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Wednesday, August 10, 2011

First Orchid..

         Pernahkah kita tertanya-tanya tentang bila orkid mula-mula tumbuh?..Bagaimanakah rupa orkid yang pertama? Hanya beberapa tahun lepas barulah fosil pertama orkid dalam bentuk debunga yang terlekat di belakang seekor lebah purba ditemui. Lebah purba ini terpelihara dengan baik di dalam  damar yang telah menjadi fosil. Penemuan menakjubkan ini telah memberikan satu bukti yang kukuh untuk mengetahui bila orkid mula-mula hidup di muka bumi..

         In 2007 the first orchid fossil has been found in amber. The orchid species is identified as Meliorchis caribea which has extinct in our world. This ancient species has been identified by Santiago R. Ramirez of Harvard University abd colleagues thay it belongs to the genus goodyerinae.. Since the time of Darwin, evolutionary biologists have been fascinated by the spectacular adaptations to insect pollination exhibited by orchids. However, despite being the most diverse plant family on Earth, the Orchidaceae lack a definitive fossil record and thus many aspects of their evolutionary history remain obscure. 

        Exquisitely preserved orchid pollinarium (of Meliorchis caribea gen. et sp. nov.) attached to the mesoscutellum of an extinct stingless bee, Proplebeia dominicana, recovered from Miocene amber in the Dominican Republic, that is 15–20 million years (Myr) old. This discovery constitutes both the first unambiguous fossil of Orchidaceae and an unprecedented direct fossil observation of a plant–pollinator interaction. By applying cladistic methods to a morphological character matrix, it was decided that the phylogenetic position of M. caribea within the extant subtribe Goodyerinae (subfamily Orchidoideae). Using the ages of other fossil monocots and M. caribea to calibrate a molecular phylogenetic tree of the Orchidaceae, results indicate that the most recent common ancestor of extant orchids lived in the Late Cretaceous (76–84 Myr ago), and also suggest that the dramatic radiation of orchids began shortly after the mass extinctions at the K/T boundary. These results further support the hypothesis of an ancient origin for Orchidaceae.

This orchid pollinarium, carried by a worker stingless bee (Proplebeia dominicana), is preserved in Miocene amber from the Dominican Republic and represents the first definitive fossil record for the family Orchidaceae.

General view of encapsulated specimen  Detailed view of the pollinia surface showing pollen units

The cover of Nature on 30 August was devoted to the discovery of the fossilised orchid.  The image shows the Proplebeia dominicana enclosed in amber with its back coated in the pollen of the Meliorchis caribea orchid.

Jadi berdasarkan penemuan ini kita boleh simpulkan bahawa leluhur orkid telah wujud sejak zaman batu kapur iaitu pada era dinosaur masih hidup..kira-kira 76 hingga 84 juta tahun dahulu..

"When at last I took the time to look into the heart of a flower, 
it opened up a whole new world; 
a world where every country walk would be an adventure, 
where every garden would become an enchanted one."
-  Princess Grace of Monaco 


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