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Journal ArticleDOI

Genetic Crossing vs Cloning by Computer Simulation

01 Jun 1997-International Journal of Modern Physics C (World Scientific Publishing Company)-Vol. 8, Iss: 3, pp 605-608
TL;DR: The process of asexual reproduction by cloning with that by genetic crossover is found to be comparable as regards survival of a species, and also if a natural disaster is simulated.
Abstract: We perform Monte Carlo simulation using Penna's bit string model, and compare the process of asexual reproduction by cloning with that by genetic crossover. We find them to be comparable as regards survival of a species, and also if a natural disaster is simulated.
Citations
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Journal ArticleDOI
TL;DR: It is shown that although both regimes present roughly the same survival rates, the diversity generated by SR is much larger, and can prevent the extinction of a population submitted to a natural disaster.
Abstract: Using the Penna bit-string model for biological ageing we compare two kinds of reproductive regimes: Sexual reproduction (SR) and meiotic parthenogenesis (MP). The last one is a common type of asexual reproduction with recombination, found in diploid organisms. We show that although both regimes present roughly the same survival rates, the diversity generated by SR is much larger, and can prevent the extinction of a population submitted to a natural disaster. The fixation of bad genes inside an MP population, after many generations, explains our results. We also study the consequences of cloning (simple copy) on population diversity.

39 citations

Journal ArticleDOI
TL;DR: In this article, the Penna model of biological aging is compared with alternative forms of reproduction as well as with models not involving aging, in order to check how sexual forms of life could have evolved and won over earlier asexual forms hundreds of million years ago.
Abstract: The sexual version of the Penna model of biological aging, simulated since 1996, is compared here with alternative forms of reproduction as well as with models not involving aging. In particular we want to check how sexual forms of life could have evolved and won over earlier asexual forms hundreds of million years ago. This computer model is based on the mutation-accumulation theory of aging, using bits-strings to represent the genome. Its population dynamics is studied by Monte Carlo methods.

29 citations

Journal ArticleDOI
TL;DR: This work generalizes the standard Penna bit-string model of biological ageing and finds strong advantages or disadvantages of sexual reproduction compared to asexual cloning, depending on parameters.
Abstract: We generalize the standard Penna bit-string model of biological ageing by assuming that each deleterious mutation diminishes the survival probability in every time interval by a small percentage. This effect is added to the usual lethal but age-dependent effect of the same mutation. We then find strong advantages or disadvantages of sexual reproduction (with males and females) compared to asexual cloning, depending on parameters.

17 citations

Journal ArticleDOI
TL;DR: Simulations of sexual reproduction based on the Redfield model may give sexual reproduction an advantage over asexual one, even if the male mutation rate is much higher than the female one, and if males do not get pregnant.
Abstract: Simulations of sexual reproduction based on the Redfield model may give sexual reproduction an advantage over asexual one, even if the male mutation rate is much higher than the female one, and if males do not get pregnant. In more realistic simulations based on the Penna model, sex helps against environmental catastrophes.

11 citations

Journal ArticleDOI
TL;DR: In this paper, a simple model for biological aging is presented and studied through computer simulations and they have found this model to reflect some features of real populations and have found that this model is more accurate than the one presented in this paper.
Abstract: We present a simple model for biological aging. We studied it through computer simulations and we have found this model to reflect some features of real populations.

10 citations

References
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Journal ArticleDOI
27 Feb 1997-Nature
TL;DR: The birth of lambs from differentiated fetal and adult cells confirms that differentiation of that cell did not involve the irreversible modification of genetic material required for development to term and reinforces previous speculation that by inducing donor cells to become quiescent it will be possible to obtain normal development from a wide variety of differentiated cells.
Abstract: Fertilization of mammalian eggs is followed by successive cell divisions and progressive differentiation, first into the early embryo and subsequently into all of the cell types that make up the adult animal. Transfer of a single nucleus at a specific stage of development, to an enucleated unfertilized egg, provided an opportunity to investigate whether cellular differentiation to that stage involved irreversible genetic modification. The first offspring to develop from a differentiated cell were born after nuclear transfer from an embryo-derived cell line that had been induced to become quiescent. Using the same procedure, we now report the birth of live lambs from three new cell populations established from adult mammary gland, fetus and embryo. The fact that a lamb was derived from an adult cell confirms that differentiation of that cell did not involve the irreversible modification of genetic material required for development to term. The birth of lambs from differentiated fetal and adult cells also reinforces previous speculation that by inducing donor cells to become quiescent it will be possible to obtain normal development from a wide variety of differentiated cells.

4,721 citations

Journal ArticleDOI
TL;DR: A simple model for biological aging is presented through computer simulations and it is finted to reflect some features of real populations to reflect the changes in real populations.
Abstract: We present a simple model for biological aging. We study it through computer simulations and fint it to reflect some features of real populations.

289 citations

Journal ArticleDOI
TL;DR: Modifying the Redfield model of sexual reproduction and the Penna model of biological aging, reproduction with and without recombination in age-structured populations is compared and sexual reproduction to be preferred to asexual one.
Abstract: Modifying the Redfield model of sexual reproduction and the Penna model of biological aging, we compare reproduction with and without recombination in age-structured populations. In constrast to Redfield and in agreement with Bernardes we find sexual reproduction to be preferred to asexual one. In particular, the presence of old but still reproducing males helps the survival of younger females beyond their reproductive age.

42 citations

Journal ArticleDOI
TL;DR: Using Monte Carlo simulations of age-structured populations, through the Penna model, it is shown that sexual reproduction with male competition can produce better results than meiotic parthenogenesis, which agrees with the strong evidence that nature chose sexual reproduction instead of partenogenesis for most of the higher species.
Abstract: In the time evolution of finite populations, the accumulation of harmful mutations in further generations might have lead to a temporal decay in the mean fitness of the whole population. This, in turn, would reduce the population size and so lead to its extinction. The production of genetically diverse offspring, through recombination, is a powerful mechanism in order to avoid this catastrophic route. From a selfish point of view, meiotic parthenogenesis can ensure the maintenance of better genomes, while sexual reproduction presents the risk of genome dilution. In this paper, by using Monte Carlo simulations of age-structured populations, through the Penna model, I compare the evolution of populations with different repoductive regimes. It is shown that sexual reproduction with male competition can produce better results than meiotic parthenogenesis. This contradicts results recently published, but agrees with the strong evidence that nature chose sexual reproduction instead of partenogenesis for most of the higher species.

18 citations