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Member (Idle past 5937 days) Posts: 563 From: Brisbane, Australia Joined: |
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Author | Topic: Evolution is random! Stop saying it isn't! | |||||||||||||||||||||||
bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
There are certainly random processes involved in evolution. But even if evolution is unequivocally defined as natural selection acting on existing variation and mutations, then I don't think it can really be characterized as random or non-random. Mutations are certainly random. But natural selection is a decidedly non-random process.
quote: Huh? I'm sorry as long as we're using English I think we should use the Webster's definition of random:
quote: Definition 2b doesn't alow bias. And you're right, there is huge bias in natural selection. It is not random. The end result of evolotion, the species produced, is random only because two of the processes involved, are random. Mutations are random and existing variation is random. It's the "shuffled deck" of conditions we have now. Shuffle it again and you get a different set of conditions, equally as improbable. Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
There is no doubt that the natural processes that cause natural selection to operate are random. But the fact that environment, even if it is random, biases the selection, removes total randomness from evolution.
Suppose a population with random variation is in equilibrium with its environment, and the environment changes. Natural selection will select the individuals that best fit the new environment. Even if the environmental factors and changes are totally random, the selection imposed by it is not. A truly random selection of individuals would appear drastically different than the selection chosen by the random swings of nature. The random selection would not be biased toward survival. It would not be biased in any way. Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
quote: I've been away from this thread for a while, but to this I just have to say, no, no, no!!! You're missing the point. Words like deformed, or it's more objective partner, non-functional, imply that there is a proper form or function. In a changing environment something that we think is "deformed" may have a survival advantage. Whatever random mutation caused the "deformity" is selected for (the opposite of randomness), and now the ones without the mutation are "deformed". Trilobites look pretty deformed to me. As for natural selection being random, I suppose we could play word games and come up with a definition for random that would include natural selection. But I prefer to stick with the standard english definition where biased and random are near antonyms. There is a real world difference between a truly random selection of a population, and a selection naturally biased toward fittness. That difference is the driving force behind evolution. Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
epo5 writes: I find it strange that you all pretty much say I missed the point. I, on the other hand, KNOW you all miss the point here.I deliberately used the non-technical words good and bad because they're broad terms that describe it to even lay people who might be reading this. You're all pointing out things that are common knowledge to anyone, including myself, who even delve into this topic. I know very well that the fossil record will not record everything. You people are completely, totally missing what's being said here. If random mutations, meaning a series of accidents caused all these life forms to develop, there should have a been thousands of life forms wich did not work out and were eliminated by natural selection. These "unfit" life forms should have far out numbered the "successful" life forms and should have been represented in the fossil record in proportion to the relative numbers they were -- which had to be huge -- even if the fossil records are not complete. They are not represented in the fossil record in any significant degree. They never happened. And if they never happened, you people are talking about a genetic design or blueprint that directed life. I don't care what name you want to give that, but that's not the scientific concept of evolution. Whether you admit it or not, you people actually believe that some Super Power directed life. Yes, the fossil record does PROVE Darwinian evolution never happened.
It's not that good and bad are non-technical, they literally have no meaning at all in this context. The words assign value to utterly valueless physical observations. And you're right, there should be thousands, countless numbers even, of life forms which did not work out and were eliminated by natural selection. These would have existed for relatively few generations, maby a few thousand years. A snapshot of geologic time. To expect these to be preserved in appreciable numbers is unreasonable. That issue has been addressed by Eldridge and Gould and other PE theorists. Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
Don't want to speak for epo5 but I think he was talking about the unsucessful evolutionary experiments. The tiny little thorns on the tree of life. It's true that most of the species represented in the fossil record are now extinct. But most were very sucessful. Trilobites are extinct now but were very successful, and occupied a large branch on the tree of life. But there undoubtedly countless evolutionary experiments that didn't work and amounted to aborted little buds on the tree of life that had no hope of ever being represented in the fossil record.
Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
crashfrog writes: If the 99% of species that went extinct aren't "unsuccessful", exactly what are they? Every individual is an evolutionary experiment. The ones that fail are the ones who die without having offspring. Surely it should be sufficiently obvious that some individuals die without having offspring. At the risk of going off topic, there are two different types of extinction, those where descendant species are left and those where no descendants are left. Eohippus is extinct but is the ancestor of modern horses. Dinosaurs left no descendants. But which was more successful? Are those species that currently occupy the outermost growing shoots of the tree of life the most successfull simply because they are alive now? There are undoubtedly evolutionary experiments going on right now that are doomed to failure (I'm 46 and single, so I'm probably one!). And it doesn't look too good for the unique species that have evolved on the Galopagos. Are they successful just because they're alive now? From a naturalistic perspective it is possible that humanity will be a failed experiment. Which species was more successfull, humans surviving a few million years, or trilobites dominating the Paleozoic, or dinosaurs dominating the Mesozoic? Looking at the tree of life now there is no way to know what it will look like in the future. But we can look back in amazement at large branches that are no longer growing. It's hard for me to think of dinosaurs as unsuccessful just because a ET impact terminated their branch. They represent one of the most explosive radiations and branching the tree of life has ever seen. Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
Yes that's true. I think YECs want evolution to be random so they can make ridicoulous straw men like monkeys with typewriters producing the works of Shakespear, or the random chaos of the big bang evolving by random chance into what we see today. They mistakenly equivocate random with purposeless, and ignore non-random processes. They are related but not synonymous. I'd rather not characterize evolution as either random or non-random. It involves both types of processes.
Brent
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bdfoster Member (Idle past 4907 days) Posts: 60 From: Riverside, CA Joined: |
I'll be God's advocate here
The definition I gave before from Webster included the phrase "equal probability of occurrence" and "definite probability of occurrence" which is basiclly the same as the probability distribution in the American Heritage definition. Both definitions are true, but the second one is a little misleading. It simply means that random selections are governed by the laws of probability and not influenced by anything other than probability. Probability distributions are complex mathematecal functions that scare the crap out of me, and I want nothing to do with them. There are different kinds of distributions that describe probability of an event happening, and of course not all events have the same chance of happening. The odds of pulling a queen of spades out of a deck are 1 in 52. But there is an equal chance of pulling any card. They all have the same 1 in 52 chance. Suppose the deck is stacked with 10 queens of spades. The odds of pulling a queen of spades are no longer the same as pulling any other card. But in both cases, random selections from the deck will conform to a predictable probability distribution. Each random selection has an equal probability of occurrence, that is it conforms to the same probability distribution. Even in the second deck, each random selection has a probability of drawing a queen of spades exactly the same as any other random selection (assuming the card is replaced and the deck is shuffled). A selection that does not conform to the probability distribution is ...probably... not random. In a population with variation, a random selection will conform to a probability distribution. That distribution will be affected by statistical factors such as the number of individuals with certain types of variation. Natural selection will sellect individuals on tha basis of fittness relative to an environment. If the environment changes the probability distribution for a random selection doesn't change, but of course fittness relative to the new environment does change, and there is a difference between random selection and natural selection. Brent
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