Notices
Results 1 to 6 of 6

Thread: Flowers are feedback interrupters?

  1. #1 Flowers are feedback interrupters? 
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,328
    All that energy spent to accomplish what? Defeat genetic monotony? A flowering plant seems torn between promoting a set of genes on one hand, and casting its fate to chance, on the other. I understand why a plant would facilitate and guide pollinators, but why (how?!) it would evolve complex and expensive strategies to defeat its own genetic integrity is hard for me to grasp. It seems like the plant can't trust itself to indiscriminately cause its own genetic change. Thus the extraordinary lengths to achieve sexual reproduction free of feedback, via random insects.

    Does the flower embody accumulated struggle between the forces of genetic conservation and variation? Which "side" are the pollinators on?

    Does the randomizing function apply to sexual reproduction in animals too?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
    Join Date
    Mar 2008
    Location
    Montreal
    Posts
    2,256
    In many angiosperms it is not completely random though, in some plants if the pollen carries the same surface markers as it's own the fertilized embryo is aborted. Thus, although the chance of pollen from an unrelated plant comming in contact with it's anthers is random, the chance of succesful reproduction is not.

    There are other strategies employed by plants like being single sex rather than hermaphroditic, thus not being able to mate with plants that have similar sex determination genotype.

    The reality is though that inbreeding does occur often in plants, although the flowering plants are actually much better at avoiding it than the older plant phylums.

    Pterophytes (the ferns) reproduce by releasing sperm into water when it rains, which means that they will innevitably be constantly reproducing with close relatives in the same area. Trusting to the wind to blow the seeds somewhere good.

    Likewise bryophytes (the mosses) rely compltely on wind for sexual reproduction.

    It may not be a perfect system in flowering plants, but it is far better than what came before.

    Anyway something about flowering has to work because they are estimated to have evolved 100 million years ago and quickly became the dominant plant life on land. Flowers evolved as a symbiotic adaptation to animals, I don't think the evolution is very well understood though, plant evolution is largely speculation since we have very very few fossils.


    Reply With Quote  
     

  4. #3  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,328
    Quote Originally Posted by i_feel_tiredsleepy
    In many angiosperms it is not completely random though
    That's what I'm getting at. It's like the plant is playing this game of chance but also cheats the game. So it evolves better randomizing features. So it evolves better cheats. And so on. The precarious balance of those opposing forces piled up over time, is the flower.
    Reply With Quote  
     

  5. #4 Re: Flowers are feedback interrupters? 
    Forum Cosmic Wizard spuriousmonkey's Avatar
    Join Date
    May 2005
    Posts
    2,191
    Quote Originally Posted by Pong
    but why (how?!) it would evolve complex and expensive strategies to defeat its own genetic integrity is hard for me to grasp.
    Because the plant cannot influence its interests into the next generation. In fact it has no genetic integrity. You might want to read the popular science book; 'the selfish gene' by Dawkins.

    You get your genes from all sort of different ancestors. You would be surprised to hear that some of your genes have a closer relationship to monkeys than to other humans. For instance your entire Y chromosome (if you are male). Human females don't even have it. Male monkeys do.

    The human genes on it are more closely related to male monkeys than anything in the human female genome.

    Integrity? Sex got rid of that.
    "Kill them all and let God sort them out."

    - Arnaud Amalric

    http://spuriousforums.com/index.php
    Reply With Quote  
     

  6. #5 Re: Flowers are feedback interrupters? 
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,328
    Quote Originally Posted by spuriousmonkey
    Because the plant cannot influence its interests into the next generation. In fact it has no genetic integrity.
    I understand. But I still don't get why genes that render flower sex convoluted and burdensome would be successful. Flowers are really weird!
    Reply With Quote  
     

  7. #6  
    Forum Cosmic Wizard spuriousmonkey's Avatar
    Join Date
    May 2005
    Posts
    2,191
    That's ok. I dont think there is a consensus on the benefit of sex. There are many theories, but no dogma.
    "Kill them all and let God sort them out."

    - Arnaud Amalric

    http://spuriousforums.com/index.php
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •