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This article describes the growing and invaluable contribution that quantitative mathematical frameworks are making to generating and testing hypotheses in developmental biology, and in shaping new ways of understanding developmental processes across molecular, cellular and tissue scales.
The concept of fitness is fundamental to understanding natural selection, but defining and measuring fitness involves some subtle distinctions. This Review explains theoretical aspects of fitness, introduces current experimental approaches and highlights issues that remain unresolved.
The rapid evolution of many important pathogens, particularly RNA viruses, means that their ecological and evolutionary dynamics occur on the same timescale. This Review discusses the insights into the transmission and epidemiology of viruses that have been provided by analyses of their evolutionary dynamics across a wide range of biological scales.
Copy number variation is a major source of variation between individuals that is increasingly recognized as influencing genome evolution and human disease. But how does it arise? The authors discuss predicted mechanisms of copy number change, including non-homologous end-joining and non-homologous repair of broken replication forks.
Understanding the basis of phenotypic variation is one of the most challenging problems in biology. The arrival of high-throughput genomic technologies now looks set to allow an integrative systems genetic approach to dissecting the genetic component of complex traits.
Constructs containing artificial microRNA target sites have the potential to improve a range of therapeutic strategies that are based on gene delivery or viruses. The same technology can be used for experimental purposes, in animal transgenics and to study the functions of microRNAs.