Nov 24 2017

Evolution Observed in Darwin’s Finches

Published by under Uncategorized
Comments: 54

galapagos finchJust two weeks ago I wrote about “Evolution Caught in the Act” – I was writing about fossils that are clearly transitional and occur within a major evolutionary change, like a land animal adapting to aquatic life. Now we have another report that justifies the same title, although this one is in living species.

For this observation we go back to the beginning, to the Galapagos where Darwin made observations critical to his development of evolutionary theory. The Galapagos are a chain is relatively young volcanic islands, far enough from the mainland to provide relative isolation, but close enough for life to find its way there. Most famously, some ancestral finch species found its way to the island. Their descendants then adapted to a variety of food sources, most obvious in the change in beak size and shape, optimized for its new use.

What Darwin observed is that the Galapagos finches filled many of the same niches as other bird families in other parts of the world. He had to puzzle out why on the Galapagos all those niches were filled by finches. He figured out that they must be descended from an ancestral finch, which also means that they have speciated into a large number of different finch species as they adapted to different islands and different food sources.

Modern evolutionary scientists have also capitalized on the unique natural experiment represented by the Galapagos. They have been closely observing the finches for decades, and this has provided a massive set of direct data. All this work has paid off in the observation of a chance speciation event.

Scientists report that in 1981 they observed the arrival of a male cactus finch (Geospiza conirostris), a non-native species, to the island of Daphne Major. The relatively large male mated with native female members of Geospiza fortis, a medium ground finch. They produced fertile young. In the 36 years since the descendants have produced a stable and isolated population (now about 30 individuals) – researchers all calling this the big bird population.

Importantly, this big bird population has remained completely genetically isolated from native populations (called “endogamous” – mating only within a group). The big bird population are larger than the native ground finches, and this has enabled them to exploit a new food source. Further, the native females do not seem to recognize the song of the big bird males, and so do not mate with them.

The one critical ingredient for speciation is genetic isolation. However, this direct observation documents the fact that isolation does not have to be geographical. Genetic isolation can occur in species that exist in the same physical location – which is called “sympatry”. This would therefore be an example of sympatric speciation.

Once populations are genetically isolated there are a number of processes that can make them diverge over time. Simple genetic drift may be enough – random and non-directed changes in gene frequency with occasional new mutations thrown in.

However, if the populations are under different selective pressures they will also demonstrate directed changes over time. That is the case here, as the larger big bird finches are exploiting a new niche.

In this case the researchers were expecting that the immigrant bird and his offspring would simply be absorbed into the native population. This can introduce new genes into the population, but would not establish a new species. They were surprised to find that the population remained genetically isolated. The mating habits of the finches, however, made this possible.

This, of course, is just one case, but it adds to other examples of population changes in living species. This is now one of the best cases of a speciation event observed in real time in a living species. I also shows how quirky evolution can be. Random events, like the chance migration of a single male finch 65 miles to a nearby island, can trigger evolutionary change. Further, there are many things that can genetically isolate populations, and simple behavior is one of them. Even very similar and fertile species can be genetically isolated by behavior, such as mating song.

It is cool that almost two centuries later the finches of the Galapagos are still teaching scientists about evolution.

54 responses so far

54 thoughts on “Evolution Observed in Darwin’s Finches”

  1. SteveA says:

    To nit-pick. Darwin paid the finches very little attention while he was on the islands. The topic of ‘Darwin’s Finches’ has become somewhat mythologised.

    You can read more here:
    http://www.truthinscience.org.uk/content.cfm?id=3160

  2. edwardBe says:

    Steve, can you provide a citation for your sources? There’s something here that doesn’t quite add up for me. The original big bird was able to mate with the native females, but now his descendants can’t? Were they able to recognize his songs, but not those of his descendants? What changed? The songs? If so, why would they?

    If the original male bird, was a cactus finch (Geospiza conirostris) are his descendants not a branch of that species as opposed to a whole new species? I probably don’t understand exactly what constitutes a species, but this seems more like divergent evolution than speciation.

    Also, what new niche, a new food source are these big birds exploiting? I thought finches ate seeds of different types. Are there plants that have seeds that the smaller birds can’t eat? I would think that they would have evolved to eat the seeds that the big birds are now eating, as discussed in “The Beak of the Finch”, where Jonathan Weiner describes the work of Mary and Peter Grant who have spent decades studying the finches of the Galapagos Islands and have shown how the islands are like a laboratory expressly built for the study of evolution since natural selection occurs so quickly that they can see it in action, specifically the differences in beak size and shape from one island to another.

  3. BBBlue says:

    edwardBe- Pardon me for jumping in on your question to Steve. Evidently, the first mating was a rare, chance event between native medium ground finch and immigrant large cactus finch. Guess it was getting close to closing time.

    The authors state that choice of mates arises from cultural, non-genetic imprinting based on song and morphology. So once a unique population got started (a highly inbred population) and there were choices to be had, those choices served to isolate the population.

    Larger bill size allowed the new hybrid species to “efficiently exploit the large wood fruits of Trilbulus cistoides [puncture vine] in dry seasons, and particularly during droughts and limited food supply…”

    http://science.sciencemag.org/content/early/2017/11/20/science.aao4593

  4. michaelegnor says:

    Wow. Populations of birds change. This just proves evolution by RM NS is true. Evolutionary biology is the most rigorous science ever.

  5. bachfiend says:

    Michael,

    I was expecting hardnose to appear first as our resident troll. I was wrong. RM NS is a caricature of evolution which exists only in the tiny minds (both conscious and unconscious) of creationists.

    Steve,

    I had a looked at articles dealing with this report of incipient speciation. It’s been known for many years that hybridisation on the Galápagos Islands occurs between different finch species, even native ones on a single island, not just involving immigrants.

    The lesson I take from that is that evolution and speciation is very slow, which is one of the reasons why I don’t like the idea that Punctuated Equilibrium means that evolution can occur rapidly..

    Polar bears and brown bears can mate to produce fertile offspring, despite diverging around 800,000 years ago. Australian black swans have been introduced into Europe as exotics and there are reports that interbreeding with native white swans have occurred.

    The question that occurred to me is whether the ‘new’ species has a different breeding season to the ‘parent’ species, in order to have enough food supplies to feed their young (I haven’t expressed this very well, some teleology has crept in). Whether larger tougher seeds for the larger birds might be available at different times.

    The birds might be able to interbreed, but not ‘want’ to, because their breeding seasons don’t overlap? I can’t find out whether this is the case or not from what I’ve read.

  6. chikoppi says:

    [michaelegnor] Wow. Populations of birds change. This just proves evolution by RM NS is true. Evolutionary biology is the most rigorous science ever.

    Here’s about three million more studies of genetic variability and differentiation in environmentally isolated populations, including genetic mapping, analysis of mutations, gene flow, and population dynamics:

    https://scholar.google.com/scholar?as_vis=1&q=genetic studies in isolated populations&hl=en&as_sdt=1,14

    Your ignorance of the science is not a weakness of the theory.

  7. BillyJoe7 says:

    This article….

    http://www.nature.com/news/2009/091116/full/news.2009.1089.html

    …says that a single specimen of the “big bird” happened to migrate to the Galapagos island of Daphne Major from the nearby island of Santa Cruz. It mated with one of the two species of finches on Daphne Major. After four generations, a severe drought reduced this population to a single pair, a brother and a sister. From then on the population became genetically isolated. They suggest that the cause of the genetic isolation was “mate preference”. The females “preferred” males with long thin beaks like their own and that sang the song of the original immigrant. They don’t know if they can breed with the local finches, just that they “choose” not to.

    They also refer to this as a possible case of early speciation. They are not ready to actually call it a new species. In fact they think the chances of it becoming a new species are pretty slim. Of course it depends on your definition of a species.

  8. BBBlue says:

    Immigrant song? Is this what the large cactus finch sounds like? https://www.youtube.com/watch?v=y8OtzJtp-EM

  9. Rogue Medic says:

    Michael Egnor – the man who calls Pope Francis a criminal and a fraud for being honest about the human causes of climate change,

    Wow. Populations of birds change.

    There is a great article about the Catholic church and the Church’s appropriate rejection of Creation science in the Catholic magazine Crux

    “Within the general public using public education as a battleground, there is a debate. But it’s a cultural clash,” said molecular biologist Kenneth R. Miller, the lead expert witness for the plaintiffs in the 2005 case and a practicing Catholic, in an interview with Crux.

    “Those who wish to introduce the creationistic debate are profoundly skeptical of science,” Miller said. “It’s a revolt against the very culture of scientific discovery. As a scientist, this is the thing that bothers me the most.”

    https://cruxnow.com/global-church/2017/11/24/origin-species-milestone-experts-ponder-impact-faith/

    Likewise, the Templeton Foundation rejects the Discovery Institute’s nonsense as not science

    From our FAQ…

    Does the Foundation support I.D.?

    No. We do not support the political movement known as “Intelligent Design.” This is for three reasons 1) we do not believe the science underpinning the “Intelligent Design” movement is sound, 2) we do not support research or programs that deny large areas of well-documented scientific knowledge, and 3) the Foundation is a non-political entity and does not engage in, or support, political movements.

    It is important to note that in the past we have given grants to scientists who have gone on to identify themselves as members of the Intelligent Design community. We understand that this could be misconstrued by some to suggest that we implicitly support the Intelligent Design movement, but, as outlined above, this was not our intention at the time nor is it today. — John Templeton Foundation[86]

    https://en.wikipedia.org/wiki/Discovery_Institute#John_Templeton_Foundation

    You claim to know more than the people who know what they are doing.

    You claim science is an impossibly large conspiracy.

    You wonder why scientifically literate people do not take you seriously.

    .

  10. edwardBe says:

    BBBlue, thanks for the link!

  11. hardnose says:

    The new species is just a type of finch, with no new or more complex features.

    So more and more evidence is gathered to convince us of the obvious. And the real controversy continues to be ignored.

    https://en.wikipedia.org/wiki/James_A._Shapiro

    “He has proposed the term natural genetic engineering to account for how novelty is created in the course of biological evolution. It has been criticized by some.[20][21][22][23] His work is also widely supported.[24]”

    Commenters here think James Shapiro is an idiot, a fringe pseudo-scientist. Wikipedia doesn’t think so.

  12. chikoppi says:

    [hardnose] The new species is just a type of finch, with no new or more complex features.

    Speciation is evolution.

    Evolution does not require “more complex features.” Any change, even if that change is a decrease in complexity and especially if it isolates a population, is evolution.

    “He has proposed the term natural genetic engineering to account for how novelty is created in the course of biological evolution. It has been criticized by some.[20][21][22][23] His work is also widely supported.[24]”

    Good! You accept that genetic mechanisms can result in additional genetic information.

    You have finally acknowledged the evidence.

  13. bachfiend says:

    Hardnose,

    ‘Commentators here think James Shapiro is an idiot, a fringe pseudo-scientist. Wikipedia doesn’t think so.’

    We don’t think he’s an idiot. We just think he’s wrong. Being wrong isn’t a bad thing in science. Occasionally it turns out that a scientist is right despite almost all his fellow scientists thinking that he’s wrong.

    A scientist who has never been wrong throughout his career probably hasn’t achieved anything of note. Being willing to be wrong occasionally is necessary to achieve significant breakthroughs.

    You, on the other hand, almost all commentators here agree, are an…

    ‘His work is widely supported.’ Based on a single reference on ‘the Third Way of Evolution’ website compiled by an unknown author, which lists 63 names. 63 scientists is a vanishingly small fraction of the world’s scientists.

  14. BillyJoe7 says:

    More hardnose bv||$h! …

    “The new species…”

    The troll does not understand nuance, or can’t read, or can’t comprehend what he reads.
    Here is what the article actually says:

    The Grant’s aren’t yet ready to call 5110’s lineage a new species, a term fraught with difficulty for evolutionary biologists. “There is no non-arbitrary answer to the question of how many generations should elapse before we declare the reproductively isolated lineage to be a new species,” they say. “For the present it is functioning as a [separate] species because its members are breeding only with each other”. The Grants think there is only a small chance that 5110’s descendants will remain isolated long enough to speciate.

    “…is just a type of finch…”
    He thinks that, unless it evolves into a crocoduck, it can’t be evolution.

    “….with no new or more complex features…”
    He thinks there must be an increase in complexity for there to be evolution.

    “So more and more evidence is gathered to convince us of the obvious”
    He doesn’t even understand what it is that is so obvious.

    “…And the real controversy continues to be ignored…https://en.wikipedia.org/wiki/James_A._Shapiro
    There is no controversy and he has not been ignored. He has taken apart.

    “It has been criticized by some”
    He has been demolished by experts in the field of evolutionary biology.

    “His work is also widely supported”
    He is supported widely by the fringe who are supported widely by the Templeton Foundation.

    “Commenters here think James Shapiro is an idiot”
    I’ve lost count of the number of times hardnose has lied about this.

    “a fringe pseudo-scientist”
    He has a cardboard cut-out caricature of evolutionary biology because he has not kept up to date because it is outside his field. That’s why he is on the fringe.

  15. BillyJoe7 says:

    SteveA,

    “You can read more here: http://www.truthinscience.org.uk/content.cfm?id=3160

    I’d be wary of quoting from a Christian site.
    First they get the name of the book wrong:

    “Darwin did not mention the finches in his book The Origin of Species”

    As every school boy knows, his book is called “On The Origin of Species”.
    Further, Darwin does mention the finches in his book:

    “The most striking and important fact for us in regard to the inhabitants of islands, is their affinity to those of the nearest mainland, without being actually the same species. [In] the Galapagos Archipelago… almost every product of the land and water bears the unmistakable stamp of the American continent. There are twenty-six land birds, and twenty-five of these are ranked by Mr. Gould as distinct species”

    However, what you said about Darwin paying the finches little attention while on the islands seems to be correct; and they did not play much of a role, if any, in the deveolpment of his theory

  16. BillyJoe7 says:

    BBBlue,

    “Immigrant Song?”

    I’m glad you got the reference. 🙂

  17. hardnose says:

    “Good! You accept that genetic mechanisms can result in additional genetic information.”

    “You have finally acknowledged the evidence.”

    You must be crazy chikoppi, I have been saying this all along.

  18. chikoppi says:

    [chickoppi] Good! You accept that genetic mechanisms can result in additional genetic information. You have finally acknowledged the evidence.

    [hardnose] You must be crazy chikoppi, I have been saying this all along.

    What you have been saying is that “natural selection cannot explain evolution.”

    What you meant to say is that you don’t understand how blind evolutionary processes can result in more complex organisms.

    The mechanisms that Shapiro categorized (they were known mechanisms) are those that result in a recombination or integration of genetic material. In other words, he created a handy list of just some of the ways variation in the genome might result in an increase in complexity (though these processes do not necessarily increase complexity).

    Shapiro’s list is just another example of how genetic variation arises. However, the factor that determines what, if anything, among that variation is functional or beneficial to the organism is the environmental conditions to which that organism is subjected.

    It is just the same as the random gene duplication in Lenski’s E. coli, which produced a trait that was useful to the population in its present environment. The specific variation occurred in only one population. It wasn’t “guided” or “chosen.” It was merely one possible probability out of the countless mutations constantly occurring, most of which are inconsequential at best if not outright harmful. Variation that is produced randomly by constrained processes and selected for by environmental conditions.

  19. bachfiend says:

    Hardnose,

    You have also been saying all along that mutations are non-random, directed and to the benefit of the organism, for which you have no evidence, all in order to maintain your worldview that the universe is not only conscious but also intelligent, and that there’s a teleological tendency in biological systems to increasing complexity and intelligence.

  20. hardnose says:

    “Shapiro’s list is just another example of how genetic variation arises. However, the factor that determines what, if anything, among that variation is functional or beneficial to the organism is the environmental conditions to which that organism is subjected.”

    We KNOW that variations are selected after they are generated. You are saying nothing.

    Shapiro showed that variations can happen that are NOT errors.

  21. hardnose says:

    “You have also been saying all along that mutations are non-random, directed and to the benefit of the organism, for which you have no evidence, all in order to maintain your worldview that the universe is not only conscious but also intelligent, and that there’s a teleological tendency in biological systems to increasing complexity and intelligence.”

    I have explained, over and over, that I DO NOT consider my opinion to be scientifically verified. You claim that yours is, even though you have no evidence for it.

    You are all very good at creating confusion and detracting from the main points. You are NOT any good at clarification or logic.

  22. chikoppi says:

    [hardnose] Shapiro showed that variations can happen that are NOT errors.

    He “showed” nothing of the sort.

    There are no “errors.” Get that idea out of your head. Variability is a feature or DNA, not bug. There are mechanisms that increase mutation rates and these can evolve and become fixed/selected just like any other trait, as demonstrated (again) in the variable evolutionary paths of Lenski’s E. coli.

    All mechanisms have two features: 1) a molecular trigger, 2) a variable output constrained by the operation of the mechanism.

    A mechanism doesn’t “choose” when to function. If the trigger is present it functions, whether or not doing so might result in benefiting or crippling the organism.

    A mechanism doesn’t “choose” the resulting output. It will randomly produce whatever outputs are within its range of constraints. The mechanisms Shapiro cites are just as capable of producing deleterious results as any other source of mutation (what you would call “errors”).

    No genetic change is intrinsically right or wrong. Changes that ultimately impare the organism in its current environment get weeded out of the population. The result is that over time the aggregate variability in a population tends toward greater fitness.

  23. chikoppi says:

    [hardnose] have explained, over and over, that I DO NOT consider my opinion to be scientifically verified. You claim that yours is, even though you have no evidence for it.

    Let’s settle this. What lines of evidence would you examine to determine whether or not a process was random?

  24. BillyJoe7 says:

    Hardnose,

    “Shapiro showed that variations can happen that are NOT errors”

    It’s about time you actually read his book:
    https://www.amazon.com/Evolution-View-21st-Century-paperback/dp/0133435539
    The kindle version is only $18.

    When you erroneously said that “variations can happen that are NOT errors” what you meant is that mutations can be non-random.

    However….
    There is no evidence for non-random mutation
    There is no known mechanism for non-random mutation.
    There is no possible mechanism for non-random mutation.

    What are purported to be non-random mutations can easily be explained as constraints built up in the genome by the already well-known, evidence-based mechanisms of evolution. There is no need to wait for future validation of your gut feeling opinion. It is already superfluous.

  25. bachfiend says:

    Hardnose,

    ‘I have explained, over and over, that I DO NOT consider my opinion to be scientifically verified. You claim that yours is, even though you have no evidence for it.’

    Science doesn’t ‘verify’, meaning it doesn’t provide proofs. This has been pointed out to you numerous times. Science is in the business of finding the best theories – models – of reality, which describe the observations already made, make predictions of future observations and haven’t been falsified.

    What you call ‘materialism’ is the best overarching model of reality, and which hasn’t been falsified.

    There’s no evidence that your intelligent and conscious universe exists. There’s no evidence that there’s teleology in nature, with features such as intelligence arising before it’s needed, before benefits exceed costs, that mutations are non-random, directed and to the benefit of the organism.

  26. michaelegnor says:

    [All mechanisms have two features: 1) a molecular trigger, 2) a variable output constrained by the operation of the mechanism.]

    Actually, all mechanisms have a third feature. They’re designed.

    [No genetic change is intrinsically right or wrong. Changes that ultimately impare the organism in its current environment get weeded out of the population. The result is that over time the aggregate variability in a population tends toward greater fitness.]

    i.e: things change and survivors survive. Quite a theory you got there.

  27. michaelegnor says:

    [There’s no evidence that your intelligent and conscious universe exists. There’s no evidence that there’s teleology in nature, with features such as intelligence arising before it’s needed…]

    Riiiight. Einstein’s theory of relativity, which is the most accurate model of the universe that we have, entails absolute differential calculus so difficult to understand that Einstein needed the help of mathematicians (e.g. Grossman) to lay the mathematical framework. General relativity is described by ten tensor field equations, and there are very few exact solutions.

    Quantum mechanics is the most accurate theory in science, good to 14 decimal places. It is mathematically difficult and profound.

    The most simple processes in nature require substantial mathematical physics even to understand them in a rudimentary way.

    And yet you assert that there’s no evidence for intelligence as the ground of existence of the universe. What an incredibly stupid thing to say.

    This is the synopsis of the last five centuries of modern science: a massive Intelligence is at the ground of existence.

  28. hardnose says:

    “Science doesn’t ‘verify’, meaning it doesn’t provide proofs. This has been pointed out to you numerous times.”

    Don’t be stupid. Well I know you can’t help it. You know that I meant your theory has no evidence. I have said that a zillion times. I didn’t say “proof,” because I know how nitpicky you are. Some ideas have evidence to verify, to support, them, while others do not. We have evidence to verify that evolution happened, but there is not evidence showing how it happened.

  29. hardnose says:

    “There’s no evidence that your intelligent and conscious universe exists.”

    You insist on going in an endless circle. I have said, over and over and over, that I am not claiming scientific evidence for my belief about why evolution happened.

    YOU are claiming scientific evidence for your belief, but you don’t have any.

  30. hardnose says:

    Well they moderate comments now, to make sure no good arguments against materialism show up.

  31. Cdesign Proponentsist says:

    Hey, at least Ignore Michael finally admitted that evolutionary biology is a science! And he even correctly described it as “population changes over time!” Friends, I think we’re finally making progress! 🙂

  32. BillyJoe7 says:

    For some reason, “recent comments” has disappeared on the side bar.

  33. Hardnose – you just make up shit to suit yourself, huh.

    We migrated NeuroLogica over to a new server. This meant we had to reinstall all the plugins, including the spam filter. For a day the spam filter was off, and everything went into moderation.

    Everything should be back on now, with the same settings as before.

    See, no conspiracy against you.

  34. Willy says:

    hardnose–It was pretty obvious that something was “haywire” with the site as no new posts had been made all day long yesterday. Anyone with a brain could see that, yet YOU manufacture a plot aimed at you. Pretty damned funny, and now your silliness is recorded forever in this thread. Nonetheless, I bet you won’t learn a thing from this.

  35. chikoppi says:

    [michaelegnor] Actually, all mechanisms have a third feature. They’re designed.

    Aren’t.

    i.e: things change and survivors survive. Quite a theory you got there.

    Strawman (either willful ignorance or refusal to engage the facts).

    This is the synopsis of the last five centuries of modern science: a massive Intelligence is at the ground of existence.

    Isn’t.

  36. chikoppi says:

    [hardnose] YOU are claiming scientific evidence for your belief, but you don’t have any.

    We’ll be happy to provide reams of evidence. All you need to do is to stop being obtuse.

    What lines of evidence would you examine to determine whether genetic processes are directed or random with respect to the needs of the organism?

  37. Rogue Medic says:

    hardnose,

    Well they moderate comments now, to make sure no good arguments against materialism show up.

    I thought that you and Michael Egnor were here to make sure that there are bad arguments to make the rest of us look good.

    The deviously clever plan is working.

    Poor, poor, you. Reality conspires against you in ways that are indistinguishable from coincidence, but you know that it is all about you.

    .

  38. Willy says:

    I’m still chuckling over hardnose’s unsupported conclusion–“…to make sure no good arguments against materialism show up.”

    There are several comical layers to his hasty post. As the former VP of manufacturing for the company I worked for would put it: hardnose really drug his dick in the dirt on that one.

    C’mon hardnose; show up and defend yourself on this one. Splain to us what a fine thinker you are.

    And Dr. Egnor, I’m still waiting for you to defend the 3-D chess player regarding his boastful, incoherent, and just plain WRONG thoughts on “healthcare”. We know you check in frequently. Your silence is the same as an admission of defeat.

  39. bachfiend says:

    Michael,

    ‘The most simple processes in nature require substantial mathematical physics even to understand them in a rudimentary way. And yet you assert that there’s no evidence for intelligence as the ground of existence of the universe. What an incredibly stupid thing to say.’

    What an incredibly stupid thing to say. ‘The substantial mathematical physics’ doesn’t allow understanding the ‘most simple processes in nature’ (quantum physics and gravity) – it just allows reality to be predicted and described rigorously. It hardly adds to understanding describing mass as curving space-time or everything (matter, energy, time and space) consisting of multiples of miniscule indivisible units.

    You might want to think that there’s an intelligence behind all of this, but there’s no evidence for it, let alone that’s its your God, who somehow or another (if he actually exists that is) managed to allow his adherents to write such physical nonsense in sacred texts, such as the Earth is the centre of the universe.

    Hardnose,

    There is plenty of evidence that evolution occurs as a result of changing environments acting on populations with natural variants, with the mechanism of natural selection eliminating the less ‘fit’ variants. There’s no evidence for your teleological worldview that somehow mutations are non-random, directed and to the benefit of the organism.

    ‘Materialism’ is the best description of reality.

  40. mumadadd says:

    Rogue Medic,

    Let’s not be hasty. hn may well have posted a sound refutation of materialism in the time comments were down. And it may still be in moderation while Steve N comes to terms with having his worldview ripped from under him. I am confident that Steve will publish it anyway so let’s give him chance to claw back his sanity just a little bit.

  41. hardnose says:

    “There is plenty of evidence that evolution occurs as a result of changing environments acting on populations with natural variants, with the mechanism of natural selection eliminating the less ‘fit’ variants.”

    You won’t listen bachfiend, ever. There is NO evidence that theory can explain the origin of new more complex species. You are explaining adaptation of existing species.

    “There’s no evidence for your teleological worldview that somehow mutations are non-random, directed and to the benefit of the organism.”

    I NEVER SAID THERE WAS. I SAID WE DO NOT HAVE SCIENTIFIC EVIDENCE SHOWING HOW EVOLUTION HAPPENS.

    You say you have evidence, although you don’t. Then you accuse me of not having evidence, although I never said I did.

  42. chikoppi says:

    [hardnose] You won’t listen bachfiend, ever. There is NO evidence that theory can explain the origin of new more complex species. You are explaining adaptation of existing species.

    If you are looking for evidence that an eel can give birth to a chimpanzee, you’re not going to find it. BECAUSE THAT’S NOT EVOLUTION.

    There is no species that produces offspring of another different species. Adaptation *is* the process of speciation. All the intermediate steps are necessary, as each step changes the range of possibilities available to the generations that will follow.

    And you have been provided reams of evidence that evolutionary processes are perfectly capable of adding complexity to the genome.

    Lenski’s experiment demonstrated a stepwise increase in complexity when E. coli evolved the ability to metabolize citrate. That mutation alters the parameters for what potential genetic changes are available to that population versus its non-citrus metabolizing cousins. “Citrate” (via the Cit+ gene) now becomes a card on the table that can be accessed by or combined with mutations in future generations to produce yet other new traits. Over time it will contribute to the complexity that arises in a future species.

    I know, I know…the E. coli didn’t turn into a talking octopus. It’s “just adaptation.”

    I assume you would consider the emergence of the antibody based immune system, bioluminescence, or articulated limbs to be bonafide examples of speciation that involves “greater complexity.”

    http://www.pnas.org/content/102/1/169.short
    http://www.pnas.org/content/112/20/6419.short
    https://averof-lab.org/web/publications_files/2010_Paleo.pdf

    It is YOU who won’t listen. You have a cartoonish grasp of evolution that doesn’t reflect actual evolutionary history, evolutionary processes, or the theory that describes them.

  43. bachfiend says:

    Hardnose,

    ‘You won’t listen, bachfiend, ever. There is NO evidence that theory can explain the origin of new more complex species. You are explaining adaptation of existing species.’

    Then how about the K-Pg event 65 MYA due to the environmental change resulting from the Chicxulub impact, eliminating the non-avian dinosaurs and allowing the radiation of numerous new mammalian species and bird species?

    During the Mesozoic, mammals were just small shrew-sized animals. The demise of the full range of non-avian dinosaurs opened up a enormous range of ecological niches, and the populations best fitted to fill an empty niche were favoured by natural selection.

    Evolution is caused by changes in environment. Changes in climate – which the K-Pg event definitely cause. And changes in predators, prey or competitors – which the mass extinction of the non-avian dinosaurs definitely did too.

  44. BillyJoe7 says:

    Bachfiend, you weren’t there so you couldn’t possibly know what happened 64mya 😀

  45. RickK says:

    There is no evidence that evolution explains development of complex species – except the entirety of the DNA record.

    Materialism is not supported by anything other than every foundational fact upon which science and technology are based.

    Hn and ME are both equally blinded and intellectually ossified by their respective ideologies. If you quote evidence or argue details with either of them, you’re simply playing pigeon chess. Both have more than proven their ability to ignore a universe of facts to preserve their preconceptions.

  46. hardnose says:

    bachfiend,

    You show evidence that species evolved. Same old story. That never was the controversy. You are impervious to reason.

  47. hardnose says:

    And of course changes in the environment can be a factor in evolution. But it makes no sense to say that evolution of new species is CAUSED by environmental changes. It is ONE factor.

  48. BillyJoe7 says:

    “You are impervious to reason”

    ^the troll looking in the mirror.

    I’ve noticed this trend amongst denialists of using language that applies so aptly to themselves against their opponents. He is the epitome of someone so impervious to reason – and facts and logic – that it beggars belief.

  49. Willy says:

    What are the other factors, hardnose?

  50. chikoppi says:

    [hardnose] You show evidence that species evolved. Same old story. That never was the controversy. You are impervious to reason.

    This is a precise illustration of your misconceptions of evolution.

    Species don’t just “appear.” There is no bright line between homo sapiens and homo heidlebergensis.

    The heidlebergensis genome evolved over time, with adaptations gradually accumulating in the population and expanding the range of what variations were possible in successive generations. The HH population diverged into the partially-isolated genetic populations of homo neanderthalensis and homo sapiens.

    At no point did HH suddenly become HN or HS. The term “species” is a label that is applied in retrospect to demarcate the genetic isolation of populations at different periods of time. At no point is an offspring so genetically different from its parent(s) as to not be considered the same species. This is underscored by the presence of HN genes in modern humans. The genetically divergent descendants of HH were fertile.

    The presence of the Cit+ gene in one population of E. coli means that population has a different range of genes and proteins for evolutionary mechanisms to act on than its otherwise genetically-similar cousins. This means its potential for variability has expanded, with future mutations having access to a protein that might be incorporated into other phenological traits, traits not available to the cousin populations. Traits that reflect greater “complexity” which will distinguish the post-Cit+ generations from the pre-Cit+ generations.

    These are the same processes that led to differentiation between HH and HN/HS, including the different evolution in “complex” traits between HN and HS.

  51. bachfiend says:

    Hardnose,

    ‘You show evidence that species evolved. Same old story. That was never the controversy. You are impervious to reason.’

    I was hoping that you’d ‘got it’ with your first sentence, but then you ruined your brief display of reason.

    That’s exactly what evolution is – changes in species (although it’s better to say populations) in response to changes in their environment. Big changes with major changes in climate and mass extinction events. Small changes with small changes in climate and other species.

    If the environment of populations doesn’t change, then evolution stops. Natural selection doesn’t cause evolution. It just allows it to happen. If the environment isn’t changing, then natural selection tends to stop evolution occurring (with the exception of sexual selection as in the Galápagos finch hybrids, and neutral drift in small populations), because populations tend to be well adapted to their current conditions. Changes in the population will largely be deleterious rather than beneficial. It’s never happened that populations evolve traits in advance of them becoming necessary. The dodo on Mauritius didn’t, and couldn’t, evolve flight in advance of the English and Dutch sailors arriving in the 17th century, and went extinct. Evolution isn’t teleological.

    What is your explanation for the mammalian radiation? Did it just happen? Perhaps because there’s an innate tendency towards increasing complexity and intelligence in biological systems after the intelligent universe decided to do a reset on the Earth with the Chicxulub bolide wiping much of the slate clean?

  52. Willy says:

    “…impervious to reason.” So says the man who was convinced his comments were being deleted because his arguments were too good.

  53. RickK says:

    Curious what is triggering moderation for posts without links.

  54. Rogue Medic says:

    Willy,

    “…impervious to reason.” So says the man who was convinced his comments were being deleted because his arguments were too good.

    Dr. Novella deletes all of hardnose’s good comments, until hardnose becomes so irate that his writing is incomprehensible.

    I do this to President Trump.

    I can do that, because my name it T. Witter.

    I couldn’t think of anything better than naming after myself.

    You would be amazed at the wisdom in the Teflon Don‘s original drafts, which I keep from being seen. Poets would weep at their beauty. Or is it that Poes would weep at their . . . ?

    😉

Leave a Reply