Science and Human Evolution

Question from EvoE:
What is the proof humans have evolved from a common ancestor? If the scientific method is observation, data collection, internal and external validity and reliability; then how can one observe human evolution?

Answer by SmartLX:
We don’t observe human evolution. Scientists genuinely don’t know whether it’s still happening, and discuss it often.

This means little, because science does not always require direct observation of a past event to confirm that it’s happened. If it did, the police would have to be present at every murder in order to charge any suspects. We can instead observe and collect evidence that humans have evolved from ancestors we share with other animals.

The evidence includes but is not limited to:

1. Comparative physiology
We often say we evolved from apes, but it’s just as correct to say that we are apes. Without even considering genetics, we can be classified as apes using physical characteristics such as our long arms, omnivorous teeth and lack of a large tail. It goes far beyond superficial physical qualities, because our internal organs and body chemistry have countless analogues in other primate bodies. We’ve even got some organs that are practically useless to us but essential to other primates, such as the appendix and the muscles for moving our ears. (These and other human vestigial organs speak loudly against the Intelligent Design proponents’ claim that all the similarities are due to the other animals having the same Designer. Why wouldn’t He just leave out the useless organs, rather than leave them in place to potentially kill us?)

2. Genetics
The genes linked to the analogous systems mentioned above can be sampled from each species and compared directly. Now that the whole human genome has been sequenced, it can be compared all at once to the genomes of other animals. The results are as expected: our DNA diverges less than 2% from some species of apes, such as chimpanzees and gorillas. (By comparison, the most distantly related humans differ from each other by about 0.1%.) As we compare ourselves to other non-primate mammals, reptiles, plants and so forth, the genetic difference rises accordingly, exactly as we would expect if we diverged from these other branches of life earlier on.

Even knowing single comparative facts, like that chimpanzees have one more chromosome than we do, we can predict and discover evidence of very specific biochemical events that happened during our own evolution, such as the mark where two of our ancestors’ chromosome pairs fused to make one of our own pairs, specifically Chromosome 2.

3. Observed natural and artificial selection (and speciation)
We have watched some species with relatively short life cycles breed and diversify to the point where two populations of the same animal became unable to breed with each other. We’ve conducted breeding programs which have deliberately achieved the same thing, just to see what’s needed for it to happen. These are instances of speciation, or the splitting of one species into two, because part of what defines species is that they can’t produce fertile offspring with other species. There have been billions of years for this kind of thing to happen all over the world without any external help, and there’s no reason to think our own origins are any different.

If you want the rest of the evidence, start at the Wikipedia page for evidence of common descent. It’s not solely concerned with humans, but a lot of it has to do with us. If there’s something specific there that you don’t accept, bring it up in a comment.

Understanding Christians

Question from Kage:
So what exactly is a Christian, and why do they believe that someone died, and somehow managed to raise himself from the dead and all? Is there a reason they believe this? Any evidence at all? Any contrary?

Answer by SmartLX:
Christians are followers of Jesus Christ, as the name suggests. Some self-proclaimed Christians don’t let this affect their daily life very much, to the point where being a “follower” of Jesus Christ means no more than being a “follower” of someone on Twitter. Still, Jesus is their central figure.

Trinitarian dogma varies between denominations, but since a common belief is that Jesus was not just the son of God but God himself, it’s fair to say many Christians do believe he raised himself from the dead.

The reasons why Christians believe this is often different from the reasons they give others to believe it. For most, they believe it simply because they were taught it from a very young age. For some, they’ve had a “religious experience” and think they’ve seen the risen Jesus first-hand.

The evidence for the resurrection of Jesus is entirely document-based. The Bible states that it happened, and some other sources mention it (though there are no contemporary accounts), and people simply argue for accepting the fact based on this. That gets you into long discussions about scriptural reliability and fulfilled prophecies. If you search this site for Jesus and/or the resurrection, you’ll find a lot of this kind of thing.

The only thing which might count as evidence against the resurrection is the lack of evidence for the resurrection, but it depends on how much evidence you would expect there to be.

Proof? We don’ need no steenkin’ proof!

Question from Madoka:
I’m a Catholic but I’m open minded. I keep hearing about how God does not exist but how can you PROVE he doesnt exist? I’m just looking for your opinion because I read about some atheists who had near death experiences and became Christians so it’s kinda confusing. Have you ever thought that He might exist?

Answer by SmartLX:
I can’t prove God doesn’t exist, and I still think that He might exist. Neither of these is a good reason to believe in something, though.

In order to prove God didn’t exist, with our vague concept of what a god actually is, we would have to rule out every place in (and outside) the universe where He might be hanging out. This would be impossible to anyone except a being which itself had godlike powers, so it’s not worth trying. Thing is, it means very little that we can’t prove God’s non-existence if whether he exists makes so little difference to the pursuit. Put another way, we can’t prove that there’s never been any such thing as a leprechaun, but that doesn’t mean we should all believe in them.

I used to think God existed, because I grew up Catholic. When I realised there’s no good reason to think He does, and lost my faith, I didn’t suddenly declare that God can’t exist. I could still be wrong, and He could be out there somewhere. I just think that’s very unlikely, for reasons I’ve given here, and until we know that it’s the right God and not a jealous alternative deity it’s no use worshipping any particular one.

God in the numbers? The devil’s in the details.

Question from Neil:
As a ill-educated atheist how do I best explain the Golden Ratio and Fibonacci sequence being nothing to do with a god?

Answer by SmartLX:
The same way Darwin explained that the diversity of life need have nothing to do with a god: by showing the Ratio’s natural origins.

For those unfamiliar with the terms, here’s the basic math: take two 1’s as the start of a sequence and make each new number in that sequence the sum of the previous two:
(1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144…)
That’s the Fibonacci sequence, named after the first European to document it.

The interesting thing about it is that the ratio between any two adjacent numbers in it (after the first few) tends toward about 1:1.618, which is called the Golden Ratio. What’s interesting about that number is that ratios close to the Golden Ratio appear regularly in nature: it’s about the ratio between the different segments of your fingers, for example. Some believers see these natural occurrences as a kind of signature by the Creator – a sign of the created order of living beings.

The problem with this idea is the fact of how simple it is to create a sequence that features the Ratio: I started with two equal numbers (they don’t have to be 1), and started adding. Nature can do this too, particularly genetic instructions: “build this part using these two other parts as a reference”. The omnipresent Ratio is an observation we make afterwards; rather than an inbuilt standard, it’s an emergent property of a simple, common, repeated process. No god is necessary, or even of use.

Sai Baba’s Bread

Question from Alex:
Hi, I am an atheist. But one of my friend told me that she had got some sai baba bread (appam) from her friend. And if she keep it in one vessel and pray him daily, it will become double. As usual i have not believed. And today she said that it becomes double. I want to prove her wrong that it is not because of sai baba.. Can you please explain me the reason.

Answer by SmartLX:
It’s not your job to prove her wrong as long as she hasn’t presented any evidence. All she’s given you is a story, and a pretty vague one at that. If we even assume she’s telling the truth, pretty much anyone could have put a second appam in the “vessel”. Sathya Sai Baba had a lot of followers, and some would probably engage in some mild deception in order to sustain belief in his divinity.

What we have here is a rare example of a supposedly repeatable, and therefore testable, miracle. If your friend wants you to believe, she can do it again with a fresh appam – but this time, ensure by means of surveillance or a locked container that no one can get to it but the spirit of Sai Baba until it’s time to check for the extra bread. If he pulls it off in these conditions, then you’ll have something to disprove. Until then, the burden of proof is not on you.

The Bible, and Pascal’s Wager, in that order

Question from Quentina:
What problems have you found with the Bible?

And what if God is real and you’re wrong?

Answer by SmartLX:
The basic problem with the Bible is that it was written between 3000 and 1900 years ago by a varied group of authors, some of whom had read the others’ work but most of whom never knew each other, and who by today’s standards were woefully uneducated. Furthermore, while there’s plenty of evidence outside the Bible that people believed the stories soon after they were written, there’s little to no evidence that the central events therein (especially the supernatural events) actually happened.

If you want to get into specifics, the Skeptic’s Annotated Bible is a great start. Yes, since it was created others have devoted themselves to reconciling every single criticism it levels at the Bible, and links to some of the responses are in the SAB itself. The majority of those reconciliations, however, rely on a single interpretation of the text being the right one, and in each case there’s little support for that particular interpretation – other than that it’s the one that makes the Bible correct, which is an argument from consequences.

If I’m wrong, it doesn’t make any given believer right. If I’m wrong and God is real, God might still not be the one you think He is (assuming you believe in God), or behave as you think He does, or want from us what you think He does. In fact, if there’s a god, there are so many possible gods that the chances of your god being the real one are so very small that you’re almost certain to be worshipping a false god. You may be punished by the real god when you die, depending on how jealous he or she is.

If on the other hand you can demonstrate, or otherwise provide evidence or a logical argument, not only that there is a real god but that your god is the real one, you don’t need to rhetorically make atheists wonder whether they’re wrong; you can actually persuade them that they are wrong and you’re right. The fact that you haven’t simply attempted this straight away suggests that you know you don’t actually have such evidence or arguments. If you do have something, lay it on the table.

Evidence and Proof

Question from Pachomius aka yrreg:
What is your concept of evidence and proof?

Please give five examples of evidence as of proof.

By stating what five things are evidenced by what evidence.

And what five things are proved by what proof.

I understand there is a difference between evidence and proof, of course they are connected.

Answer by SmartLX:
As he’s written elsewhere, Pachomius here basically wants an atheist’s definitions of evidence and proof so that he can reference them as he attempts to prove the existence of God, pre-empting anticipated objections by the atheists he’s trying to convince. Those atheists are regulars on the James Randi Educational Foundation forum, so his work’s cut out for him. (Hiya JREF.) Besides, no other atheist is obliged to accept my definitions, so the best he can really do is pre-empt definition-based objections by me personally.

That said, I’ll give him an answer, because I’d like to see what he has to offer. In my concept, evidence and proof are indeed connected, but here’s the difference between them:
Evidence for a claim is an object, event or argument which makes the claim more likely to be true.
Proof of a claim is an object, event or argument which makes the claim certain to be true.

Therefore proof is the ultimate evidence, but evidence is not necessarily proof.

Here are five examples of evidence that would at least make me re-evaluate the probability of a claim:

– A man’s unique dental imprint on a woman’s arm would be evidence that he bit her.
– Markers appearing in the middle of the second pair of human chromosomes, which normally only appear on the ends of chromosomes, are evidence that our (ape) ancestors had one more chromosome pair at one stage, and two of them later fused together.
– A man’s amputated arm growing back seconds after he bathed in the shrine at Lourdes would be evidence for the shrine’s advertised healing properties.
– A prophecy in the Bible which predicted the day and time of three 21st century earthquakes, which then actually happened, would be evidence that its author had some prior knowledge.
– An increase in the number of Christians worldwide which coincided with a similar decrease in the number of atheists would be evidence that non-believers were converting to Christianity in large numbers. (The reality is that Christianity today mostly increases through reproduction or, in some populations unaccustomed to missionaries, at the expense of more established religions.)

Proof is a lot harder to come by. As absolutes, proofs may only exist in pure mathematics, and even then they rely on axioms which are questioned by some philosophers. Each of the following five examples, however, would be good enough for me in its own context that I would unreservedly accept the given claim:

– Seeing a gaping wound in my leg after an accident, but not feeling any pain after several hours, would be proof that I had lost the feeling in that leg. (The wait would be necessary to make sure I wasn’t simply in shock.)
– If a positive integer is divided by every positive integer between 1 and itself (non-inclusive) and none of the results are integers, that proves the integer is a prime number.
– As JBS Haldane famously said, the discovery of fossilised rabbits from the Precambrian era would prove that there was a serious flaw in the theory of evolution, given that rabbits are thought to have evolved well after the Cambrian era.
– If when we first arrived on Saturn’s moon Titan we found that a stick figure ten kilometres tall had been burnt into the surface by a laser, it would prove that intelligent life had been there before us.
– If there’s an afterlife, its existence is proved to everyone after they die through their own continued existence. (Of course, this is no help to the living.)

In the end, if people think they can establish the existence of God I don’t care whether they call their material evidence or proof. I judge it on its own merits.

Dave’s Old Pad

Question from Dominic:
What are we to make of the possible discovery of King David’s palace by Dr. Eilat Mazar? Do you believe this gives more credit to the Bible?

Answer by SmartLX:
Not very much, based on the discoveries and research so far.

The discovery of what’s now blandly called the Large Stone Structure was almost six years ago, and they’re still trying to date it authoritatively. Mazar was out specifically looking for Biblical artifacts, sponsored by an institution that supports political Zionism (and would therefore love proof that the Israelites were established in that area). Most of the external support since has come from Mazar’s second cousin at a Jerusalem university. None of this is sufficient grounds for dismissing the possibility that the discovery is really Biblical, but none of it helps the positive case either.

It strikes me that Mazar has apparently assumed that David was king at the time in order to conclude that the structure belonged to him, and at the same time the structure is now the bulk of the physical evidence supporting the existence of King David himself. (Other than the structure, and not counting the Bible, there’s one ambiguous carving on a piece of rock and that’s about it.) To uphold one as evidence for the other may be circular reasoning.

Of course people who try this usually haven’t based their own beliefs on the archaeological evidence, having begun to believe well before learning of it, so their personal journeys to belief are another matter.

Absence/Evidence of Evidence/Absence

Question from Mark:
Hey guys.

I am an atheist, but I’m also getting a bit confused lately. People say that atheism does not need to be proved, because it does not make any claims, but disproving the claims of theism. Is this true? Does atheism need to provide evidence of absence? To me, neither side sound convincing enough to prove their own points…

Answer by SmartLX:
Atheism is a lack of belief in gods. Evidence of absence isn’t necessary to not believe in something, merely absence of evidence.

Do you believe in leprechauns or gremlins merely because there’s no hard evidence that they don’t exist? Of course not. You don’t believe in them because there’s no evidence that they do exist, and for creatures as exotic as these there would have to be some evidence before you did believe. Perhaps you allow for the possibility that they exist, which is fine because you could always be wrong, but that’s not belief.

That said, absence of evidence can be evidence of absence in the right circumstances, and in the case of an all-powerful and belief-hungry god I think it is. My full argument to this effect is here.

Evidence For Atheism

“…absence of expected evidence can indeed be evidence of absence, like the absence of any bat guano in your attic.”

Question, often asked of atheists by Shockofgod:
What is the proof or evidence that atheism is accurate and correct?


Sometimes an apologist will hit upon a question which is not easily answered off the cuff and, by asking it repeatedly, give the impression that there is no good answer and the opposing position is unsupported. You can usually tell such a question by the fact that it’s asked with almost exactly the same wording every time. The above is Shockofgod’s personal weapon. Obviously, asking tough questions is a valid persuasive technique, but if they’re intended to be tough then one may need time to answer them the right way. A written response can be a great help, especially when you’ve read it before being asked the question verbally.

The question is hard to answer as is because atheism itself is the absence of a certain type of belief, not the presence of an equivalent belief. It feels wrong to advance the lack of a belief as correct, let alone proven.

What we need to sort out beforehand is the position of atheists (or at least the majority of them) on the existence of gods and the truth merit of religions. This can be defended, as “what atheists think”, far less awkwardly.

This attempt is probably not definitive, but here goes: the atheist position is that there is no available, substantive evidence for the existence of any god. Therefore it’s likely that there isn’t one.

Now that we have a defined position, what evidence or proof can we offer? It’s hard to support a negative like this, but “available substantive evidence” narrows the field a bit. It essentially means significant evidence which we’ve actually got. There might well be evidence which is not available, like God’s signature in three-inch letters on the surface of Ganymede. There’s plenty of “evidence” which is not substantive, like claims of personal experience and unverified miracle stories. Neither of these is a good reason to abandon atheism. Available substantive evidence for a god, on the other hand, would be good reason.

Therefore the evidence (proof is going too far) is the appearance that there is no such evidence for gods. If it did exist, and were substantive and available, it would be paraded around the world. Whichever god it supported would be vindicated. So it’s very unlikely that evidence is available and substantive and yet appears as though it’s not there.

Another possible piece of evidence for the likelihood of the absence of gods (remember, the position on gods is a statement of probability) is precedent. Unsubstantive “evidence” for gods often takes the form of supposedly impossible things, everything from the beginning of the universe to the diversity of life to Peter Popoff’s inexplicable knowledge of his audience members’ business. As Tim Minchin says in his brilliant beat poem Storm, every such mystery which has been solved has turned out to be “not magic”. Evolution explained the diversity of life brilliantly. Popoff’s earpiece, through which his wife fed him information, was revealed by James Randi. Such cases speak well for the chances that many remaining mysteries will soon be solved. Most importantly, gods seem less and less likely to be necessary in the areas where we have no good natural explanation yet.

Finally, we must address the possible impression of an overreach or a non-sequitur. Why does the absence of good evidence make it likely that there are no gods? Because gods as described by religions which have them (a) have visible, even obvious effects on the world and (b) want people to believe in them. (One or both is usually true even for deistic gods.) The lack of available substantive evidence suggests that either they aren’t both true, or there isn’t a god. Of course theology has reconciled this many times over, but not in ways with any evidential support behind them.

The evidence for atheism, in short, is the lack of available substantive evidence for gods when there probably should be a lot. On hearing that response, an apologist will probably retort in one of two ways:
1. Argue despite any clarification you make that absence of evidence is not evidence of absence, in which case it’s helpful to remember that absence of expected evidence can indeed be evidence of absence, like the absence of any bat guano in your attic.
2. Actually present some supposed evidence for the existence of a god, in which case the discussion will then be about that.

In any case, the unanswerable question isn’t.