World / Biology
A Simple And General Explanation For The Evolution Of Altruism
03.09.2008 08:21
medicalnewstoday.com
The evolution of altruism poses a problem in evolutionary theory: How can natural selection favour individuals that carry altruistic traits over those carrying selfish traits? This paper presents a simple framework that highlights the most fundamental requirement common to all competing theories for the evolution of altruism: sufficient assortment between carriers of helping traits and help from other individuals in the altruists' interaction environments.
World
Biology
Genome Size And Wing Parameters In Passerine Birds
03.09.2008 08:21
medicalnewstoday.com
Amounts of DNA per genome vary more than 7,000-fold among animal species. Some groups such as amphibians exhibit a large range in genome size, whereas others like birds are limited to relatively small genomes. Genome size correlates positively with cell size, which is associated with an inverse relationship between DNA amount and metabolic rate in mammals and birds.
World
Biology
A Killer-Rescue System For Self-Limiting Gene-Drive Of Anti-Pathogen Constructs
03.09.2008 06:15
medicalnewstoday.com
One of the concerns of citizens with the development and use of genetically engineered mosquitoes in the fight against dengue fever and malaria is the fact that most of the current approaches result in released engineered strains remaining in the environment. We provide a novel approach that enables self-limiting spread of an engineered construct and describe its population genetic and mechanical properties.
World
Biology
Survival And Recovery Of Phaeocystis Antarctica (Prymnesiophyceae) From Prolonged Darkness And Freezing
03.09.2008 06:15
medicalnewstoday.com
Phaeocystis antarctica is a key planktonic plant species in the Antarctic ecosystem. Its complex life cycle involves solitary and colonial morphotypes. In parts of the Southern Ocean it must cope with freezing water temperature and complete darkness during the austral winter. To understand how this species thrives in such an extreme environment, we conducted a series of experiments in the United States McMurdo Station using natural P. antarctica assemblages.
World
Biology
High Variability In Patterns Of Population Decline: The Importance Of Local Processes In Species Extinctions
03.09.2008 06:15
medicalnewstoday.com
In the current extinction crisis, it is well-known that some species are more vulnerable to extinction than others. But do species always respond in the same way to human impacts? Our study of how primates respond to habitat disturbance indicates that any one species can show a range of responses, including population increases as well as declines, depending on the locality.
World
Biology
Duration And Outcome Of Intergroup Conflict Influences Intragroup Affiliative Behaviour
03.09.2008 04:13
medicalnewstoday.com
Soldiers regularly engage in a period of rest and recuperation with their comrades following active service in a conflict zone. My work reveals that birds act similarly. Green woodhoopoe group members increased their preening of one another following conflict with neighbouring groups, especially when they lost the battle or it lasted a long time (the most stressful situations).
World
Biology
Assessment Of The Role Of Sutures In A Lizard Skull- A Computer Modelling Study
03.09.2008 04:13
medicalnewstoday.com
Sutures form an integral part of the functioning skull, but their role has long been debated among vertebrate morphologists and palaeontologists. Furthermore, the relationship between typical skull sutures, and those involved in cranial kinesis, is poorly understood.
World
Biology
New Method To Investigate Origin Of Life Developed By Scientists
03.09.2008 04:13
medicalnewstoday.com
Scientists at Penn State have developed a new computational method that they say will help them to understand how life began on Earth. The team's method has the potential to trace the evolutionary histories of proteins all the way back to either cells or viruses, thus settling the debate once and for all over which of these life forms came first.
World
Biology
B-Vitamin Deficiency May Cause Vascular Cognitive Impairment
03.09.2008 04:13
medicalnewstoday.com
A deficiency of B-vitamins may cause vascular cognitive impairment, according to a new study. Researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University used an experimental model to examine the metabolic, cognitive, and microvascular effects of dietary B-vitamin deficiency. Their findings appear in Proceedings of the National Academy of Sciences (PNAS).
World
Biology
An Age-structured Model To Evaluate The Potential Of Novel Malaria Control Interventions: A Case Study Of Fungal Biopesticide
03.09.2008 04:13
medicalnewstoday.com
It has recently been proposed that mosquito vectors of human diseases, particularly malaria, may be controlled by spraying with fungal biopesticides that increase the rate of adult mortality. Though fungal pathogens do not cause instantaneous mortality they can kill mosquitoes before they are old enough to transmit disease. A model is developed..
World
Biology
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