Incidentally, I’d like to ask the same question of the creationists: is there anything that ever makes you think, “hmmm… maybe evolution is true?”
Retrogenes, for instance?
Not really. Creationism is based on faith and on faulty logic. They assume that it’s not possible that organisms could evolve the way they have and that an outside creator must have made things the way they are.
Even if you accept the existence of a “creator,” that still doesn’t automatically mean the physical processes of how lifeforms developed can’t be described by evolutionary theory.
If you believe in a god, one possiblity is of a god that simply started the universe and let things happen as they would.
Your italicized question is actually different than your explanation of the question.
It seems that what you are really asking is not whether there are unanswered questions in evolutionary studies (to which the answer is “Surely, we do not know everything”), but whether Creationists have proposed any solutions to evolutionary questions that made sense.
Sadly, they have not. This stems from the fact that Creationism is not science, it is belief. Science looks to determine origins and methods and to make predictions. Creationist origins are “God made it.” their methods are “God wanted it that way,” and they are not capable of making predicitions based on their “science.”
For example, the latests foray of Creationism is Intelligent Design. Unfortunately, if it had validity it would short-circuit science. It is nothing more than an extended “god of the gaps.” Anything we can’t yet discern (the questions of your italicized question) gets relegated to “we can’t know, because God did it.”
If we look at two of Behe’s “irreducibly complex” interactions, the rotating flagella of bacteria and the various chemical processes of blood coagulation, what do we do when we get to Behe’s position of “irreducibly complex”? We stop looking. If there is no evolutionary predecessor to the process of coagulation or to the rotating flagellum, we have no reason to continue searching for that which cannot be found.
On the other hand, if we continue to ask, “How did this come about?” we will continue to delve deeper into the process, look for analogues in nature, and (as we have done with Behe’s examples) discover the actual evolutionary predecessor.
I have yet to see one. They may point out facts which are valid - there are gaps in the fossil record, for example. Yes, there are. And we have explanations for them which don’t involve resorting to Special Creation (and Intelligent Design can shed no light whatsoever on the issue).
They may even point out valid problems with certain theories. But those tend to get hammered out over time, by scientists working in the field, not by creationist theory-snipers (many creationists seem stuck on Darwin’s work, ignoring the 150+ years of research that has occurred since then. I’ve yet to see a creationist attempt to refute anything Dobzhansky, Mayr, or Futuyma has said, for example). Even Darwin acknowledged that much of what he wrote in his time would eventually be overturned, but that the essence would likely remain. And he was correct.
And there are certainly gaps in knowledge, but I have yet to encounter anything that has made me think evolution, as explained by current theories, couldn’t have “done it”. Specific evolutionary pathways may never be known, but that does not invalidate any given mechanism. To invalidate a mechanism, one has to show it could not work, period. To show that it may not have operated in a specific instance, and attempting to extrapolate from there to a supposed invalidation of the entire mechanism, demonstrates ignorance about the statistical nature of evolutionary mechanisms. Natural selection, for example, acts primarily, but not solely.
Most arguments made by creationsts are made against strawmen labelled as “evoltuionary theory”. If those strawmen were real, the creationists might raise valid points. But the strawmen aren’t real, and the points aren’t often valid.
You are correct in this, my apologies.
However, as I look at this question I posed I see huge flaw. How can a Creationist put forward a solution that answers a evolutionary question since anything they put forward will be that “God did it”? I think a light bulb just went on above my head…lol
I do have a question to say Ben or Tom, please see my situation below and let me know what you think.
Example, I argued evolution vs creation with a friend of mine and she brought up that it has been shown that mutations are almost always harmful and that the number of mutations needed to go from a single cell to the complex life forms on earth couldnt possibly happen with mutation alone since the mutation would more than likely kill the organisim. Now, me, being less versed in the ways of genetic mutations than some, thought this an intriguing argument. I even checked a few web sites and found some interesting stuff by what looks to be some well credentialed people, albiet, what seem to be fundies.
I don’t think it makes a bit of difference that harmful mutations outnumber the beneficial by a wide margin. So harmful mutations are quickly eliminated. So what? Successful life forms are so infernaly fertile that the 1 in a million or billion, or whatever, form that survives can rapidly populate any environmental niche.
It’s certainly not the case that a single mutation will always kill an organism. It depends on the nature of the organism, the nature of the mutation, and environment factors.
Mutations that affect the basic cellular machinery usually do lead to death. That’s one of the reasons all life is so similar on a cellular level.
Plants can undergo massive genetic changes without dying. For example, many of the fruits you purchase are polyploid – they have multiple extra copies of certain chromosomes. They do just fine.
I’ve observered three types of creationists. There are ignorant ones, who really believe that evolution says dogs turn into cats. Then there are stupid ones, who just don’t have the intellectual capacity to understand how evolution works, even when explained.
The third type is the type who people are talking about here, who start with the assumption that the Bible is literally true and who believe that any evidence to the contrary must be faulty by definition. You can categorize this type anyway you please.
Baker Street Irregulars begin with the premise that the Holmes stories are the literal truth, and twist them to explain away inconvenient facts. (For fun, of course.) Teaching creationism in schools would be the same as teaching the history of Victorian England as if the Baker Street Irregulars were right.
I’ll write up a longer explanation later, when I get a chance, but let me point out for now that evolutionary biologists already deal with the idea of genetic load (which is what your friend is talking about.)
When you do calculations on gene flow in populations and accumulation of beneficial mutations and so forth, you have to accept that all organisms will have a certain number of deleterious mutations that they will be carrying around. There are a number of reasons for this. For example, maybe the organisms are adapted to old conditions that no longer exist, and are currently in the process of evolving to meet current conditions. (For example, the komodo dragon is arguably adapted to eat pygmy elephants, which are now extinct. They’re getting by, but are generation by generation getting better at hunting and eating small rodents and Sharon Stone’s husband.)
More to the point of your question, you can have genetic load just because a certain percentage of mutations are deleterious. Don’t let the creationists fool you: most mutations are neutral. (In fact, the dividing line between “neutral” and “positive” is a blurry one, since a neutral or slightly deleterious mutation could become very advantageous when it’s matched up with a second, subsequent mutation such that the two mutations work well together.)
Let’s say that out of 1000 mutations, 600 are neutral, 399 are deleterious, and 1 is beneficial. If you want to bring about some new trait in bacteria, you could crank up the mutation rate- but then each bacterium would have 1000 mutations, of which 399 are deleterious. Therefore, all the bacteria would die.
But if you tune down the mutation rate so that each bacterium gets 1 mutation, then in a flask of 1000 bacteria, 600 will get mutations that make no difference, 399 will have deleterious mutations that will do anything from kill them outright to just make them a little sluggish, and 1 will have a good mutation. That 1 will have more offspring than the rest. In a couple of generations you have 1000 bacteria all of which have that good mutation, and now 600 of them get a second mutation which makes no difference, 399 get a second mutation which is deleterious, and 1 gets a beneficial mutation. That one reproduces to make a flask full of bacteria with two beneficial mutations, and so on. Wait 3 billion years, and you’ve accumulated so many mutations that the bacteria have evolved into humans. (Remember, too, that sex changes the picture a lot. You no longer need to get the second beneficial mutation happening in an organism which has the first mutation. Instead, two organisms, each with one mutation, can mate and have children with both mutations.)
In short, your friend is presenting genetic load as a problem, but evolutionary biologists already know more about the subject than she ever will. It’s all fine and well to say “deleterious mutations prevent a bacterium from ever becoming a human!” but if you actually do the math instead of just making declarations, then you find that there’s no real problem.
And a “neutral” mutation can suddenly become a benefit – or a liability – if circumstances change: when the environment shifts, or another mutation occurs that warps the organism’s physiology, a formely inconsequential attribute can be good or bad.
When a minor trait suddenly becomes an advantage, it’s called “pre-adaptation”.
Plus, you should look at the dates on some of those quotes. Most of the ones on mutation come from the 1960’s. We didn’t crack the genetic code until the mid 1960’s, and we couldn’t sequence genes until some time after. It’s only fairly recently that we’ve been able to look directly at how mutations act at the DNA level in the course of evolution. It’s just typical creationist quote mining- use an out of date quote whenever a modern one would support evolution.
Plus, note the quote about how selective breeding of domesticated strains makes plants ill-equipped to survive in the wild. Of course it does! The plants started out adapted to live in the wild, and we bred them to survive in a completely different situation, and we bred them to put most of their energy into things that would benefit humans. (i.e. larger grains.) I bet anything that if you looked up that quote in context, it wouldn’t say anything even remotely like what the creationists are claiming for it.
Meanwhile, out the other sides of their mouths, the creationists go on about how they believe in “microevolution.” But if microevolution is true, then doesn’t that mean that deleterious mutations aren’t a barrier?
One problem is that your friend can’t see the forest for the trees. Mutation alone does not drive evolution; mutation plus selection does. The fact that an organism with a harmful mutation does die (or, at least, fail to reproduce) is selection in action. That is, after all, why they are considered harmful in the first place. Those that are not harmful are passed on to subsequent generations, those that are clearly beneficial will tend to increase in frequency throughout the population over time, while the frequencies of those that are neutral will tend to wander somewhat randomly. (Note that what makes a given mutation harmful, neutral or beneficial is determined by the circumstances in which an organism finds itself at the time.) Over time, then, with each subsequent generation, the relative frequencies of the intially-few beneficial mutations will increase, while the frequencies of a given harmful mutation will tend to decrease. And that is the essence of adaptation. From there, it’s just a short logical hop to speciation.
So… when God started the Creation, He was blind?
Explains a lot, actually.
There is a fourth type; the liar - folks like Gish and Hovind - they know that (at least) a substantial portion of what they are asserting is false, but they argue it anyway because the folks in the other three groups will accept it uncritically.
Yeah, well this not being the Pit I didn’t want to give that label - which is pretty much the one I use for my third class. It’s not the belief in the Bible that does it, it is the quote mining, misrepresentation and distortion of information that the top creationists you mention resort to.
Liars seek to deceive. The third class has deceived themselves, but they’re often honest (in their own eyes) towards those they try to convince.
I believe in evolution. In a round about way, I believe in god too. I did grow up going to private christian schools that tought creationism, and for a while, I believed it, and even debated it often. However, the more I learned about science, and in particular, geology the less and less I believed my own rhetoric. There are still a few questions I have about certain animals or traits, but I haven’t heard a good argument from a creationist since Jr. High.
One thing in particular that bugs me, and it really isn’t about evolutionary theory, more about certain individual animals showing up in times/places where it makes no sense in the fossil records, are the large number of africa-like animals that existed around the last Ice age in north america. Some of the animals fit the model (of crossing a land bridge over the bearing straight) like the whooly mammoths, but others, like the american cheetah, lion, zebra, and camel, don’t exactly mesh with this. I haven’t done in depth study into it mind you, but what erks me about it, is I haven’t seen any evidence of transitional or migrating animals in siberia/kamchatka, etc. Just that at some point, cheetahs and zebras and camels (oh my!) are wandering around north america.
The cheetahs, I can almost believe, if we assume they evolved from the same cats that came over and evolved into smilodons, artic lions, pumas, jaguars, et al. Though for anyone that knows anything about cheetah physiology, that’s a stretch. They are pretty distinct from other cats and have been seperate for quite a while in africa to get that way. There just doesn’t seem to be the time, to me, for them to evolve in the migration into the empty americas.
The camels and zebras, would make sense, if they came with man (who migrated out of africa), both are capable of surviving in colder weather (the camel more than the zebra), but they showed up long before man, and the zebra never shows any singns of domestication (that I know of).
There are plenty of instances of animals showing up in odd places/times such as this that I have heard of. But honestly I assume that there is a rational explanation for them that I just haven’t read yet.
Heck, while we’re at it, if anyone knows that explanation, could they spit it at me. It’s been bugging me the last few days.
Part of your confusion may stem from having the migration patterns backwards: camels (actually, early tylopods) and the common ancestor of cheetahs, pumas and jaguarundi started out in North America, then migrated elsewhere. See here (cheetahs), here (cheetahs again), here (camels), and here (horses and other odd-toed ungulates).
Note that the science of biogeography is devoted to sorting out the patterns of life that we see: who lives where, and why? Seemingly strange distribution patterns are often found to be relict (a population now found in but a small sub-set of its original range), disjunct (two or more isolated populations of a species), or otherwise modified versions of a once-larger distribution. The finding of fossil cheetahs (for example) in North America does, indeed, seem strange if one assumes an African origin. However, it does not seem so strange if one realizes that they started in North America, and the African species is the only remaining remnant.
I don’t think you have your facts entirely right. If you look at The Book of Life it has a brief section on the savanna-like biome in Pleistocene North America, with a side-by-side comparison of the different species. It’s not that you had the same species in each case. Instead, convergent evolution selected for the same traits as a result of similar environments. Thus in modern Africa there’s a giraffe, and in ancient North America there was a creature that had a long neck like a giraffe, but wasn’t related to the giraffe at all.
Is this directed at me, or stick monkey?