The Missing LinkThere persists an idea that we haven't yet found the "missing link" between humans and our ape-like ancestors. There's two major problems with this idea.
(1) The Fossil Record
(a) It's really hard for bones to fossilize. They normally disappear completely. We're lucky to have what we have. Wishing for this perfect midway point between modern man and modern* ape is wishing for something you're not going to get.
(b) Despite the difficulty in fossilization, we actually do have a respectable amount of fossils of our ancestors. Many intermediate species have been found. Wikipedia has more on this for a basic primer. The more interesting advancements in evolutionary understanding are coming from molecular evidence nowadays.
(2) Outdated Biology
The classic drawing of the evolution of humans is misleading. It's seen below.
The problem with this is the straight line. This gives people the impression it's a straight path from A to B. Started out as what looks like chimps, end up as modern humans. A --> B. End of story. That's not quite the case. Evolution isn't one linear path. It's more like a tree with many branches. They go off in different directions and sometimes cross back again. You can start with one species on a planet, come back in a million years and have thousands (if not millions) of different species. While each "end product"** did have a linear path from its earliest ancestor, there are many different end products. The early ancestors went in many directions.
Someone quipped that creationists will never be happy with the fossil record anyway, since each new find creates two more gaps in the record. Stop and think about that for a minute. We have #1 in hand. We have #50 in hand. Someone complains that we don't have anything representing the gap in between. So we happen to find #25. There, found your gap. They can just turn around and complain that now there's two gaps - we need # 15 and #42. Each discovery opens up two additional gaps. You can't find them all unless you find every fossil which has ever been in our lineage. And that's not gonna happen, due to the nature of fossilization.
Biology has also learned a lot in the past hundred years. It used to be thought that the line from species to species was very distinct. Species A stops here, Species B starts here, never the twain shall meet. It doesn't actually play out that way though. It's more shades of gray.
I wish I still had The Ancestor's Tale handy. My memory fails me on the name of the species, but one part of the book talks about a group of critters that lives in a large region with a river in the middle. They cover a wide area, but they stay in small areas in groups. I'll try to draw a crude map from memory. (Remember, this blog is by the retarded for the retarded!)
There, that looks hideous. It'll do. The blue in the middle is the river. The reds are critter clusters.What I haven't told you yet is that the creatures on the far left and the creatures on the far right are actually different species. Very similar, but not quite the same. The groups keep mostly to themselves, and over many many generations they have started to evolve independently from one another. There are actually several different species, technically speaking, as you go from left to right. Very very similar, but not exactly the same species.
But they're so closely related that they can interbreed with their closest neighbors. They don't usually do it, but they can. The ones from the far left (group #1) can breed with the ones that are just to the right of them. We'll call that group #2. Group #2 can breed with group #3. Group #4 can breed with group #5. So on and so forth. But when you get to the far right (I'll call 'em group #10), they can't breed with group #1. The two species have become so different that they can no longer produce offspring. The black-and-white differences between Group #1 and Group #10 are filled in along the way with the shades of gray in Groups 2-9.
This is a pretty good example of how evolution works. Colonies separated by distance (or other factors) keeping to themselves, eventually creating offshoots just different enough that they become genetically incompatible. Thus, we cannot breed with modern apes today.
Just think of all of our cousin apes were still viable species today. Think if we couldn't mate with an ape, but we could mate with a (whatever #1), which could mate with a (whatever#2) and so on and so forth until you get to modern apes. Think of what this would do for sex laws! Bestiality might be OK if you could produce offspring. You think? I don't know. But I do know one thing. Apes Gone Wild would be a best-seller.
* which presents a whole other issue, because people expect "modern" apes to be our ancestors, which is not the case
** even the term "end product" is misleading. there is no goal or end. evolution is, after all, just a baby-making contest. it only stops when the baby-making stops, though it might seem to take breaks at times.
Labels: evolution, missing link
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