“It’s not a camel, it’s a dromedary”. It’s the kind of thing the uncle you always try to avoid at family gatherings says – just to correct you. Next comes his lecture on how “it’s actually a dromedary on ‘those’ cigarette packs”, followed by an excursion into “the only true camel is the Bactrian camel”, before his final advice is dispensed: “one hump for a dromedary, two for a camel”. But despair not! If you’ve had enough, there’s good news! “Camel” is just fine, and hump counting isn’t! Should you ever feel the uncontrollable need to school your uncle in these matters, here’s how.

For starters, in English, the dromedary (Camelus dromedarius) is also widely known as the Arabian camel. The word “dromedary” stems from the Ancient Greek dromas, meaning runner, a term that well describes the fast‐moving Arabian beast. The word “camel” entered English via the Ancient Greek kamêlos, which in turn was borrowed from ancient Semitic forms of the word used in the Middle East (that is, within the dromedary’s historical range). Thus, English has two words of ancient origin both likely used in reference to Camelus dromedarius (yeah, the clue’s kind of in the scientific name!). The use of the word camel in place of dromedary is therefore justified without appealing to vernacular support.

Now that you’re warmed up you might wish to argue that the use of the term camel is further justified when one takes into account the existence of hybrids between Arabian and Bactrian camels. Like the Arabian camel, the Bactrian camel (from Central Asia–western China) is a domesticated form of an extinct predecessor. The Bactrian actually comes in two extant forms: domesticated and wild. It was once believed that the former was descended from the latter, but molecular analyses have recently shown that both types split from a common ancestor about 1.1 million years ago (Sci Rep 2017; 7: art9970). Domesticated and wild Bactrian camels now sport the names Camelus bactrianus and Camelus ferus, respectively. It is these domesticated Bactrians that have been mated with domesticated Arabian camels to produce hybrids. What, then, are we to call these crosses? Camels? Or must we invent permutations of “came‐dary” to reflect their various genetic mixes?

Should your uncle protest that this hybrid business must be some modern thing, you can safely retort “Not so!” We may need to look deep into antiquity for the first hints of Bactrian camels moving westward from their natural range – animals used by traders that at some point would have provided the raw material for crosses with Arabian camels (J Econ Soc Hist Orie 2004; 47: 143–65). By the second century BCE, crossing was likely well underway where both animals were present. F1 hybrids between Bactrian males and Arabian females are much larger and stronger than either parent, and for centuries they were bred to carry heavy loads along Asian trade routes such as the iconic Silk Road. There is hard evidence of hybrids traversing European soil too. In 1683, during their second attempt to take Vienna, the armies of the Ottoman Empire used hybridized‐camel muscle power for ferrying military supplies. We know because the skeleton of a camel, recently found at an archaeological dig in the Austrian town of Tulln, was dated to this time and was shown by both morphological and molecular analyses to be a hybrid (PLoS ONE 2015; doi.org/10.1371/journal.pone.0121235). Make no bet that it was the first! In modern‐day Turkey, Bactrian × Arabian hybrids are little used as pack animals, but they are still bred as wrestlers (yes, camel wrestling is a thing), while farther east in Kazakhstan there is a vigorous industry centered on the fermented milk of camel hybrids (ask for a shubat).

And now for the coup de grâce. It’s time to take down Uncle’s “counting humps method” of camel identification. While pure Arabian camels have only one hump, and pure Bactrian camels have two, their F1 hybrids usually have a single massive hump occupying most of the back. It may also show a slight indentation in the middle, leaving the impression of two tops to their one hump (Figure 1). Backcrosses can lead to a 3/4 Bactrian with two humps oddly close together, while a 3/4 Arabian may have a whopper hump too (WebFigure 1). Ergo, the simple counting of humps cannot truly reveal what type of camel a camel is! Interestingly, these odd hump arrangements may actually redeem the reputations of bygone artists. Old renditions of camels often showed them with humps seemingly oddly shaped or in the wrong place, leaving one to speculate on whether the artists who depicted them had ever seen their supposed subjects. They may, however, have simply been recording the appearance of hybrids.

Job done! Your uncle has fallen silent. No more insufferable lectures from him! And it feels great! Until, that is, you realize you have just become your uncle.

Adrian Burton