Yearly Archives: 2007

First Bacterial Genome Transplantation Changes One Species To Another:

Researchers at the J. Craig Venter Institute (JCVI) have announced the results of work on genome transplantation methods allowing them to transform one type of bacteria into another type dictated by the transplanted chromosome. The work, published online in the journal Science, by JCVI’s Carole Lartigue, Ph.D. and colleagues, outlines the methods and techniques used to change one bacterial species, Mycoplasma capricolum into another, Mycoplasma mycoides Large Colony (LC), by replacing one organism’s genome with the other one’s genome.

But, if you think about it as “transplanting the cell membrane and wall of one species onto another” than it does not sound so epochal, does it?
Cloned Pigs Help Scientists Towards A Breakthrough In Alzheimer’s:

The first pigs containing genes responsible for Alzheimer’s disease will be born in Denmark in August. This event is a landmark achivement in the effort towards finding a cure for the disease.

RNA May Play Larger Role In Cell’s Gene Activity, Researchers Find:

Large, seemingly useless pieces of RNA – a molecule originally considered only a lowly messenger for DNA – play an important role in letting cells know where they are in the body and what they are supposed to become, researchers at Stanford University School of Medicine have discovered.

The Newest Artificial Intelligence Computing Tool: People:

A USC Information Sciences Institute researcher thinks she has found a new source of artificial intelligence computing power to solve difficult IT problems of information classification, reliability, and meaning. That tool, according to ISI computer scientist Kristina Lerman, is people, human intelligence at work on the social web, the network of blogs, bookmark, photo and video- sharing sites, and other meeting places now involving hundreds of thousands of individuals daily, recording observations and sharing opinions and information.

Book Makes Case For Using Evolution In Everyday Life:

Evolution is not just about human origins, dinosaurs and fossils, says Binghamton University evolutionist David Sloan Wilson. It can also be applied to almost every aspect of human life, as he demonstrates in his first book for a general audience, Evolution for Everyone: How Darwin’s Theory Can Change the Way We Think About Our Lives (Bantam Press 2007). Using witty, straightforward language and compelling anecdotes, Wilson outlines the basic principles of evolution in a way that can be easily understood by non-experts. He then uses the principles to explain phenomena as diverse as why beetles commit infanticide, why dogs have curly tails, and why people laugh and make art.

Bald Eagle Soars Off Endangered Species List:

Secretary of the Interior Dirk Kempthorne announced the removal of the bald eagle for the list of threatened and endangered species at a ceremony June 28 at the Jefferson Memorial in Washington, D.C. After nearly disappearing from most of the United States decades ago, the bald eagle is now flourishing across the nation and no longer needs the protection of the Endangered Species Act.

Seabird Diet History Revealed Through Analyisis Of Museum Samples:

Using feathers from museum collections all over the world, a University of Guelph integrative biology professor has tested a new hypothesis about what led to population decline of a species of seabirds in Canada.

New Study Shows How Often Juries Get It Wrong:

Juries across the country make decisions every day on the fate of defendants, ideally leading to prison sentences that fit the crime for the guilty and release for the innocent. Yet a new Northwestern University study shows that juries in criminal cases many times are getting it wrong.

A whole bunch of papers got published on PLoS-ONE yesterday. I did not have time to check them out very closely yet, but a few titles immediatelly caught my attention:
High Costs of Female Choice in a Lekking Lizard
by Maren N. Vitousek, Mark A. Mitchell, Anthony J. Woakes, Michael D. Niemack and Martin Wikelski

The cost to males of producing elaborate mating displays is well established, but the energy females spend on mate choice is less clear. This study monitored the heart rates of female Galápagos marine iguanas (Amblyrhynchus cristatus) and found they expended almost a days’ worth of energy a month choosing a mate. More choosy females lost weight, produced smaller follicles, and were less likely to survive El Niño years.

Female Sexual Polymorphism and Fecundity Consequences of Male Mating Harassment in the Wild
by Thomas P. Gosden and Erik I. Svensson

Genetic and phenotypic variation in female response towards male mating attempts has been found in several laboratory studies, demonstrating sexually antagonistic co-evolution driven by mating costs on female fitness. Theoretical models suggest that the type and degree of genetic variation in female resistance could affect the evolutionary outcome of sexually antagonistic mating interactions, resulting in either rapid development of reproductive isolation and speciation or genetic clustering and female sexual polymorphisms. However, evidence for genetic variation of this kind in natural populations of non-model organisms is very limited. Likewise, we lack knowledge on female fecundity-consequences of matings and the degree of male mating harassment in natural settings. Here we present such data from natural populations of a colour polymorphic damselfly. Using a novel experimental technique of colour dusting males in the field, we show that heritable female colour morphs differ in their propensity to accept male mating attempts. These morphs also differ in their degree of resistance towards male mating attempts, the number of realized matings and in their fecundity-tolerance to matings and mating attempts. These results show that there may be genetic variation in both resistance and tolerance to male mating attempts (fitness consequences of matings) in natural populations, similar to the situation in plant-pathogen resistance systems. Male mating harassment could promote the maintenance of a sexual mating polymorphism in females, one of few empirical examples of sympatric genetic clusters maintained by sexual conflict.

Interethnic Differences in Muscle, Liver and Abdominal Fat Partitioning in Obese Adolescents
by David Liska, Sylvie Dufour, Tosca L. Zern, Sara Taksali, Anna M.G. Calí, James Dziura, Gerald I. Shulman, Bridget M. Pierpont and Sonia Caprio

Our study indicates that obese Hispanic adolescents have a greater IMCL lipid content than both Caucasians and African Americans, of comparable weight, age and gender. Excessive accumulation of fat in the liver was found in both Caucasian and Hispanic groups as opposed to virtually undetectable levels in the African Americans. Thus, irrespective of obesity, there seem to be some clear ethnic differences in the amount of lipid accumulated in skeletal muscle, liver and abdominal cavity.

As always, if you read the papers and have questions or comments, post them at the paper, not on this post.

Mathematicians Discover A Simple Way To Formulate Complex Scientific Results:

A new analysis of behaviour in a structured population illuminates Darwin’s theories of co-operation and competition between kin, and provides an abstract model that could simplify scientists’ quest to map behaviour among disease-causing organisms within a cell. The study by Queen’s Mathematics and Statistics professor Peter Taylor, and co-authors Troy Day (Queen’s) and Geoff Wild (University of Western Ontario) presents a simple formula for balancing the benefit and cost in altruistic acts, allowing researchers to predict behaviour and summarize disparate results in a simple framework.

Global Climate Change And Toxic Chemicals: A Potentially Lethal Combination:

As temperature influences the toxic effects of chemicals, so does chemical exposure influence the temperature tolerance of an organism. The consequences of this harmful reciprocal relationship on four freshwater fish are explored in a new study published in the latest issue of Environmental Toxicology and Chemistry.

Letting Plants ‘Talk’ To You:

The greenhouse manager of the future walks around the greenhouse, pointing an infrared “flashlight” at potted plants. A tiny screen tells whether each plant has too much, too little, or just the right amount of nutrients. During the past three years, at a new facility in Toledo, Ohio, Agricultural Research Service (ARS) plant pathologist Jim Locke and horticulturist Jonathan Frantz have made a great deal of progress toward realizing this automated future. Frantz is testing commercial nutrient sensors with a view toward developing improved portable ones. Devices like these can give greenhouse growers a few–often critical–extra days to correct nutrient problems before their plants are seriously damaged.

Tasmanian Tiger Extinction Mystery:

A University of Adelaide project led by zoologist Dr Jeremy Austin is investigating whether the world-fabled Tasmanian Tiger may have survived beyond its reported extinction in the late 1930s. Dr Austin from the Australian Centre for Ancient DNA is extracting ancient DNA from animal droppings found in Tasmania in the late 1950s and ’60s, which have been preserved in the Tasmanian Museum and Art Gallery.

Female Iguanas Pay High Costs To Choose A Mate:

Picking a mate isn’t easy–if you are a female iguana. In a study published in the June 27th issue of PLoS ONE, Maren Vitousek of Princeton University and colleagues found that female Galápagos marine iguanas spend a lot of energy picking a mate from a wide range of suitors — energy they could otherwise spend foraging, producing eggs, or avoiding predators. Scientists have generally assumed that being choosy about potential mates carries low costs for females. These costs were thought to be particularly small when male territories are clustered together in groups, known as ‘leks’, which make it possible for females to assess many candidates without traveling far.

Study Confirms Importance Of Sexual Fantasies In Experience Of Sexual Desire:

Scientists of the Department of Personality, Evaluation and Psychological Treatment of the University of Granada have studied how some psychological variables such as erotophilia (positive attitude towards sexuality), sexual fantasies and anxiety are related to sexual desire in human beings. The researcher Juan Carlos Sierra Freire states that there are very few reliable and valid instruments in Spain to evaluate sexual desire. Due to this vacuum, the researchers have adapted the Sexual Desire Inventory by Spector, Carey and Steinberg. This inventory is a tool that enables the researcher to measure, on the one hand, the solitary sexual motivation and, on the other hand, the interest in having sexual intercourse with another person (didactic sexual desire). This fact is of a great importance because “it gives relevant information about possible disagreements in sexual desire that may appear in a couple”. Regarding figures of the Spanish Association for Sexual Health, a loss of sexual desire is one of the main factors that cause sexual dysfunction in the Spanish female population.

Foreign Herbivores May Be Key To Curbing Invasive Weeds:

Joint research with scientists in Argentina, Australia and China could lead to discovery of new biological control agents for several exotic weeds plaguing Florida and other U.S. states. Some of the worst offenders are hydrilla, Brazilian pepper, Chinese tallow and Australian pine. These and other aggressive invasive weeds occupy diverse habitats and cause many environmental problems, especially a decrease in biodiversity within infested areas.

How Fish Punish ‘Queue Jumpers’:

Fish use the threat of punishment to keep would-be jumpers in the mating queue firmly in line and the social order stable, a new study led by Australian marine scientists has found.

The Beetle’s Dilemma:

Large jaws are efficient in crushing hard prey, whereas small jaws are functional in capturing elusive prey. Researchers have suggested that such trade-offs between “force” and “velocity” could cause evolutionary diversification of morphology in animals such as birds, fish, and salamanders.

Which Came First: Primates’ Ability To See Colorful Food Or See Colorful Sex?:

The adaptive significance of the unique ability in many primates to distinguish red hues from green ones (i.e., trichromatic color vision) has always enticed debate among evolutionary biologists. The conventional theory is that primates evolved trichromatic color vision to assist them in foraging, specifically by allowing them to detect red/orange food items from green leaf backgrounds.

New Line Of Communication Between Nervous System Cells Discovered:

In a host of neurological diseases, including multiple sclerosis (MS) and several neuropathies, the protective covering surrounding the nerves — an insulating material called myelin — is damaged. Scientists at the Weizmann Institute of Science have now discovered an important new line of communication between nervous system cells that is crucial to the development of myelinated nerves — a discovery that may aid in restoring the normal function of the affected nerve fibers.