Discussion in 'Biology & Genetics' started by Wexler, Jun 21, 2015.
It's your fantasy, I figured you had thought it through a bit...
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We are no less stable than the universe as a whole. Things come and go. Absorbed and dispersed, over and over again.
Stability would be boring.
I hope we find such a planet. Furthermore, I hope that once this planet is found it turns out to be just chock full of benign, benevolent lifeforms that were never exposed to predation.
So we can eat them... Please Register or Log in to view the hidden image!
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If there's a niche with an untapped food source, an organism will adapt and evolve to exploit it.
If that niche happens to have "other organisms" as its food source, well, it seems that predation is inevitable.
But why did you snip the main point of my post, which was: " If you have bacteria and viruses that can poison or disrupt the cells of an organism, the only way it can defend itself is via an immune system, surely? This generally involves cells that ingest, i.e. eat, the invaders. Do you really envisage a form of ecosystem in which none of this exists?"
This reminds me of the kind of stuff that Young Earth Creationists say about every animal being a herbivore - at least until that incident with the apple...
Snap! That is also my suspicion - someone trying to concoct a scientific basis for the theology of the Fall.
The sort of thing C S Lewis did - as science fiction - in his "Space Trilogy". Please Register or Log in to view the hidden image!
Is the planet broken and did this cause predation?
Carnivorous animals are assured to be the only predator animals. However, vegetarian animals are also predators. They are predators of plants. Plants are alive and are part of the cycle of life. The carnivore type predators are far more sporting, because their prey usually has the means to mobilize and get away; legs and wings. The poor plants are stuck, anchored to the ground, unable to escape plant killing and maiming machines.The only hope for the plants is their large numbers will some them. Global plant eaters, populate faster, and will eat more weight in plants, than meat eaters eat in meat.
If I am not mistaken, the Sahara Desert was formed, in part, by the overgrazing of plant predator animals; sheep and cattle. These plant predators changed the landscape, and altered the earth in terms of land and weather, making it barren of all but certain life. Man has chosen to team up with the plant predator animals and they too altered the landscape. Man hunted the meat predators to almost extinction.
Way back in evolution, as plant predator animals, multiplied and added stress to the plant world and earth, carnivore predators evolved as protectors of the plants and earth. My dog will not eat my garden plants, but protects these, from those plant eating predators, who would make the garden barren. My dog helps the trees, by peeing on them for fertilizer. This friendly relationship between plants and meat eaters is always overlooked.
The meat predators and plants, as a team, is what restores the earth to balance. We raise cattle who eat the grass. If we did not eat some of these, they would expand until the local earth is laid barren. The human meat eaters create a balance that saves many plants and keeps the meadow from extinction, by the fast breeding plant predators.
Humans eat far more plant material than meat material. This makes us closer to the plant predators who are raw one who alter the landscape of the earth. Consider the number of farms that grow plants which often requires all the local floral being removed. Grazing of cattle for meat eaters, better balances the natural landscape.
Thanks for the responses, unfortunately we had a massive storm last night and lost power...will be back to respond once back online. Thanks!
WTF? It kind of seems like you are online to say you aren't online??
I think this is too narrow. Billvon mentioned scavengers, but more broadly even than that, all organisms compete with other organisms for resources. And whether they are actually consuming those other organisms or just killing them by taking their resources or choking them to death with their waste, all organisms are violently hostile toward other organisms and destructive of the environment. In many ways, plants are among the more powerfully desrtructive and hostile:
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This article is interesting. This article offers no support for your statement that predation did not exist until around 600,000,000 years ago. Thank you for the interesting article, but please now provide the evidence that predation did not appear till around 600 m.y. ago.
What he may possibly be thinking of is the evolution of the mouth. Martin Brasier's book "Darwin's Lost World", about the pre-Cambrian and Cambrian, contains the hypothesis that the "small shelly fossils" that are the first of the conventional fossils we have are from organisms that developed shelly armour in response to the evolution of the mouth, a very important and overlooked stage in the evolution of animals. This would have been around 600my bpe.
But as several of us have pointed out, it seems a bit arbitrary - or at any rate to need justification - to regard the creatures that ingested others by means of a mouth "predators" but not those that ingested other organisms in other ways, which certainly must have been happening a lot earlier than this.
Oh, I've read that book. I liked it. I didn't remember the part about the mouth. I was thinking he associated predatory behaviour with the emergence of mulitcellular life, or perhaps complex organisms, but the dates still do not match I think.
Really. I thought the idea that the mouth gave rise to shells (and burrowing to hide) was almost the most interesting idea in the book!
Yes, I do. The example of that ecosystem is in the article I posted earlier.
Similarly, single-celled algae quickly evolve into spherical multicellular organisms when faced with predators that eat single cells.
These findings back the emerging idea that this leap in complexity isn't the giant evolutionary hurdle it was thought to be."
Thus, there were two different behaviors at play.
What I keep thinking about relative to this is that at some point RNA was under attack on the molecular level...I even wrote earlier in the thread "the garbage bags were under attack"....so even back then in the early stages of life there was a predator and prey...the issue is that the "prey" did not advance into being the predator and then splitting into two different behaviors until the bacterial cell containing mitochondria some how got into the host.
Had some time to go back and re-read Selfish Gene...Chapter 2, page 19, "The Replicators":
"There was a struggle for existence among replicating varieties...they were struggling in the sense that any mis-copying that resulted in a new higher level of stability, or a new way of reducing the stability of rivals was automatically preserved and multiplied. The process improvement was cummulative. Some of them may even have 'discovered' how to break up molecules of rival varieties chemically, an to use the building blocks so released for making their own copies. These proto-carnivores simultaneously obtained food and removed competing rivals."
Now, to contradict that statement, we have another passage, and the example of the article I posted earlier.
Chapter 4, page 46, "The Gene Machine":
"This easy life came to an end when the organic food in the soup, which had been slowly built up under the energetic influence of centuries of sunlight, was all used up. A major branch of survival machines, now called plants, started to use the sunlight directly themselves to build up complex molecules from simple ones, re-enacting at much higher speed the synthetic process of the original soup."
I see a contradiction here. There are not one, but many different life forms, and an equally different number of survival mechanisms based on strategy to consume an energy source.
I guess that's possible.
The way I view it is that the number of planets that are possibly habitable can be looked at as a broad spectrum. If Earth is somewhere in that spectrum, think about the spread on either side.
Same thing with Suns. If the Sun is in the middle, there is a broad spectrum of Suns larger or smaller, more powerful or less, longer living and shorter.
You know what Billvon, I thought a lot about your statement "likely happened far before that"...and agree. That's why I went back to Selfish Gene...but there is a repeating pattern of behavior...as in the article I posted, the multicellular creature advanced from a threat...meaning that prior to that, the multicellular creature was just...living...not eating, not attacking, not threatening.
As for the "cycles" and the "materials", the only thing I can offer is that there are planets and suns out there made up of wildly different materials and elements than Earth. Can they support life? I have no idea, but if we look at England's lecture, I don't recall him saying specifically what materials were necessary for life, on that there needed to be molecules and energy in a stable environment (a warm bath).
Yes, I thought about the use of the 600 mya...that's probably an error...I mean the mouth did form around then, but when rethinking when living organisms started consuming each other was much earlier than that.
The mouth, then teeth, then jaw are the most tangible form to visualize "eating" another...and can be seen in the fossil record...
Yes, see other response.
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