Co-Evolution - Is There an Epigenetic Solution?

[jimmydasaint]

As you know the yucca plant has a unique method of pollination - and it is quite recondite:

 

A specific moth that is genetically programmed for stuffing a little ball of pollen into the cup-shaped stigma of each flower. Like fig wasps and acacia ants, the relationship is mutually beneficial to both partners, and is vital for the survival of both plant and insect. In fact, yuccas cultivated in the Old World, where yucca moths are absent, will not produce seeds unless they are hand pollinated.

 

http://waynesword.palomar.edu/ww0902a.htm

 

The selection pressures on both the pollinator and pollinated are slightly different - for example, the yucca plant does not have to survive predators.

 

The method of evolution of both the yucca plant and its moth has been termed co-evolution - a marvellous term! The question is that the mechanisms by which co-evolution occurs are mysterious although theories exist. I just wanted to stimulate discussion on the possibility that epigenetic factors exist where the co-evolution of species can occur in a short time scale.

 

Reading material: http://en.wikipedia.org/wiki/Coevolution

 

http://www.jstor.org/pss/3298524

 

Epigenetics

http://en.wikipedia.org/wiki/Epigenetics

[jimmydasaint]

OK - no bites huh? I asked two questions but they merged into incomprehensibility or inconsequentiality.

Let me try again:

 

1. Co-evolution must involve different selection pressures - any ideas on which pressures?

2. Evolution has worked at multi speeds in the past. Is it possible that evolution of 'master switches' of genes allows Nature to put the foot on the evolution accelerator pedal?

[Sisyphus]

 

1. Co-evolution must involve different selection pressures -

 

Why? I think I'm missing something.

[jimmydasaint]

You are not missing anything. I assumed that the yucca plant had different selection pressures from the moth. For example, different diseases, different predators (moth), different biogeological pressures for the plants as a result of non-motility and requirement to photosynthesise. But the pressure for fertilisation of the plant by pollination has resulted in a niche for the moth. I just wondered if there was rapid evolution for one species possibly by mutation of genes with pleiotropic effects. Maybe this thread should be moved to speculations.

[Sisyphus]

Oh, ok. I thought you meant the selection pressures would be of a special kind if it was co-evolution. Which I guess is what you're suggesting. What is especially mysterious about it?

[jimmydasaint]

Well, I don't understand it, that is the short answer. If we are looking at the DNA scale and then at the accumulation of mutations in both the plant and the moth that is its sole pollinator, I need to get answers on how they were both so lucky that they escaped being wiped out. I just wondered if master gene switches were the answer. As an example which does not seem to be related to epigenetics but seems an example of biochemical pleiotropy, calmodulin, the calcium binding protein, seems to be responsible for beak sizes in finches. That is an astonishing find because it allows finches to find microhabitats - some will live in the trees some lower down due to beak length. This, believe it or not, was the inspiration for my O.P.

[Sisyphus]

Where does luck come in? I'm still not getting it. Yucca and moth are parts of one another's environment. Of course they're going to influence one another's evolution.

[foodchain]

OK - no bites huh? I asked two questions but they merged into incomprehensibility or inconsequentiality.

Let me try again:

 

1. Co-evolution must involve different selection pressures - any ideas on which pressures?

2. Evolution has worked at multi speeds in the past. Is it possible that evolution of 'master switches' of genes allows Nature to put the foot on the evolution accelerator pedal?

 

If the moth was pollinating the plant then that would produce a niche that mutations could come to be fit in, basically that is, I don't of course know the details. Pollination of plants by insects is not something rare, so with that I would make the assumption that such behavior basically allowed for some mutations to be beneficial in a temporary sense that are not without the moth or something in its place, which then makes them disadvantageous to the organism again without such. My best guess to research this question would to be looking at mutually beneficial relationships between other organisms, like with people and microorganisms.

[GDG]

You are not missing anything. I assumed that the yucca plant had different selection pressures from the moth. For example, different diseases, different predators (moth), different biogeological pressures for the plants as a result of non-motility and requirement to photosynthesise. But the pressure for fertilisation of the plant by pollination has resulted in a niche for the moth. I just wondered if there was rapid evolution for one species possibly by mutation of genes with pleiotropic effects. Maybe this thread should be moved to speculations.

 

If the plant is completely dependent upon the moth to reproduce, and vice versa, then their selection pressures are going to overlap substantially. If bats start eating the moths, then the plants are going to suffer because they're not being pollinated. Similarly, if the plants are attacked by fungus, the moths will suffer because their primary (sole?) food source is depleted.

 

I think the reason you didn't get the response to the OP you were looking for is because nobody saw a big connection between co-evolution and epigenetics. Perhaps you could expand a bit on why you think there might be one?