dorsal/arxiv
View SchemaSimulations of a mortality plateau in the sexual Penna model for biological ageing
| Authors | Veit Schwämmle, Suzana M. de Oliveira |
|---|---|
| Categories | |
| ArXiv ID | q-bio/0502027 |
| URL | https://arxiv.org/abs/q-bio/0502027 |
| DOI | 10.1103/PhysRevE.72.031911 |
Abstract
The Penna model is a strategy to simulate the genetic dynamics of age-structured populations, in which the individuals genomes are represented by bit-strings. It provides a simple metaphor for the evolutionary process in terms of the mutation accumulation theory. In its original version, an individual dies due to inherited diseases when its current number of accumulated mutations, n, reaches a threshold value, T. Since the number of accumulated diseases increases with age, the probability to die is zero for very young ages (n < T) and equals 1 for the old ones (n >= T). Here, instead of using a step function to determine the genetic death age, we test several other functions that may or may not slightly increase the death probability at young ages (n < T), but that decreases this probability at old ones. Our purpose is to study the oldest old effect, that is, a plateau in the mortality curves at advanced ages. Imposing certain conditions, it has been possible to obtain a clear plateau using the Penna model. However, a more realistic one appears when a modified version, that keeps the population size fixed without fluctuations, is used. We also find a relation between the birth rate, the age-structure of the population and the death probability.
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"abstract": "The Penna model is a strategy to simulate the genetic dynamics of\nage-structured populations, in which the individuals genomes are represented by\nbit-strings. It provides a simple metaphor for the evolutionary process in\nterms of the mutation accumulation theory. In its original version, an\nindividual dies due to inherited diseases when its current number of\naccumulated mutations, n, reaches a threshold value, T. Since the number of\naccumulated diseases increases with age, the probability to die is zero for\nvery young ages (n \u003c T) and equals 1 for the old ones (n \u003e= T). Here, instead\nof using a step function to determine the genetic death age, we test several\nother functions that may or may not slightly increase the death probability at\nyoung ages (n \u003c T), but that decreases this probability at old ones. Our\npurpose is to study the oldest old effect, that is, a plateau in the mortality\ncurves at advanced ages. Imposing certain conditions, it has been possible to\nobtain a clear plateau using the Penna model. However, a more realistic one\nappears when a modified version, that keeps the population size fixed without\nfluctuations, is used. We also find a relation between the birth rate, the\nage-structure of the population and the death probability.",
"arxiv_id": "q-bio/0502027",
"authors": [
"Veit Schw\u00e4mmle",
"Suzana M. de Oliveira"
],
"categories": [
"q-bio.PE"
],
"doi": "10.1103/PhysRevE.72.031911",
"title": "Simulations of a mortality plateau in the sexual Penna model for biological ageing",
"url": "https://arxiv.org/abs/q-bio/0502027"
},
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