What Common Ancestor Would the Basic Fantasy Races Evolve From?

Question

In the world that I am building, I have four (major) races: Human, Elf, Orc, and Dwarf.

Humans are the run of the mill; average in physiology, psychology and magical ability. They can survive almost everywhere.

Elves are tall, thin, and significantly faster than any other race. Higher than average intelligence, but significantly weaker in magical ability. They don't survive very well in colder climates, but can.

Dwarves are short, stocky, but proportionate. Their muscles are denser than humans and elves, so they are stronger than average. They are not fast, but can easily outlast their opponent in battle. Their magical ability somewhere between a human's and elves, with elves being behind. They do not do well in warmer climates.

Orcs are thick, massive, and brutish. Their race is the strongest in physiology and magical ability, and lacking in psychology. Literally can survive anywhere.

The way the races' bodies are set up are basically the same.

The problem I am having though, is what's a plausible common ancestor to all these races? Since all these races are humanoid, and bipedal, would they still come from a monkey like common ancestor? Or would it be that millions of years ago, a human was their common ancestor?

Knowing a plausible answer to this would impact how the Orcs and elves of this world would view the other races around them.

Answer 1

If one took a common ape ancestor, one could consider these as terrain-related specialisations:

Elves come from heavily forested regions where little light and little of value reaches the forest floor, so they have remained arboreal. Consequently they are light, deft in movement and have excellent spacial awareness. If you wanted to break from the classic fantasy forms, you could give them long arms and fingers, strong for climbing and swinging between branches.

Dwarves may come from one of two places- conventionally they may live in caves, so a smaller body is strongly selected for as it allows them to travel deeper and escape through narrower crevices, escaping dangers of various kinds. To break from classic forms you could give them some of the adaptations of cave creatures- loss of skin pigmentation, poor eyesight, enhanced spacial senses.

Alternately they could be a consequence of island dwarfism, a little like Homo Floriensis are believed to be, which is a very common evolutionary occurrence.

Orcs may be the kind of creature that one thinks of as being brutal and destructive, but their large body type and large population suggest to me that they might actually be more like a hominid bison. A bipedal body layout wouldn't make sense if they were grazing, but living on low-level vegetation would still make sense. This is quite an interesting concept to me as it indicates a very peaceful origin to these people.

Humans present more of a problem as the classic generalists - they will adapt and destroy the environments that produce these other subspecies if they can. Consequently they either need to have good reason to avoid them altogether during the speciation process or they need to be geographically separated- maybe on another continent with challenging sea conditions dividing them. Once the subspecies do meet, the humans are likely to force the others into more defensive situations through natural aggression and destructiveness, which would be a natural source of conflict.

Answer 2

Humans, elves, dwarves, and orcs (HEDOs henceforth) all have the same basic body plan -- they are upright bipeds with four limbs. So the same would be true for their latest common ancestor (LCA).

For reference, the split between humans and chimps occurred about 6 million years ago, and that between humans and gorillas about 10 MYA. So you are looking at a similar timescale between the "present day" and the time of the LCA for HEDOs.

Most likely, the LCA would not closely resemble any of the HEDOs. The common ancestor of humans, gorillas, and chimps was basically ape-like, but clearly different from all three modern species.

A more interesting question is what selective pressures created the differences between the HEDOs. As with the famous Galapagos finches studied by Darwin, adaptations occur because they provide a survival advantage. What was different in the environments of elf-ancestors and orc-ancestors, such that elves are slender and delicate while orcs are big and muscular?

Answer 3

As far as we know, developing sapience is a rare thing. So having four races develop sapience at the same time seems highly unlikely. Therefore there common ancestor should have sapience.

Now how would it look? Well as long as it keeps most of the traits common to all four races, that means that it is bipedal. However how much fur it would have is complicated given that we don't know where it lived. In any case knowing where this common ancestor lived could help. Maybe your four races then separated because they went and adapted to different climates?

Answer 4

Since the races are very similar, they are essentially all subspecies the same species, in fact, in fantasy it is common to have an ability to crossbreed.

So essentially some time in the last million years or, probably nearer the short end of the scale, but more than 100ky or so, an earlier species of humans was split by geography and the separated parts have evolved in different directions and have not have time to "fuse" back together. This implies the geographical obstacle was removed relatively recently, in the last thousand years or so, or that the species are still mostly separate.

In practice, seas and deserts are most likely separating factors as sea levels and rain fall patterns change with climate, so new seas and deserts are born. For example, you could have four continents that used to be linked by land bridges (like the Bering Strait), but the land bridges were lost to rising waters and drifting continents over 100 000 years ago, and Ur-humanoids on the continents evolved in different directions. This would have been helped by mixing with previous human population as happened when humans migrated out of Africa. But recently people have learned how to build ships capable of crossing the oceans...