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Results: 5

1.
Figure 1

Figure 1. From: Medea selfish genetic elements as tools for altering traits of wild populations: A theoretical analysis.

Characteristics of Medea allele and genotype spread as a function of introduction frequency, and of allele and population fitness as a function of Medea allele frequency. (A) The frequency of individuals lacking Medea (Non-Medea), heterozygotes (Heterozygous), and homozygotes for Medea (Homozygous Medea), are plotted with respect to Medea allele frequency. The fitness of the Medea allele, the non-Medea allele, and the population is also shown. (B) Medea allele frequency is plotted as a function of the number of generations for different introduction ratios of homozygous Medea/non-Medea males into a population of non-Medea females. (C) The population frequency of individuals with Medea (Medea Genotype Frequency) is plotted as a function of generations for different introduction ratios of homozygous Medea/non-Medea males into a population of non-Medea females. (D) Plot of allele and population fitness, and genotype frequency, as a function of Medea allele frequency, for a Medea that carries a 10% embryonic fitness cost. The UIEAF and SIEAF are indicated. Thin arrows indicate the directions in which the Medea allele frequency moves on either side of the UIEAF and SIEAF.

Catherine M. Ward, et al. Evolution. 2011 April;65(4):1149-1162.
2.
Figure 5

Figure 5. From: Medea selfish genetic elements as tools for altering traits of wild populations: A theoretical analysis.

When Medea located on the X chromosome in a male heterogametic species spreads, the non-Medea allele is eliminated from the population. (A) Plot of allele and population fitness as a function of Medea allele frequency, for a Medea that carries a 10% embryonic fitness cost, located on the X chromosome. Lines and labels and other conditions are as in Fig. 1D. (B) Medea genotype frequency is plotted as a function of the number of generations for Medea elements on the X with different levels of an embryonic fitness cost, introduced into a population of non-Medea females using a fixed 1:1 ratio of Medea:non-Medea males. (C) Plot describing the number of generations required for Medea to be present in 99% of individuals, for a Medea element on the X with a 10% embryonic fitness cost. Compare with Fig. 3B. (D) Medea allele frequency is plotted as a function of the number of generations for the elements shown in (B).

Catherine M. Ward, et al. Evolution. 2011 April;65(4):1149-1162.
3.
Figure 2

Figure 2. From: Medea selfish genetic elements as tools for altering traits of wild populations: A theoretical analysis.

Equilibrium characteristics of autosomal Medea elements with fitness costs. (A) Diagram partitioning (VHet, VHomo) fitness parameter space into regions in which linear stability analysis indicate qualitatively similar behaviors are observed. This diagram is identical for a Medea with parental fitness cost. Qualitative behavior changes as each curve is crossed, with the occurrence of a bifurcation. Transcritical bifurcation occurs as Equilibrium 3 moves through Equilibrium 4 (i.e. the two collide), with the two equilibria exchanging stability. Curve c separates regions B and C. On this curve, Equilibrium 2 and 3 are coincident. Transcritical bifurcation occurs as the two equilibria collide, with the two equilibria exchanging stability. (B) Stable internal equilibrium values of the non-Medea allele are plotted as a function of fitness cost/fecundity loss for embryonic, sex-independent parental, or maternal costs.

Catherine M. Ward, et al. Evolution. 2011 April;65(4):1149-1162.
4.
Figure 3

Figure 3. From: Medea selfish genetic elements as tools for altering traits of wild populations: A theoretical analysis.

When an autosomal Medea with a fitness cost and t1=0 spreads, it drives the elimination of non-Medea individuals, but not non-Medea alleles, from the population. (A) Plot describing the number of generations required for Medea to be present in 99% of individuals, for a Medea element with a parental fertility/fecundity cost. Homozygous Medea male:non-Medea male introduction ratios are indicated on the Y-axis, and parental fertility/fecundity cost on the X axis. Area between lines indicates regions of parameter space within which a specific number of generations (indicated by numbers and arrows) are required for the frequency of Medea individuals to reach 99% or greater. Line color, shown in the heat map in the lower right, provides a measure of how many generations are required. Black lines (50+) indicate that fifty or more generations are required. The border between the black-lined region and the lower unlined region defines the critical male introduction ratio (CMIR). (B) Plot describing the number of generations required for Medea to be present in 99% of individuals, for a Medea element with an embryonic fitness cost. (C) Plot describing the number of generations required for Medea to be present in 99% of individuals, for a Medea element with a maternal fecundity cost.

Catherine M. Ward, et al. Evolution. 2011 April;65(4):1149-1162.
5.
Figure 4

Figure 4. From: Medea selfish genetic elements as tools for altering traits of wild populations: A theoretical analysis.

When Medea is located on an autosome, and heterozygous Medea offspring of homozygous Medea mothers do not always survive, the non-Medea allele experiences a cost that can result in its elimination from the population. (A) Diagram partitioning (t1, VHet) parameter space into regions in which linear stability analysis indicates qualitatively similar behaviors are observed. Qualitative behavior changes as we cross each of these curves, with the occurrence of a bifurcation, as described in the legend to Figure 2. (B) Plot of allele and population fitness, and genotype frequency, as a function of Medea allele frequency, for a Medea that carries a 10% embryonic fitness cost and has t1=0.5. Compare with the Medea shown in Fig. 1D, in which t1=0. (C) Medea-bearing genotype frequency is plotted as a function of the number of generations for Medea elements with zero fitness cost and different levels of heterozygous offspring lethality (t1), introduced into a population of non-Medea females using a fixed 1:1 ratio of Medea:non-Medea males. (D) Plot of Medea allele frequency as a function of the number of generations for the zero fitness cost Medea elements in (C). (E) Plot as in (C) for Medea elements with a 10% embryonic fitness cost. (F) Plot of Medea allele frequency as a function of the number of generations for Medea elements with a 10% embryonic fitness cost.

Catherine M. Ward, et al. Evolution. 2011 April;65(4):1149-1162.

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