Saturday, April 9, 2016

Earth Day 2016: Death of a living fossil - Oliva (Cycad)

It is a loss of a beautiful landscape that transports us to the enigmatic Mesozoic world when man was not yet conceived to evolve through a long path to becpme what we are today.  .
Dr Abe V Rotor
Living with Nature - School on Blog (avrotor.blogspot.com)
Paaralang Bayan sa Himpapawid (People's School-on-Air) 
with Ms Melly C Tenorio
738 DZRB AM Band, 8 to 9 Evening Class, Monday to Friday

The  Cycad is a living fossil, older than the dinosaurs.  It appears today as it was some 200 millions years ago. Among its secrets is its benevolence as host of a variety of organisms living in a state of dynamic balance which characterizes an ecosystem. But alas! one day this beautiful palm-like tree died. It is a great loss to students in biology, for it has not been fully studied and understood.  It is a loss to a beautiful landscape that transports the viewer to the Paleozoic era when man had yet to evolve into what we are today. 
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 Young Markus is introduced early in the study of living things with the help of his Nanny. The twin crown once lush in radial symmetry for half a century has dried up, so with all the plants clinging on its trunk.  
                                      
The palm-like tree gas succumbed to drought and pest, bringing down all its symbionts - orchid, fern, lichen, moss, blue-green alga, and a host of small organisms from insects to reptiles - to their inevitable demise.  A tree is actually a miniature ecosystem. Thus the death of this cycad put an end to the ecosystem it built and maintained throughout its life.   


Oliba, Oliva, pitogo (Cycas revoluta) has been called the "living fossil" because of its origin traced to the ancient flora of early Mesozoic era, (200 million years ago). A native to Japan and southern China, it is now cultivated mainly for ornamental purposes.

Cycads are generally toxic because the stems, leaves and seeds contain high amounts of cycasin alkaloids, macrozamin or methylazoxymethanol. Both cycasin and macrozamin are harmful to the liver; cycasin and methylazoxymethanol are neurotoxic and carcinogenic.
 
Reproduction of cycads, typical of all Gymnosperms (pines and cypresses) showing cone with seeds. Right, new set of leaves after the seeds have been disseminated. There are cycads which asre dioeicious (distinct male and female individuals).
  
Sago flour is derived from the pith but requires an ethnic process to wash out the toxin. Same is true with the fleshy seeds which are consumed as food and medicine in southern Japan, the natives of Guam, New Guinea, Australia, and the western Pacific Islands. The ethnobotanical uses extend to the cure of high blood pressure, headaches, congestion, rheumatism and bone pain. Leaves are used in the treatment of cancer and hepatoma, while the terminal shoots are used as astringent and diuretic.


The main folkloric use of cycad today in the Christian world is for palaspas. Fresh whole leaves are harvested and “blessed” on Palm Sunday. Whole trees are often stripped of their crowns, weakening and predisposing them to extreme conditions of the environment, pest and diseases. Although cycads are deciduous (they lose their crowns periodically), this practice retards growth and reproduction, and may cause the plants to die. A popular traditional practice is suob.  The leaves are dried and powdered, and added to incense (insenso) for the ritual. Its aroma therapeutic effect is well known to many ethinic communities.


The Cycad offers vital research topics that challenge the scientific mind, particulalrly among our youth.  Perhaps we may learn from the prototype world of this living fossil plant answers to our ailing health and deteriorating environment. Indeed the Cycad is Nature's primordial laboratory of natural history

A. Medicine and Pharmacology

  • Presence of aromatase inhibitors
  • Lectin and Peptide Analysis
  • Antimicrobial and Antioxidant
  • Bactericidal/Antibacterial properties
  • Chitinase isolation and analysis

B. Biology and Ecology

  • CO2 and pollution tolerance
  • Nitrogen-fixation with cyanobacterium 
  • Lichen and floral composition
  • Species diversity and phylogeny
  • Evolution and longevity
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Cycads are gymnosperms (naked seeded), meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific species of beetle. They have been reported to fix nitrogen in association with a cyanobacterium living in the roots. These blue-green algae produce a neurotoxin called BMAA that is found in the seeds of cycads. This neurotoxin may enter a human food chain as the cycad seeds may be eaten directly as a source of flour by humans or by wild or feral animals such as bats, and humans may eat these animals. It is hypothesized that this is a source of some neurological diseases in humans. (Internet)





 

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