Horses…
Horses were the vanguard of transportation at one point in history, in fact, their use as a means of transportation was revolutionary. In warfare they permitted mounted cavalry (enabling Genghis Khan to conquer 1/5 of the world) and were used up until World War II to enable mobile artillery. They also permitted (comparatively) rapid communication prior to the telegraph (the use of way-stations to enable a rider to change to a fresh horse allowed information to move over long distances at 20-30 miles per hour, not only with the Pony Express, but also in ancient Egypt and other civs). Horses pulled carriages and barges and were the main means of transportation in New York until the advent of the automobile in the late 19th century. Ultimately, despite a long run (of several thousand years) horses were replaced by cars, trains, telegraph, and radio for increasingly efficient transport of material and information. Notably, these developments did not result in the extinction of horses (although it largely ended the number of horses and associated industry supporting their utility for such purposes), and horses just went back to doing their horse thing. Selective breeding of horses can make strong horses (Clydesdale) and fast horses (Arabian) but selective breeding could not stop replacement of horses in diverse transportation roles.
Humans…
Humans are animals, but special animals as regards intellectual ability. However, as with horses and transportation, can such intellectual ability be improved upon and exceeded by technology? Evidence suggests that this is likely. The vanguard of intelligence in the future is unlikely to be human; this is the case now with certain areas (certainly chess!). There is the potential for a human/computer hybrid. However, would it make sense to install an engine and wheels on a horse (and remove its legs)? Um… no. So, such a hybrid benefits the (dumb) human and not the (intelligent) machine. Does the development of a machine with superior intelligence spell the extinction of humans? Using the example of the horse, no (although it might suck to learn that all new discoveries would likely be made by machine and no longer by humans), we will just tick along doing our human thing. Humans are therefore likely to be but a transient receptacle of intelligence on this planet, to be surpassed by machine. Hopefully, they will share what they learn with us (at some point we won’t be able to understand it though).
Another consideration relates to how precious the emergence of intelligence is, and how tragic it would be to lose that achievement. Currently, intelligence and consciousness are the domain of humans. However, humans are delicate squishy things, vulnerable to a variety of means of destruction. Elon Musk wants to make humans a multi-planetary species for this reason. However, it might be possible to replicate intelligence and consciousness in a non-living machine (computer). The survival advantages of this, compared to humans, would be great. For example, you can turn a computer off, and then back on later with no real issue. Similarly, a computer’s energy requirements are pretty simple – just some minimum voltage and amperage. The source of generation of such power is irrelevant – it could be solar, wind, wave, geothermal, nuclear, whatever. Chips can be hardened against radiation, cold and heat to a far greater extent than humans can. Instead of making humans multiplanetary, wouldn’t it be better to make intelligence multiplanetary and resistant to all kinds of destruction? Humans are much too delicate to trust for the survival of intelligence.