Natural Selection- Deterministic or Stochastic?
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Jerry Coyne sez that natural selection is deterministic and non-random. However a simple reading of the definitions says natural selection is stochastic:
As for natural selection:
OK so it is a result of three processes- ie an output.
What drives the output? The inputs.
The variation is said to be random, ie genetic accidents/ mistakes.
With sexually reproducing organisms it is still a crap-shoot as to what gets inherited. For example if a male gets a beneficial variation to his Y chromosome but sires all daughters, that beneficial variation gets lost no matter how many offspring he has.
Fecundity/ differential reproduction- Don't know until it happens.
Can't tell what variation will occur. Can't tell if any of the offspring will inherit even the most beneficial variation and the only way to determine differential reproduction is follow the individuals for their entire reproducing age.
Then there can be competing "beneficial" variations.
In the end it all boils down to whatever survives to reproduce, survives to reproduce.
But anyway- all of the variables of natural selection are either entirely stochastic (variation) or have a stochastic element. Therefor, by definition, natural selection is stochastic. Or at the very least natural selection cannot be deterministic.
Sorry Jerry, you lose... (again)
Jerry Coyne sez that natural selection is deterministic and non-random. However a simple reading of the definitions says natural selection is stochastic:
Deterministic:
Deterministic model
Definition
noun
A mathematical representation in which every variable alters according to a mathematical formula, and not to random fluctuations.
Supplement
It is one in which every set of variable states is uniquely determined by parameters in the model and by sets of previous states of these variables. Therefore, deterministic models perform the same way for a given set of initial conditions.
For instance a deterministic model can be applied to describe the predator-prey systems wherein the prey shows an age-specific vulnerability to predation.
Stochastic:
detereministic: Referring to events that have no random or probabilistic aspects but proceed in a fixed predictable fashion.
Stochastic (from the Greek στόχος for aim or guess) is an adjective that refers to systems whose behavior is intrinsically non-deterministic, sporadic and categorically not intermittent. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac[1] and E. Nelson,[2] any kind of time development (be it deterministic or essentially probabilistic) which is analyzable in terms of probability deserves the name of stochastic process.
As for natural selection:
“Natural selection is the result of differences in survival and reproduction among individuals of a population that vary in one or more heritable traits.” Page 11 “Biology: Concepts and Applications” Starr fifth edition
“Natural selection is the simple result of variation, differential reproduction, and heredity—it is mindless and mechanistic.” UBerkley
“Natural selection is the blind watchmaker, blind because it does not see ahead, does not plan consequences, has no purpose in view.” Dawkins in “The Blind Watchmaker”?
“Natural selection is therefore a result of three processes, as first described by Darwin:
Variation
Inheritance
Fecundity
which together result in non-random, unequal survival and reproduction of individuals, which results in changes in the phenotypes present in populations of organisms over time.”- Allen McNeill prof. introductory biology and evolution at Cornell University
OK so it is a result of three processes- ie an output.
What drives the output? The inputs.
The variation is said to be random, ie genetic accidents/ mistakes.
With sexually reproducing organisms it is still a crap-shoot as to what gets inherited. For example if a male gets a beneficial variation to his Y chromosome but sires all daughters, that beneficial variation gets lost no matter how many offspring he has.
Fecundity/ differential reproduction- Don't know until it happens.
Can't tell what variation will occur. Can't tell if any of the offspring will inherit even the most beneficial variation and the only way to determine differential reproduction is follow the individuals for their entire reproducing age.
Then there can be competing "beneficial" variations.
In the end it all boils down to whatever survives to reproduce, survives to reproduce.
But anyway- all of the variables of natural selection are either entirely stochastic (variation) or have a stochastic element. Therefor, by definition, natural selection is stochastic. Or at the very least natural selection cannot be deterministic.
Sorry Jerry, you lose... (again)
11 Comments:
At 12:35 AM, Rich Hughes said…
Can you qoute Coyne directly?
At 7:12 AM, Joe G said…
LoL!
In a blog Jerry Coyne sez:
"A brief correction first: natural selection is not a “random process.” It’s a process that combines the random production of mutations with the deterministic process of natural selection itself. I hope he understands that."
Now what, Richie?
At 4:43 PM, jeph cartter said…
Ei ,este blog é muito bom ... muito divertido !
Mas acho biologia muito complexa,ainda mais falando de genética.
Fico impressionado com a fraca retórica evolucionista.
São assim tão burros !São mesmos !
At 6:14 PM, Joe G said…
muito obrigado
My Portuguese is not so good...
At 2:33 PM, GODKILLER85 said…
It's so sad when people with no experience or learning in a specific field think they are smarter than those people whose life it has been to study said field. You even quoted Jerry Coyne's exact words, which explain it in very understandable English - I'm not sure how you can't understand what he said because it makes perfect sense, perhaps before delving into evolutionary biology you should take a few classes in the English language. Let me try to illuminate things for you a little more.
A deterministic model will always produce the same output from a given starting condition or initial state, and natural selection does just that, in that it ends with the same output - that it favours the genetic traits which improve fitness of the individual and it's offspring. It doesn't matter if the "inputs" are random because the output is always the same, and it is therefore predictable. An example of a stochastic process would be stochastic drift, or as it is known in biology, genetic drift, which is the random fluctuations of alleles due to random combinations of gametes during fertilisation, which is clearly not deterministic because the outcome is always random.
So you see, so it is the outcomes which determine the difference between the two, one predictable the other random. Hope that helps you, because if you are going to "educate evotards about ID and the alleged theory of evolution one tard at a time and sometimes in groups", it's probably best you have at least a basic grasp of the words used in said field of science if you are going to fool anybody.
At 4:46 PM, Joe G said…
Wait- natural selection produces many different outcomes starting with a given starting condition- see Lenski's long term evolutionary experiment. Also, according to Dan Dennett, there is no way to predict what will be selected for at any point in time.
So obviously you don't have a clue.
At 6:27 PM, GODKILLER85 said…
That's your response? Sorry but no, you are still the clueless one. The same predictable output is evolution of traits. Yes the outcome in terms of which traits arise in which populations will be different due to different selection pressures but it is still deterministic in that it results in predictable evolution of traits (we know traits will evolve as a result of natural selection).
I commented my part to try and help you as we must all start some where and what we actually know about reality is often a good place to start (as opposed to ancient books). I won't reply any further as I don't have time to waste trying to explain factual information to people who don't seem interested in facts. I continue to try and learn more about this world, and I would urge you to do the same, if you are going to argue about biology then at least go learn some basic biological concepts, it really does make sense.
At 11:51 PM, Joe G said…
LoL! You must be a clown.
The same predictable output is evolution of traits.
Evolution by design produces that and we have genetic algorithms that model evolution by design.
What traits can natural selection produce? Please be specific and show your work.
At 11:54 PM, Joe G said…
that it favours the genetic traits which improve fitness of the individual and it's offspring.
Faster, slower, taller, shorter, fatter, skinnier, better eyesight, no eyesight- whatever is good enough. With natural selection it is nothing but contingent serendipity. Whatever is good enough.
At 7:06 AM, yugendar said…
learn Stochastic Process online at virtulearn
Stochastic Process Online Videos
At 1:39 AM, Ganesh said…
Thanks for your information Have a nice day
Stochastic Process online videos
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