Uncommon Descent Contest Question 15: Can Darwinism – or any evolution theory – help us predict life on other planets?

Pure science predicts; forensic science reconstructs. If we are to use earthly evolution theory as a predictive tool we will need to break down the findings of evolutionary biology into its constituent parts. The modern evolutionary synthesis is based upon three distinct disciplines and these can be informally described as: the study of life, its common features and relationships; the study of changes, principally changes within the DNA; and the study of the development of complex information systems that is the earthly code of life. While relationships between life forms on earth have been clearly established and DNA manipulations are now common place, the development of complex information is a subject that has so far totally eluded the understanding of pure science. The failure of SETI to cast any light on the subject has forced science to predict life on other plants by the presence of necessary components: water and a usable energy source such as a suitable star. This deductive method, of course, fails as it does not include the other necessary component of life: the development of complex information – assuming other life in the universe will be at least that much similar to life on earth. So the problem of life throughout the universe is the same as that on earth – complex information and how it can be generated. It is here that entropy comes into the question - this degradative feature of the natural world where mathematics and observation concur – how can random events produce a coherent, broad-ranging, multi-level, interdependent, flexible, life system. The given answer, based upon a 150 year-old theory - that randomness is refined as a result of a step-by-step process and small feature differences selected on the basis of a positive outcome - is not supported by mathematics, logic or indeed laboratory observations. Over a hundred thousand experiments on life forms ranging from fruit flies to micro-organisms have failed to support evolution’s main theses. Perhaps this fascination with other life in the universe is the fault of theists. They frequently highlight the marvel and uniqueness of planet earth and its resulting life. Extraterrestrial life has therefore become a battle cry for atheists – if life can be shown to be ubiquitous within the universe then the final nail can be hammered into the concept of God (pun intended). But there is no religious imperative or Biblical requirement for life on earth to be unique. GFrancis

No one has mentioned Firmi's Paradox - where are all the evidences of alien contact, of the at minimum sublight "slowboat" journeys from all these other alien civilizations that would be expected to have colonized the galaxy long before the present? Such a level of technology would not be hugely beyond present physics and other scientific knowledge. Star Trek presumptuously assumes no Firmi's Paradox. So I believe we can rule out multiple alien civilizations and a Star Trek scenario. The only way out would be to hypothesize that the first exophobic alien civilization proceeded to wipe out all the following ones, and we're next. The Independence Day scenario. Maybe Crick's first idea is the case. And Ward and Brownlee's Rare Earth hypothesis is the truth. Then intelligent life would be exceedingly rare or unique in the galaxy. These models seem to be better founded in the evidence. Of course this would just push back the origin of life problem, the current failure of Darwinistic hypotheses to explain that origin. I think extraterrestrial life, its existence and its nature is too speculative to have much relevance to the debate. magnan

CannuckianYankee I considered saying "The Next Generation" but I thought I would sound like a geek. Probably too late anyway. Collin

"When and if scientists find life on other planets, I predict that they will use ID principles like complexity and the presence of a blueprint code like DNA to determine if it is really life. Darwinism does not help with this, for natural selection variation applies to black holes and neutron stars as well as life." Collin, Interesting thoughts. I agree. When talking about Star Trek's 5 television series though, for the uninitiated, you should refer to ST:TNG as opposed to simply Star Trek(:TOS). :) CannuckianYankee

Mr Mung, And yet, aren’t there Orchids which are not fertilized by insects at all? In fact, aren’t there orchids that self-fertilize? OK, so this helps shape the confidence interval of the prediction but does not negate it. As in "Ghosts of Evolution" finding half a partnership will let you predict the other half. Not that that will help make predictions from a distance before landing on a planet... Nakashima

I don't know if you are allowed to supplement your answer for the contest, but I remembered an anedote from Star Trek that might help. Data, the android, asks Dr. Crusher if she thinks he is "alive." She gives him the standard definition of what life is: basically something that consumes food, reproduces and dies. Data makes the point that by that definition fire is alive. Dr. Crusher says, "Fire is a chemical reaction." As if that answered the question. Then they talk about other things and never resolve what life is and why fire is not alive. When and if scientists find life on other planets, I predict that they will use ID principles like complexity and the presence of a blueprint code like DNA to determine if it is really life. Darwinism does not help with this, for natural selection variation applies to black holes and neutron stars as well as life. Collin

An orchid that flowers in harsh conditions pollinates itself unassisted by any of the usual agents. Mating in flowering plants normally relies on animals, wind, gravity or secretion to convey pollen grains from the male (anther) to the female (stigma) organ1. Apart from that, a new type of self-pollination mechanism in the tree-living orchid Holcoglossum amesianum, is observed in which the bisexual flower turns its anther against gravity through 360° in order to insert pollen into its own stigma cavity — without the aid of any pollinating agent or medium. This mode of self-pollination, which occurs under windless, drought conditions when insects are scarce, adds to the variety of mechanisms that have evolved in angiosperms to ensure their reproductive success.

Does evolutionary theory predict this? Mung

For example, in his book Fertilization of Orchids, Darwin predicted that since there are Orchid with very long nectary, then there must be a moth or other insect with an equally long proboscis.

And yet, aren't there Orchids which are not fertilized by insects at all? In fact, aren't there orchids that self-fertilize? Given those two facts, it should be clear that evolutionary theory makes no prediction about the existence of insects, their role in the fertilization of orchids, or the shape of their probosces. It also shows us that this tale about a "Darwinian prediction come true" can't instruct us about the course of life on another planet. Mung

Mr Mung, It should almost go without saying, that if there’s no predictable outcome, no prediction can be made. I can't quite bring myself to agree. I think a Darwinian, non-telic theory could make predictions, not about the sequence of forms or specific stages, but about some statistical properties of ecologies. For example, a power law distribution of biomass by species. I think this kind of thing is on the edge of evo theory vs law of form. Another issue is that based on our own planetary experience, another world sampled at a random point in its history will only find very simple life. We don't know today (or I don't know, but would be happy to be told) why metazoans etc. took so long to show up. Did it take a really long time to shake down metabolic and developmental pathways before they could start to be duplicated, mutated, etc? Is that a fact of life everywhere, or are we just way out on one tail of a distribution? I keep coming back to the idea that speciation is an inevitable consequence of evolution, when played out on a large enough canvas. Maybe Lenski's flasks of E. coli will never contain multiple species because their environment is intentionally kept so simple, but on the scale of a planetary surface, speciation and ecological diversity are inevitable. In that vein, parasites are inevitable. Life that eats the waste and the dead is inevitable. These things can't break down fast enough to avoid being used by some other life as a source of energy or spare parts. For a planet with any significant oxygen in its atmosphere, a Darwinian theory should predict a large and thriving ecosystem, even if the biomass is mostly stromatolites and grazers. Sensory apparatus is inevitable, though the timing is uncertain. This "situated Darwinism" or evo-eco would be a non-telic theory, but still make such predictions. Nakashima

Dear Mr. Nakashima, Your first mistake is in thinking that Darwinism is a non-telic theory. I mean, just look at the language employed by Darwin and Darwinists, it's chock full of teleological language. Now, any prediction that can't be correlated with time, can't speak of the "course of life" on this planet or any other. If there is no "course," no prediction can be made. Has anyone proposed that life on other planets would display a pattern of nested hierarchies? If not, I find that hugely interesting. I suppose that one could predict that the course of life on another planet would show no course. I don't know what theory would predict that, though. It seems to me, that in order to predict a particular outcome, or ranges of outcomes (say, sentient conscious organic creatures), one must have some "end" in mind. It should almost go without saying, that if there's no predictable outcome, no prediction can be made. Mung

Mr Mung, I don't think that is quite right. I think non-telic theories like modern Darwinian evolution can be extended to make predictions about species diversity whther correlated with time or not. I don't happen to know of any such evo-eco theory available right now, but I don't see a fundamental problem with developing one. The research I linked on one of the climate threads that used evolutioinary algorithms and global climate models together is an example of research that could be included in such a larger framework that dealt with evolution in a more 'situated' way than just the abstractions of population genetics. Nakashima

ok, some good clarification going on:

“Darwinian evolutionary theory will help find alien life...

This was the claim that opened the post. But the contest question is:

Would any theory about the evolution of life on Earth predict the course of life on other planets, and if so which one and why?

Any such theory would of necessity be teleological in nature, as any non-teleological theory would be incapable of predicting anything. Mung

Unlike the actual creative evolution that made all life, Darwinian evolution does not originate but only culls. I'm speaking of a more general creative process that Darwinism doesn't recognize, so I agree with Nakashima. With the contest in mind, I add two further points about exo-biologies: 1. According to the work of Bjorn Merker (q.v.), consciousness evolves to meet the demands of animal mobility. Its anatomical hallmark is a central nervous system, versus the distributed one seen in insects and most invertebrates. Thus we would expect to find large conscious animals, analgous to vertebrates, to evolve after a planet has enough oxygen. 2. The particular suite of secondary metals used by our biochemistry, such as copper, vanadium, molybdenum, selenium, etc., are utilized in rough proproportion to their priomordial terrestrial abundances, whereas poisons such as arsenic and cadmium wer rare in the early earth. Thus we would expect a distribution of exo-biochemical secondary metals reflecting their own home world's primordial abundances, whether there is an in-situ abiogenesis or a special creation by Somebody. PS. We should probably change 'q.v.' (which see) to 'q.G.' (which Google). Interstelar Bill

The question posed here is answered fully (in physics terms) by the Constructal Law : "For a finite-size flow system to persist in time (to "live") it must evolve in time in such a way that it offers greater and greater access to its currents" (1996). The published record shows that the Constructal Law accounts for the generation and evolution of "life" and "design" across the board, as flow configurations, from river basins to animal design and social dynamics. For the latest progress with the Constructal Law see www.constructal.org and this 2009 review article in Physics of Life Reviews: http://prattpress.pratt.duke.edu/duke_law_unify The latest example of how to predict animal movement on a planet by invoking the Constructal Law see: http://www.physorg.com/news167027175.html For the prediction of all the features of "vegetation design", from roots and canopies to the design of the forest floor, see: http://www.physorg.com/news137929476.html%3E/ Adrian Bejan

Mr CJYman, Thank you! Because we have differed in many previous discussions, I know your kind words are honestly given and I appreciate them all the more for that. Nakashima

Nakashima @8, IMHO, good thoughts on the subject. CJYman

Would any theory about the evolution of life on Earth predict the course of life on other planets, and if so which one and why? Yes. While the cited article about the speaker from NASA focused on the utility of Darwin's theory of evolution, the question is phrased in a generic way. In order to answer the question as posed, we have to free ourselves from the presumption of Darwinism. First let us consider whether a theory like the modern Darwinian theory would be helpful. Here the answer is probably not. Darwinian theory does not predict anything specific about life on our own planet. All it says is that life with heritable and variable traits will change over time to adapt to the environment. That is a pretty bleak outlook, and one at odds with our experience. One reason is that little account is taken for living organisms being the "environment" for each other. We usually think of the adaptation of a simple organism to an inorganic environment, climbing a fixed adaptive peak, when we think of simple examples of adaptation. But once the world gets crowded, the undirectedness of evolution become questionable. Organisms don't just exploit niches in the environment, they become niches to each other. Parasites invade other organisms. Waste products (like oxygen) become resources. Accumulating wastes begin to make large changes in the physical environment, opening new chemical resources to exploitation. Organisms predate and cooperate. While I started out saying Darwinian evolution wouldn't predict any direction, it seems that I've just proved the opposite, that Darwinian evolution predicts a 'tangled bank', a lush and diverse ecology. But I don't think any Darwinian theory actually makes that end to end argument, that heritable, variable traits in selectable individuals will inevitably lead to Gaia. Peter Ward, one of the authors of Rare Earth, actually argues the opposite in his Medea Hypothesis. So for now, I would discount strictly Darwinian theories from being able to help make such predictions. Similarly, there are process and structural insights, laws of form such as the Cube-Square Law, which we can expect to hold as surely as we expect the laws of physics and chemistry to hold. For example, the bigger the animal, the thicker its legs will be. But this is the nuts and bolts of the universe, not a particular evolutionary theory. On the other hand, telic theories of evolution would predict that just as organisms on Earth are designed or nudged in certain directions (by black monoliths or the Finger of God, it doesn't matter) we should expect life on other planets to be similarly nudged. I admit that this is applying the Principle of Mediocrity in addition to a telic theory. But that principle seems to underly the question itself. Why would I make any assumption at all about the relevance of Earth's experience, except that I accept the idea that we are not, or may not be, unique? So my final summation would be that a telic theory may predict that a similarly priviledged planet would have a similarly complex biosphere. We haven't found any such similarly priviledged planets yet, but I think the Principle of Mediocrity combined with a telic theory would make that prediction. Nakashima

Would any theory about the evolution of life on Earth predict the course of life on other planets, and if so which one and why?

Teleport back to December 2005: Unified physics theory explains animals' running, flying and swimming:

"Our finding that animal locomotion adheres to constructal theory tells us that -- even though you couldn't predict exactly what animals would look like if you started evolution over on earth, or it happened on another planet -- with a given gravity and density of their tissues, the same basic patterns of their design would evolve again," Marden said

Oops this isn't the time-travel thread but I think it hit the topic. Joseph

Mung, I beg to differ. The origin of life is the real issue. If we can't predict the origin of life, then we can't predict evolution or any other process that allows for life. Life is a unique mystery, which can only really be predicted from a procreation standpoint - once the evolutionary or life process has already begun. Evolution only shows us the processes involved in life changes, but not the processes involved in originating life - at least as far as we can know at present. Those looking for life on other planets such as Mars, and other orbital bodies are making assumptions about the conditions that allow for evolutionary genesis. However, such assumptions are just that - assumptions. They have no predictory power. Collin makes a good point that just because conditions similar to earth's conditions may be present or have been present on other planets, is no indication that life could or did arise on those planets. CannuckianYankee

Would any theory about the evolution of life on Earth predict the course of life on other planets, and if so which one and why?

The answer is no. It appears that the responses so far aren't really addressing the question. The origin of life isn't the issue, it's the course of life, once present. Evolutionary theory doesn't even predict the course of life on this planet, where life actually does exist, and where we have much more data. It follows that it lacks any principles which would permit one to make predictions about the course of life elsewhere in the universe. Mung

Can Darwinism – or any evolution theory – help us predict life on other planets? Since Darwinism suggests that life evolves without a plan or goal, it would be difficult for Darwinism to predict any condition that would precede its processes. If I don't know where Darwinian evolution is going, I really cannot know where Darwinian evolution has been apart from a presumption of the fact of Darwinian evolution. Furthermore, If I can't predict how Darwinian evolution got started in the first place, then it would be difficult to even attempt a prediction of what Darwinism might be able to do on a planet where it currently has not occurred. Therefore, to ask if I can predict anything through Darwinism is to ask an absurdity. Besides this point, if I find that life developed on another planet, it would also be a presumption to insist that such life arose through Darwinian processes. If I am wrong, then I shall never know exactly how such life arose. If I find that such life actually arose through some sort of design, using the elements that exist on the planet, then I am better able to make predictions about the possibility of life on planets where such elements also exist. However, this too, does not allow me to predict if life could exist without the prime element of complex specified information needed to form complex structures such as cells and DNA. Since I cannot know (through current knowledge) if any planet has the presence of a source for such information, then I would have to conclude that at present, life on other planets is unpredictable through Darwinian evolution, or through any other evolutionary process, including intelligently designed evolution. The origin of life is not predictable in my view, because the origin of life is a conscious choice by a conscious intelligent being. We cannot predict such choice. We can only know that such a choice was made after the fact. CannuckianYankee

Darwin's theory can help, but not much. Darwin's theory of evolution helped biologists think about nature as adaptive and fitting into the niche of its environment. For example, in his book Fertilization of Orchids, Darwin predicted that since there are Orchid with very long nectary, then there must be a moth or other insect with an equally long proboscis. His prediction was confirmed when in 1903 the "Morgan Sphinx" moth was discovered. See http://en.wikipedia.org/wiki/Xanthopan_morgani. Astrobiologists can make similar predictions and inferences when (and if) they discover life forms on other planets. Nevertheless, Darwin's (and Darwinists') continued adherence to materialist constraints in biology can and will be a stumbling block and a blind spot in their quest to understand life; whether here or on some other world. I think that the biggest stumbling block will be to assume that where there are conditions favorable to life, then life will almost certainly exist there. I find this idea espoused frequently on space.com. For an example see this article http://www.space.com/scienceastronomy/091201-am-super-earths-alien-life.html. But the most frustrating commonly-held belief, in my mind, is the insistence that there must be life on Mars, Titon or Europa. I don't say that it is impossible, but since, as mentok pointed out, there is no understand of how life began on Earth, so how do we know it could possibly begin, even in favorable environments? Collin

The gaps in Darwinian evolutionary theory are not small holes but large chasms of plausibility that exist in Darwinian evolution. They are fundamental breaches in aspects of biology that the theory of evolution has been incapable of bridging. As Mentok astutely notes, without knowledge of how life began on Earth, no theory can begin to explain how life would begin on other planets. Commenting in general on the validity of various scientific theories, science writer John Horgan observed: “When the evidence is tentative, we should not be embarrassed to call on common sense for guidance.” It simply does not make sense to acknowledge that a house needs a designer and builder and at the same time claim that a complicated cell accidentally sprang into existence. While other organisms might use chemical or light energy in different ways, this does not even touch the question of where these life forms came from. There would also be no explanation for how these life forms developed the ability to use alternate energy sources such as UV light or wave energy. Barb

In order to predict the possibility of life on other planets, the first thing you need to do is understand how life began on Earth. Without a scientific understanding of how life began here, it is nothing more than fantasy to propose an understanding of how life can originate on planets we have very little understanding of in comparison to our own. There is no scientifically plausible theory for the origin of life on Earth. The simplest life forms are so complex that no one has been able to determine how random interaction of chemicals on an early Earth environment could possibly coalesce into those complex living bodies. It has been suggested by prominent scientist Fred Hoyle that the possibility of that occurring was as likely as an airplane being constructed by a tornado blowing through a junkyard containing airplane parts. How can you predict evolutionary schemas in an environment if you don't know if life can even exist there? The only reason that people can make evolutionary predictions on Earth is because of the vast array of life forms surrounding us. If there was no life here, and if there was no plausible way to conceive of how life could originate here, then any prediction about evolution would be moot. Therefore any predictions about evolution on other planets are moot -- unless and until you can come up with a plausible theory on how life on this planet originated. mentok