Feb 20 2012
Evolution – It Could Have Turned Out Differently
A century and a half ago scientists knew very little about how life works, at least compared to what we know today. They knew little about the organelles that make up each living cells, the biochemical pathways involved in living processes, and knew absolutely nothing about genetics (which didn’t even exist yet as a discipline). It was in this context of relative ignorance that Charles Darwin proposed his particular theory of evolution and presented his argument for common descent and natural selection. The notion of evolution and common descent predates Darwin – scientists before him noticed a pattern in the sequence of fossils appearing in successive geological layers. Life seemed to be changing over geological time, with species in younger layers seeming to be derived from species in older layers.
Darwin added to that that basic observation his extensive personal observations of nature – that there is actually a great deal of variation within species, and that many species on the Galapagos seem to be derived from related species on the mainland, but changed to adapt to various niches on the islands. Still, evolution through natural selection was a remarkable hypothesis, but little more than a hypothesis. It is perhaps a good thing that there was so much left to discover about basic biology when evolution was proposed, for that created the opportunity to test this crazy theory.
Every major biological discovery post Darwin was an opportunity to falsify his theory. It could have turned out that the mechanism of inheritance involved a blending of characteristics from both parents (the prevailing notion of the time). This presented a problem for evolution, for then how do newly developed traits persist and change a species, rather than just being swallowed up and diluted in the large population? Mendel discovered that traits are actually discrete things (genes) that are not diluted. They persist as discrete units, so a new mutation would not simply be diluted, but can persist undiminished and spread throughout a population.
Sticking with genetics, it could have turned out that different species or different groups of species had their own pattern of genetic information, or even genetic code. Instead we discovered that every living thing uses the exact same genetic code (which three DNA base pairs code for which amino acids, etc.). Further, when we map out genetic variation we see a branching pattern of relatedness that roughly follows what we would expect from morphology – what living things look like. This same branching pattern of relatedness holds true no matter what bit of genetic code we look at. The same is true when we look at amino acid sequences in various proteins.
This didn’t have to be the case. If common descent through evolution were not true, and let’s say each species were created “according to its kind” then there is no reason why mammals and reptiles could not have had different genetic codes, or completely different proteins, or a different arangement of genes to achieve certain basic functions of life.
When we look at living things we also see this same pattern of relatedness. Structures all seem to have a derivation, and related species share certain features in common. Giraffes and humans have the same number of vertebra in their necks. Mammals tend to have five digits on each extremity, and when they have fewer than five we see that lose the extra digits through embryological development. Horses are not coded to have one hoof and that’s it. They are coded to have five digits, but then four wither and don’t develop and one toe becomes the hoof. In some cases a mutation results in horses with a couple of extra toes – a throwback to their evolutionary past and connection to other mammals. Some mammals have more that 5 digits, like the panda. When we look closer, however, we see that the extra sixth digit, which functions as a thumb, is really an expanded wrist bone.
This brings up the issue of embryology and developmental biology. We could have discovered that each species develops from a single fertilized egg through an optimal straight path to its adult form – but we didn’t. We found that creatures take a twisting and turning path to their eventual form. While they do not pass through the adult form of evolutionarily more primitive ancestors, the developmental path they do take does reflect this history.
I haven’t even discussed the fossil record yet. We didn’t have to find the fossils that we did, but they were there to be found. We could have found any pattern of fossils, but what we did find is a pattern of changing species through geological time – confirming those earlier observations. We have never found a fossil that is impossibly out of sequence if evolution were true – no horses in the Cambrian fauna. We also do not see species arising without any possible antecedents – completely new morphologies not derived from earlier ones. We could have, but we didn’t. The branching pattern of relatedness we do see follows a temporal and even geological sequence that is compatible with the idea that all life evolved over time from a common ancestor.
Obviously there are still gaps in our knowledge. Evolutionary theory does not predict that there should be no gaps. Over time, however, the gaps are being filled in. It didn’t have to be that way, but it is. Each time critics of evolution point to a gap in the fossil record, the gap gets filled in. No connection between whales and other mammals? No problem, here is Ambulocetus and other “walking whales” and species between whales and terrestrial mammals. Birds and dinosaurs? Here is a host of feathered dinosaurs and primitive dinosaur-like birds. Humans and apes? There are numerous and growing Australopithecus and Homo species to flesh out the branches in between.
Now critics point to bat evolution – where are the missing bat links? Give it time. There are gaps, there will always be gaps – evolution does not predict no gaps, it predicts that they will be filled in as we find more fossils. The gaps are being filled in – but it didn’t have to be that way.
The theory of evolution through natural selection is an overarching theory of life that ties all the biological sciences together with one theory about how life arose. Of course such a theory makes numerous predictions that span every other aspect of biology. Each such prediction was an opportunity to falsify evolution. Instead, over the last 150 years, everything we discovered in biology is compatible with evolution and much of it profoundly supports evolutionary theory, to the point that “it would be perverse to withhold provisional assent” (to quote Stephen J. Gould). There is no other theory that makes the same predictions, or that can tie everything we have discovered about biology into one cohesive theory.
The result of 150 years of biological science is that evolution (natural selection and particularly common descent) is a proven scientific fact, beyond all reasonable doubt. It didn’t have to be that way, but it is.
38 Responses to “Evolution – It Could Have Turned Out Differently”
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To paraphrase Popper, the better the theory the more possible worlds it excludes.
None of the evidence that corroborates evolution is incosistent with an intelligent designer. Neither is a world in which there was no correlation amongst morphological, genetic, and embryological evidence.
This is why evolution is a superior theory. It is the point I try to impress upon people who argue that alternative theories explain the data just as well, and the point you have made so well here.
Tantulus Prime,
“None of the evidence that corroborates evolution is incosistent with an intelligent designer. Neither is a world in which there was no correlation amongst morphological, genetic, and embryological evidence. ”
I think Steven Novella’s post was about evolution rather than evolution vs creationism, but you have hit the nail on the head.
An intelligent designer could have designed the universe, and life within it, in an almost infinite number of different ways. It is a remarkable coinicidence, then, that he designed it exactly the way cosmology, particle physics, and evolution have done so.
In short, gods are unnecessary hypotheses.
“It is a remarkable coinicidence, then, that he designed it exactly the way cosmology, particle physics, and evolution have done so.”
Explain what life as it has evolved is remarkably coincidental to, because one presumes it’s not coincidental to itself.
Drunkard’s Walk. You need only assume several basic components that we KNOW to be true. Stable host environment replete with nutrition and other energy input, simple celled organisms capable of reproducing, a “left wall” of zero cells, and a LOT of time.
Rewind the clock 4+ billion years, run the experiment again, and you probably wouldn’t get blogs etc.
cwfong,
My reply is to Tantalus Prime.
If he doesn’t understand my reply, I’m sure he will let me know.
You, on the other hand, are a lost cause.
But I thought that anyone here was allowed to reply to anyone else. Hasn’t that always been your habit, as a case in point?
And again, you have been unable to explain a rather unintelligible comment. But why make them if you aren’t prepared to explain them? Seems you can dish it out, but you can’t take it. Figures.
My positive comment (to all but BillyJoe7) as to evolution is that since we live in a probabilistic universe, the direction of evolution was not determined, determinable, or predictable in advance. The intelligence involved was evolved by the living forms that used nature’s strategies to subsequently, and sometimes by happy accident, use the benefit of their experiences to evolve themselves.
cwfong,
Everyone has a right of reply and everyone has a right not to reply.
I just exercised that right.
And my comment is self-explanatory.
As for this comment:
“The intelligence involved was evolved by the living forms that used nature’s strategies to subsequently, and sometimes by happy accident, use the benefit of their experiences to evolve themselves.”
Obfuscation or what?
But I know your history, so permit me to laugh out loud at the mental image of a socially active bacterial colony side-lining natural selection.
Folks, I kid you not.
BillyJoe7: “But I know your history, so permit me to laugh out loud at the mental image of a socially active bacterial colony side-lining natural selection.”
Perhaps they worked something out during a cocktail party….
Well written piece Dr. Novella.
I do have to pick one nit though:
I believe it is more accurate to say “how the diversity of life arose” since otherwise we’d be speaking about abiogenesis. Dawkins (and I agree with him) believes that the basic principles of evolutionary theory apply to abiogenesis as well. However, to my knowledge, that small gap hasn’t been bridged yet satisfactorily.
I only raise this point, because a common creationist trope is that evolution does not explain how everything (life) began. My response is always, “That’s correct. It is not supposed to. It is a theory on how life progressed and became diverse after it began” and then I refer them to abiogenesis (in particular a great Neil Tyson video on the topic).
I’m certain you know the distinction well, but just figured I would (attempt) to head off any creationist comments on it.
I knew that old deterministic lackey BillyJoe7 couldn’t ignore the statement about our freedom to evolve ourselves. He tried to finesse the point of the main post that evolution was not determined in advance by coming up with some cockamamie comment about coincidence, which when asked t explain, he couldn’t. Having been caught out several times with these inanities, he now has a standard reply that all such comments are self explanatory. (True that.)
And of course bacteria do not sideline natural selection, even though BillyJoe (and apparently SteveA as well) thinks they were magically the result of predetermined accidents. I don’t know that I’ve recommended reading what Carl Sagan’s son and ex-wife have written on the subject, but if not, I recommend it now:
What Is Life? by Lynn Margulis, Dorion Sagan, Niles Eldredge (Foreword by)
http://search.barnesandnoble.com/What-Is-Life/Lynn-Margulis/e/9780520220218
(Also previewed at Google Books.)
I advise BillyJoe7 not to even try to read it, since it was written by actual evolutionary scientists and incidentally atheists – except they aren’t full on determinists and believe (like Carl did) there’s other life out there in the universe, etc. But they aren’t even adaptive mutationists as far as I can tell, though that’s a pity.
And again, BillyJoe and SteveA won’t want to read it, it will hurt their brains. All creationists and other predeterminists should avoid it as well.
Say something dumb now BillyJoe, that’s your established role here.
“Say something dumb now BillyJoe, that’s your established role here.”
Good post cwfong.
———————————————-
cwfong’s method is to never say anything explicit and to quote authors and link to their articles and books. Most of his favoured authors are in the borderlines of science if not over the edge, but he presents them as progressive mainstream.
http://search.barnesandnoble.com/What-Is-Life/Lynn-Margulis/e/9780520220218
And talk about being side-lined…..
I give you Lynn Margulis: one good idea driven to ridiculous and unsupportable extreme.
Just read the blurb to see what I mean.
This is great post because it points to the most powerful piece of evidence for evolution: convergence. I’ve sent it to a few people who’ve asked me why I’m so confident that common descent is correct because it lays it out so well.
Incedentally, does CW Fong do anything aside from bust BillyJoe’s balls and try to cryptically appear smarter than everyone else?
IF he does, I haven’t seen it….
Hell, I’m just kidding around, as BillyJoe7 is so smart that he should start his own blog. I’m just jealous that he’s better at quorum sensing than bacteria. Or so he says in any case. By the way, Steve12, who are you, and are you smarter than BillyJoe7? Just asking.
“I give you Lynn Margulis: one good idea driven to ridiculous and unsupportable extreme.
Just read the blurb to see what I mean.”
Why don’t you tell us what you mean, if you can, that is.
Otherwise just repeat the mantra: “And my comment is self-explanatory.”
By the way, Steve12′s convergance tends to prove Margulis’ point as reflected in the blurb that says:
“Mammalian cells are descended from the amalgamation of different strains of ancient bacteria. All life is connected to us through time and space. Species of organisms diverge into new kinds, yet earlier patterns never entirely disappear.”
cwfong,
You introduced Lynn Margulis, so perhaps, rather than just link to her book, you could explain why exactly it is so important for us to read her book.
(As opposed to a book by someone like Richard Dawkins and Steven Gould.)
Because she has done more ground breaking work as an evolutionary biologist than Dawkins or even, in my view, Gould, and she understands the ways that organisms take advantage of experience much better, again in my view, then Dawkins. And I’ve studied and worked with the subject for years, and kept up with the most credible advances in the science, while I don’t think Dawkins, regardless of his earlier contributions, has done. He has overly committed himself to his own theories (of an essentially dead universe, etc.) and he’s stuck with them.
Further, most of those interested in the subject have already read several books by Dawkins, as have I, and to not read some of the more recent books that have a new viewpoint is not the way to educate oneself, at the very least. If you don’t take your time to study all reputable viewpoints of the subject, you don’t learn.
And learning is or should be an ongoing project for all of us, including the best of us. And Margulis, now dead, was one of the best.
You don’t have to agree with everything to understand the value of most of it. There are areas where I disagree with her, but at the same time where I’m made to wonder if in the end she might again be found right. That’s how science works, and pooh poohing new ideas and related discoveries out of hand is not the way it works, or should work.
If that’s not an exact enough explanation for you, then too bad. I’m not interested at this point in proving anything to you. Time for you to learn for yourself, or refuse to. Your choice.
Turns out the answer to my earlier question is a resounding “no”.
Who are you again? Is your opinion worth anything?
cwfong,
“I’m not interested at this point in proving anything to you.”
cwfong, not only are you not interested in putting your view, you are incapable of it.
All we have ever had from you is quotes and links, and when you do say something yourself it comes in two forms: a screed you seem to have memorised from some book you’ve read which seems to make no sense out of the context from which you’ve pulled it; or a personal attack on those who have exposed your view as nothing but fringe science pretending to be progressive mainstream.
“There are areas where I disagree with [Lynn Margulis]”
I would hope so.
Here are some choice quotes:
“[modern evolutionary biology is] a minor twentieth-century religious sect within the sprawling religious persuasion of Anglo-Saxon biology”
“Neo-Darwinism, which insists on (the slow accrual of mutations), is in a complete funk”
“This is the issue I have with neo-Darwinists: They teach that what is generating novelty is the accumulation of random mutations in DNA, in a direction set by natural selection”
“Natural selection eliminates and maybe maintains, but it doesn’t create”
“Whatever is brought together by sex is broken up in the next generation by the same process”
For her it’s all about symbiosis
She won with mitochondria and chloroplasts back in the 70s.
Then she wasted the last forty years of her life finding it everywhere.
I agree with most of those quotes, even when taken out of whatever context you googled them. They’re not however in the book I referenced. (Don’t read it, you’re not predisposed to gain from it.)
I also liked her forcefulness and combativeness, although clearly you don’t when she attacks the neo-Darwinists with the vigor that their deterministic and complacent ignorance asks for.
You don’t think symbiosis (endosymbiosis) has gone anywhere since the 1970s? It’s gone past your neo-Darwinism and paved the way for virtually all of the present research in evolutionary biology.
But you knew that, right?
You feel comfortable hanging out with the more amateurish neoDarwinists here and parrot whatever you think you understand about their dogma. But even then you get it wrong. Probably why you don’t comment in the more sophisticated neoDawinist sites. They’d just laugh at your interpretations.
This is not a comment against this blog owner’s knowledge as a neuroscientist. It’s superb. He’s also not a full determinist, as this present post was meant to demonstrate. You’ve slyly attempted to set him straight on this, but it won’t work. Sorry.
Depends on what you mean by a “full determinist”. Where have I denied quantum physics. Certainly there are those who unjustifiably drag quantum physics into the debate about evolution and consciousness and I have simply pointed out that this is based on the false idea that consciousness collapses the wave function. But that is a separate issue.
And I defy you to quote where Steven Novella says anything at all about determinism in this post and where I even responded to him in any way to “set him straight”. You are just flat out lying now to save face. His post has nothing at al to do with determinism
Also, instead of just stating it to be the case, I defy you to point out where anything I have said would be laughed at by those who support the modern synthesis. Not being an evolutionist, I accept the consensus on evolution by evolutionary biologists and have enough knowledge of the subject to recognise fringe science when I see it. Except for her work on mitochondria and chloroplasts forty years ago, Lynn Margulis operated on the fringe of science. Period.
Anyway, you have now stated your rejection of modern evolutionary theory so you now stand exposed as a fringe dweller on this issue. That was my only motivation for challenging your views which you were trying to present as progressive mainstram. So thanks very much for coming clean.
I have to laugh at your usual tactic of defending your dishonesty by claiming it’s the other party who’s lying. Also you have no idea what physicists refer to as the wave function so you’d be well advised to stop presenting any argument that depends on an understanding of the concept.
Statement that anyone with a scientific mindset would laugh at: ”
An intelligent designer could have designed the universe, and life within it, in an almost infinite number of different ways. It is a remarkable coinicidence, then, that he designed it exactly the way cosmology, particle physics, and evolution have done so.”
Absolutely backwards and meaningless, and you don’t seem to know that even when it’s pointed out.
And cutting edges are not fringes, but of course you don’t seem to know that either.
Here’s what Jerry Coyne, a prominent neoDarwinist, had to say about Margulis:
“I am informed, and this seems reliable, that Lynn Margulis died yesterday of a stroke she suffered last Thursday. I had my differences with Margulis, for in her latter years she took to making repeated and unfounded attacks on modern evolutionary biology and speciation. Nevertheless, there is no doubt that her work formed one of the most profound contributions in twentieth-century evolutionary biology. I refer in particular to her idea that organelles—especially mitochondria and chloroplasts—descended from ancient bacteria that formed symbiotic relationships with cells that engulfed them. She faced strong doubt, criticism and even derision for this idea, but in the end evidence from DNA and other sources proved her correct.
She wasn’t so correct about evolution in general, or in her views that such symbioses were both ubiquitous and a driving factor in evolution and speciation, but she was right about some important stuff: facts that revolutionized our understanding of the history of life.”
You’d probably want to call that damning with faint praise, but I’d say it show the respect that the more competent scientists have for those that disagree with and challenge them.
You on the contrary have no standing or ability to challenge anyone.
Margulis and I attended the same University, by the way, so I’ll admit to a certain bias just for that reason.
“Who are you again? Is your opinion worth anything?”
Because “CW Fong” is a well known quantity in the scientific community.
What kind of question is this?
One that I can answer but apparently you can’t.
“One that I can answer but apparently you can’t.”
OK. Have at it then.
Wrong answer.
Whatever. If it makes you feel like superior to play put down anonymously, be my guest.
I don’t know any scientists who talk to people as you do, at least not any who would gain satisfaction from doing so with non-scientists on a general audience blog, so I’m not sure what the superior complex is all about. Maybe you were bullied?
Anyway, carry on…
cwfong,
What is worth a real belly laugh is that you just quoted someone whose view of Lynn Margulis echos my own exactly. And yet you are using it to criticise me! Read what I said again and then read again what Jerry Coyne said and tell me where the difference lies? Our views are identical.
And I see you are still denying you are on the fringe.
Cutting edge? You’re obviously want me to die laughing.
BillyJoe: “An intelligent designer could have designed the universe, and life within it, in an almost infinite number of different ways. It is a remarkable coinicidence, then, that he designed it exactly the way cosmology, particle physics, and evolution have done so.”
Let me construct this paragraph for you:
The universe and life within it looks like it evolved scientifically.
An intelligent designer could have designed it anyway he wished using any method he wished.
So it is a remarkable coincidence, then, that he chose to design the universe in such a way that it looks like it evolved scientifically.
In other words, gods are unnecessary hypotheses.
Okay, so now I challenge you to deconstruct it.
BillyJoe7-
Why not read a biology journal–
An interesting paper from ‘Biological Theory’ volume 6
http://www.springerlink.com/content/845x02v03g3t7002/
“We trace the history of the Modern Evolutionary Synthesis, and of genetic Darwinism generally, with a view to showing why, even in its current versions, it can no longer serve as a general framework for evolutionary theory. The main reason is empirical. Genetical Darwinism cannot accommodate the role of development (and of genes in development) in many evolutionary processes…”
sonic, BillyJoe7 doesn’t read cited papers, because he already knows anything they could possibly teach him. I show him where even a neoDarwinist such as Coyne has respect for his scientific adversary, Margulis, and BJ7 thinks it proves his own right to disrespect her. An interesting study in the persistence of ignorance, that one. He runs on curiosity, which is good, except that he has managed to run it in reverse, not so good.
And note that the abstract of your cited paper also says:
“We go on to discuss two conceptual issues: whether natural selection can be the “creative factor” in a new, more general framework for evolutionary theorizing; and whether in such a framework organisms must be conceived as self-organizing systems embedded in self-organizing ecological systems.”
Once he senses that this is almost exactly what Margulis’ has perceived, he’ll rev up his denial apparatus to full backwards speed.
BJ7, you have challenged me to deconstruct that revised paragraph.
The universe and life within it looks like it evolved scientifically.
(Which is a sentence that assumes that it might not be what it looks like?)
An intelligent designer could have designed it anyway he wished using any method he wished.
(Which assumes that if he could have, he chose to evolve it scientifically?)
So it is a remarkable coincidence, then, that he chose to design the universe in such a way that it looks like it evolved scientifically.
(Where’s the coincidence that if he chose to be scientific, he chose to be scientific?)
In other words, gods are unnecessary hypotheses.
(Except in this odd scenario, god has been seen as necessarily scientific?)
As I noted to begin with, there is nothing here that’s coincidental with anything except itself. Which by definition is not a coincidence.
coincidence |kōˈinsədəns; -ˌdens|
noun
1 a remarkable concurrence of events or circumstances without apparent causal connection
So instead of finding a coincidence you’ve made a causal connection between an intelligent designer and science, just as the creationist crowd have done.
You seem incapable of logically hypothesizing that since the concept of God is illogical, the connection between design and construction might be found in the organisms themselves.
Again, what I said about Lynn Margulis is no different to what Jerry Coyne said about her. Yet what he said about her is apparently okay with you but what I said is not.
As for the linked article:
Can you say cherry picking?
And as for me not reading linked articles, I have done so extensively in the past only to find that most of the time the linked articles either do not say what you think they say, or they regurgitate the same old fringe views that have been circulating unsuccesfully for decades and that your other links have already informed me about. Frankly, I prefer to spend my time in more fruitful pursuits.
And I see you cannot deconstruct my paragraph.
Simply quoting it with a gratuitous insult is the way you always operate. That way no actual work is required on your part. Like simply quoting the words of your heroes and posting links. None of it requires any actual work on your part. Yet you expect everyone else to run off and study your links but show no interest in any follow up when we read them and post a commentary.
Not that you’re averse to using insult in lieu of explanation, but where was the insult in that deconstruction?
Or is this your way of arguing it’s not true that you’re incapable of constructing logical hypotheses?
And please tell us of the more fruitful pursuits where you prefer to spend your time, except that somehow you spend all your time denying that the pursuit of new scientific discoveries is fruitful.
And actually it was sonic who found that latest cherry, which was, if I may say so, well picked.
So again…
Where did Steven Novella mention determinism in his post?
How was what I said about Lynn Margulis different from what Jerry Coyne said about her?
How does my paragraph regarding god hypotheses not make sense?
What have I said that could possibly be laughed at by neo-Darwinists?
Hey, if you don’t agree, you don’t agree. Catch you later..