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Evolutionary pets: offspring numbers reveal speciation process in domesticated chickens.

Tiemann I, Rehkämper G - PLoS ONE (2012)

Bottom Line: We want to forward the question to the animal itself: With whom do you reproduce successfully?Due to selection and mate choice we state that breeding in principle can generate new species.Therefore, we see domestication as an evolutionary process that integrates human interests of animal breeding with innate mate choice by the animal.

View Article: PubMed Central - PubMed

Affiliation: Bruno-Dürigen Institute, Poultry Research Centre, Rommerskirchen, Germany. tiemanni@uni-duesseldorf.de

ABSTRACT
Since Darwin, the nature of the relationship between evolution and domestication has been debated. Evolution offers different mechanisms of selection that lead to adaptation and may end in the origin of new species as defined by the biological species concept. Domestication has given rise to numerous breeds in almost every domesticated species, including chickens. At the same time, so-called artificial selection seems to exclude mechanisms of sexual selection by the animals themselves. We want to forward the question to the animal itself: With whom do you reproduce successfully? This study focused on the sexual behavior of the domestic chicken Gallus gallus f.dom., particularly the White Crested Polish breed. Experiments on mate choice and the observation of fertilization and hatching rates of mixed-breeding groups revealed breed-specific preferences. In breeding groups containing White Crested Polish and a comparative breed, more purebred chicks hatched than hybrids (number of eggs collected: 1059). Mating was possible in equal shares, but in relation to the number of eggs collected, purebred offspring (62.75% ± 7.10%, M ± SE) hatched to a greater extend compared to hybrid offspring (28.75% ± 15.32%, M ± SE). These data demonstrate that the mechanism of sexual selection is still present in domestic chicken breeds, which includes the alteration of gene frequencies typical for domestication and evolutionary speciation. Due to selection and mate choice we state that breeding in principle can generate new species. Therefore, we see domestication as an evolutionary process that integrates human interests of animal breeding with innate mate choice by the animal.

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Hatching rates of the breeding groups (stars indicate significant differences between performances after hybrid and purebred mating, respectively).
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pone-0041453-g004: Hatching rates of the breeding groups (stars indicate significant differences between performances after hybrid and purebred mating, respectively).

Mentions: Fertilization and hatching rates are given in table 2 and visualized in figure 3 and figure 4, respectively. In the first year with WCP and RL, WCP hens laid a total of 247 eggs. Pure-breed mating resulted in higher fertilization and hatching rates compared to hybrid mating. This was statistically significant for WCP hens in groups 1a+b which were mated with a WCP cock compared to WCP hens in groups 2a+b which were mated with a RL cock, for the fertilization rates χ2 (1, n = 247)  = 9.846, two-tailed p≤.01, as well as for the corresponding hatching rates χ2 (1, n = 247)  = 7.563, two-tailed p≤.01.


Evolutionary pets: offspring numbers reveal speciation process in domesticated chickens.

Tiemann I, Rehkämper G - PLoS ONE (2012)

Hatching rates of the breeding groups (stars indicate significant differences between performances after hybrid and purebred mating, respectively).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3412861&req=5

pone-0041453-g004: Hatching rates of the breeding groups (stars indicate significant differences between performances after hybrid and purebred mating, respectively).
Mentions: Fertilization and hatching rates are given in table 2 and visualized in figure 3 and figure 4, respectively. In the first year with WCP and RL, WCP hens laid a total of 247 eggs. Pure-breed mating resulted in higher fertilization and hatching rates compared to hybrid mating. This was statistically significant for WCP hens in groups 1a+b which were mated with a WCP cock compared to WCP hens in groups 2a+b which were mated with a RL cock, for the fertilization rates χ2 (1, n = 247)  = 9.846, two-tailed p≤.01, as well as for the corresponding hatching rates χ2 (1, n = 247)  = 7.563, two-tailed p≤.01.

Bottom Line: We want to forward the question to the animal itself: With whom do you reproduce successfully?Due to selection and mate choice we state that breeding in principle can generate new species.Therefore, we see domestication as an evolutionary process that integrates human interests of animal breeding with innate mate choice by the animal.

View Article: PubMed Central - PubMed

Affiliation: Bruno-Dürigen Institute, Poultry Research Centre, Rommerskirchen, Germany. tiemanni@uni-duesseldorf.de

ABSTRACT
Since Darwin, the nature of the relationship between evolution and domestication has been debated. Evolution offers different mechanisms of selection that lead to adaptation and may end in the origin of new species as defined by the biological species concept. Domestication has given rise to numerous breeds in almost every domesticated species, including chickens. At the same time, so-called artificial selection seems to exclude mechanisms of sexual selection by the animals themselves. We want to forward the question to the animal itself: With whom do you reproduce successfully? This study focused on the sexual behavior of the domestic chicken Gallus gallus f.dom., particularly the White Crested Polish breed. Experiments on mate choice and the observation of fertilization and hatching rates of mixed-breeding groups revealed breed-specific preferences. In breeding groups containing White Crested Polish and a comparative breed, more purebred chicks hatched than hybrids (number of eggs collected: 1059). Mating was possible in equal shares, but in relation to the number of eggs collected, purebred offspring (62.75% ± 7.10%, M ± SE) hatched to a greater extend compared to hybrid offspring (28.75% ± 15.32%, M ± SE). These data demonstrate that the mechanism of sexual selection is still present in domestic chicken breeds, which includes the alteration of gene frequencies typical for domestication and evolutionary speciation. Due to selection and mate choice we state that breeding in principle can generate new species. Therefore, we see domestication as an evolutionary process that integrates human interests of animal breeding with innate mate choice by the animal.

Show MeSH
Related in: MedlinePlus