raises new questions about how we are to measure and understand the rotation of the large gas planets.

Saturn first dumbfounded planetary theorists who study dynamo models by having a highly symmetric internal magnetic field. A field that is symmetric about the rotation axis violates a basic theorem of magnetic dynamos (2). The second puzzle came with the detection of a systematic rotational modulation of the radio emission similar to a flashing strobe, which should not occur in a symmetric magnetic field. Meanwhile, radio measurements have revealed that last year that Saturn's day has become about 6 to 8 mins longer--it is now roughly 10 hours and 47 min--since the 1980s when measured by the Voyager missions (3). And the spin rate seems to keep changing. In their new work, Gurnett et al. show how Saturn's radio emission, the magnetic field measured in the magnetosphere, and the density of plasma trapped in the magnetic field are all modulated with the same drifting period. And the plasma produced by Saturn's moon Enceladus may hold the key to the puzzle of the radio emissions.

Cassini images of geysers on Saturn's small moon Enceladus (4) triggered great excitement, primarily because they implied that warm, potentially life-harboring water might lurk just below the icy surface. But to magnetospheric scientists, Enceladus'geysers evoked the volcanic plumes of Jupiter's moon Io. Io's plumes spew forth gases that are ionized at a rate of about a ton per second, forming a dense toroidal cloud of plasma trapped in Jupiter's strong magnetic field. The torus of plasma emanating from Enceladus is much weaker (at most a couple of hundred kilograms per second) than that of Io, with most of the gases remaining as neutral atoms or molecules (5, 6). Cassini observations show that the Enceladus plasma torus slowly spreads out to fill Saturn's magnetosphere.

Gurnett et al. argue that the process that transports plasma radially outwards could be stronger on one side of Saturn than the other (see the figure). They suggest that this circulation pattern also produces higher plasma densities in the region of stronger outflow. Gurnett et al. propose that plasma production stresses the electrodynamic coupling between the magnetosphere and the planet, causing the pattern of weaker/stronger outward flow to slowly slip in phase relative to Saturn's internal rotation.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

3.

Science 20 April 2007: Vol. 316. no. 5823, p. 373 DOI: 10.1126/science.1130345

Book Review: Coming to Life: How Genes Drive Development

by Christiane Nüsslein-Volhard

Kales Press, Carlsbad, CA, 2006. 180 pp. $29.95, C$42. ISBN 9780967007670.

While most scientific disciplines have undergone remarkable advances in the past few decades, the field of developmental biology has seen truly astonishing progress. In her book Coming to Life: How Genes Drive Development, Christiane Nüsslein-Volhard offers a very accessible whirlwind tour of what modern developmental biology has taught us about the way in which a fertilized egg becomes a complex organism. In just under 150 pages, the reader is treated to a primer on genetics and molecular and cell biology; an overview of the development of the fruit fly Drosophila melanogaster; a summary of the general principles of vertebrate development; and, lastly, a concise presentation of some of the moral challenges that our advances have created. From a scientific perspective, Nüsslein-Volhard is eminently qualified for the task, having been at the forefront of the discipline for many years and sharing the 1995 Nobel Prize for Medicine. However, not all great scientists are endowed with the gift to communicate lucidly, especially in a way that is understandable to a layperson. This book succeeds because its brevity is matched by its clarity. (Nipam H. Patel)

More information about this book at: http://www.amazon.com/exec/obidos/ASIN/030012080X/scienceweek

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

4.

Science 20 April 2007: Vol. 316. no. 5823, pp. 374 - 375 DOI: 10.1126/science.1142263

Book Review: Baby at Risk: The Uncertain Legacies of Medical Miracles for Babies, Families, and Society

by Ruth Levy Guyer

Capital Books, Sterling, VA, 2006. 181 pp. $22.95. ISBN 9781933102269.

To the uninitiated, the neonatal intensive care unit is a frightening place: rows of incubators; alarms and buzzers going off at irregular intervals, followed by the scurrying of nurses and doctors; and the quiet murmurs (and, sometimes, sobs) of families surrounding their tiny babies. But the neonatal intensive care unit is also a place of great hope and joy, as the newborns grow into babies capable of crying, eating, and smiling.

The trials of these infants, though, do not stop at the nursery's door. How these children affect both their families and society is the subject of Ruth Levy Guyer's Baby at Risk: The Uncertain Legacies of Medical Miracles for Babies, Families, and Society. Guyer (a science writer who teaches bioethics at Haverford College) uses conversations with neonatal professionals, parents of prematurely born infants, and medical ethicists to present what she hopes is a realistic picture of the survivors of neonatal intensive care. Ultimately, Guyer hopes that "the media will stop hyping 'miracle baby' stories Zand start reporting truthfully about the benefits and the burdens of neonatal intensive care and new reproductive technologies." (Scott A. Lorch)

More information about this book at: http://www.amazon.com/exec/obidos/ASIN/1933102268/scienceweek

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

5.

Nature 446, 865-866 (19 April 2007) | doi:10.1038/446865a; Published online 18 April 2007

Neurobiology: Feeling Right About Doing Right

Deborah Talmi & Chris Frith

Reason and emotion come into conflict in making all kinds of judgements. Results of work with brain-damaged patients constitute one line of evidence that the emotional component is not to be dismissed.

In resolving moral dilemmas, should emotion be our guide? This is a question prompted by various research avenues, including work described in the paper by Koenigs et al.1 on page 908 of this issue.

In a typical moral dilemma, we have to choose between the lesser of two evils. Causing the death of one person is bad, but causing the death of five people is even worse. So, if you are on a runaway trolley with no other options, many people say that it is better to switch to the left fork in the track, resulting in the death of one person, than to carry on along the right fork and kill five. But what if there was no fork in the track and the only way to stop the trolley killing five people was to throw a large person, who happens to be standing next to you, under the wheels? From a utilitarian point of view the dilemma is the same: should we sacrifice one person for the sake of five? But, given this version of the dilemma, most people will choose not to throw their companion to his death. Why the difference?

There is increasing evidence that there is a strong emotional component to our moral intuitions, and that this determines, to a large degree, how we make moral judgements2. Thus the benefit from sacrificing a single life for the greater good must be pitted against the emotional aversion associated with the taking of life, particularly when we are face-to-face with our victim. Measurement of brain activity while people are presented with these dilemmas confirm this intuition: the moral dilemma involving throwing our companion onto the track elicits more activity in emotion-processing regions of the brain than the standard runaway-trolley problem (see ref. 3 for a review).

The implication of these ideas is that people with impaired emotional responses will have altered moral intuitions. Koenigs and his colleagues1 have tested this hypothesis with a group of patients with damage to part of the brain called the ventral medial prefrontal cortex (VMPFC). As is typical after such damage, the autonomic nervous system in these patients showed reduced responses to emotionally charged pictures and, according to their spouses, the patients showed reduced feelings of empathy and guilt. When confronted with moral dilemmas, the patients with VMPFC lesions were more likely to choose the utilitarian option than were control participants and patients with lesions in other brain regions. This effect was particularly marked when there was high conflict between the utilitarian and the emotional component. The finding seems to be robust, as Ciaramelli et al.4 report essentially the same results in a separate VMPFC patient group.

This result engenders a paradox. On the one hand, believing that emotion is the enemy of reason, our society still goes to great lengths to prevent emotional considerations from influencing important decisions, in particular moral decisions. Intriguingly, the result reported by Koenigs and colleagues1 seems to show that damage to the VMPFC does not impair moral decision-making, but rather improves it through eliminating the effects of emotion. On the other hand, there is abundant evidence that decision-making in other spheres is severely impaired in these patients5. Indeed, it is on the basis of this latter evidence that Damasio6developed the 'somatic marker' theory, which affords a major role to emotions for making good decisions. Emotions clearly have a role in our moral intuitions, but do they improve moral decision-making, or impair it?

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

6.

Nature 446, 866-867 (19 April 2007) | doi:10.1038/446866a; Published online 18 April 2007

Quantum Mechanics: To Be or Not To Be Local

Alain Aspect

The experimental violation of mathematical relations known as Bell's inequalities sounded the death-knell of Einstein's idea of 'local realism' in quantum mechanics. But which concept, locality or realism, is the problem?

The development of quantum mechanics early in the twentieth century obliged physicists to change radically the concepts they used to describe the world. The main ingredient of the first quantum revolution, wave–particle duality, has led to inventions such as the transistor and the laser that are at the root of the information society. Thanks to ideas developed by Albert Einstein and John S. Bell, another essential quantum ingredient, entanglement, is now leading us through the conceptual beginnings of a second quantum revolution — this time based on quantum information1, 2.

In contrast to wave–particle duality, which is a one-particle quantum feature, entanglement involves at least two particles. In entangled states such as those discovered by Einstein, Podolsky and Rosen (EPR)3, quantum mechanics predicts strong correlations between measurements on two systems that have previously interacted but which are separated at the time of the measurement (Box 1). To interpret these correlations, Einstein said, one must accept the concept of local realism. This principle states that results of measurements on a system localized in space-time are fully determined by properties carried along by that system (its physical reality) and cannot be instantaneously influenced by a distant event (locality).

But after Bell's discovery that local realism entailed a limit on the correlations — a limit he expressed in his celebrated inequalities4 — a series of ever more ideal experiments (ref. 5 and references therein) has led us to abandon the concept. It is then natural to raise the question of whether one should drop locality — which equates to the impossibility of any influence travelling faster than light — or rather drop the notion of physical reality.

There is no logical answer to that question: one can choose to abandon either concept, or even both. Tony Leggett has explored6 one of these possibilities by considering a particular class of physically plausible theories that abandon locality, but maintain realism. He found these theories to be incompatible with quantum mechanics, and expressed the disagreement by new inequalities6. As there was no experimental result available to test Leggett's inequalities, a new type of measurement was necessary.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

7.

Nature 446, 857-858 (19 April 2007) | doi:10.1038/446857a; Published online 18 April 2007

Book Review: The Curious History of Relativity: How Einstein's Theory of Gravity was Lost and Found Again

by Jean Eisenstaedt

Princeton University Press: 2006. 384 pp. $29.95 £18.95

Einstein's general theory of relativity sparked research that led to the understanding of black holes. Einstein created two surprising theories between 1905 and 1915. His special theory of relativity in 1905 altered our understanding of space and time such that, rather than being viewed as aspects of the physical world that could be used to describe and explain other features, both came to depend on the observer. By 1915, his general theory of relativity meant that space and time were now even more fluid, also depending on the state of matter in the surrounding Universe. Gravity was now seen as an aspect of time and space. (William Unruh)

More information about this book at: http://www.amazon.com/exec/obidos/ASIN/0691118655/scienceweek

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

8.

Nature 446, 859 (19 April 2007) | doi:10.1038/446859b; Published online 18 April 2007

Book Review: Science Business: The Promise, the Reality, and the Future of Biotech

by Gary P. Pisano

Harvard Business School Press: 2006. 256 pp. $29.95

I have an aversion to management books, and it is based on the way they are written. Why use a sentence when a chapter will do? Why use standard English when you can invent meaningless phrases? Gary Pisano suffers from this predilection in his book Science Business. He takes more than 70 pages to tell the reader that drug discovery is complex and risky, involving several disciplines and lots of money, and that biotechnology has simply increased the complexity. A further 30 pages are required to conclude that many commercialization strategies are being followed, but that it is too early to know which are right. (Keith Redpath)

More information about this book at: http://www.amazon.com/exec/obidos/ASIN/1591398401/scienceweek

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=