<span>Unlike the methods of early scientists, Sir Francis Bacon believed basic laws of science should be determined by using inductive reasoning based on empirical evidence. You cannot formulate a law in science if you don't have evidence to support it - so you cannot just take a basic truth and formulate your law based on that - there has to be some kind of evidence to prove your theories. Also, based on those evidence, you will induce a conclusion necessary for such laws, which is something Bacon understood, unlike early scientists.</span>
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The best evidence of such phenomena could be a population's genetic variation decrease.
When a population bottleneck occur it means that for some reason (i.e. environmental events) the size of a population is largely reduced. This leads to reduction of the genetic variation in that new smaller population. When a bottleneck occur, the founder effect is normally seen, which is that one population is established by a small group of a previously larger population leading once again the genetic variation, now though with a bigger population, to be very reduced.
