Why do so many people fight the idea that humans evolved from simpler life forms?
Perhaps, this resistance is the natural consequence of the “chain of being,” the long-time teaching that God and the Angels are the most superior forms of existence, humans inferior to them, and “beasts” and plants more inferior still, with rocks at the very bottom.
[The 1579 drawing of the great chain of being from Didacus Valades, Rhetorica Christiana]
Even though biology does not recognize a status hierarchy among living things, the “chain of being” schematic nonetheless lingers in the minds of some people, especially among people who fail to appreciate the immense biological record uncovered by dedicated scientists, the importance of the scientific method and the elegance of evolutionary theory.
Those who oppose evolution tend to be the same people who go around dissing organisms traditionally plotted lower on the chain of being diagram. A good example would be the (lack of) respect given to sponges. You can almost hear the fundamentalists spitting and hissing as they utter something like the following: “How dare those evolutionists claim that we come from sponges!”
To me, however, this reasoning does not reveal a scientific dispute, but only ignorance regarding the intimate biological relationship between humans and sponges. I find the harsh anti-evolutionary rhetoric of fundamentalists to be, essentially, anti-spongist. Since one can further trace human ancestry all the way to bacteria, I find such reasoning also anti-bacterialist. It makes me want to shout: You anti-spongists! You anti-bacterialists!
The remedy for this attitude problem of fundamentalists is that they need to take the time to honor and appreciate the complexity of “simpler” organisms. It turns out that sponges aren’t so simple. They are incredibly complex. They are a most honorable ancestor for humans. Those who allegedly oppose evolution need to appreciate the following, for instance:
[It]’s with the sponge that pre-animals began to take shape, [evolutionary microbiologist Mitchell Sogin] believes, because the sponge was first to grow different cell types. For all their simplicity, sponges have “a lot of organization.” With their choanoflagellate-like choanocyte cells and a second type of cell, an archaeocyte, that can shift shape and function as needed to absorb food, secrete new skin, or reproduce, they became the first multicellular animals. All the other animals emerged from this simple architecture and are built upon this platform.
An excellent DVD set tracing human evolution from sponges is “The Shape of Life.”
The remedy for all of those rampant anti-bacterialists would be to take the time to appreciate the beauty and complexity of single-celled organisms. An elegant and detailed book addressing the complexity of single-celled organisms is The Way of the Cell, by Franklin M. Harold (2001). Consider the respect and admiration Franklin shows for the complexity of single-celled organisms and the molecules that constitute them:
One response to the question, “What Is Life?” is simply, Look around! Note the birds and butterflies, zebras and ammonites, the intricate web of life present and past, and join the unending struggle to ensure its continuance in the face of human arrogance and mindlessness . . . For the past 40 years I have been immersed in research on the biochemistry and physiology of microorganisms, with emphasis on the fundamental aspects such as bioenergetics and morphogenesis. In consequence, the central problems of life present themselves to me at the interface of chemistry and biology. How do lifeless chemicals come together to produce those exquisitely ordered structures that we call organisms? How can molecular interactions account for their behavior, growth, reproduction? How did organisms and their constituents arise on an earth that had neither, and then diversify into a cornucopia of creatures that enlivened each drop of pond water? My purpose is not to “reduce” by biology to chemistry and physics, but to gain some insight into the nature of biological order. In an earlier book, I wrote that “Living things differ from nonliving ones most pointedly in their capacity to maintain, reproduce and multiply states of matter characterized by an extreme degree of organization.” This still rings true; biological organization is the key to the nature of life, and the central theme of this book.
We must also inquire how molecules are organized into larger structures, how direction and function and form arose, and how parts are integrated into holes. Besides, we must never forget that molecules, cells and organisms are all creatures of history, brought forth by the interplay of chance and necessity. There can be no simple answer to the question, “What is life?” It is an invitation to explore the successive levels of biological reality, and a lecture on molecular biology is intrinsically no more (and no less) illuminating than a walk through the woods in the springtime.
More than half of the people in the United States claimed that evolution has nothing to do with the existence and form of human animals. In my personal experience, these sorts of people despise the thought that humans are animals. I don’t think such people should be registered as opposing evolution, however. I hold this view because most “anti-evolutionists” to whom I have spoken have no understanding of what evolution actually is. Most of them claim that evolution is just a theory that says that everything here is just an accident. For this reason, honest future polls should first determine whether people really understood the scientific theory of evolution before asking them for their opinions. If this were done properly, almost all of the people currently opposed to evolution would no longer register as “opposed.” Instead, they would fall into the category “I don’t know enough about evolution to answer this question.”
Those who don’t yet have a detailed grasp of evolution need to dedicate a measly 5% of the time they spend tending to their soap operas, sporting events, sitcoms and Bible-thumping religious leaders and to reallocate this time to reading a few good books on evolution. If they would dare to do this, they would be positioned to truly understand the immensity, the grandeur and the elegance of the still-evolving human story. A good place to start would be The Ancestor’s Tale, a 2004 work in which Richard Dawkins describes human pilgrims walking back in time on trails corresponding to the evolutionary tree, passing forty rendezvous points at which the humans meet their own ancestors. It is a terrific read filled with fascinating details. One example illustrating the great power of evolution (in this example, by artificial selection) is this: taking the tamest wild silver foxes of each generation, one group of zoologists produced foxes that behaved like border collies in only 20 years!
For some, however, careful study won’t be enough. Perhaps their religious leaders have succeeded in making the topic of evolution just too toxic a thought for them. Perhaps, for them, we’ll have to invoke desperate temporary “trojan horse” measures. Perhaps they could at least be enticed to pretend that tiny bacteria read tiny Bibles and worship a big bacterium in the sky on Sundays. Using that as a cognitive beachhead, we could then slowly stir in some real biology. It would be a mistake to use such a crutch for very long, however. To do so would be to miss the most spectacular story on the planet.
Although individual organisms are genetically locked in–frozen accidents–populations of organisms are always on the move, even when they appear to be sitting relatively still, like sponges. A toast, then, to our worthy ancestor, the sponge!
It seems to me, after seeing more than a few shows on the religious television networks, that many Christians simply *want* to believe evolution is nonsense; that life did not arise spontaneously on our planet; and that humans did not descend from prosimian ancestors. They *want* to believe the Bible creation is literally true.
Similarly, they *want* to believe that same-sex marriages will damage the institution of marriage (whatever that means); that mandating prayer in public schools will make kids more earnest in their studies; that sending more people to prison will reduce crime; that global warming is a hoax invented by radical liberals; that "abstinence-only" sex education is more effective than any other type of sex education; that handing out free condoms in schools will increase the incidence of STDs; that banning abortions will stop them from happening; that banning flag burning will make people more patriotic; that bombing innocent people in Iraq will reduce terrorism…the list goes on and on and on. In sum, time and time again, I have seen examples where Believers simply don't care what the facts are about much of anything. They *like* being told they're special; they *like* being told God listens to their prayers; they *like* being told that people who disagree with them will burn forever in a lake of hellfire; they *like* being flattered by nice-looking preachers who wear expensive custom-made suits and French-cuffed shirts; they *like* being told America is winning the war on terrorism (whatever that means)….
Of course, what is unusual about these Believers is not that they prefer to hear things they already agree with or that they want to be told they're right — most humans are the same way — what is unusual about these Believers is that their *desire* to believe a particular worldview (or their desire to bloviate about their religious beliefs) trumps all real-world data. They have apparently been so deeply infected with cognitive dissonance, for such a long period of time, that they actually think they are healthy and the rest of the world is diseased.
I've seen a variety of those polls, and often when you see a large number of people saying they disbelieve in evolution, they usually just disagree with the part that includes humans. In many of the polls on the subject that I've seen, anyway, the question at hand deals only with human evolution from monkeys (perish the thought!) and not evolution of "lower" life forms. Most people don't dispute the evolution we can witness in fruitflies or in Darwin's finches, for example. I think this supports your "chain of being" connection, Erich. Most people don't find "animal" evolution particularly threatening, but as soon as it rises to the sacred tier of humanity, then it seems blasphemous and insulting.
What anti-evolutionists need to realize is that the origin of humans through natural processes does not, in any way, take away from their humanity. It doesn't matter how we got here, or what our ancestors were like—that's completely irrelevant! The point is that we're here, and we have amazing traits that distinguish us from the rest of the animals: our superb intelligence, our complex method of communication (both verbal and written), our amazing creativity and imagination, and our highly-developed emotions and sense of morality. Because of these incredibly advantageous characterisitcs, our species was able to take control of the environment and to rise above all the other animals, eventually taking over the entire planet. There's no denying that human beings are astonishing creatures, and sharing a common ancestor with other primates does not take away from that in any way. If a human wants to claim that he or she is fundamentally different from the other animals, the best way to defend that position is to cite evidence for our advanced cognitive functions, etc., instead of saying that we're special because we were created by God.
Because I'm an evidence-based being, I will admit that I am intrigued by a recent report that human ancestors bred with chimpanzee ancestors long after they had initially separated into two species. None of this new information dissuades me from believing in evolution. We're not talking about first cousins, after all; therefore such "relations" would not have violated state marriage laws, certainly not any laws in place at relevant times . . .
That was a very interesting report, Erich. It made me consider the possibility of human-chimpanzee hybrids, and I wondered why scientists haven't attempted to create any today. After all, humans and chimps differ by only one chromosome pair: humans have 46 chromosomes, and chimps have 48. Plus, they share 95-99% of the same DNA sequence. Since horses and donkeys are able to breed despite having a slightly different number of chromosomes (they also differ by one pair), and many other species are able to do this and in some cases even produce hybrids that are actually fertile, why shouldn't humans and chimps be able to breed, as well? I think they can. The problem is that most people would find this morally objectionable—not because it requires bestiality (since there are artificial ways of impregnating female chimps), but because experimenting with the human species is considered to be unethical. Besides, this would raise many difficult ethical questions, such as deciding whether human-chimpanzee hybrids can have human rights. . . . If a half-human-half-chimp can't qualify for this, suppose it breeds with another human, producing a being that is 25% chimp and 75% human. At what point do you draw the line and decide to treat such a being as if it were really human?
This also brings up the fact that evolution implies that humans evolved from other species in a gradual process, so at what point can a particular hominid be considered human? And if souls exist, at what point can it truly possess a soul? I don't think souls exist. . . . not only because consciousness has many different degrees, but also because I don't see how souls can be compatible with neuroscience.
Perhaps some people don't like the idea of evolution because of the thorny problems mentioned above; they want to be able to point to a particular species and say, in a black-and-white statement, whether it is a human or not. Just yes or no, with nothing in between.
Yesterday, my six year old daughter thought it was funny when someone mentioned "human bean" in a conversation. I explained to her that the term is really "human being," a "being" who is "human." But my own explanation made me wonder.
Why use that strange phrase ("human being") when the alternative phrase "human animal" would be direct and accurate? [of course, you could also just say "human"]. The general use of "human being" makes me suspicious that our use of the term "human being" is yet more evidence that many people are uncomfortable with the notion that humans are any sort of animal.
I'm going to continue with my very small (just me) campaign to use the phrase "human animal" wherever others typically use "human being." One might right in calling it schadenfreude, but I do enjoy the confused look I often get when I inject it right into someone else's consciousness that humans are, indeed, animals. As I've written before, the failure to make this basic connection is the beginning of much mischief in the world.
I've always thought the "being" in "human being" suggests some kind of spiritual or mental presence; some kind of "essence" of humanity like a soul or something equally illogical. Since I don't like the term because it either a) separates a human's body from their "being" (which psychologically and neurologically you simply cannot do); or b) equates humanness with having a soul, I think I'll try the "human animal" campaign, too.
Further to Yana's comment, horses and donkeys are just one example of hybrid species. Whale-dolphin hybrids — unofficially known as wolphins — are also known to occur both in nature and in captivity:
http://www.livescience.com/animalworld/ap_050415_…
As regards human-chimp hybrids, I could make a joke about President Bush, but that would be too easy.
Evolution is the purist form of understanding how it is that we are here. Science is the way that we seek to understand the reality of which we are a part. There is no such thing as superior or inferior outside of the human ego's need to feel that way. We are not just a part of nature, we are nature, and this realization makes my life worth living.
Most of the chatter we hear comes due to the human games that we all play, most of us unaware that the universe will continue long after our species, but not us, are all gone. How can that be? Because we are nature, she is our reality. You and I will die someday, but our deepest reality lies within our souls which are at one with nature herself, or us ourselves. I love being with that truth.
Why is that truth? The universe exploded about (depending upon the astronomers you talk to) about 15 billion years ago.
if you actually want to know the truth let me tell you that the truth is already within you, and there is no way that it could ever had existed anywhere else! If you understood what I just said then you already know your own soul which of course is my soul also.
We all came from the ONE. The highest form of man is his recognition of his union with the ultimate form of himself, which is the nature of his beginnings, or you, or us. or all of us. You are the same thing as me, and as long as you pretend you are not, All i can say is that I am just another human being like you, trying to make sense of our very short lives here on this planet, and just add that bit of glory that although I will die in my body, I will be with you all in my spirit.
Yana writes: "It made me consider the possibility of human-chimpanzee hybrids"
Interesting that you ask… Carl Zimmer reports that scientists now think that humans and chimpanzees did interbreed over a period of about 1 million years. They have been coined "humanzees".
http://scienceblogs.com/loom/2007/04/12/meet_the_…
"One of the biggest surprises came when one team of researchers concluded that the ancestors of chimpanzees and humans interbred for over a million years, producing hybrid humanzees."
Would you like to know more about the nervous system of the sponge? Go to Neurophilosophy.
Sea sponges are sedentary organisms that attach themselves to the sea bed and filter nutrients from the water that they force through their porous bodies with flagella. They are the most primitive of all multicellular animals, with just four different types of cells making up partially differentiated tissues in a simply organized body.
Truth is not determined by a show of hands…
However 'Truth' is determined by a show of hands…
i usually tell the young post-secular humanists i meet that ants are more evolved than humans and have been more successful at propagating their genes without risking environmental cataclysm. blank stares typically result.