In April I was asked by the BBC’s science magazine, BBC Focus, to provide them with a short essay identifying and discussing some major unanswered questions in evolutionary biology. (This is part of their regular “Questions at the Frontiers of Science” series.) I identified three, and at my request the magazine has kindly put one of them online for my readers. The question is “Was the course of evolution inevitable?”, and you can read my answer here.
In the next two days I’ll post the other two questions and my answers; these are available only in the print magazine but I’d like to give readers to have a chance to see them. Alternatively, since there was some editing of what I submitted, if you email me I’ll send you a Word document with my original questions and answers.
One issue that I didn’t tackle was the thorny problem of how the first organism (or replicator) came into being. There’s not much to be said here yet: we have lots of hypotheses but are approaching the answer only slowly. (Do note, though, that studies of the origin of life, or “abiogenesis” aren’t formally part of evolution, which takes over only when a replicator has come into existence.) And even if we can produce life in the laboratory under conditions approximating those of the early Earth, that only shows us that it could have happened, not how it happened. Still, such a demonstration—and I think we’ll see one in the next 50 years—would go a long way toward blunting one of the few arguments left in the creationist arsenal. For it would dispel the main creationist claim about this issue: that there’s no way life could have originated spontaneously without the help of God.
Actually, the “How did life start” is NOT an objection to plain fact of evolution, any more than “Where did the atoms come from?” (not answered until the 1950s) was an objection to Dalton’s atomism.
Excellent point, and one that I emphasize to my high school freshmen biology students who’ve been brainwashed into believing that evolution is anti-religion.
how can i get tht decument with the question ???
Email Jerry [look in “research Interests” link in right sidebar of this page for the address]
No such link or sidebar for research interests on any page I can see-
Top right of this very page that you are reading you will see the below. Just look inside “Research Interests”
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Sadly, even when a replicator is generated, it won’t blunt the creationists. They hold to their notions in spite of all evidence. Adding a bit more probably won’t make a lot of difference.
Nothing will ever convince the creationists themselves. Fortunately, that isn’t necessary. What is necessary is to be able to counter their arguments, to parents, students, legislators, school board members, judges, and juries, who will sometimes respond to rational argument.
Yes.
It’s the old, “Don’t confuse me with the truth; my mind’s made up.” response. But that pretty much sums up the current YECs and most fundies’ thinking.
Nice short piece. As for evidence of inevitability of human-like (defined how, I’m not sure), one possible kind would be confirmation of such from extra terrestrial sources.
I have a theory that once some abiogeneticist creates life from non-living material, all the hatred directed toward Darwin will suddenly be redirected toward whoever this new villain is.
I have suggested to several Biblewhacks who scream about Darwin that they should find a good biography of Galileo and read it. They have no clue that before Darwin came along, the venom was all for Galileo.
“What’s wrong with Galileo?”, they ask. Duh. L
Suggest that Festinger’s, et al, “When Prophecy Fails” be perused. Seemingly, there are 17 million liters of ethanol in the Milky Way.The brew master? Let the creationists “hop” on that! The anointed ones
are beyond the sobering logic of science and common sensing!
» D. Reid Wiseman:
The anointed ones are beyond the sobering logic of science and common sensing!
I don’t think that can be true. You don’t suppose, I suspect, that their logic modules are just fried somehow, or even entirely absent. They are capable of making logical and common sensical decisions in most areas of life. That is not the problem. The problem arises only when arguments and/or evidence conflict with some dearly-held belief.
Mind you, that kind of conflict is something all of us experience. And the decision we then make is a choice. It is not (and could not be) dictated by logic. Any logic is only as good as its premises.
The road to perdition starts at the point where you declare some premises to be unassailable, to be justified in a positive, absolute sense. (Which, incidentally, involves the assumption of infallibility at some point.) The only way we have found out of this dilemma to date is a methodological decision: not to try to insulate our ideas from any kind of critical assault but, on the contrary, to try to expose them to as much criticism as possible so as to weed out as many flaws as possible. And even that is impossible if we do not accept the fundamental logical premise of non-contradiction.*
So the problem is not that we are sometimes irrational. That’s why we have got science (broadly construed as the pursuit of objective knowledge): to average out the mistakes that inevitably fallible human beings will make. The problem is this:
Justificationism – the idea that certain knowledge is attainable: you’re half-way to Crazy Town.
The idea that you have attained that certain knowledge: delusion.
Not accepting the principle of non-contradiction: any rational discussion is instantly doomed.
* This is a fairly straightforwardly Popperian analysis, whose ideas are invaluable in this regard, if you ask me. A brilliant introduction is Bryan Magee’s Popper.
Good Morning Peter Beattie: Well articulated! Thank you. Have you read Festinger’s, et al, “When Prophecy Fails” and/or Sagan’s, “A Demon Haunted World.” Yes, as an ageing, addlepated scientist, I relish Popper’s criterion of FALSIFIABILITY. DRW
How sure are we, really, that human-like intelligence evolved just once? I think we can be fairly certain that no technological civilization existed on Earth in, say, the Triassic. But can we rule out the possibility of dinosaurian hunter-gatherers on the level of, say, Homo habilis? If they were geographically localized and lasted only a few hundred thousand years, would we know about them?
I’m not saying I think this actually happened, just wondering if we can be sure it didn’t.
Well…. since there is no evidence of Triassic stone tools and no plausible argument based on brain morphology…
I grant that none of the dinosaur species we know about had the brains of hunter-gatherers or left stone tools behind. The question is how comprehensive is our knowledge of dinosaur species? Can we rule out the possibility of some as-yet-undiscovered intelligent dinosaur in some underexplored region of the world?
Can we rule out the idea that the smaller ones traveled in dirigibles while vacationing at theme parks?
I think I stipulated that in my first comment.
Do you (or anyone else) have a serious answer to the question of how comprehensive our knowledge is? Have we explored enough places where evidence ought to be found to say with confidence that there’s no evidence waiting to be found in places we haven’t looked yet?
We will never have explored enough places to say our knowledge is comprehensive enough. But knowledge is not just a matter of accumulating facts. It also involves considering possibilities in light of plausibility. There is nothing in the fossil record for dinosaurs that indicates that Homo-style intelligence developed. And, I no of nobody who has provided a plausible scenario for the existence of such a thing among dinosaurs. (Science fiction doesn’t count.)
But we probably can’t “prove” that they didn’t get together now and then and pray to the lord in a language very similar to English. Or maybe ASL, since their vocal biology wouldn’t have been structured for our kind of language.
Maybe I’m not being clear. If we believed we had a detailed and complete phylogeny of dinosaurs down to the level of, say, families, with only species remaining to be filled in, I would consider that comprehensive enough. The question is are we there yet? Or are there still large blanks in the picture in which intelligence (however unlikely) could conceivably hide?
I think you are clear enough but I don’t think you are being sensible.
We probably don’t have a complete phylogeny of trilobites. Does that make them candidates for human-style intelligence?
Do we have a complete enough phylogeny to be confident that dinosaurs didn’t play Blackjack? Do we need a complete phylogeny to reasonably think they didn’t?
Evidence of intelligent activity can be seen from space and will surely outlive our species. Absence of evidence is evidence of absence.
Evidence of technological activity can be seen from space. But humans and near-humans existed for millions of years before building the Great Wall of China.
One also wonders how visible the Great Wall will be 100 million years from now.
And therefore maybe there was human-like intelligence among the trilobites, too! Have we gathered enough evidence to prove that that didn’t happen? Maybe it was found among the early insects, too!
At some point you have to allow plausibility to play a role in generating hypotheses.
Good question. But, assuming a truly intelligent species disposing of far better remote sensing capabilities than ours, be they technological or biological, 100 Ma from now, is actually capable of discerning whatever faint traces of human building activity remain: how will they interpret them? I like the point made by NASA’s K.P. Lulla: “In fact, it is very, very difficult to distinguish the Great Wall of China in astronaut photography, because the materials that were used in the wall are similar in color and texture to the materials of the land surrounding the wall – the dirt.”
http://www.nasa.gov/vision/space/workinginspace/great_wall.html
Already, the major anthropogenic artefact detectable from space over China is the ghastly level of atmospheric pollution.
Would our remote successors regard as intelligent a species which multiplied out of control and irremediably destroyed its own habitat in a geological second? Or as a compulsive structure-building species endowed with considerably less environmental acumen than beavers, and socially less advanced than termites? Whichever way you turn it, an anthropocentric view of intelligence is probably insufficient.
This is turning into a semantic argument over definitions of intelligent. My point still stands: we should expect to see intelligent/technological remains from dinosaurs. We haven’t, so there isn’t.
FYI: our Genus is a few million years old but our species is only half a million at most.
gillt: So we agree then that intelligent hominins (“humans and near-humans”) existed for millions of years without global technological civilization.
Now suppose, for the sake of of argument, that a genus of highly encephalized therapods evolved in a remote region of China or Siberia, and persisted for maybe a million years before going extinct. If their most advanced technology was sharpened sticks and carved bones, what evidence would you expect to see today? And can we say with confidence that such evidence doesn’t exist undiscovered somewhere?
Absence of evidence is evidence of absence only if we’ve thoroughly searched all the places where the evidence ought to be.
What would I expect to find? Carved bones and flaked stone. We find carved bones and flaked stones for early hominins so why not your brainy dinosaurs?
Maybe I’m not understanding your point here. There is simply no evidence for human-style-braininess in dinosaurs. There is no plausible argument for it to ever have have existed. Are you just trying to say “humans think we’re so smart but we’re no smarter than velociraptors”? Or what?
No, that’s not what I’m saying. And I know there’s no evidence. What I’m asking (and have asked several times now) is could there be evidence that we haven’t found yet? I’m not claiming it exists; I’m asking whether it could exist undiscovered somewhere.
“We find carved bones and flaked stones for early hominins so why not your brainy dinosaurs?”
Two possible reasons:
1. Any hypothetical dino tool remains would be 50-100 times older than hominin tool remains. Apparently there’s some disagreement about whether bone fragments found with Australopithecus can be unambiguously identified as tools. It seems reasonable to assume dino tools (if they exist) would be even harder to recognize.
2. We know where to look for hominin tools. We don’t know where to look for hypothetical dino tools. They might be limited to a geographic region we haven’t thoroughly explored yet. They might be deep underground, or underwater. Many more fossils exist than will ever be found.
So far I haven’t heard convincing answers to these two points. All I keep getting is “If they existed, we would have found them by now.” But that assumes we’ve looked hard enough for the right things in the right places. My question is whether that assumption is warranted in this case.
Again, I’m not claiming that smart dinos existed; in fact I think it’s pretty unlikely. But I prefer to base that conclusion on something other than personal incredulity. So I remain agnostic.
Having said all that, this is not an issue I care to defend to the death. So if I still haven’t managed to make my position clear, then I’ll stop trying.
But you keep missing the point about PLAUSIBILITY. Plausibility is important.
Could there be evidence that we haven’t found yet? Logically yes. Plausibly, no.
Could there be evidence that dolphins once constructed villages at the bottom of the ocean, complete with whalebone shelters? Maybe we just haven’t looked in the right places?
If your notion of implausibility is independent of logic, and based solely on intuition, then I’m not seeing the difference between that and what I’m calling personal incredulity. If you have cogent arguments why dinosaur tool use is inherently less plausible than, say, primate tool use, let’s hear them.
In fact we have examples of living dinosaurs (i.e. birds) that make and use rudimentary tools. If it can happen today, it’s not obvious that it couldn’t have happened in the Cretaceous. (I don’t believe it did happen, but that’s not the point here.)
Who said that plausibility has nothing to due with logic?
Bird-style tool use (and similar examples from modern ethology) are not, to my mind, examples of “human-like” intelligence. It is completely plausible that such behaviors were present in the Mesozoic. Is that the kind of behavior you are talking about? If so, it would have been nice if you had said so long ago.
You haven’t addressed the difference between your dinosaur hypothesis and my dolphin hypothesis. Could it be that my hypothesis is correct? How would we know if we had gathered enough evidence to say “no”? Could, perhaps, an extraterrestrial being search more carefully and find that dolphins did in fact build villages at the bottom of the ocean?
The question is probably how you define intelligence.
I just watched a documentary about orcas hunting stingrays in Whangarei Harbour (NZ). In a stunning display of tactical intelligence and cooperation, the most experienced orca flips upside down, seizes the stingray by its tail, carefully avoiding the poisonous spike, and then flips back, turning the stingray with its belly up, thus inducing tonic immobility. The next orca bites the stingray’s head off, others help themselves to the wings. The technique is described as “cultural”, learned by members of the social group.
At comparable levels of tactical intelligence, physical skill, coordination, and communication, this behaviour would match the performances of most anthropologically documented hunter groups that I know of. And yet it would leave no direct trace in the paleontological record, if the hominid hunter-gatherer paradigm is the pattern you’re looking for. So the question is: how and why would a dinosaur species have traded the advantages of its omnivore or predator specialisation in the course of its evolution for the more doubtful benefits of becoming a jack-of-all-trades relying on dino-made tools? How many mutations and what selective pressures would have been needed?
Wouldn’t such an evolutionary path have required many more stages?
I suspect the hominid hunter-gatherer paradigm is too narrowly anthropocentric when defining intelligence.
Besides, a truly intelligent dinosaur would have done everything nano, and wireless 🙂
Re the link… Chance? Random?
What is your position on free will again?
At what point anytime after the instant of the big bang did a random act occur that was not predetermined by the state of the universe immediately before it?
Is not all that has happened in the universe only but what must have happened (including me posting this comment)?
No, it isn’t. The outcome of quantum events (including some types of point mutations in DNA) is not deterministic. In fact the distribution of galaxies is contingent on genuinely random quatum fluctuations in the early universe. A replay of the Big Bang would yield a different set of galaxies.
The idea that all of future history was determined at the time of the Big Bang is simply wrong (and has nothing to do with the free will debate anyway).
Good article …
And are you ?
(Beyond Usain Bolt) !!
I think the whole “life originated spontaneously” idea is itself a holdover from the religious concept of the “spark of life”. More likely, replicating molecules, or even metabolism, evolved from what we would now describe as “non-biological” chemical processes going on in the early earth, or elsewhere. There was no magic event on which we can look back and say here is where life started.
Agreed. There is a process there on which we can only speculate. The speculation is entertaining and may provide insight but is unlikely to provide definitive answers.
Human-level intelligence apparently evolved only once, and after quite a long time span, on earth. This suggests that it requires a very special set of conditions and pre-adaptations (say, an opposable thumb) in order to arise. It also suggests that increased intelligence does not automatically and to an unlimited extent lead to increased fitness. So no, I don’t think human-like intelligence is an inevitable outcome of evolution (unless we give it infinite time).
Or you could use PZ Myers’ model from one of his seminars. Diversity is mostly recaptured after mass extinctions. (But according to the latest survey a few weeks back, it can equally likely end up on a lower or higher level.)
Land life has seen 2-3 major extinctions, so we have observations of 3-4 independent worlds.
On one of those language capable technological intelligence arose. So the frequency of inhabited terrestrials with ETI may be in the tens of percent.
I would guess the answer lies somewhere between that and a minute likelihood.
Vertebrates, to which we belong, evolved only once. They survived all the major extinction events since the Cambrian. So you can’t really maintain that there have been 3 or 4 independent experiments. One could argue instead that the mass extinctions removed one or more stumbling blocks to the evolution of human-like intelligence. It’s hard to draw statistical conclusions from a sample of one.
I presume you are familiar with G. G. Simpson’s 1964 article on the non-prevalence of hominoids.
Couple of science fiction stories. Aliens arrive and are cordial to humans, but are here to visit with the dolphins. Dinosaur artifacts are found on the moon. It is discovered that dinosaurs had a high level civilization, and became extinct as a result of global nuclear war.
Please note email address to use to request full text of questions and answers in Word format. Much thanks.
Jerry’s email address is not hard to find by Googling, and he prefers not to expose himself to spam by publishing it on this site.
speaking of spam, don’t we all use spam filters at this point, to make concerns about spam moot.
Psst. It’s on the “Research interests” page!
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“Would humans — or at least human-like intelligence — have inevitably evolved? We don’t know. All we know is that, unlike streamlined aquatic beasts or gliding mammals, it evolved just once. We can never be sure it could evolve again.”
Interesting to read a metaphysical naturalist saying “We do not know”. For them the question should be easy to answer, as each event in the universe is the product of physical laws, constant in space and time, there is no way to escape that humans would evolve again. Because the initial conditions of the earth should be fixed by the physical laws, the asteroid will strike again the earth at that time I will write this again and you will be reading again.
Quantum physics says there is no unique sequence of events that must play out. See my reply to Lowen Gartner above.
So the physic laws are not constant in space and time. It depends on quantum oscilations. Then any extrapolation of actual observed laws is only tentative. Then our knoledge is limited in spave and time.
I’m not sure what point you’re trying to make. Yes, our knowledge is limited; we don’t know everything. What we do know tells us that the laws of physics are constant; but they yield probabilities rather than certainties. The future is inherently unpredictable even in principle.
“What we do know tells us that the laws of physics are constant”
My point is that it is no true. If all depends on quantum oscillations, laws cannot be constant.
Your point does not make sense. There is no true? That is a bit like saying “I always lie”.
What do you mean by “true”?
You are the one who made the assertion: “My point is that it is no true.”
Perhaps you didn’t mean “there is no true”? You meant possibly “that is not true”?
In any case, if the latter, the statement “If all depends on quantum oscillations, laws cannot be constant.” is not logical. The laws of physics are not invalidated by quantum physics.
The laws are the same. The outcomes are not. You do not have to postulate a different physics in order to reach a different outcome.
Seriously, it’s apples and oranges.
Indeed. The laws of physics do not need to be unstable to result in uncertainty as to how the universe plays out over space/time.
If DNA mutation and galaxy formations depends on ramdom quantum mutations how can we think that exist physics laws at all?
“You are the one who made the assertion: “My point is that it is no true.”
I mean: “What we do know tells us that the laws of physics are constant it is not true”
What is a random quantum mutation? And why would the existence of a random event invalidate physics?
“What we do know tells us that the laws of physics are constant it is not true”
Really? What do you mean by “we” and how do “we” know that? I think there are a number of physicists who would disagree.
The decay of radionuclides is a random process. No one can predict when a C-14 nucleus will decay, other than to give a 50% probability that it will decay in some 5700 years. Nevertheless, one can write a mathematical expression that will predict, to a high degree of precision, just how much of a macroscopic sample of C-14 will decay in any given time interval.
Just because the laws of quantum mechanics are probabilistic in nature, it does not mean there are no physical laws.
Really? What do you mean by “we” and how do “we” know that?
I used “we” copying you, so you can explain who are “we”.
“I think there are a number of physicists who would disagree.”
Well the point should be demostrable that any physical law was and will be constant at any time/place of the universe.
It is pretty clear that you have no idea what you are talking about and are just stringing sciency words together (like “random quantum mutation”) and tacking a question mark on at the end. Sorry to be blunt, but that process doesn’t result in a coherent question.
“It is pretty clear that you have no idea what you are talking about and are just stringing sciency words together ”
Sorry for disturb your intelligence.
Come on, Blas, don’t go all persecuted on me. You made an outlandish assertion, that “What we do know tells us that the laws of physics are constant it is not true”.
I’m just calling on you to put up reasoning behind this claim. I don’t think there is any. But if you can answer it, you should. Otherwise your question has the flavor of religious trolling, making sciency-sounding assertions in hopes of undermining the fact that science actually works.
“I’m just calling on you to put up reasoning behind this claim. I don’t think there is any. ”
So you said that is evident that the laws of physics are constant in space and time and I have to demostrate the contrary?
You said:
“In fact the distribution of galaxies is contingent on genuinely random quatum fluctuations in the early universe.”
Then the formation of planets could be contingent ramdom quantum fluctuations, then if the planets follow the law of gravity in their formation is contingent and ramdom, maybe the law of gravity is contingent to quantum fluctuations.
Well, no, I didn’t say that.
And you can’t just throw a “maybe then” into a sentence and hope it is logical.
The fact that galaxy formation is contingent on random events doesn’t meant that the laws that govern how galaxy formation happens are unstable.
“The fact that galaxy formation is contingent on random events doesn’t meant that the laws that govern how galaxy formation happens are unstable.”
Let me to refrase what you are saying:
“Given defined condition in space and time depending on a ramdom event like quantum fluctuations, a galaxy could be formed or not, or if you want could be formed in one place/time or another.
Then given the result the laws of physic form the galaxy in one place/space or in another.”
You can rephrase the Gettysburg Address if you like. It will no longer be the Gettysburg Address. You do not make sense just because you start with someone else’s words.
What you have produced is nonsense, similar to the assertions you made earlier. They don’t make sense in the English language.
Within the universal wave function, everything that can happen will happen. What “has” happened is just an artefact of the eigenstate we happen to be experiencing.
Don’t ask me to explain that! 😉 Cox and Forshaw do a much, much better job.
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There is no determinism on scales of time, because it is untestable. We also know of quantum stochasticity and deterministic chaos, which prevents it.
However, according to theoretical physicist Max Tegmark the universe repeats itself on spatial scales. [You can google his home page with easily readable material.]
This is because the observable universe is finite and the universe is likely infinite, so you are bound to find exact copies of the universe if you go out far enough and they _will_ repeat “us”.
Similarly if eternal inflation shows that multiverses are a fact, among an infinite sets of them you will have repeats which contains copies of our observable universe.
To clarify, a finite observable universe contains a finite set of particles with finite combinations. (Or equally, finite entropy in a finite volume.) So you have to repeat the combinations eventually, as you proceed over the distributions of observable universes.
Also, eternal inflationary multiverses may admit determinism “in time” in the sense that they can be “concurrent” by comparison of worldlines (which possibility of comparison between universes is arguable at best).
Since life seems to have started very quickly on our blue dot I’m rather fond of the idea that very sturdy pre-DNA replicators [not just precursors to life] arrived on the early Earth via a cometary interstellar taxi service.
According to Wiki: “Current models of Oort cloud formation indicate that more comets are ejected into interstellar space than are retained in the Oort cloud, by a factor of 3–100. Other simulations suggest 90–99% of comets are ejected. There is no reason to believe comets formed in other star systems would not be similarly scattered”
I don’t think anyone could sensibly deny the possibility, but someone has probably done a detailed assessment of the likelihood (more recently than Crick, for example). One of the most salient relevant facts, it seems to me, is that the solar system is actually pretty old relative to the universe, so there is no overwhelming preponderance of pre-solar time in which replicators may have originated.
What is your definition of “pretty old”? The earth is only about a third of the age of the universe.
It it is possible but not very likely IMO. The speed with which life established itself on Earth means it is easy, so it can have happened very fast. Depending on models, astrobiologists mention ~ 10 000, ~ 100 000 or ~ 100 million years.
The shorter times leave a very short window for replicators to take over the indigenous chemical evolution.
For example, It is currently estimated that Earth may have formed ~ 30-40 million years after the protoplanetary disk formed, while Mars may have formed in ~ 3-4 million years. Mars impactors launch material that is delivered to Earth at a mass rate of ~ 200 kg every year.
But cells in those impactors had to survive 2 hypervelocity impacts and the cosmic radiation over geological time in 10s to 100s of millions of years of space travel. Flash frozen spores can survive impact, perhaps multiple impacts. but even if shielded deep in a large impactor they will accumulate radiation destruction without repair.
Frozen interstellar replicators over cosmological times? I am fairly certain all biochemicals will degrade by CR on those time scales. Chemical evolution is based on continuous production.
Jerry’s argument about determinism and the unimportance of quantum effects is is probably valid regarding his definition of free-will. But as the time scale grows, the effect of the indeterminacy quantum processes will grow. Since some mutations are themselves affected by such processes and the multiplying process of the butterfly effect, on the scale of millions of years the process of evolution would accordingly be like an entirely different set of events.
Surely many kinds of functions would evolve in a similar way. Convergent evolution is largely caused by problems that bring a lot of evolutionary pressure and a limited set of plausible solutions. But just as surely that set will in some cases be different on a rewind, since the starting point will be somewhat different.
We don’t even know how likely RNA and DNA are to be the only or even best replicators. Suppose an entirely different replicator was created, how then might things be different? We might be better asking, what things could still be the same?
I think you did the right thing avoiding the question of where the first replicator came from because, whilst an unanswered question for science it is not one for evolution, in my opinion. Biological evolution is just concerned with what happened afterwards – you cannot study evolution if there is nothing capable of evolving!
It’s evolution without genetics or ontogeny, but still a matter of physiology, ecology and biogeography…
“blunting arguments”. No, neither the generation of life from the bottom up nor the discovery of extra terrestial life will alter a creationist’s opinions.
The first will usually attract the response “Well, what can’t you do with several billion dollars and enough time” and the second some tinkering with the interpretation of their Holy Book. (eg. John 14.2 “In my Father’s House are many Mansions——.” This is considered by some to refer to other planets which have life forms but are being enriched for receipt of God’s children)
It’s best to give up at this point.
Most excellent answer sir! A joy to read. A model of humility — in contrast with religious statements!
There’s not much to be said here yet: we have lots of theories but are approaching the answer only slowly.
Tsk, Jerry. You know that the creationists love to use “theory” in that colloquial sense when speaking of evolution, to muddy the waters.
Yep, you’re right; I’ve changed the word. I hate to always look over my shoulder for creationists waiting to pounce on stuff like this!
Thanks.
Ah,yes! How Socratic! Not only do we not know, but we (some of us at least) know that we don’t know. But that’s no reason to give up – keep working on it! Keep pursuing wisdom; and to pursue something presupposes that you haven’t got it yet.
I think there has been good progress on OOL in the last few years.
Bottom up, there are recent efforts to:
– test models (say, on chemical evolution rates), because we have an embarrassment of riches regarding theories.
– model chemical evolution wholesale, because “pure” models are unrealistic.
– evolve the RNA world under anoxygenic conditions.
Top down, there are recent progress in:
– phylogenies penetrating down and testing the RNA/protein world and the DNA LUCA. [“The evolution and functional repertoire of translation proteins following the origin of life”, Goldman et al, Bio Dir 2010; and similar work]
– uncovering robust LUCA roots of autotrophic metabolism and lipid membrane biosynthesis both. [“The Emergence and Early Evolution of Biological Carbon-Fixation, Braakman et al, PLoS Comp Bio 2012; “Ancestral lipid biosynthesis and early membrane evolution”, Peretó et al, TRENDS in Bio Sci 2004.]
– whole cell modeling has been accomplished, and points to self-regulation of cells earlier not known AFAIK:
“The high variance in copying time once the proteins have already bound, however, depends on the age of the cell. If the cell is young, copying periodically stalls because the cell has not had time to stockpile the dNTP nucleotides required to build DNA. If the cell is old, it already has a lavish stockpile so copying occurs very quickly. So, cells that are fast initiators are slow copiers, and those that are slow initiators are fast copiers. This cancelling-out means that all M. genitalium cells take about the same amount of time to divide, and it is controlled solely by metabolism, not genetics.”
– minimal genome cell synthesis is ongoing, Venter plans to finish two competing attempts this summer:
“Venter explained that he was just days away from trying the first synthesis of a minimal genome. For two years, even as the team at S.G.I. has been working to cultivate algae, the institute has been poring over research to design a new genome. Eventually, the process grew tedious. “Up to three weeks ago,” Smith said, “we were on a very gradual course, and we were looking at a long time to get the thing completed. So Craig says, ‘Damn it, let’s make a guess, and synthesize the darn thing based on what we know, and maybe it’ll work!’ ”
Venter laughed. “I call it the Hail Mary Genome.”
Just days earlier, he said, they completed two designs — one led by the office in Maryland, the other by Hutchison’s team in California. In the days ahead, they would begin assembling both. If either worked, it would represent the smallest genetic code of any free-living creature on earth, one that would be impossible to dismiss as a copy.”
Those two later is mostly applicable for modern cells as of yet, but point to results on simpler cells.
Interestingly I think the traditional top down biology has made the most progress. I think Darwin would have been pleased.
But there is also potential closure in the bottom up approach. RNA is known to be enzymatically activated by polyphosphate which leads into ATP et cetera cofactors, polyphosphates are now known to be produced in alkaline hydrothermal vents in subduction zones (or at least suspected to in geochemistry work), and the anoxygenic work indicates that RNA may be chemically selected on terrestrials by way of its enzymatic enhancement by iron.
Oops. “Anoxic” conditions, among a lot of simpler mistakes.