Confidence in evolutionary science

So why am I so confident?

Converging linesI am not going to go into all the pieces of evidence, in all their glorious detail here. Some examples might follow. If I ask someone for directions and he points northwest. I don't follow his directions and later I ask someone for directions to the same place and she points northeast. I might infer, assuming honesty, that the location of my destination is somewhere near where lines extending from the fingers of the two pointers cross. That is to say, the lines converge upon a single location. If I wander aimlessly around and continue to ask people, and whenever they point I draw another line on a map I should expect to find that the lines all cross at a particular point. If I have wandered in something of a circle around my destination, I should have quite a pretty pattern of lines all converging on one spot on my map (excuse the crudeness of the diagram): We can, in this case, be fairly confident that we know where X happens to be (I choose X because it is visually representative of converging lines pointing to a single place, X marks the spot! I could have used * which might indicate more data points, but how that looks is kind of dependent on a person's computer/browser profile). Indeed - we no longer have to assume honesty. It is incredibly unlikely that even if all people were liars, that they would point in such a fashion as to create a point where all the lines cross at the same time.Of course, there is a big problem that is easily overlooked. What happens if my destination's location is the unwitting victim of a common misconception? Everybody thinks they know where it is (and everybody agrees where they think it is), but everybody is wrong in the same way. In my home town, there is a building that looks exactly like this. If I ask for directions to the town hall I am quite likely to encounter a number of people who will point me at this. However, the official council building is located a few miles away.So, if I want to be really careful, I would look to completely different types of evidence that doesn't suffer from the same kinds of errors or problems as people do. Let's go universal, and say that I am trying to find the magnetic north pole - I have so far asked eight people and have got the pattern in the diagram above (I've pretty much circumnavigated the globe to ask for directions!). It is unlikely they are lying, but they might be under a misconception. So each time somebody tells me, I also take a look at my compass. I find that the compass agrees, more or less, with the people each time and so I begin to follow one of the lines. I also look to where the sun rises and sets and make sure that is consistent with me heading to magnetic north. I look for stars, such as the North Star and make sure I'm travelling correctly as per that, and finally I use my knowledge of geography to ensure I am maintaining something of constant correct direction. If I was in London yesterday and Manchester today - I'm doing well because Manchester is closer to the North Pole than London is. I might even get out my GPS equipment, measure shadow lengths at various times and any other creative methods you might think of.I can even continue to circumnavigate the globe making sure that I am creating converging lines of evidence again - only this time...they are independent of each other. One might have certain potential problems, another might have different ones. If they are all pointing in basically the same direction, converging approximately on a point I can increase my confidence with each independent line that I know where the North Pole is.Occasionally, I'll make a measurement that points in a completely crazy direction as being North. This is interesting. It might be that I am using the technique wrong, forgetting to compensate for something (if I'm on a metal ship, a compass could be affected by the metal and start going crazy), or maybe I've just discovered something new and interesting. We'll call these outliers, most of the time they are mistakes and we might not understand how they happen, perhaps we'll explore them later but for now we'll simply discard them. The more outliers we find, the lower our confidence is, and it might even be possible to make some statistical calculations of confidence to work out which is the most likely location what the probability of that is.Having read a multitude of books, read primary literature, conducted simple home tests of my own, spoken personally with scientists who conduct more complex tests, seen various practical applications of knowledge all surrounding the the subject of evolution I am confident that there are multiple independent converging lines of evidence that point to the conclusion that life has changed over time on earth, that all life is related, that the modern synthesis pretty much explains how this all happens, and that it has happened over billions of years. In short (heh) - this is why I have the degree of confidence I have in evolutionary science. Edited by Admin, : Shorten long link.Edited by Modulous, : Culling 2,100 of my babies words.Edited by Modulous, : No reason given.Edited by Modulous, : No reason given.

There are a number of errors in there since I was still editing the post before release. They aren't huge problems, but my 1 in a 100,000 was meant to be 1 in 1,000 for instance, and this obviously impacts the numbers that follow it - I got a little carried away.I'm having issues editing it - they might be related to the reasons it got posted twice rather than previewed once. Perhaps due to its size? I'll leave it alone for now...

I did some merciless murdering of my words, (nah just kidding - they've been moved into cold storage). It stands at about 900 words now and is just the set-up for discussing the centre piece of my point: independent converging lines of evidence. If you really want - I'll hunt around to take it down to below 800. Either way I'm going to get some sleep.

Why did you bother to type that? For whose benefit did you think you were typing it for?Solipsism: keep it to yourself.

Ahem, seems like a good shoe-in for resurrecting some of the words I put into stasis last night/this morning.

Common Ancestry

Here are eight living things:RED KANGAROO
HUMAN
CHIMPANZEE
MISSISSIPPI ALLIGATOR
PLACENTAL MOUSE
MARSUPIAL MOUSE
SONG THRUSH
VAMPIRE BATSo let's try and think of some characteristics that some or all of them have. Motile might be a good one. All of them are motile (they can move), this is a characteristic that is shared by all of them. All of them are heterotrophic (they need to eat to sustain themselves). So we have shared characteristics there common to all of them. Any member of this group we'll call, for simplicity: "Animals".It also happens to be true that at some point during their life cycle, they have a notochord. So they are all "Animals", and they are all "Chordates". So far so uninteresting.What about Mammary glands? Well the Kangaroo has mammary glands, so too do humans, chimps, both the mice types, and the Vampire Bat. The others don't. So we'll call the ones that have mammary glands "Mammals". Of the mammals, only two of them have a pouch - the marsupial mouse and the kangaroo. We'll call them Marsupials, the others we'll call "Placentals" because the Placenta makes a significant contribution to nutrition which it doesn't in the "Marsupials".Finally, two of the Placentals have grasping 'hands', with flat nails (as opposed to claws). We'll call them "Primates", that includes humans and chimps.We can keep naming characteristics and assigning groupings for as long as we like. There is a problem though. All Mammals have mammary glands, but all birds have wings. What about a creature that has mammary glands and wings? Like a bat.Of course, our characteristics are somewhat arbitrarily picked, it is difficult to know what characteristics are important and what is not, but we still need a way of objectively resolving these character conflicts. One method - which should be an obviously good start is to list all the shared characteristics of bats and other mammals and likewise with birds. Whichever group has most in common with bats, is where we should place it. In this case, mammals win by a mile. This method (which I have simplified), called Maximum Parsimony, is far from perfect.Here is a tree we might compose based of physical characteristics: Now - being able to come up with a single, or a small selection of family trees based of physical characteristics and some objective collision resolution methods is something we might expect if evolution was in fact, true. Under certain conditions, if evolution were true, it must be the case that we could do this. Those conditions are true in this world, but if there were only a few life forms, closely related, it might be very difficult to create such a tree (would you expect to be able to create a family tree of your own extended family, based only on what the family member look(s/ed) like at age 25?). Other conditions may cause problems for this, but for the most part - they don't apply fully so we can, within certain error margins (that are often calculable), generate these trees.When we have eight members, there are 135,135 possible trees. (The calculation for that is 1 x 3 x 5 x 7 x 9 x 11 x 13, deriving that calculation is left as an exercise for the student). Some of those trees might look a little like each other, but most of them would be very different indeed.So let's find a way to create a tree of these animals using a completely different method. There is a protein, cytochrome b which "is one of the cytochromes involved in the electron transport in the respiratory chain of mitochondria." It is a protein that has no impact on the way an animal looks. This means that that comparing the cytochrome b genes of the animals above and creating a tree that way is a completely independent method of building a tree. If we are generous, there is a 1 in a 1,000 chance that if the animals were unrelated it would create a tree similar to the one I created above. As I said, there are 135,135 possible trees and most of them are radically different.Well, I just pulled the genes off pubmed and tested it for myself, here is a Dendogram tree I created using ClustalW. All that sounds complicated, at this time we'll just say that there are certain methods of computing trees based on differences in the way proteins are put together, some can quickly be done online for free by amateurs. That seems pretty close to me. Evolutionary prediction had a 999 in 1,000 chance of getting it badly wrong, but it didn't. That gives me 99.9% (approximate, naturally) confidence that evolution successfully predicted this tree and it was not due to just chance.OF course, we can do this for other genes, for larger sets of animals. I will skip to the chase: we get similar results. What are the chances? Astronomical. The only reason for these two completely different methods to come up with trees that are even remotely similar (and they are rarely exactly the same, due to known problems in the various methods used) is if the animals share a common ancestor and have been slowly diverging, their genes mutating, and their traits changing by descent with modification.The only other explanation that is in any way consistent is that they have been specifically designed this way in order to deliberately confuse geneticists.The theistic position on its own could never have derived this - once we invoke the miraculous power of a supernatural agent, the unit of inheritance doesn't even have to be material, it could be itself supernatural. There was no reason that there had to be genes, but even Darwin was able to see that if his theory was to work, something like genes would have to exist.Here, just to show you, is the tree I generated when I entered random characters instead of the actual gene sequences I found: That is just one of the many trees that could have been built, that would have essentially served as a strong falsification of the concept of common ancestry. Common ancestry of all life is almost certainly true based on the evidence and "perceived facts". Above listed are two independent and converging lines of evidence that both point in the same direction. The primary literature has thousands of similar tests from independent genes using different methods all coming up with very similar looking trees. Is that enough of a drawn conclusion for you?

It would take time, but I don't mind doing it that much if you don't mind waiting. I recommend you learn how to do it yourself since it is shockingly easy.See Message 138 or Sequence comparisons (Bioinformatics?) or my post on everything2. The hardest part is tracking down the proteins, everything else can be simplified to copy/paste press a button (you can tweak things a little).Using http://align.genome.jp/ there is a drop down menu after you've run the analysis that will create a tree for you - and there are other stand alone programs that will do a more complete job for you with a little know how. Hope that helps.Edited by Modulous, : No reason given.

Thanks for the input, and improved diagrams RAZD. I've added another section in my reply to Bertot, hopefully that helps with the curiosity. This gives me a good excuse to post another couple of smaller sections I deleted.Expert opinionThen again, maybe I'm in no position to judge this. Who better than the relevant experts in the fields in question? I can be sure they have studied the subject for a long time, read more primary literature than I, and I know there isn't a great deal of money in the field so I think I can trust them not to be in it for the money. Well over 99.9% agree that the facts of the matter (common ancestry, evolution) have been settled and that the rest is just filling out the details and explaining exactly how it all happened (honing the theory).This consistent expert opinion gives me increased confidence.And once again we turn to converging lines. Disparate fields such as geology, cosmology, archaeology, agriculture, medicine etc., are all consistent with natural history, evolution, common ancestry and so on with very little in the way of dissent from this opinion.The only argument against this kind of thinking is that there is some vast conspiracy. This is always the case when someone has a pet idea that simply doesn't line up with, or is flat contradicted by such an overwhelming body of evidence...everybody is in on a conspiracy. Maybe its an atheist conspiracy, perhaps it is a materialist one. It doesn't matter that while scientists may on the whole be biased towards certain political or philosophical preferences, there are still thousands of scientists who swing the opposite way. How a conspiracy with so many people who disagree on religion, politics, morality etc, can keep itself together is conveniently left unexplained.The arguments against evolution and common ancestryAre almost universally obviously wrong, the identification of the errors involved require a few months of proper study into the subject. They are the equivalent of someone arguing that the The Epistle of St. Paul the Apostle to the Romans was written by the Romans who were pagan which disproves God. The vast majority are just plain bad. There are quite a few that do sound reasonable, but they rely on strawmen of evolution or playing on fears...this is a problem of education and can easily be rectified. A small minority sound like killer arguments and are really hard to either see why they are wrong, or it is difficult to explain in straightforward terms the error being made.Very very often, the arguments are raised by those with a religious agenda, or those that don't like the implications of not being specially created for some reason.If evolution were wrong, after 150 years I'd expect at least some intelligent people with integrity to have criticised it in a way that wasn't ludicrous, childish, silly, based on understandable but pervasive misconceptions/straw men etc etc. Maybe they have. To date, none has been presented to me. This also boosts my confidence in the claims in question (though only in an ancillary fashion).

Hi olivortex,
Allow me to welcome you to the site. Thank you for your kind words. If I am viewed as a poster to be envied by some, it is only so because of years of practice There are two types of creationist, those that listen and those that don't, and you'll have to be prepared to deal with a lot of the latter and few of the former whatever forum you find yourself on though I like to think that, with a strong selection pressure here at EvC we've managed to preserve some of the better samples of their species!I had a look at the forum, I saw an extremely ludicrous argument being advanced by "Robert Newman" where he argues that evolutionary scientists get confused between breeds and species in the same post as he gets confused between 'genus' and 'species'.
It's quite sad really, to see such arguments advanced with such bluster and confidence from people who clearly don't realize how little they know.