One of my peeves against anti-evolutionists is those moderates who fully accept gene drift and mutations for short term changes (breeds, "micro-evolution") but not longer term changes (species, types, "macro-evolution"). Try to pin one of those people down on a definition of species and type, and one can always show them an observed example of something that crossed the line, or else multiple species that are obviously different but on the same side of their line. But this post is broader than that. For example, Pluto was a planet. Everyone knew that. Recently it was demoted to dwarf-planet. There are groups still dedicated to its reinstatement as a planet, like the Society for the Preservation of Pluto as a Planet. My presumption is, because that's what they were taught in their youth, therefore it's "As God Intended". Nothing changed in the sky, nor in our understanding of how things work. But a category changed and our world shook. Well, at least the world of those of us who noticed. What of moons? An excellent article is here: Meet our Second Moon! We now have two moons? And in my lifetime, the origin of our main moon changed from an unlikely captured or even less likely co-congealed object to a reasonable and most probably ejected one. I remember being disturbed when the moon count around Jupiter went from 12 (the 19th century standard) to 63 (care of Voyager etc). The count varies depending on how you define "moon". One has to be broadly accepting of both size and ballistic classification to accept 3753 Cruithne as a moon of the Earth, but it is there. Speaking of the moon, here is an incredible new way to see our moon up close (with pan and zoom) taken from ground based cameras. Things change. As I have mentioned many times on this blog, most people are hung up on the misconception that words accurately define things. The thinking that, if you have a name for it, then you understand the thing. You get the collector's fallacy: The confusion of the joy of matching names to things with the understanding of the things themselves. Knowing the names of thousands of birds (or bugs or species or stamps or diseases) and accurately matching them to the subjects is useful. But it is not complete in terms of understanding the similarities and differences. That is what is meant by the quote "Biology without evolution is but stamp collecting". One cannot understand things without also understanding the relationship between things (species, astronomical objects, populations, etc) and knowing the latest (most complete, so far) underlying set of theories (scientific definition, not vernacular). Humans are better than most other creatures at recognizing patterns. We regularly see patterns in random observations: Pareidolia. Any set of words will be an incomplete definition of any object. Defining a class of things is even more nebulous. Do species change over time? Certainly, given either enough time or a precise enough definition. How many moons are in the solar system? Good question. Define "moon", and show me the latest ballistic data on the 100,000 largest object so far discovered inside of the Oort Cloud. By the time I have an answer, something will have changed.