When Charles Darwin published his landmark observations in 1859, he lamented that the fossil record was still quite poor at that time.  It was only in the last century or so earlier that anyone had even proposed the possibility that a single species could completely die out, and the first dinosaur wasn’t discovered until Darwin was a boy.  Fossils were known by previous generations of course, but extinct and therefore unfamiliar varieties were often mistaken for the fanciful monsters of mythology –if they were recognized at all –which usually requires a well-trained perception of both geology and animal morphology.  That’s especially rare when you’re talking about an organism no one has ever seen alive. 

When something dies, it is usually disassembled, digested, and decomposed.  Only rarely is anything ever fossilized, and even fewer things are very well-preserved.  Because the conditions required for that process are so particular, the fossil record can only represent a tiny fraction of everything that has ever lived.  Darwin provided many environmental dynamics explaining why no single quarry could ever provide a continuous record of biological events, and why it would be impossible to find all the fossilized ancestors of every lineage.  But despite this, he predicted that future generations, -having the benefit of better understanding- would discover a substantial number of fossil species which he called “intermediate” or “transitional” between what we see alive today and their taxonomic ancestors at successive levels in paleontological history. 

In fact, in the century-and-a-half since then, we’ve found millions of evolutionary intermediaries in the fossil record, much more than Darwin said he could reasonably hope for.  There are three different types of transitional forms and we have ample examples of each.  But creationists still insist that we’ve never found a single one, because what they usually ask us to present are impossible parodies which evolution would neither produce nor permit. 

“You’ve gotta be able to prove transitional forms;
one animal transitioning into another. 
And all through the fossil record and life,
we don’t find one of these, a crocoduck. 
There’s just nothing like it.”

In fact, Darwin explained in detail why we should NOT find anything like this.  We’re not looking for a blend of two species that both currently exist. Such a thing would actually go against evolution.  Instead, he said, that if his theory were true, then what we should find would be a basal form potentially ancestral to both current species.  And in this one case alone, we’ve found dozens of them in a near continuous lineage dating beyond the dawn of the Mesozoic era.       

The most famous one was the first ever recognized as such.  Archaeopteryx lithographica was discovered in 1860.  It was the first of many lines of evidence revealing that birds had evolved from dinosaurs.  So Darwin’s theory was first vindicated while he was still alive.  Of course creationists will never accept that, and still complain that archaeopteryx can’t be intermediate because we can’t prove it’s the single crown species from which all other birds emerged.  But it doesn’t have to be, and that’s not what transitional means.  In biology, species can be precisely identified genetically.  But in paleontology, they’re determined morphologically. 

So creationists argued that Archeaopteryx still doesn’t qualify because it’s “100% bird”.  But they’re difficult to pin down as to why they say this, because this animal, like all other quasi-birds of that age, lacks many definitive features of modern birds, and it retains so many distinctly saurian features that when the last Archaeopteryx was found in the 1960s, the traces of its feathers weren’t immediately evident, and it was thus mistaken for a small dinosaur called Compsognathus. 

But creationists continue to use every excuse they can think of to dismiss Archaeopteryx as an intermediate species.  They complained that its lungs weren’t right to be transitional, or that it had the wrong kind of pelvis. They even tried to imply that every such fossil found so far were fakes.  They think any excuse will do, and they’ve done the same attempting to summarily dispute every additional intermediary ever seen since.  No matter what, creationists will not admit that anything we ever find can fulfill Darwin’s prediction of transitional intermediates.  

This is why creationists demand only monstrous absurdities or issue challenges they know still couldn’t be satisfied no matter how true evolution may be; because they know already that whatever they insist on seeing today we may show them tomorrow, and if that happens, they’ll have to make up new excuses for why it still doesn’t count.  So they won’t request to see anything evolution actually requires, and they usually won’t define any criteria they would accept either, because they already know they won’t accept anything even if we show them everything they ever ask for. 

It doesn’t help that they won’t look at what they don’t want to see either.  Many people think there are no transitional species because the only fossil forms they’re aware of at all are a handful of plastic pieces in a prehistoric play set.  They’ve no idea how rich the fossil record is!  We know of several hundred species just within dinosaurs, to say nothing of the thousands of examples of each of hundreds more taxa apart from that.  Experts estimate that all the collective genera still roaming around now only amount to about 1% of all the species that have ever lived.  Practically everything there ever was ain’t no more.  Every species living today has definite relatives both extant and extinct, and evident in the fossil record.  And in one sense, all of them, even the things still alive, count as transitional species.  

But of course creationists don’t accept that, and insist on a much more restrictive definition.  That’s fine.  But in order to determine for certain whether anything does or doesn’t meet the requirements, we have to know what those requirements are, and there is one creationist website brazen enough to post a definition of transitional species which is also correct according to evolutionary biologists.  So at least we can verify there is a common set of criteria both groups can agree upon.   

However, this site also says that no such evolutionary links have ever been found.  But then it goes on to list several that have been –attempting to dismiss extant examples of single-cell to multicellular transitions, the successive phylogeny of insects, the emergence of vertebrates, and of whales, amphibian fish, therapsid “mammal-like reptiles”, and acquired adaptations for flight in dinosaurs, pterosaurs, insects, and bats.  I wrote to one of the webmasters of this site, and pointed out all these items in their list of things never-found that we actually have, and explained how all of them meet every one of the criteria he himself laid out.  He wrote back saying he knew that of course, but wouldn’t make any corrections on the excuse that he could even ignore his own rules if he needed to. 

A decade ago, Kathleen Hunt, a zoologist with the University of Washington, produced a list of a few hundred of the more dramatic transitional species known so far, all of which definitely fit every criteria required of the most restrictive definition.  Myriad transitional species have been, and still are being, discovered; so many in fact that lots of biologists and paleontologists now consider that list “innumerable” especially since the tally of definite transitionals keeps growing so fast!  Several lineages are now virtually complete, including our own.

“By the way, the missing link?  It’s still missing!”

No it isn’t.  Hasn’t been for a long time now.  There was a missing link in 1859 when there were only two species of humans yet known in the fossil record, and no intermediate fossils to link them with any of the other apes we knew of at that time.  Since then, we’ve found the fossils of thousands of individuals of dozens of hominid species, many of which provide a definite link to the other apes.  But there were two particular pieces predicted to complete the puzzle: 

First, it was never supposed that we evolved from any ape species still alive today.  Instead the theory held that chimpanzees and humans were sibling species, daughters of the same mother.  So the first link we needed to find was an ancient ape apparently basal to either of us –to prove there was a potential progenitor of both groups.  We had already found that link in Europe five years before Darwin went public.  So we already had an evident “chain” of transitional species from which only one more “link” was needed. 
The theory then required that another extinct hominid be found in strata chronologically between the Miocene Dryopithecus fontana and the earliest known human species, which from 1891 to 1961,  was Homo erectus.  We’ve found lots of candidates, as many as fifty species of apes which are now all extinct.  But more than that, the theory also demanded that we find one “half-way” between humans and other apes in terms of morphology.  We found exactly that too way back in 1974.  Australopithecus afarensis proved to be a fully bi-pedal ape who’s hands, feet, teeth, pelvis, skull, and other physical details were exactly what creationists challenged us to find, yet they’re still pretending we never found it. 

But worse than that, we didn’t just find that one.  In 1977, three years after we discovered the no-longer-missing link in the human evolutionary lineage, Harvard paleontologist, Stephen J. Gould mentioned an “extreme rarity” of other clear transitions persistent in the fossil record ‘til that time, and his comment, -taken out of context- remains a favorite of creationist quote-miners to this day.  But in the more than 30 years since then, there has been a paleontological boon such that we now have way more transitional species in many more lineages than we ever needed or hoped for.

Now the problem for evolution is that there are too many contenders, while a compounding problem for creationists is that not even one of them should exist if their story was true.  And yet they do –by the bushelful!  Despite their complaints to the contrary, the intermediate gradations in the human evolutionary line are now so fine that paleoanthropologists can’t agree whether they’re all different species or merely mildly modified varieties of the same ones, such that there are no more links needed for human evolution anymore. 

But creationists still say we’ve never found anything that was “half-ape and half-human”.  Adhering always to black or white absolutes, and being thus unwilling to admit any degree of variance other than 100% or zero, they make sure to divide every find into one of two boxes even when they can’t make up their minds which side of that imaginary partition each one belongs to. 

Demanding an “ape-man” is actually just as silly as asking to see a mammal-man, or a half-human, half-vertebrate.  How about a half dachshund, half dog?  It’s the same thing.  One may as well insist on seeing a town half way between Los Angeles and California.  Because the problem with bridging the gap between humans and apes is that there is no gap because humans ARE apes –definitely and definitively.  The word, “ape” doesn’t refer to a species, but to a parent category of collective species, and we’re included.  This is no arbitrary classification like the creationists use.  It was first determined via meticulous physical analysis by Christian scientists a century before Darwin, and has been confirmed in recent years with new revelations in genetics.  Furthermore, it is impossible to define all the characters exclusively indicative of every known member of the family of apes without describing our own genera as one among them.  Consequently, we can and have proven that humans are apes in exactly the same way that lions are cats, and iguanas are lizards, and whales are mammals.  So where is the proof that humans descend from apes?  How about the fact that we’re still apes right now!  

The 9th falsehood of Creationism:
“No transitional species have ever been found.”