Wednesday, February 09, 2005

Notes (a similarity)

secondary traits and quality of male

are like

phenotype and genotype difference

Influences on the genome

This diagram is just a preliminary mess to help remember stuff and to sort my ideas

This may not be correct or accurate and definitely isn't displayed in a clear manner

http://photos1.blogger.com/img/45/3508/1024/genome%20influences.jpg


Random stuff Posted by Hello

Sunday, February 06, 2005

Wearing your genes on your sleeves

^ A good way to describe sexual signalling.

Honest signalling is as I understand it, generally accepted

In a species that has a sexually selected trait, a long tail or bright plumage is hard to lie about. Because you either won't have the nutrition to produce the 'fake' trait or you'll die while producing it. (although im sure exceptions to this must occur).

In a species without secondary sexually selected characteristics where sexual conflict occurs lying is almost assumed because no one can 'prove' whether they are good or not, therefore the system is open to manipulation. e.g. Drosophila seminal proteins, manipulate the females reproductive system to benefit the male and stop other males mating with her.

If recessive mutations can be assumed to be 'invisible' will there be honesty or lying. Or because the costs of heterozygous recessive mutations can be minimal or most commonly nothing does nothing occur. Is it all neutral.


Research project title

Simulating the spread of mutations in a sexual population

Computing supervisor - Jason Noble
Domain supervisor - Dr Tom Tregenza
This interdisciplinary project involves using techniques from computer science to examine a question in theoretical biology. The project was suggested by Dr. Tom Tregenza of the School of Biology, and he will be the domain-stream supervisor.
The plan is to construct a simulation that tracks changes in gene frequencies in a large, sexually reproducing population. The specific theoretical question we want to look at concerns mutational load, i.e., the number of deleterious mutations that an individual carries. A complication is that mutations are typically recessive, meaning that their negative effects on fitness "lie in wait" and are not expressed until two such genes meet up in the same individual. Orthodox thinking in evolutionary genetics suggests that females will be on the lookout for any signs of high mutational load when selecting a mate. However, we suspect that the recessive nature of deleterious mutations may mean that there is not much for the females to look out for (i.e., the mutational load expressed in the phenotype is just the tip of the iceberg) and they would be better off ensuring that any males they mate with are genetically as distinct from them as possible, in order to lessen the chance that two recessive deleterious allelles will be combined in their offspring.
You don't need to be an expert on genetics to do this project: Dr. Tregenza and I will be happy to supply input on that front. You do need to be interested in a project that has scientific modelling at its core. You also need to be a capable programmer: the basic framework of the program that needs to be written is similar to a simple genetic algorithm. However, we want to work with large genotypes and large population sizes, which will require some cleverness in devising data structures (for the genotypes) and algorithms (for operators such as mutation and crossover) that will allow the program to run at an acceptable speed.
Feel free to contact me (jasonn@comp.leeds.ac.uk) if you are interested in the project and would like to learn more about it.