The term “missing links,” as I understand it, refers to evolutionary steps, considered neccessary in the evolution of man, and yet not found in the fossil record. Is this an accurate definition? If so, how many steps are there in our evolution from our nearest common ancestor? How many have we found and where? Are there missing links in the evolution of other animals? I am sorry for my complete ignorance in this matter, but biology has never been my best subject. Thank you in advance for your help. -jarrod
“Missing link” is a term more often used by jounalists than scientists. Every person is a link to those who came before and those who will come after, and the same can be said of populations in time. It’s somewhat arbitrary how we define what a species is from the fossil record, and a lot depends on whether you are a lumper (fewer species) or a splitter more species).
We do have a pretty good fossil record of the past for humans and our pre-human ancestors, even if we’re not always sure which earlier species gave birth to which later species. The Peabody Museum web cite gives a pretty good summary, and note that they haven’t drawn lines from one speices to another-- they just show the general timefram when that species lived. The last species shown on that chart is from right around the time that the human and chimp lines split-- about 6M years ago.
One of the other groups of mammals that we have a surprisingly good fossil record for is whales. I don’t have a cite for it, but if hunt around on the internet, I’m sure you can find a good one.
BTW, we had a similar thread in GD just a few weeks ago:
What is the “Missing Link” in science versus evolution?
Also, I should note that some of the species shown on that Peabody Museum chart are almost certainly not ancestors of ours, but side branches on the tree-- eg, those in the genus Paranthropus.
The term missing link dates way back into paleontological history, from a time in which the evolution of humans was not at all understood. Although a few very old skeleton parts had been found in the 19th century, most people, including many scientists, thought there was at most a single ancestor that lay between modern humans and the apes.
The Piltdown Man hoax played to these expectations. The hoaxers put together and claimed to find a human-looking skull with ape-like teeth, which was exactly what people were expecting to find. This was the missing link, ta da.
Except that over the years more and more and more remains have been found. We now understand that a great many species and even genera lay between us and our pre-ape ancestors. We did not evolve from apes. Apes and humans both evolved from a more primitive earlier ancestor. There isn’t a missing link and never was one.
So what is the line of descent from that common ancestor? Truth is, nobody knows. The fossil record is so crowded and so confusing that few specialists agree on much of anything except that a lot more needs to be found.
The site I linked to earlier, TalkOrigins.org, has lots of useful information on evolution. Its Hominid Species pages has a listing of the many human ancestors known or claimed, as well as a timeline that shows a relative listing of ancestry. But there are no lines at all. Who beget whom remains unknown for want of better evidence.
However, anyone who still today talks about “missing links” is likely to be a Creationist either ignorantly or deliberately trying to confuse the subject. You need to dump the term from your vocabulary along with anyone who uses it to you.
Actually, we did evolve from an ape ancestor and, technically speaking, we are still apes today. This gets somewhat semantic, but it’s hard to call chimps, bonobos, gorillas and orangs “apes” without also calling us apes. This is due to the fact that humans and chimps/bonobos are each other’s closest living relatives. But there is absolutely no question that the common ancestor of humans and chimps would be called an ape. And it’s ancestors, too, would be called apes going back at least 20 or 25M years.
It’s more than merely semantic. Ape fossils are in far worse shape than human fossils in terms of continuity. The breaking point even between chimpanzees and other apes is hard to find.
My understanding is that no one is willing to commit on a solid time or place for the separation or what that ancestor looked like. And that’s a separate issue from those who insist that humans are apes and that we never split.
The Smithsonian does say that:
However, this common ancestor is postulated but not known. It lies somewhere between the split of monkeys and great apes about 20 million years ago and known chimp fossils. Even the apeness of the later (c. 17 million years ago) Proconsul is disputed.
We may be descended from an early ape. The split may be somewhat earlier.
We are not descended from any of the species of apes that currently exist, which is what most people meant when they talked about missing links and being descended from the apes. If that’s the semantic distinction you want me to clarify, gladly.
The vernacular term “ape” generally does not inlcude humans, but in scientific usage (Hominoidea) it generally does.
True. We have almost no chimp ancestor fossils other than a few from around 500k years ago, for example.
We don’t know what the ancestor looked like, but most biologists put the split at about 6M years ago based on the DNA data-- which is probably a better predictor anyway. We probably wouldn’t know the last common ancestor even if we saw its fossils-- it was probably one of many late Miocene apes of which there were lots (lots more than there are today). However, no biologist that I can think of would call that ancestor anything but an ape.
Procunsol was once thought to be a human ancestor (after the human/chimp split) decades ago, but no one that I know of puts it in our post-human/chimp split line. In fact, we really don’t know if that ape was in the human/chimp/bonobo/gorilla line at all-- the Miocene had a plethora of ape genera. To be more specific, “Proconsul” referes to a range of species that lived over a long span of time, but arose sometime near the time of the monkey/ape split.
Earlier than what? There is some evidence that the two lines split about 10M years ago, and then merged again for time about 5M years ago, but I don’t know of anyone who puts the split earlier than 10M years ago.
True-- we are not descended from any **extant **ape species. But I was responding to the more general statement you made earlier that we did not evolve from apes. That was incorrect, as written.
The seems a rather severe way of dealing with the matter.
It’s good advice, although I think it’s important to understand why the term is not a good one, and to be able to explain that to others rather than just insisting that it be “dumped”. We are, unfortunately, stuck with that term and will be for a long time. And while it’s often used by creationists to obscure the facts, there are plenty of non-creationists who use the term out of simple ignorance.
I think Exapno’s first paragraph in his first post expains the situation fairly well (except it couldn’t be “at most one”, since there has to be at least one 
). It’s an antiquated term that implies some simple evolutionary sequence of: ape -> missing link -> modern humans. As the link to the Peabody Museum I gave above shows, there are lots and lots of species on the bushy branch that formed after the human and chimp/bonobo lines split some 6M years ago. Some of them, maybe most of them, have no living descendants today, but we derive from somewhere in that ancestral stock of upright apes.
It is probably worth noting that the early hominoids were most likely plains apes, with a “generalized” anatomy from which humans have adapted for large brains, upright stature, and relative hairlessness. The extant apes are adapted for rain forest/jungle habitats, specializing in a number of ways. So it might perhaps be more accurate to suggest that the apes evolved from “early manlike creatures” than the other way around.
Do you have a cite for that? When you say “early hominoids”, what exactly do you mean by “early”? “Hominoid” is synonymous with “ape”, and the early apes (~20M years ago) were not, AFAIK, plains apes. Do you mean early African Apes (Homininae)? Even then, I’ve never heard that hypothesis before.
I’d also be interested to hear in what way such apes would be considered “manlike”. They would have been neither upright nor large brained (larger than extant great apes), which are the two most significant features defining “manlike”.
So are you a user or an enabler? 
The missing link is a term that has not been used except historically for decades now. I find it hard to believe that any textbook talks about the missing link or missing links in general. It’s more than merely wrong: it represents a complete misunderstanding of the process, of a type we have completely abandoned.
I say we, because I deliberately do not mean to include Creationists. I very much fear that someone who starts a question asking about missing links has been subject to Creationist harangues. I don’t think it is extreme for someone who is generally curious about science to get Creationists out of earshot. They have no purpose to serve except to confuse and obfuscate.
I recently read The first human: the race to discover our earliest ancestors, by Ann Gibbons, the paleo writer for Science. While she concentrates on the personalties of the hominid hunters she gives a good deal of background on the hunt for the earliest fossils, and details how that line has been moved farther and farther back with the decades. I got it from the library so I don’t want to try to give details of the ape/human split - obviously my memory isn’t up to it given how long it took me to hunt down the title of the blasted thing - but it would be a good starting point for someone who is seriously interested in the subject and wants something thorough but readable rather than academic.
These are the choices you’ll allow me if I resist the notion that those who use the term “missing link” should be “dumped”?
I say let 'em stay within earshot or walk away, just as they choose. The science behind evolution is robust enough that there is no need to enforce any sort of ideological purity during discussions of it.
Should someone seek to control the discussion, refuse to consider evidence, reject other’s views without reason, etc. then they certainly should be asked to leave. But that would be right in any rational discussion, regardless of their ideology.