The following is an excerpt from a passage in Scientific American:
Paleoanthropology has come a long way since Georges Cuvier, the French natural historian and founder of vertebrate paleontology, wrote in 1812 that "l’homme fossile n’existe pas" ("fossil man does not exist"). He included all fossil primates in his declaration. Although that statement seems unreasonable today, evidence that primates lived alongside animals then known to be extinct - mastodons, giant ground sloths and primitive ungulates, or hoofed mammals, for example - was quite poor. Ironically, Cuvier himself described what scholars would later identify as the first fossil primate ever named, Adapis parisiensis Cuvier 1822, a lemur from the chalk mines of Paris that he mistook for an ungulate. It wasn’t until 1837, shortly after Cuvier’s death, that his disciple Édouard Lartet described the first fossil higher primate recognized as such. Now known as Pliopithecus, this jaw from southeastern France, and other specimens like it, finally convinced scholars that such creatures had once inhabited the primeval forests of Europe. Nearly 20 years later Lartet unveiled the first fossil great ape, Dryopithecus, from the French Pyrénées.
I don't understand the conjunction "although" in the sentence in bold. When I looked it up in the dictionary, I found that it is used to introduce a subordinate clause which contains a statement which contrasts with or modifies the strength of the statement in the main clause. However, I don't see why on earth "statement seems unreasonable today" can do this to "evidence was quite poor". It doesn't make any sense to me. How should I understand this conjunction?