在尋找伴侶的時(shí)候,，雌古比魚（孔雀魚）會(huì)尋找特殊的另一半,。根據(jù)最近在線發(fā)表于《自然》雜志上的新研究,，雌古比魚在擇偶上的價(jià)值選擇——特別是對(duì)那些閃亮的、有彩色標(biāo)志的雄魚的偏好——可能會(huì)促使野生魚群產(chǎn)生令人驚訝的多樣性,。
在實(shí)驗(yàn)室中,，雌古比魚顯示出對(duì)有著罕見標(biāo)志的雄魚的偏好?，F(xiàn)在，研究人員已經(jīng)通過改變特立尼達(dá)島的魚塘中不同鰭形的比率證實(shí)了該結(jié)果,。他們根據(jù)野生雄魚的尾鰭的大部分是透明還是彩色的,，將其分成了兩組,，然后重新將其放入不同的飼養(yǎng)池,。他們等待了16到17天，雌魚與其最喜歡的雄性進(jìn)行了配對(duì),，然后研究人員對(duì)這些雌魚的幼魚進(jìn)行了親子鑒定,。
根據(jù)第一輪后代（共693條古比魚）測(cè)試的結(jié)果,，他們發(fā)現(xiàn),，一種罕見的雄魚比普通雄魚的后代多兩倍,，而無論它身上的圖案是怎樣的。這一結(jié)果背后的進(jìn)化原因尚不清楚,，不過這可能是一種避免基因相似的魚發(fā)生近親交配的方法,，由此可能創(chuàng)造出更加多樣化的種群。(生物谷Bioon.com)
生物谷推薦的英文摘要
Nature doi:10.1038/nature12717
Mating advantage for rare males in wild guppy populations
Kimberly A. Hughes,Anne E. Houde,Anna C. Price & F. Helen Rodd
To understand the processes that maintain genetic diversity is a long-standing challenge in evolutionary biology, with implications for predicting disease resistance, response to environmental change, and population persistence1, 2, 3. Simple population genetic models are not sufficient to explain the high levels of genetic diversity sometimes observed in ecologically important traits2. In guppies (Poecilia reticulata), male colour pattern is both diverse and heritable, and is arguably one of the most extreme examples of morphological polymorphism known4, 5. Negative frequency-dependent selection (NFDS), a form of selection in which genotypes are favoured when they are rare6, can potentially maintain such extensive polymorphism, but few experimental studies have confirmed its operation in nature7, 8. Here we use highly replicated experimental manipulations of natural populations to show that males with rare colour patterns have higher reproductive fitness, demonstrating NFDS mediated by sexual selection. Rare males acquired more mates and sired more offspring compared to common males and, as previously reported, had higher rates of survival8. Orange colour, implicated in other studies of sexual selection in guppies, did predict male reproductive success, but only in one of three populations. These data support the hypothesis that NFDS maintains diversity in the colour patterns of male guppies through two selective agents, mates and predators. Similar field-based manipulations of genotype frequencies could provide a powerful approach to reveal the underlying ecological and behavioural mechanisms that maintain genetic and phenotypic diversity.
