Would a human-like symbiotic pair of the same race be possible?

Question

Would a human-like race be possible where the young and their parents live and work etc in a symbiotic pair?

My idea is inspired by the character(s) Ferra Torr from the game Mortal Kombat X, the young of the species would be the ‘jockey’ and the old the ‘brute’. The young would be smart and cunning but weak and small and the old less intelligent but much stronger, tougher and bigger but in need of the jockey to guide and help the most of the time. This would mean the species must undergo a change at some point in which their muscles, bone etc. Would rapidly grow but parts of the brain responsible for thought and decision making would decay.

Would this mean an extreme puberty for the species could happen but one in which this is the only period of fertility so a mate must be found so the offspring can become the ‘jockeys’?

As a development on this how would they develop as a civilisation and what kinds of weapons and warfare might they use?

The world I imagine them to live is an arid desert and with an Aztec style of architecture and design. I also don’t want any magic or sorcery just seeing if anyone can help me with ideas of how this species may have evolved and if it would be possible.

Answer 1

Is it okay if we turn it around a bit?

That is, have the Tank be the youngster, and the Jockey be the older one.

Why? Well ... it makes more sense for the old one to be the clever one. Imagine a species which evolves in an environment poor in food except for certain periodic windfalls, like a salmon run which only comes every several years. Here's how it works:

The adult, stable form of the creature is the skinny one. It needs all its cunning to survive the lean years, and its smaller form requires less food. Shortly before the salmon come, the creature spawns. The younglings gorge on the plentiful food, and grow large, fast. They'll need all this extra mass, because they're not yet smart enough to hunt the other, more clever prey in the region. When the lean season comes, the youngsters go through a kind of "reverse molting" where, as they deplete their food reserves, they shed their outer layers to reveal a smaller armor shell. Eventually you're left with the adult-form creature.

So there are actually four forms, of which we only care about two:

• Newborns -- too small to be ridden, they're busy eating salmon and getting fat

• Tanks -- These are the adolescents; they're big, dumb, and just the right size to bear a Jockey

• Jockeys -- These are the dangerous ones. Still vigorous, smart, nasty, and fast.

• Geezers -- Jockeys eventually get too old to ride into battle. So they retire, sit on the porch, and tell lies to the wide-eyed Tanks.

Answer 2

It is a cheeseball Mortal Combat inspired question I have been pondering. But I am not thinking of a battle team. I am thinking of a family. I can imagine the grandmother in exactly this role, because sometimes she is. Here is a piece of an interview with anthropologist Sarah Hrdy.

http://www.froes.dds.nl/HRDY.htm

It is a very gripping image of a male who has an infant in his mouth. The image is blurred, you can just see the tail of the infant, its body flying off in space. And two females are charging the male to try to get that infant back.  The fascinating part is that neither female is the infant's mother. They are both older females in the group. The one in the forefront, a female called Sol, was almost certainly a close relative of the infant, perhaps a grandmother, perhaps a great aunt…  

What about the mother of the infant?
 
The mother of the infant herself was a young female at the peak of her reproductive career. Much more cautious, sitting on the sideline, letting the older females protect the infant.  In fact there are other cases where a mother for example allows her infant to drop from a tree, the male will rush to it, and it is not the mother who goes down to save it, it is again these older females.

  Why these older females instead of the mother?  

What I believe is going on is that females with a lower reproductive value have a different cost-benefit ratio for taking chances on behalf of relatives. This can be seen in other contexts. So for example McCarthy and Bugos, when they collected data on maternal infanticide among the Ayoreo Indians in South America, found that very young mothers and mothers with high reproductive value were much more likely to give up, and not go on with an infant under bad circumstances. Whereas an older mother will go ahead, no matter what, because she is getting near the end of her reproductive opportunities.

When the baby is in trouble and saving it requires personal risk, it is the old ones who rush in and risk themselves. The mother can have another baby, but not if she is dead. The grandmas and great-aunts are not going to have more babies: the young that are there are their whole genetic legacy. So they have more at stake and less to risk preserving the genetic legacy.

Imagine the grandmother: fearless and durable. Large. Her English is not good. No education, not too smart but paying close attention. The daughter is little and wily, making decisions, calculating the odds, shucking and jiving, working to find what they need in the world - she and the grandmother and probably the baby. The grandmother follows along.

And when the bad man comes, the grandmother steps in front. "You think you will kill me? You will kill me. But as you kill me, I will hurt you so hard you will always remember me." Bad man sizes her up, weighs the odds, decides to move on.

You know there are grandmas exactly like this in the world now. Can you picture them? You have to go through them to get to the family, and it might just not be worth it. A good team, I think.

Answer 3

I do not think that your suggested scenario is feasible.

One of the big advantages of the old age is experience and knowledge. If your people lose their ability to think clearly and make decisions after puberty, intergenerational knowledge transfer will be severely compromised. All the useful experiences that they encountered during their lifetimes will be forgotten and lost.

It will be also almost impossible for any more or less advanced technology to develop. It takes many years of practice to master many skills. Moreover, a lot of pre-industrial technologies rely on muscle memory and experience. Take metalworks as an example.

A well-trained and experienced blacksmith can determine whether a metal is hot enough to be worked just by its colour. However, it takes years of practice and master supervision to acquire this skill. In the Middle Ages, blacksmith apprenticeships lasted from 7 to 10 years. After that, a young smith would work for several years more as a journeyman, basically a hired help for local smiths within a day journey distance. So, it took about 15 years for a person to become ready to open their own blacksmith shop. It might take even longer to become a recognised master.

You also need to consider that while today physical strength does not mean much it was very important in earlier times. Without mechanisation and power tools a weak and small person will have a lot of troubles doing any crafts no matter how smart and cunning they are. You could use your older 'brutes', but it might be difficult to produce anything delicate or intricate since they require constant help and guidance as stated in your conditions.

Care for 'brutes' might also take too much time. The way you describe it, your young will be on constant duty of watching after strong, big, tough, and not very intelligent beings. Imagine you have to take care of a child twice your size... Not to mention all the food that has to be produced to feed them.

I think that in order to make this work you can do one of the two: 1) reverse the age relationships, i.e. youngsters are big and stupid and elders are small and smart; 2) make it two species that evolved together to live in complementary relationships.

No matter what you choose, the most important thing for a successful civilisation is passing knowledge on next generations. Also, smart and cunning < wise and experienced.