為什麼男性生物體進化速度快於女性

The secret to why male organisms evolve faster than their female counterparts…
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The secret to why male organisms evolve faster than their female counterparts comes down to this: Males are simple creatures.

In nearly all species, males seem to ramp up glitzier garbs, more graceful dance moves and more melodic warbles in a never ending vie to woo the best mates. Called sexual selection, the result is typically a showy male and a plain Jane female.

Evolution speeds along in the males compared to females.

The idea that males evolve more quickly than females has been around since 19th century biologist Charles Darwin observed the majesty of a peacock’s tail feather in comparison with those of the drab peahen.



How and why males exist in evolutionary overdrive despite carrying essentially the same genes as females has long puzzled scientists.

New research on fruit flies, detailed online last week in the journal Proceedings of the National Academy of Sciences, finds males have fewer genetic obstacles to prevent them from responding quickly to selection pressures in their environments.



“It’s because males are simpler,” said lead author Marta Wayne, a zoologist at the University of Florida in Gainesville. “The mode of inheritance in males involves simpler genetic architecture that does not include as many interactions between genes as could be involved in female inheritance.”

The finding could also shed light on why diseases show up differently in men and women.

Complicated chromosomes

Wayne and her colleagues examined more than 8,500 genes shared by both sexes of the fruit fly Drosophila melanogaster. Of those genes, about 7,600 have different expressions [alleles] that do different jobs in males and females.

The flies were identical genetically, except for their sex chromosomes.

In flies and humans, thousands of genes made up of DNA are packaged into tiny units called chromosomes. Each parent contributes one set of 23 chromosomes to offspring, resulting in little ones with 23 father given chromosomes and 23 mother chromosomes 46 total. One pair of these is called the sex chromosome. In this case, the females have two X chromosomes [XX] and males, XY.

Many genes are found on the X chromosome, whereas few are associated with the Y chromosome. For female fruit flies, the X~chromosome genes can come in two flavors called alleles that not only interact with each other but also with other genes.

For instance, if one allele is dominant over the other, that allele would get “expressed” while the recessive allele would stay hidden. Though under cover, the recessive allele kind of hitches a ride on the X chromosome and can be passed on to future generations.

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這個秘密，為什麼男性生物體進化速度快於女性歸結到這一點：男性是簡單的動物。

在幾乎所有的物種，男性似乎加大glitzier garbs ，更優美的舞蹈動作和更旋律warbles在永無止境爭相雨的最佳伴侶。所謂的性選擇，其結果通常是華麗男一素雅女性。

進化的速度沿的男性相比，女性。

男性的想法，發展速度快於女性，因為已經在19世紀的生物學家查爾斯達爾文觀察陛下的孔雀尾巴羽毛相比，那些單調孔雀。



如何以及為什麼男性存在進化過，儘管基本上是相同的基因作為女性長期以來困擾科學家。

新的研究果蠅，詳細的在線上週在學報的國家科學院，發現男性少遺傳障礙，以防止他們迅速作出反應，以選擇壓力的環境。



“這是因為男性更簡單的說， ”主要作者瑪爾塔韋恩，動物學家在中佛羅裏達大學蓋恩斯維爾。 “的模式在男性繼承涉及簡單的遺傳結構，不包括許多基因之間的相互作用可參與女性繼承權。 ”

這一發現還可以揭示為什麼出現不同的疾病在男性和女性。

複雜染色體

魯尼和她的同事們檢查超過8500基因男女雙方共同的果蠅果蠅。這些基因，約7600具有不同表現形式[等位基因] ，但不同的就業男性和女性。

蒼蠅是相同的基因，但他們的性染色體。

果蠅和人類，成千上萬的基因的DNA了包裝成細小的單位稱為染色體。每位家長有助於一套23染色體給後代，導致小孩子的父親給的23染色體和第23染色體上46共計母親。一個對這些所謂的性染色體。在這種情況下，女性有兩條X染色體[二十]和男性，代理。

許多基因被發現與X染色體上，而一些相關的Y染色體。女果蠅的X 12316;染色體上的基因可以分為兩種方式稱為等位基因，不僅相互交流，而且還與其他基因。

例如，如果一個基因是顯性的其他，即等位基因將獲得“表示” ，而隱性等位基因會留隱患。雖然掩護下，隱性等位基因種故障騎在X染色體，可以傳給後代。

所有跟帖： 

• 嗯，男性是簡單的動物 -講不清- ♀ (108 bytes) () 06/05/2009 postreply 10:11:29

• 正是Y染色體這種特性， 有科學家認為男性將在未來消失。所以在沒消失之前，對老婆和 -AnitaM- ♀ (28 bytes) () 06/05/2009 postreply 10:25:56

• 男性生物體進化速度慢於女性，所以是簡單動物 -小芬- ♀ (0 bytes) () 06/05/2009 postreply 13:33:23