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Mosaic fossils?
Published: 24 October 2015 (GMT+10)

When describing so-called ‘transitional’ fossils, we often call such fossils ‘mosaic fossils’. What do we mean? Ryan B. from the United States writes:
Hi CMI, I have been reading some of your articles about mosaic fossils such as Archaeopteryx, Tiktaalik and the mudskippers and you say that mosaic fossils don’t qualify as transitional fossils. I am having trouble understanding the whole mosaic idea; if a fossil contains both fish and reptile features doesn’t that make them transitional? Same thing with archaeopteryx. I was talking to my brother’s friend who is going to med school and his professor showed him Archaeopteryx as “proof” of bird evolution and proceeded to show me how Archaeopteryx had bird and dino features. Can you explain to me how “Mosaic” features is not the same as transitional features? And also do evolutionists recognize this difference?
CMI’s Shaun Doyle responds:
First, we do not talk of mosaic features, but of mosaic creatures. My article on the mudskipper illustrates this point:
“Mudskippers are unique mosaic creatures, not transitional forms. This means that, while they have some traits fish have, and other traits amphibians have, they are all fully formed traits arranged in a unique combination not found in either fully aquatic fish or amphibians. It’s not the individual traits that matter; it’s the way they are arranged to form a functional creature that matters. If evolution were true, we would expect to see a half-fin-half-leg. Instead we see a functional fin, with modifications determined by function, not evolution.”
In other words, we grant that e.g. mudskippers, Tiktaalik, and Archaeopteryx have features of their supposed ancestors and descendants; this is not the issue. The problem for evolution is that these features can typically be designated ‘ancestral’ or ‘derived’, a ‘transitional’ feature is much rarer than a transitional creature, and even where it might appear to be so, on closer inspection such ‘intermediate features’ are usually readily identifiable one way or another (see e.g. It’s all talk, Tiktaalik can’t walk and ‘Transitional form’ in mammal ear evolution—more cacophony).
Would evolutionists accept this sort of talk? Probably not, if my previous interactions with evolutionists are anything to go by. But why should that matter? Just because they don’t like the way we interpret the fossil evidence doesn’t mean that they’re right. And when evolutionists use terms like ‘mosaic’, ‘transitional’, and ‘intermediate’, we must remember that they don’t use these terms in any strict genealogical sense. Rather, they are understood in the context of cladistics, which never identifies proper lineages. And in this context, ‘mosaic evolution’ is the idea that evolutionary change takes place in some body parts or systems without simultaneous changes in other parts. They infer this from the fact that there are many discontinuities and reversals in individual character state changes as ‘revealed’ by their cladograms (see Mammal-like reptiles: major trait reversals and discontinuities and Bird evolution: discontinuities and reversals). In other words, the cladistics picture is messy and modular, so they assume evolution was messy and modular because they think that cladistics ‘reveals’ how evolution happened. But cladistics doesn’t demonstrate anything of the sort: see Cladistics, evolution and the fossils for more information. You can organize a collection of teaspoons (or other man-made objects) into a cladogram, but clearly this does not prove some sort of evolutionary relationship between the spoons.
Readers’ comments
But of course evolution won't give up, and they will say, "wow, look at all that evolutionary homology and homoplasy in nature," even though common Designer better explains it.
And when they get an awkward moment of living fossils, they will say, "isn't evolutionary stasis amazing after millions of years," despite irreversible genetic entropy leading to meltdown.
As long as you attach the word evolution and throw in millions of years, everything is fine for the story to continue uninterrupted.
What would the "mosaic creature" be that forks came from then? A spork? And how did knives ever evolve and what from? A spoo-nife?
Would that make a two-pronged serving fork a product of genetic mutation from a regular fork?
What about the evolutionary interpretation of how the dinner knife crawled into the butter and "devolved" into a round ended butter knife, only to later crawl back into the dinner plate and regrow a point AND became serrated!? Don't tell me someone CREATED the knives?! That can't be true! :D
(Some additional thoughts, this time from a non-expert)
Regarding lifeform "mosaics":
1. It might help to note that lifeform classification is NOT as tight as, say, chemical-element classification. The latter has extremely high rigor. All findings are by reproducible experiment, the attributes leading to classification are objective in nature, and so on. For example, the grouping of noble gases is clear, and hydrogen is not in that grouping.
The situation is very different in lifeform classification. Please see CMI Don Batten's article on how Linnaeus produced the still dominant (though challenged by cladistics) lifeform classification--while guessing at some of it. (Later, he experimented and said, "Oops.") Later taxonomists seem often not to have the patience to do lengthy and difficult reproduction longitudinal-research and likewise used their fallible intuition in some taxonomy. (Please see the 2nd chapter of Darwin's "Origins" for then-current examples of classification confusion.) In this imperfect setup, it should not be surprising that creatures sometimes show up that don't completely fit the current classification system--mosaics. They are thus NOT automatically evidence for transitional forms.
2. In a recent CMI article, John Woodmorappe reminded us that Duane Gish gave us a very helpful example of what would indisputably constitute a transitional form: seeing a heavy-lobed fish going from 100% fin, to 90% fin and 10% foot, to ... Another (ICR?) writer has pointed out that this SERIES of fossils should transition vertically in the SAME SUITE or rock. No candidate transitional form has come anywhere close to this evidentiary standard.
Mosaics are perfectly functioning creatures not perfectly classified by us.
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