Population genetics largely rests on a 'standard model' in which random genetic drift is the dominant force, selective sweeps occur infrequently, and deleterious mutations are purged from the population by purifying selection. Studies of phenotypic evolution in nature reveal a very different picture, with strong selection and rapid heritable trait changes being common. The time-rate scaling of ...

As an alternative, Speakman has put forward a non-adaptive scenario — the drifty gene hypothesis. According to this idea, genetic drift — the change of gene frequencies due to random, non-selective processes— could explain the current incidence of obesity seen in modern, industrialized populations. Speakman has hypothesized that the threat of predation on early humans may have provided a strong...

Associations between extinction and habitat fragmentation have been modelled and described, but we document the first clear mechanistic link between habitat fragmentation and population persistence, demonstrating that a rapid evolutionary response to fragmentation can yield conditions wherein some populations are more vulnerable to extinction. Historical differences in the partitioning and tenu...

The changing patterns of admissions to an intensive care unit (ICU) were investigated in relation to age. The local population and the patients admitted to ICU in each year from 1996 to 2002 were stratified by age. The trend in the ratio of admissions to population showed the most extreme changes in those aged > or = 60 years. For this group, there was an increase of 2.62 admissions per 10,000 ...

background: cytochrome p450 2c19 (cyp2c19) is important in metabolism of wide range of drugs. cyp2c19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (urm). distribution of this variant allele has not been well studied worldwide. the aim of present study was to investigate allele and genotype frequencies of cyp2c19*17 in...

A standard assumption in integrated assessment models of climate change is that population and productivity are growing, but at a decreasing rate. We explore the signi cance of the assumption of population and productivity growth for greenhouse gas abatement. After all, there has been no long run slow down in the growth of productivity over the past few centuries, and the rate of population gro...

The rapid development of urban ‘sprawl’ surrounding many North American cities has many potentially detrimental effects including enhanced energy consumption and greenhouse gas emissions from increasing private vehicle use. Over the past 5 years in Canada a number of studies have been undertaken to address transportation-related energy consumption with the view to formulating relevant policies ...