Equus Asinus

*Nuevo: traducción en castellano etc. con Google Translate. Tambien hay menu de paginas en castellano y francés.

I decided early on that my research into the origins of the Andalusian donkey breed needs to be built on a foundation of existing methodology regarding early domestication of the wild ass in Africa and then its dispersal around north-east Africa, Egypt and Mesopotamia, particularly focusing on the recent work in the fields of palaeozoology, archaeology, genetics – including geographical DNA flow – and even drawing upon art history, literature and the economic records left by early civilisations. So, this study is truly multidisciplinary and it is entirely in keeping with the cross-disciplinary academic study skills I have developed over a lifetime working across diverse but complementary disciplines.

Donkey domestication research questions

Patterns of early domestication of donkeys are much harder to reconstruct than for cattle, sheep, or horses, for reasons explained below, and the methodological limits – in analysis of bones, genetics, and archaeology, as well as historical bias – suggests a complexity which is challenging. Why is the early donkey domestication record still fragmentary? A number of factors are outlined here.

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1. Osteological ambiguity: wild asses equus africanus africanus vs. early domesticated equus asinus africanus are hard to separate in finds. Simply put, the core problem is early domestic donkeys look almost identical to African wild asses.

• Size reduction (a classic domestication marker) is subtle or absent.
• Skeletal proportions overlap heavily between:
  • Wild asses
  • Early domestic donkeys
  • Later hybrids

Unlike cattle or sheep, there is no dramatic morphological breakpoint.

What researchers rely on instead

• Pathologies: vertebral compression, joint stress, hoof wear
• Demographic profiles: unusual age/sex ratios (e.g., many adult males due to selective culling)
• Contextual clues: association with trade routes, settlements, animal pens, and funerary burials

These indicators are probabilistic, not definitive. Result: many early donkey bones are conservatively classified as “equid sp.” rather than “donkey”!

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The best known collection of early domesticated donkeys was discovered within mud-brick tombs linked to an Egyptian pharaoh. (Image credit: PNAS, National Academy of Sciences, Copyright 2008.) The find at Abydos, Egypt, which is about 480 kilometers south of Cairo and dating from c.3000 BCE is especially interesting because this is a direct geographical relation to the Sudan, Eritrea and Somalia to the south. The Horn of Africa is the area where fossil evidence shows the earliest interactions between hunter-gatherers and wild ass. I will expand on the Abydos donkeys in a later post.

2. Wild ass extinction erased comparative baselines

Several ancestral populations of Equus africanus are now extinct.

• Nubian wild ass: possibly extinct
• Atlas wild ass: extinct
• Other regional populations: poorly sampled or unknown

This matters because to identify domestication, you need comparisons:

“This bone is smaller / different than the wild form.”

But when the wild form is gone—or was never sampled—you lose the baseline.

Genetic lineages that appear “mysterious” today may represent lost wild populations, not separate domestications.

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3. Genetic limitations (especially ancient DNA)

a) Preservation bias

Donkeys lived in hot, arid environments, which are:

• Terrible for DNA preservation
• Especially bad for ancient nuclear DNA

Most ancient donkey DNA:

• Is mitochondrial only
• Comes from later time periods
• Is geographically patchy

b) Mitochondrial over-interpretation

mtDNA:

• Tracks only maternal lines
• Preserves ancient splits even after population mixing

This can falsely suggest:

• Multiple domestications
  when the reality may be:
• One domestication + multiple female lineages

Whole-genome ancient DNA is still rare, and without it, population models remain uncertain.

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4. Secondary introgression obscures origins

Even after domestication began, donkeys likely:

• Continued to interbreed with wild asses
• Were captured and incorporated into domestic herds

This creates:

• Blurred genetic signals
• Mixed ancestry profiles

From a methodological standpoint, this makes it difficult to say:

“Domestication happened here and only here.”

Instead, domestication may have been a long, leaky process, not a clean event.

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5. Bias in archaeological recovery

Equids are under-recovered

• Donkeys were rarely eaten → fewer butchery marks
• They die away from settlements (on routes, in deserts)
• Their bones are often fragmented or scattered

Compare this to sheep or cattle:

• Slaughtered near villages
• Dumped in domestic rubbish tips or “middens”
• Much easier to detect archaeologically

Donkeys leave a thin archaeological footprint.

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6. Trade animals leave “invisible” archaeology

Donkeys were:

• Mobile
• Owned by traders or pastoralists
• Used along routes, not inside cities

Trade routes are archaeologically ephemeral:

• Campsites reused or eroded
• Minimal architecture
• Few durable artifacts

So the very behavior that made donkeys important also made them hard to trace.

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7. Textual bias: donkeys were too ordinary to record

Early writing systems focused on:

• Kings
• Gods
• Taxes
• Prestige animals (horses, hybrids)

Donkeys appear in texts mainly when:

• Accounted for administratively
• Valued as caravan assets

They are almost never described in ways that help with origin questions.

This creates a historical illusion that donkeys “appear suddenly,” when in fact they were long-established.

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8. Domestication as a process, not an event

Modern domestication models increasingly reject the idea of “One place, one time, one moment” Instead, donkey domestication likely involved:

• Gradual taming
• Repeated capture
• Long-term human–animal mutualism
• Regional variation

But archaeology and genetics are both better at detecting sharp events than slow processes.

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Synthesis: Why the Picture Is Still Blurry

Limitation	Effect
Skeletal similarity	Wild vs domestic hard to separate
Wild ass extinction	No baseline for comparison
Poor DNA preservation	Few ancient genomes
Ongoing hybridization	Blurred ancestry
Trade-based lifestyle	Few settlement remains
Textual neglect	Sparse historical clues

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Summary

Donkey domestication is hard to see because it happened among mobile people, in marginal environments, using an animal that changed very little and left few traces. Ironically, the donkey’s success as a quiet, utilitarian animal is exactly why its early history remains archaeologically elusive.

In tracing the history of the Andalusian donkey some of the factors listed above – in the experience of those researching the prehistory and early donkey domestication in ancient civilisations – will also come into play.

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