花朵“始祖”長啥樣?像白蓮花和白百合結(jié)合體
All living flowers ultimately derive from a single ancestor that lived about 140 million years ago, a study suggests.
一項研究表明，地球上現(xiàn)存的所有花卉都起源于1.4億年前的同一個“祖先”。
Scientists combined models of flower evolution with the largest data set of features from living flowers ever assembled.
科學(xué)家將花卉演化的模型與最大的現(xiàn)存鮮花的特征數(shù)據(jù)集組合在一起。
From this the team was able to infer the appearance of the ancestral flower.
該研究團(tuán)隊據(jù)此推測出鮮花始祖的樣貌。
The flower had many concentric cycles of petal-like organs in sets of three, arranged in whorls, and was bisexual.
這種鮮花雌雄同體，花瓣以同心圓方式環(huán)繞成多層，每層三片，層層呈齒輪狀分布。
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."
《自然通訊》上周刊載了這篇論文。法國巴黎第十一大學(xué)的埃爾韋•索凱是論文的作者之一。他說，“現(xiàn)存的所有花朵都與它們的祖先不同，原因在于鮮花始祖存在于至少1.4億年前，經(jīng)過了相當(dāng)長的時間才演變出今天的多樣性。”
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."
英國伯明翰大學(xué)的杰森•希爾頓博士沒有參加這項研究，他稱：“鮮花始祖的結(jié)構(gòu)和組織依然還是個謎。例如，我們不知道最古老的花朵是單性的還是雙性的，或是依靠風(fēng)還是昆蟲授粉。”
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.
為了重現(xiàn)世上第一朵鮮花的外觀，科學(xué)家記錄了792種現(xiàn)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.
他們將這些特征分布繪制成開花植物的進(jìn)化樹，從而重現(xiàn)花卉在關(guān)鍵的進(jìn)化節(jié)點上的樣貌，其中就包括所有現(xiàn)存花卉的最后一個共同祖先的樣子。
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.
第一朵鮮花被重構(gòu)成齒輪狀排列的花瓣狀結(jié)構(gòu)，像一朵常見的百合(但花瓣更多)，所有花瓣出現(xiàn)在同一個平面里，而非像蓮花一樣花瓣圍繞花莖重疊呈螺旋狀排列。
"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.
埃爾韋•索凱說：“關(guān)于鮮花始祖特征的一些研究結(jié)果讓我們感到意外，特別是它的器官(如萼片、花瓣、雄蕊)可能是齒輪狀排列的，而并非是人們通常認(rèn)為的螺旋狀”。
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.
花的性進(jìn)化一直備受爭議，鮮花可以是單性或雙性的。這項研究推斷花卉祖先是兩性的，同時擁有雄性和雌性器官。
"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•希爾頓說。“這項研究意義重大，因為它告訴我們鮮花始祖可能有多復(fù)雜，現(xiàn)在研究者正努力在化石中搜尋它或此類東西。只有時間和進(jìn)一步研究才能證明，這個鮮花始祖模型是否正確。”
