"If I descended from an ape, how come apes are still here?"

If we descended from apes, how come apes are still here?What’s wrong with this picture? Well nothing or pretty much everything — depending on what you think it shows.If you see it as man evolving over millions of years from ape-like ancestors, you’re right. But if you see it as a picture of how modern monkeys change into people, that’s probably why you may ask the question:If we descended from apes, how come apes are still here?To ask that question means that there’s a vital piece of information missing from the questioner’s understanding of what evolution is. That vital piece of information is the concept of the tree of life, that all things are related to each other.An evolution scientist on hearing that question might ask you a question back. Such as:"if I'm descended from my grandfather, how come he still exists?"orIf dogs are descended from wolves, how come there are still wolves?Here’s fuller explanation.Chimpanzees are apes and one of our closest animal relatives - their scientific name is Pan troglodytes.Now, imagine that you are standing face to face with a female chimpanzee - let’s call her Pan. With your left hand you are holding the hand of your mother and your mother is holding the right hand of her mother and so on for thousands of generations back into the past. By doing this, you know as an absolute certainty that you are descended directly on your mother’s side to everyone in the chain.Imagine that Pan is doing the same but with her right hand.You now have two imaginary lines of women and female chimps holding hands going backwards in time - like a railway track with women and chimps lining each side.You can now walk down the centre of the rails and look carefully at your mother's family line and the chimp's family line going back millions of years.So what would do you see?Walking back about 200,000 years on the human side you see a mother who’s husband was a chap science named Heidelberg Man (Homo heidelbergensis ) she’s distinctly human, using tools and standing upright, probably hairless and very tall — the males are up to 7 feet tall. This is the first different species that we’ve come across in our chain. But you wouldn’t be able to tell exactly when Homo sapiens (people) merged into Heidelberg because each mother would look almost identical to the next — you can’t see the join. The changes from mother to mother are so gradual that you only see a change by comparing mothers thousands or millions of years apart. We only now know that Heidelberg is different from us because we’ve found his fossilised remains and we can compare it to ourselves today.This is why there’s no such thing as a transitional fossil or a missing link; every fossil is a transitional fossil and every living species is in transition to the next — if we had a fossil for every mother in the lines, even the experts wouldn’t be able to say where a separate species had been formed. We can only guess with hindsight.If you find this hard to grasp or you think it’s impossible for one species to change slowly into another we can see it happening today. For example, we call species that change slowly over geographic areas rather than over time, ring species.Here in the UK the Herring Gull and the Lesser Black-backed Gull are distinct and non-interbreeding species. But if you physically follow the Herring Gull west towards North America it gradually blurs into something more like a Lesser Black-backed Gull. It carries on changing towards Siberia and when it finally returns to Western Europe the Herring Gull has become a Lesser Black-backed Gull and the two species don’t interbreed. At no point in the ring can you say exactly where it changed species — it’s a gradual merging of characteristics over distance.As you walk back further, at about 500,000 years ago, you’d see a branch form and go off sideways from our human line, these are the Neanderthals (Homo neanderthalensis). They lived along side us but developed separately. There may even be Neanderthal mothers in our line, because we think that for some time there was interbreeding.And so on down the line of mothers through increasingly apelike creatures until at about 2.5 million years ago we reach an animal called the Southern African ape (Australopithecus africanis). This creature is small — around 4 feet, with a brain a third the size of ours and although she stands upright like us, she’s covered in hair and is distinctly apelike. We used to think that this is roughly where chimps split from the human line but modern molecular genetics tells us that it was earlier.We have to walk much farther down the lines to get to where most evolution scientists think chimps branch off - somewhere about 7m years ago. This mother would have looked something like a chap called ‘Taumai’ (Sahelanthropus tchadensis). He has the same brain size as a modern chimp but his face is a little more like a human than a chimp.No one knows for sure whether Taumai is the point where chimps start off on their own line but we do know one thing for certain:Wherever the split actually happened, at this point in the two lines of human and chimp descendants you would see that the right hand of a mother from the chimp line is now holding the left hand of a mother from the human line.
The lines have met — the ancient chimp and the ancient human have the same mother.This mother starts the lines to both Pan and you, so Pan is your distant cousin. And both you, the human, and Pan, the ape are still here.So the apes developed along one line and we humans along another. We were in competition with each other whilst in the forest but the reason that there wasn’t only one final surviving winner is because our ancestors moved from the trees onto the open savannah grasslands whilst the apes stayed in the forest.Once in the open we HAD to adapt to survive in the new environment; walking upright in order to run quickly and for long durations, losing hair to keep cool, developing tool use in order to hunt. The apes in the forest were already adapted to their environment so they developed along their own arboreal paths.

What we can surmise about Pan Prior:It lived in African forests more than 6 million years ago.
When the Ice Age made forests shrink about 7 million years ago, Pan Prior was split into two subgroups. The subgroup that spread to the grasslands became man.
It may have been tool-using, as both species to evolve from it are. (On the other hand, Chimp tool use might be geologically recent, say the past 4,300 years or so)
It was probably rather smaller than modern humans.
It was generally a very adaptable species, willing to switch up it's behavior to survive in new environments.

One obvious thing you'd see straight away as you walked down the human line would be the height and age of the mothers - they would get progressively shorter and younger wouldn't they?

On the chimp line, nothing much would change except over millennium.

Anyone know off-hand where the parallel lines meet - pan prior? - what it would look like and where it would live? (Meanwhile, Google is my friend..)

I'm trying to pull together a more complete explanation so that someone for whom the idea is both new and difficult can understand. There are plenty of people that are entirely puzzled by it but are prepared to try.

That's not the explanation; it's the cause of the confusion.

The idea that humans were all shorter, then 20th century nutrition suddenly shot them up in height is dubious. An analysis of the 43 people buried at a mass grave near the Battle of Towton (1461, for those whose British history isn't so hot) showed that their height varied from 1.5 to 1.8 metres tall. This puts them in the range of average height for English men today, and leaves the average a bit taller than men in 18th century England. These things vary.

The flip responses given by Dr. Adequate, PaulK, and others in this thread ought to be sufficient to see that the question misses the mark. Someone who cannot see that the question is facially ridiculous given those answers is never going to understand a more detailed answer. Don't waste your time.

Ah, but you've grown cynical and case hardened; I'm new here and haven't had to give the same answer a thousand times yet ;-)

- We don't know much about the details of what we would see down the chimp line. They were forest-dwellers, and things don't fossilize as well in forests as they do in the savannahs where the human line largely lived.