花朵“始祖”长啥样?像白莲花和白百合结合体

花自古便被人类视为美的象征，世上有成千上万种花卉，但从来没人知道地球上第一朵花到底是怎样。欧洲生物学家日前用计算机模拟出世界上第一朵花的模样，看来就像白莲花和白百合的结合体。

All living flowers ultimately derive from a single ancestor that lived about 140 million years ago, a study suggests.

一项研究表明，地球上现存的所有花卉都起源于1.4亿年前的同一个“祖先”。

Scientists combined models of flower evolution with the largest data set of features from living flowers ever assembled.

科学家将花卉演化的模型与最大的现存鲜花的特征数据集组合在一起。

From this the team was able to infer the appearance of the ancestral flower.

该研究团队据此推测出鲜花始祖的样貌。

The flower had many concentric cycles of petal-like organs in sets of three, arranged in whorls, and was bisexual.

这种鲜花雌雄同体，花瓣以同心圆方式环绕成多层，每层三片，层层呈齿轮状分布。

Hervé Sauquet, from Université Paris-Sud, France, one of the authors of the paper published last week in Nature Communications said: "There is no living flower that looks exactly like the ancestral one. This is a flower that existed at least 140 million years ago and has had considerable time to evolve into the incredible diversity of flowers that exist today."

《自然通讯》上周刊载了这篇论文。法国巴黎第十一大学的埃尔韦•索凯是论文的作者之一。他说，“现存的所有花朵都与它们的祖先不同，原因在于鲜花始祖存在于至少1.4亿年前，经过了相当长的时间才演变出今天的多样性。”

Dr Jason Hilton from the University of Birmingham, UK, who was not involved in the study, said: "The structure and organization of the ancestral flower has remained enigmatic. For instance, we don't know if the oldest flowers were unisexual or bisexual, or if they were pollinated by wind or insects."

英国伯明翰大学的杰森•希尔顿博士没有参加这项研究，他称：“鲜花始祖的结构和组织依然还是个谜。例如，我们不知道最古老的花朵是单性的还是双性的，或是依靠风还是昆虫授粉。”

To reconstruct the appearance of the first flower, the scientists recorded the features - such as the petals and sepals - of the flowers from 792 living species.

为了重现世上第一朵鲜花的外观，科学家记录了792种现存花卉的花瓣、萼片等外形特征。

They mapped the distribution of these features on to the evolutionary tree of flowering plants enabling them to build a picture of what flowers looked like at key points in their history - including the last common ancestor of all living flowers.

他们将这些特征分布绘制成开花植物的进化树，从而重现花卉在关键的进化节点上的样貌，其中就包括所有现存花卉的最后一个共同祖先的样子。

The first flower is reconstructed with petal-like structures arranged in a whorl, so each petal appears in the same plane, like a common lily (but with more whorls), rather than in a spiral, where petals overlap in a spiral arrangement around the stem, like a lotus.

第一朵鲜花被重构成齿轮状排列的花瓣状结构，像一朵常见的百合（但花瓣更多），所有花瓣出现在同一个平面里，而非像莲花一样花瓣围绕花茎重叠呈螺旋状排列。

"For some of the features we studied, the result was surprising, especially the fact that organs (such as sepals and petals and the stamens) were probably arranged in whorls instead of spirals, as commonly assumed for the ancestral flower," said Hervé Sauquet.

埃尔韦•索凯说：“关于鲜花始祖特征的一些研究结果让我们感到意外，特别是它的器官(如萼片、花瓣、雄蕊)可能是齿轮状排列的，而并非是人们通常认为的螺旋状”。

Sex evolution in flowers has been highly debated. Flowers can be unisexual or bisexual and this study infers a bisexual early flower with both male and female organs.

花的性进化一直备受争议，鲜花可以是单性或双性的。这项研究推断花卉祖先是两性的，同时拥有雄性和雌性器官。

"This study is important as it tells us how complicated the ancestral flower is likely to be - now the search is on to find it or something closely resembling it in the fossil record. That's if the model is correct - only time (and further study) will tell," said Jason Hilton.

杰森•希尔顿说。“这项研究意义重大，因为它告诉我们鲜花始祖可能有多复杂，现在研究者正努力在化石中搜寻它或此类东西。只有时间和进一步研究才能证明，这个鲜花始祖模型是否正确。”