Details of Award
NERC Reference : NE/C509974/1
Statistical methods for estimating species divergence times combining heterogeneous genetic data sets.
Grant Award
- Principal Investigator:
- Professor Z Yang, University College London, Genetics Evolution and Environment
- Grant held at:
- University College London, Genetics Evolution and Environment
- Science Area:
- Terrestrial
- Overall Classification:
- Terrestrial
- ENRIs:
- Biodiversity
- Science Topics:
- Population Genetics/Evolution
- Systematics & Taxonomy
- Abstract:
- When one species splits into two, the two copies of the same gene will evolve, that is, accumulate changes (mutations), in different species independently. The longer the species separated from each other, the more different their genes will be. If changes happen in the gene at the same rate in different species, the genetic molecule will act like a clock, accumulate mutations over time just as a clock ticks. This is known as the molecular clock. Evolutionary biologists use it to estimate how long ago different species separated from each other. They used mathematical models to measure the genetic distances between species and use powerful computers to compare hundreds of species at the same time. Suppose there are 10 differences between species A and B and 20 differences between species A and C. If fossils are available to suggest that species A and B separated 15 million years ago, we can use this fossil information to 'calibrate' the molecular clock to estimate the time of separation between species A and C, in this case, 30 million years ago. This is known as molecular clock dating. Unfortunately, the molecular clock is rather sloppy, and often ticks at different rates during different time periods, for example, when the planet goes through large-scale climate changes or when different species such as elephants and mice adopt different life styles. This creates a huge problem as now we cannot easily tell whether a large genetic difference is due to a long time of separation or a high rate of change. In this research project, we will develop mathematical models to describe how sloppy clock ticks, which will enable us to date species divergences even when the molecular clock is not strictly true. We will improve date estimates by using many fossils at the same time to calibrate the sloppy clock. Furthermore, it is observed that some genes are evolving fast in some species while other genes are evolving fast in other species. Thus we can get a better idea about whether a large distance is due to long time or high rate by looking at many genes at the same time since all the genes separated at the same times when the species split. Our new methods can analyse many genes at the same time and also can use many fossils to calibrate the clock. We will use the new mathematical methods to estimate how long ago different mammals (primates, rodents, carnivors, artiodactyls etc.) diverged and how long ago flowering plants first appeared on this planet.
- NERC Reference:
- NE/C509974/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £234,660
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Staff | Total - Other Costs | Total - Equipment | Total - Indirect Costs |
|---|---|---|---|---|
| £10,364 | £138,903 | £3,036 | £18,464 | £63,895 |
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