Not sure if you're being completely serious, although obviously the bit about speaking Spanish is humorous.
The "we all came from apes" idea is often misunderstood. It is easy to assume that we are the peak of evolution, and that each step on the way to
Homo sapiens was an improvement in "absolute" terms. This is not true: the slug or the great white shark, or the sparrow have evolved to fit their niches.
The Victorians were only able to accept the idea of descending from the ape by superimposing the idea of some sort of greater purpose on evolution: all of evolution was somehow assumed to be aimed towards producing the civilised white European and — horrific to us today — black people were a sort of half way house, having evolved sufficiently to be useful to white people.
However, the real idea of evolution is a series of interconnected ideas:
- From time to time, there will be small mutuations. Darwin himself would not have understood this in terms of genetics, chromosomes, and molecular biology, but we now do.
- From time to time, two animals of the same type, but with a shared "extreme" (a very slightly longer neck, thicker beak, darker fur, etc.) would mate and produce offspring that had the same characteristic, and perhaps even more so.
- These changes would fall into one of three categories:
- Disadvantageous. The creature would be less likely to survive to breed successfully.
- Neutral.
- Advantageous; The creature would be more likely to survive to breed successfully, passing on its characteristics.
It's all a probabilities game. If your species as a whole has a 25% chance of each specimen surviving to breed, then an advantage that makes your chance 26% means you are still more likely to die before breeding, but, across large numbers of specimens, your type will survive to breed about 4% more often. Over 10 consecutive generations, a 4% advantage becomes a 48% advantage, which is substantial.
The creatures best adapted to a given niche would be more likely to survive and breed.
The creatures less well adapted would be more likely to die before they reached breeding age. However, the less well adapted creatures had options including:
- Moving geographically to a different environment and finding a niche where they could survive.
- Moving to a different niche in the same environment by changing, for example, their diet or behaviour.
So what happens is a divergence. Some creatures are well adapted for the niche in which they find themselves. Others need to find a new niche or they die out. The fact that subspecies Y learns to survive on the edge of the forest does not mean that the original species X cannot continue to live in the middle of the forest.
The two populations gradually grow apart as they occupy different niches, and are less likely to interbreed. Eventually, you have a situation in which the original species X is more or less unchanged in its original environment, and the subspecies Y has continued to adapt to fill a completely different niche.
Meanwhile, the environment is constantly changing. Temperatures may increase or decrease; water levels may rise or fall; predator or prey species may evolve or migrate. Therefore, something that may be a disadvantage or merely neutral may suddenly become an advantage, and something that was previously an advantage may become a hindrance.
