The uniformitarian principle – present is the key to the past – apparently hinders our thoughts about evolution. This is simply because, if the past had been very similar to today, it casts doubts in our mind about evolution. Thus, how can one see through uniformiatarianism to extract evidence of evolution? One has to have a clear picture about things that evolved and things that did not evolve.
Dear Kenneth,
It is a 'Key problem', a key that may not open the door sometimes. The word 'guide' could have been better. OR One could have said: 'Present perhaps may not be the key to the past', to avoid people believing 100% that it is going to open the past. Evolution itself goes at different pace in different things. For example, Radioactivity of isotopes of the same element (Sm) decays at different rates. So what looks like no evolution may represent slow evolution. I am wondering whether people believing in Precambrian Plate Tectonics are considering the present as the 'Master Key' to the past.
Keerthi Perera
That sound more like a philosophy problem. I think that present is a consequence of the past and not a "key". You can not explain a chain of events, which can determine or not other events simply by considering their effects. What if the humans are not a peak of the evolution and more like a "side effect" ... or even worse - an accident in the chain of events which we like to call evolution . And let us remember that human evolution took only some 2 mil years roughly, which is just a moment in the history of the Earth. The second - we should remember that the present is only a very thin interface between past and future, how can one have the courage to take present observation , in years, and extrapolate them in the past , for several hundreds of million years...I think that is the old and potentially bad habit of people to try to enforce very raw models to a nature which have many more aspects which we tend to forget or overlook...If you have a piece of hot lava, can you explain how the volcano was formed and how it works ? How about the other volcanoes in the world?
The laws we know are functioning now as they were in the past of course. But they will explain only a "liniar" evolution of all things not the accidents, which have a very important role in the Earth history. Laws corectly predicted the nearby trajectory of the last asteroid that travelled near us recently. The laws and even the observation failed to predict the explosion of the other much smaller rock, that came from another direction and exploded over Russia, a perfect mini replica of the Tunguska asteroid ( or comet?), but now with some several hundreds people wounded in a small city.
"The universe is not only stranger that we imagine, it is stranger that we can imagine",
we should remember that more often..
Thank you Kenneth and Andrei for your contributions. Summarizing what you both pointed out, evolution really means that we are trying to solve an 'inverse problem'. That is, we are trying to explain how we reached the present in the light of physical and chemical laws which we believe are applicable to the past. So the keys we have are those physical and chemical laws, and as Andrei very correctly pointed out, key is not the present, it is only the final outcome of everything that happened in the past. Of course it is very, philosophical but it may not be possible to solve this inverse problem without making some assumptions about the starting point. As for example, one has to believe in the 'big bang' or propose a different starting point. Similarly, one tends to believe that Troilite in the Canyon Diablo meteorite is the starting composition of Pb-isotopic evolution on earth. So the picture of evolution we paint totally relies on those assumptions. Even the physical and chemical laws have those subsidiary constants built into the relevant equations, which are sometimes not constants. Decay constants for example have not remained constants over our life-span (eg. 87Rb decay constant). Hope to hear more fruitful contributions from both of you and others. Thanks.
See perhaps Steve Gould's (1987) book "Time's arrow, time's cycle" about the history of geology and Lyell's concept of uniformitarianism which included a number of distinct hypotheses, some of them were seriouly contested by later geocientists and palaeobiologists.
Lyell not only considered natural laws to be uniform throughout time (still undisputed, at least in earth science contexts) but also advocated the idea that only processes that are presently at work should be considered for the past (now declined, only as a heuristic principle) and that these processes were running at exactly the same rate as observed today (now declined).
So what is left of uniformitarianism appears to be identical to what is usually termed 'actualism': study of past through observation of and comparison to present processes/phenomena (without implementation of thought barriers).
Michael, thank you for the contribution. One cannot disregard the possibility that sometimes processes may have been actually different from one another (or the causes of a given process may have been different) in the past but their outcomes look the same because the latter were governed by the same chemical and physical laws. Then, if one interprets those outcomes as indicative of uniformitarianism it is misleading and is only an illusion.
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