These people said:
“Evolution “cannot be subjected to a test” because it is something that supposedly occurred in the past and is not occurring today. And before you jump all over that, natural selection (changes within a species that are occurring at present) is not evolution, and there is no recorded instance of a new form or function being observed to have developed through natural means.”
I thought I would jump all over them. Even though I wasn’t smart enough to figure out how to leave a comment at their blog, I can understand this one. People who expect to see radical visible changes in organisms in a handful of human generations, e.g. since we discovered evolution, are missing something. A grip on timescales possibly?
Approximately 500,000 generations (about 250,000 each, from our common ancestor) are estimated to separate us from chimpanzees, our closest relatives, a process that took about 6 million years. Whether this has produced significant differences in form or function is bound to be a subjective judgement. So check out the chimpanzee genome sequencing project, for something a bit more precise. Wikipedia gives quite a nice summary, and there’s about a million other things on the net. It’s a fun thing to research and it underlines the fact that a grasp of genetics is absolutely essential to anybody hoping to understand evolution.
Personally, I’m impressed by just how many genes have changed in so short a time, how few of the changes are visible, and how few changes you need to create visible differences (like chihuahuas from wolves).
For evolution happening today, see here. It mostly concerns nasty little things like resistance in organisms we can’t see and would rather be without. So as well as getting a grip on large time scales, you need to get familiar with small spatial ones, and with processes as well as morphology.
For the rest of this little discussion, see here and here. I have to go and teach my kiddie something before lunchtime now.
I never could figure out how to comment. I think maybe you have to register somehow? If I could have I probably would have left a comment to the post I blogged on and none of the ensuing kerfuffle would have happened.
I don’t care how many generations you have. If it doesn’t happen in 1000’s of generation (in the case of insects or other short-lived creatures) that we can observe, it’s not going to happen in 500,000 or even 500 trillion generations.
All the changes referred to in your link above are examples of change within a species. This is merely a re-shuffling of existing genetic information. No new information has been created, and no new insect, for example, is created. You start with a grasshopper, you end with a grasshopper. This certainly doesn’t explain the development of entirely new species, as evolutionists claim.
But this is a very extensive subject, as we need to consider the accuracy of the dating methods, the mathematical odds of evolution even being possible or not, the vast differences in the genomes of “related” animals, and so on. Much too extensive for me to consider writing about now in this space…
I suggest you read our latest post where we address the question of micro-evolution vs. macro-evolution.
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I disagree with the first paragraph in Brian’s comment. It clearly does make a difference how many generations you have. If major evolutionary change is a rare but sudden event, it increases the chance of it happening. If major evolutionary change is cumulative micro-evolution it gives it enough time to happen.
The accuracy of dating methods is a subject I’m very interested in right now. However for the whole fossil record to be seriously invalidated, we’re talking about inaccuracies of hundreds of millions, sometimes billions of years, not even millions.
As regards the mathematical (logical?) odds of evolution, it appears to me that when you accept that characteristics are inherited and that those characteristics have an impact on reproductive success, evolution can’t not happen.
Mathematical odds now? I can reccomend an excellent book on conquering innumeracy Brian.
Apologies to Brian and the YHH for the snark in my last response.
I can’t think of any situation where random chance and time produce order. It’s exactly the opposite. Order is only produced by a directed, external force acting upon a system.
The Second Law of Thermodynamics states that “the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium” http://en.wikipedia.org/wiki/Second_law_of_thermodynamics
In thermodynamics (a branch of physics), entropy is a measure of the unavailability of a system’s energy to do work. It is a measure of the randomness of molecules in a system and is central to the second law of thermodynamics and the combined law of thermodynamics, which deal with physical processes and whether they occur spontaneously.
Entropy change has often been defined as a change to a more disordered state at a molecular level. http://en.wikipedia.org/wiki/Entropy
A sudden “major” evolutionary change is extremely unlikely because any significant increase in complexity would either need hundreds or thousands of intermediate, incremental steps or the incredible occurrence of all these steps simultaneously. You can’t go from fish to mammal in one step.
If you know anything about probability theory, the odds of any event occurring are 1 in x, with x being the number of possible outcomes. If we use a very simple example of 3 possible occurrences, A, B and C, the odds of one of them occurring is 1 in 3.
And if we have another event, with outcomes D and E, then the odds of both A and D occurring together would be 1 in 6. There are 6 possible outcomes: AD, BD, CD, AE, BE, CE (filtering out the duplicates such as DA and AD).
But if we then have a third event with outcomes F and G, then the possible combinations are ADF, ADG, AEF, AEG, BDF, BDG, BEF, BEG, CDF, CDG, CEF, CEG, and the odds of one of these combinations occurring would be 1 in 12 (3 X 2 X 2).
So if we needed 100 incremental changes to occur simultaneously and there were only 10 possible outcomes for each (I’m being VERY conservative here) the odds of them all occurring together would be 10 to the power of 100 (1 followed by 100 zeroes).
When you consider the odds of winning a pick 6 lotto with 50 numbers, you have a 1 in 15,890,700 chance of winning http://www.wikihow.com/Calculate-Lotto-Odds . That’s only a 1 followed by 7 places, and we’re talking here about a 1 followed by 100 places (zeroes). Not very good odds, is it?
Obviously, it’s much more complicated than this, because you would have to know the number of genes and base pairs in the chromosomes before and after, and you would need to know the number of steps it would take to arrive at the “major” change. But this should help.
All of the known dating methods are based on certain assumptions. In the case of radioisotopes techniques such as potassium-argon (K-Ar), argon/argon (40Ar/39Ar), for example, it is assumed that there was a constant decay rate an isotope to reach its half-life, that the original sample was unaffected by external processes, and that they know how much of the isotope was present in the original rock http://volcanoes.usgs.gov/About/What/Assess/Dating.html
I don’t want to get into a detailed discussion about this issue now, as it’s quite complicated, but this is just one example. Your dating method can only be as good as the assumptions upon which it they are based, since there is no way to verify their accuracy through historical (human) records.
I just noticed an error in my probability caculation. I should have said 100 to the power of 10 (1 followed by 12 zeroes, still a huge number).
Brian said: I can’t think of any situation where random chance and time produce order. It’s exactly the opposite. Order is only produced by a directed, external force acting upon a system.
That force is called selection.
I don’t think all the thermodynamics stuff is incredibly relevant at this level.
Brian also said: A sudden “major” evolutionary change is extremely unlikely because any significant increase in complexity would either need hundreds or thousands of intermediate, incremental steps or the incredible occurrence of all these steps simultaneously. You can’t go from fish to mammal in one step.
Incremental steps is what we’re going for here. Now you need to work out the real probability of beneficial mutations fixing. That would be interesting. I rather suspect that the lotto analogy is just a random demonstration of the fact that probability exists, and not really relevant to this problem. At any rate, your dragging in probability, quite rightly, I think, seems to invalidate your earlier argument that it doesn’t matter how many generations you have. You want to say (earlier) that if you can’t win the lottery after 1000 tickets, it must be impossible to win. I’m quite prepared to buy several billion tickets before I make that claim.
As for radiometric dating. Obviously, there is no way to verify its accuracy through historical records. I doubt that everything scientists believe about radioactivity is radically and violently wrong, which it would have to be to produce the scale or error you’re proposing here. As a matter of maths, you could try to figure out just how wrong they have to be, to get the figures you want to see.