You can find the first post in this series here.
Before we can really dig in (if you’ll forgive the pun) to what the fossils tell us, we need to establish a timeline. Many (most?) detractors of evolution maintain that the earth is less than 10,000 years old, because if you take the Bible literally and go backwards through its timeline, you’ll find that creation should have happened somewhere between 6000 and 10,000 years ago. So this is primarily a faith position, and not something based on scientific reasoning. But I don’t want to simply dismiss it out of hand — let’s look at the evidence that would show the earth and universe are much older than a literal reading of Genesis would suggest.
In order to measure time, you need a clock. This is no less true when measuring times on an evolutionary scale. And as it so happens, we have a number of clocks that help us do this. It’s well known that you can tell the age of a tree by its number of rings. But those rings also provide additional details, like whether or not a specific year was good or bad for trees. Good years with lots of rainfall differ substantially from years of drought. Some summers are especially hot — some winters are especially cold. There are even more extreme weather events like El Niño, or large volcanic eruptions. All of those events affect the way a region’s trees grow, and this can be seen in the trees’ rings.
Our oldest living trees measure their age in the thousands of years, but these growth patters in tree rings allows us to back even further through overlaps. By comparing the ring pattern of living trees (whose age is known) with trees that have died some time back, we can match the patterns in a way that allows us to figure out when that tree lived. Once its timeline is established, we can compare it to even older trees and establish their timelines, working our way back through the millennia. This is called dendrochronology. Currently, the longest chain that’s been worked out goes back a little over 11,000 years from now. One of the nicest things about tree rings is that it is year-specific. Whereas many of our other dating techniques are accurate to within a certain standard deviation, tree rings can take us to the exact year. That makes it very useful in comparing the results of techniques like carbon dating.
Like tree rings, glaciers have layers of ice and sediment that can be broken up by seasons or years. The same can be done with coral reefs, making both of these very handy in measuring time as well.
Carbon dating, which almost everyone has heard of, is a type of radiometric dating. Radiometric dating is highly useful, and it works with many more elements than just carbon. I don’t want to get too technical with this, but I think it’s important to have an idea of how radiometric dating works.
Elements come in different versions known as isotopes. Some of these isotopes are unstable, meaning that over time, they will degrade into different elements. What’s cool here is that we know the rates at which these various isotopes degrade, and it’s different for each element. The decay rate is known as the “half-life.”
For example, carbon-14’s half-life is 5,730 years. This means that a specimen with 10 grams of carbon-14 at death will have 5 grams 5,730 years later. In another 5,730 years, it will have 2.5 grams. In another 5,730 years, it will have 1.25 grams, and so on. So in this way, it takes a very long time for all of the carbon-14 to change into something else (nitrogen-14, to be exact). But there’s still a limit to carbon-14’s usefulness, and it maxes out at around the 60,000 year mark. So while carbon-14 is very useful for archaeology in examining human artifacts, it’s not as useful in examining evolution.
However, a number of other elements are useful on an evolutionary timescale. Potassium-40, for instance, has a half-life of one billion two hundred sixty million years. Scientists can test the potassium-40 to argon-40 ratio in igneous rock (rock formed by lava) to determine approximately when the rock was formed. Potassium-40 is just one of several elements with long enough half-lives to test the approximate age of the earth, and they currently all agree that the earth is between 4 and 5 billion years old.
Another aspect tied to radiometric dating that indicates an old earth is the following:
Of the 158 unstable [isotopes], 121 are either extinct or exist only because they are constantly renewed, like carbon-14. Now, if we consider the 37 that have not gone extinct, we notice something significant. Every single one of them has a half-life greater than 700 million years. And if we look at the 121 that have gone extinct, every single one of them has a half-life less than 200 million years. Don’t be misled, by the way. Remember we are talking half-life here, not life! Think of the fate of an isotope with a half-life of 100 million years. Isotopes whose half-life is less than than a tenth or so of the age of the Earth are, for practical purposes, extinct, and don’t exist except under special circumstances. With exceptions that are there for a special reason and that we understand, the only isotopes that we find on Earth are those that have a half-life long enough to have survived on a very old planet.
— The Greatest Show on Earth p. 102-103, Richard Dawkins
Did you catch his point? If the earth is not billions of years old, how do we explain the lack of naturally occurring isotopes with (relatively) short half-lives?
Astronomy and the Hubble Constant
The last piece of evidence I want to give for an old earth is astronomy. Once we began to understand just how far away the stars really are, it caused a problem for a literal reading of Genesis. We can see stars that are millions of light-years away from us, meaning that we shouldn’t be able to see the light from those stars if the universe is merely thousands of years old. And it’s more than that. We’ve discovered through things like the Hubble constant that the objects in our universe are moving away from a central point at an ever-increasing rate. If we trace those trajectories back through time, we find an origination point around 13.77 billion years ago.
Hopefully, I’ve successfully shown that our reasons for thinking the earth (and universe) is very old come from many different lines of evidence. These various methods are frequently used against one another to weed out inaccuracies. As far as I know, there are no scientific reasons to think our universe in only thousands of years old.
As I said in the first post I did referencing evolution, I don’t think evolution and religion have to be at odds. Maybe accounts like that in Genesis were meant to be taken figuratively. Or maybe it’s totally accurate and God just made things look like they’ve been here much, much longer. Either way, we should be able to accept that the physical evidence overwhelmingly points toward our universe’s age being measured in the billions of years, not thousands. If we could all come to that conclusion, then maybe we could stop trying to sabotage the science taught in our classrooms.
26 thoughts on “The Evidence for Evolution Part 2”
Fair summary Nate. AS you know, I am not a young earth creationist, but I think the only way that position can be maintained is to believe God created the universe with all these many appearances of age. I can’t see why he’d do that, but what would I know?
Excellent post – except for your last paragraph 🙂
Just when you do an excellent job of rubbishing the Ken Ham Fan Club you leave the door ajar just enough for the Evolutionary Theists to jam their bloody feet in the gap.
You are too generous , Nate.
This is one time you are allowed to ‘Kick a Man when He’s down.’
We can’t keep pandering to GDI’s for ever. (God Did It)
A very patient person you are. Keep it up. I don’t think many creationists will be converted though. I do agree religion and evolution don’t have to be at odds. But religion and science as a whole? That’s a thornier issue.
Good job Nate. Carbon dating is one of those things you have to read through carefully several times before you really start to grasp it (for me anyway). I think the fact that all of the dating methods can be cross referenced and calibrated make them very reliable. I am reading through Dawkin’s “Greatest Show” right now. Some of it is hard to grasp, but I am enjoying most of it. It’s something I never would have looked at when I was a Christian. I don’t understand how Christians can accept evolution and still revere the Bible. Doesn’t it lose credibilty and authority? Would the Koran still be revered by Muslims if they found out that Muhammed never spoke with Gabriel? Would a religion based on all the Greek myths ever catch on? I guess it just seems like grasping at straws.
SOLD! I now believe that the universe is billions of years old! Oh wait a minute. That’s what I believed before I read this. Sorry.
Great job of trying to get my fundi brothers to try and remove their heads from their rears but I think they are too stubborn to actually dislodge their heads.
Wonderful info though. I look forward to the next post:)
will there be a part three?
Thanks for all the comments!
@portal001 — Yes, Ryan, there will definitely be a part 3. I’m not sure how many parts this series will take — at least 4 or 5, I think.
@Dave, I totally agree with you. I would personally have trouble rationalizing evolution with Christianity, but I can see how it can be done. It would still leave some pretty big questions, but I can still see it. Let me know what you think about Dawkins’s book when you finish. I also really liked his Magic of Reality book. It’s technically geared toward adolescents, but I got an awful lot out of it. I also really liked Jerry Coyne’s <Why Evolution is True, and I’ll be quoting from it in some of the future posts.
@Ark, point taken! 😉
Thanks again to everyone else for your comments!
It amazes me that people cling to theories like young earth or Jonah inside a whale when simple logic shows them to be hogwash. Show me a virologist who denies evoution – they see it all the time in simple and very fast action as these amazing things adapt themselves. Equally illogical is the Dawkins view – one would think that such a great brain would see the enormous holes in common sense a denial of universal purpose will leave.
I think the reason is because of two primary things.
1. The bible, as well as other religious texts, are written a lot like the old children’s story, “the Emperor’s new clothes.” They make claims like “only those who aren’t good enough wont see it, etc. The righteous and pure of heart will submit to god (god being the same as their religious text of choice).”
2. it has tough built in defenses like the strongest kind of peer pressure (excommunication, etc), eternal torment (punishment/torture), eternal bliss (reward/promise to see loved ones again), and that god can do anything.
nothing is impossible for an all powerful, all knowing, all perfect, all brilliant being. that means that no matter how absurd or impossible something is, god can do it. that solves it.
It doesnt make sense? not a problem. We arent capable of understanding god’s brilliance.
after all, who are we to question god… or those who claim to write on his behalf…
Like the post, Nate! But I am looking forward to further ones as thus far you have left untouched a very important point: Old Earth Creationism. I come from a Fundy group that believed in that and explained that there was an unknown number of years of Gap between Gen. 1:1 and 1:2…this is Gap Theory (though you probably already know that).
Gap Theory seemed to me such a clever and perfect explanation for an old earth and yet the bible being true (back when I was a kid growing up in my parents’ religion). But, of course, the tree rings you mention rules out the earth being in a state of “tohu and bohu” (death and darkness, basically) since they go back 11K years. A friend of mine went into detail on the Coral Clock, as well, which, again, goes back longer than a 6000yr old Re-creation of the earth, and also shows no evidence of a global Flood.
Thanks for the comment!
I’m somewhat familiar with Gap Theory, but it’s not what I subscribed to when I was a believer. I tended to hold to a version of “Last Thursday-ism” — everything actually is young, but was made as though it had been here for eons. There are plenty of problems with that position, but what’s I thought for a while…
Anyway, I plan to hit the fossil record in the next post for this series, and I hope that will help explain a lot more about how solid the evidence for evolution really is. For instance, I’m finding that many creationists complain about there being no transitional fossils (of which we have many), because they’re expecting animal hybrids, like the infamous “crocoduck.” I hope to address some of that, and I’d be interested to hear from you once it’s posted and see how well it addresses Gap Theory.
By the way, the dating of cave paintings is another example of finding things much older than 6,000 years — and they wouldn’t exist if there had been a global flood.
What is the global flood was just regional?
Oh yeah, there have definitely been regional floods in that area.
Your lack of faith has made you obtuse… i meant, what IF the great Noah flood was just large instead of encompasiong the whole world?
Ah, sorry. 🙂
But if it were just a local flood, what would the point have been in building the ark and putting all the animals on it? I can see how stories like Noah’s could have arisen as a way of explaining how man and animals survived after some massive flood in a particular culture’s past, since to them it would have encompassed “the whole world.” But I don’t think any of the events from the story actually happened… it’s just a legend, in my opinion.
The geological evidence my dad told me about stretched pretty far. From what he could tell the area would have been too large for Noah to get clear in time before the flood consumed the area. As for whther you think he had animals with him or not, THAT is your business. Love ya!
I really like the preacher at my church right now because he knows a lot about History and ties it into his lessons. That is why Jay likes him too. I do not agree with ignoring science or history either and that it can mix with religion and should. A lot of the Bible is proven, while a lot of things taught in Science class though are theories yet they can be taught while the Bible can only be in Christian schools before a certain age at least. I just wish they would teach all of it and let children truly make an educated decision regardless of their raising at home. I do not take the Bible as literally as some though and I also just don’t stress about some of the details so much, including how old the Earth is, just something else for people to argue over, whether it is thousands or billions years old I believe it was created by God and I believe we have since evolved over time but I have seen compelling arguments for both, I like to think it is thousands though honestly because I am just hoping God would not leave us on this Earth for this long. I have not made it through all of your blogs yet so maybe you have done a blog on dinosaurs already but if not I would love to see one. We discussed this once with our youth minister and he gave some good possible answers I can no longer remember lol but tying them in with religion has always been tricky for me but again I do not think proof of dinosaurs disproves anything in the Bible just makes you wonder if they are mentioned in the Bible and we not realize or why they are not mentioned maybe. For those of you saying maybe God made it appear longer to some I do not believe he would do that, however he might allow the Devil to to see if people fall into temptation and believe the Devil’s tricks while also providing evidence to the contrary I guess or to see if a person would allow the time it was created change their belief entirely about who created it when it does not have to. If your belief is based solely on when things were created it is not belief and there is no faith involved in your belief in God, you believe there if proof, saw what you thought was proof and believed that, nothing special about that.
I also want to add I graduated from Auburn with Honors in 3 years so I am very educated and I am a Christian. I did not just believe what was told to me growing up. I argued with family even at a young age about religious beliefs and questioned some even more as an adult and have been seeking truth my entire life on my own. Anything I believe is based on my own personal experience, a personal relationship with God, things I have seen and learned on my own throughout my life. Not brainwashing from family or friends that I am in denial about it as it seems to me hinted at one certain parts of this page and I actually still disagree with family and friends on certain subjects even if our overall beliefs are similar or we are all called Christians.. Maybe you chose to believe because of your family and friends but that was not the case with everyone. Not that it did not have any influence on my original choice, but ultimately like with everything else it became my own. I don’t believe you were brainwashed to be an atheist, while I do not agree with your non belief I think you are very intelligent and if anything religion being forced on you and you being misguided when it comes to religion in some ways growing up led you away from God but regardless of a lot of us disagreeing on here and as someone who is not easily offended I do find it a little offensive when atheists act like we are basically brainwashed idiots. Of course I guess they have to believe that for them to be right so I guess at the same time it is hard to fault anyone for that but I don’t think Atheists are brainwashed idiots. I think they just don’t want to go along with something because they are told to and they seek the truth in most cases anyways and I actually believe the people who do just go along with whatever when it comes to Christianity either really are not Christians or are not very strong ones and never grow a lot in their walk and are missing out. It is just like anything else in life where people just go along with something for the wrong reasons whether it is right or wrong. And Chtistians often make the mistake of giving up on Atheists when often they are the ones on the brink of conversion because they are often just seeking out the truth. In another blog I commented on I talked about I do think we all have a purpose and God gave us all different gifts, well you for example, when you called yourself a Christian and now you call yourself an Atheist, either way you have a website, you influence people, you get people discussing things, and some people as Christians view that as a bad thing now that you are Atheists but I still think you have the same gift, you are still questioning things, discussing things, causing others to question things, but you are still just seeking truth and I believe you will still find truth, some just believe the truth told to them, go along with what others say and do and follow and don’t ever discover their own purpose. If you did come back to Christianity I can only imagine the testimony you would now have.as opposed to before.
This is the main thing I disagree with you on. There is nothing in the Bible’s creation account that can be backed up scientifically or historically. Nothing. That’s not an exaggeration; it’s simply fact. There are some things about Jewish history that seem to be accurate, so I have no problem with those things being taught in schools. But when it comes to science and the history of the earth and our galaxy, I want that information to come from reliable scientific sources. When science talks about a theory, it’s not using it the same way you or I might use it to reference some idea we might have. A scientific theory is a collection of facts. The theory is what ties all those facts together. Certainly new information can cause a theory to be revised. But it needs to come from new, scientific information — not statements of faith that have no real basis.
I don’t know about your religious background, Amanda, but I was brought up with something called Gap Theory. Well, we didn’t call it that, exactly, but as I’ve studied religion I’ve found that Gap Theory is the name for it: Basically, there is a Gap of an unknown period of time between Gen. 1:1 and 1:2. One reason for this is that verse 1 says “God created the heavens and the earth” and then verse 2 says “and the earth was without form and void”. God wouldn’t create a bad earth, would he? So, it is said that the word “was” should be “became”…the earth Became in that state after the rebellion of Lucifer into Satan as (supposedly) described in Isa. 14. Thus…DINOSAURS!
Once fossils were discovered, it quickly became clear that the earth is far older than seems to be indicated in the Bible. Some went the “God buried those things there to test those weak in faith” while others re-read their bibles and came up with Gap Theory. “The World is billions of years old, yet Humans have only been here 6K years” is the explanation.
I kind of think, though, that if a child is raised in a religious household, then they already get both sides of the story: they’re taught creation at home, and evolution in school. The vast majority of the US is religious, so clearly going through science class in school doesn’t destroy faith that much (I got through with my faith as strong as ever)…so why mix science and religion? If we’re going to “teach the controversy” and let the children decide, then we need to not only include the Bible, but Hindu teachings, Native American creation teachings, Muslim, and maybe Norse, too (this place we call Earth is actually Midgard…if we die a good death in battle, the Valkaries will take our soul to Valhalla to await Ragnarok aka Armageddon…etc).
Dont get me wrong, Armageddon was an enjoyable movie, but I’d hate to have that film be my Nirvana.
And dont get me wrong, Nirvana was a decent band with several hits and a cult following, but i dont think i want to drink that kool-aid.
And dont get me wrong, I enjoyed kool-aid as much as any kid, but…
LOL @ William! 🙂
OH, hi there…back again. Speaking of Time, I recently read a great book called “The Man Who Found Time–James Sutton and the discovery of the Earth’s Antiquity”. This Sutton character came of age during the Scottish Enlightenment and figured out that Geology tells us the Earth is old.
The book goes through several of the ideas of the major geologists of his day and how they reconciled Geology and Genesis. He had a different idea, though. It was the eventual popularity of this idea, as furthered through the efforts of Charles Lyell, that influenced Charles Darwin, as it was the aspect of having “enough” time that helped spark his idea of Evolution.