Evolution and the Missing Link: Why Is It Missing?
When we say "missing link," we invoke a metaphorical chain, a set of links that stretch far back in time. Each link represents a single species, a single variety of life. Because each link is connected to two other links, each is intimately connected to past and future forms. Break one link, and the pieces of the chain can be separated, and relationships lost. But find a lost link, and you can rebuild the chain, reconnect separated lengths. One potent reason for the attractiveness of this metaphor is that it allows for the drama of the quest, the search for that elusive missing link.
Charles Sullivan and Cameron Mcpherson Smith go on to explain in the May 2005 issue of Skeptical Inquirer that while the metaphor is seductive, it's mistaken:
But the metaphor is as misleading as it is attractive. The concept that each species is a link in a great chain of life forms was largely developed in the typological age of biology, when species “fixity” (the idea that species were unchanging) was the dominant paradigm. Both John Ray (1627-1705) and Carolus Linnaeus (1707-1797), the architects of biological classification (neither of whom believed in evolution), were concerned with describing the order of living species, an order they each believed was laid out by God (Ray suggested that the divinely specified function of biting insects was to plague the wicked).
But while the links of a chain are discrete, unchanging, and easily defined, groups of life forms are not. We generally define a species as some interbreeding group that cannot, or does not, productively breed with another group. But since species are not fixed (they change through time), it can be difficult to be sure where one species ends and another begins. For these reasons, many modern biologists prefer a continuum metaphor, in which shades of one life form grade into another. Life is not arranged as links, but as shades. The metaphorical chain is far less substantial than it sounds.
Thus the chain metaphor is wrong. It doesn’t accurately represent biology as we know it today, but as it was understood over four centuries ago. The myth persists because of convenience; it is easier to think of species as types, with discrete qualities, than as grades between one species and another. In school, we learn the specific characteristics of plants and animals; this alone is not a problem, except that we are not often exposed to the main ramification of evolution: that those characteristics will change through time.
So, our idea that there can even be such a thing as a “missing link” was created in an era of biological research which is long gone. It’s a concept which is no longer valid in our current understanding of the nature of life and evolution — but, as is so often the case with appealing concepts, it continues to live on, to structure people’s assumptions, and to influence how they think about evolution.
This is almost always an unfortunate situation, but it is especially unfortunate here because the concept of a “missing link” creates confusion and misunderstandings which creationists are able to exploit. Perhaps the creationists know that they misunderstanding things; more likely, though, is that their misunderstanding is completely accidental and, in fact, one of the reasons why they are creationists in the first place.
Life is more like a spectrum than a chain, but not a spectrum with discreet ends. It’s a spectrum in that there are gradual transitions from one species to another, all of whom are certainly linked together, but no discreet links in a chain which can be broken, repaired, or readily followed. The more people understand this sort of thing, the better equipped they will be to understand evolution as a whole — not to mention the entire field of biology itself.
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Comments
I will confess, the idea of links is more intuitive than shades. A continuum works for a direct line of descendancy, but when you have branches and forks (as when 2 or more new species branch off from a common ancestor), continuums and spectrums aren’t as easy to visualize. Maybe the best analogy in this case would be the classic tree of life.
I don’t give much credence to creationists’ use of “missing links” or missing transitional fossils to somehow disprove evolution. Supply them with one, and they just ask for the one in between the missing link and its ancestor and/or descendant. If they had their way, evolution could be proven only with a complete fossil record of every plant, animal, and germ that ever lived in the history of life on Earth. (Which is to say, never.)
That’s the best you can do? Don’t worry about explaining what we can’t explain because life is a spectrum! What a load of crap!
Perhaps if you represented the argument correctly, instead of creating a straw man, it wouldn’t look like a “load of crap” anymore. Ironically, the demand for “missing links” comes from others who themselves in the process misrepresent what evolution is, so it’s really not surprising that attempts to correct this would also be misrepresented.
If the idea is so outdated and doesn’t make any sense, it’s interesting why scientists also claim to be searching for it.
http://news.nationalgeographic.com/news/2006/04/0413_060413_evolution.html
If the changes are ‘gradual’ like you say then we should have some fossils to prove that. Thanks for a bull**** article against creationists. Quit wasting peoples time.
The problem with providing links like you did is that readers can see how you are misrepresenting things. The article says nothing about scientists searching for the sort of “missing link” described in my article. In fact, none of the scientists quoted use the term “link.” Did you notice that?
That statement wouldn’t be made by anyone who understood how hard it is for fossils to form.
Whereas your comment, consisting of nothing but misrepresentations and falsehoods, represents a good use of time?
Go to the museum at the La Brea Tar Pits and see change over time. They have pleanty of fossils there.
… or check out my youtube video showing gradually progression from a common ancestor with chimps to us.
http://www.youtube.com/watch?v=1dvqq7y_SCw
For a more accurate video, check this out http://www.youtube.com/watch?v=sZ2WoHFc7eE&feature=related
To Greg and others who share his views on evolution,
You do realise that thousands of fossils of various forms of life have been found right? Including missing links. Its not open to debate anymore, go to any decent secular museum and they will most likely have such a fossil, or at least information of musuems that do have them.
So how about next time you get your facts straight before wasting people’s time?
The best comment I can make to you as a former science teacher comes from Dr. Thomas Dwight of Harvard. He states, “We have now the remarkable spectacle that just when many scientific men are agreed that there is no part of the Darwinian system that is of any good influence, and that, as a whole, the theory is not only unproven, but impossible, the ignorant, half-educated masses have acquired the idea that it is to be accepted as scientific fact.”
Tell me, from which book of dishonest apologetics or pseudoscience did you scrape that quote? Had you deigned to investigate it further, you might have learned that Dr. Thomas Dwight was an instructor of anatomy who died in 1911.
This means that the “now” of the quote was, at best, a reference to the first decade of the twentieth century — long before many of the discoveries which have proven not only the evolution is a fact, but also that evolutionary theory is as sound and solid as other scientific theories like Plate Tectonics. Don’t you suppose that there has been quite a bit of advancement in the past century?
A bit more investigation might have also revealed that evolutionary theory is the very foundation of modern biology. Evolution is the framework which binds together all the various aspects of biology in the same way that Plate Tectonics is fundamental to geology. Don’t you find it curious that there is hardly anyone in science today who takes the position which Dwight stakes out — and that those who do all do so for religious rather than for scientific reasons?
I find myself compelled to wonder if any of this disinterest in history, research, and facts is in any way related to why you are a former science teacher, and not someone who currently has any responsibility for teaching science to young people anymore. It is certainly interesting that the “best” comment you can make on a scientific matter is a century-old quote from an anatomist who is now better known for his contributions to Christian apologetics than to the advancement of science.