Hi all, my difficulty with this is that what I see as a difference of opinion continues to get characterised as a misunderstanding of evolution. Mitch, how can you state definitively that species 3 billion years ago were just as well adapted to their environment as those that exist today? It seems to me that's an empirical question. It's possible they were but why MUST it be so. And if I can provide an empirical example (Lenski's experiments) where later generations of an E.coli population were better adapted for their environment than an earlier one (by directly testing the competitive ability of the two strains) then why is it not possible that organisms today, on average, are better adapted for their environment than past organisms. I want to emphasize that I am not saying current organisms ARE better adapted, only that it's a legitimate question to ask. The answer will be in the data.
' In evolution different species can't be compared as better or worse - they just succeed or they are replaced by others.' So, we can use the term successful but not better? OK. So, is there any evidence that current organisms have more success dealing with their environment than ones from 3 billion years ago? 'The upshot is that populations and species are never adapted to their environments.' It's not clear to me what you mean here, Mitch. That they aren't perfectly adapted to their environments? I don't think anybody has suggested they are. 'That environments are always changing so 'adapted' is a moving target? That is almost certainly true but it doesn't mean, necessarily, that one step forward and one step back. It could be that there is a noisy and variable walk towards organisms that are more successful at dealing with their environments. But, bear in mind, I'm not asking anybody to believe that's true - just to acknowledge that it's possible and therefore a reasonable question to ask. There is no confusion on my part about the role of complexity. I don't think that complex organisms are necessarily better adapted and have never suggested they are (I only suggested that on the axis of complexity we have seen progress, not that increased complexity necessarily makes an organism better adapted for its environment) Liz, I've never suggested that the process would be linear. In fact, I've never even suggested that I think organisms are better adapted to their current environments than ancient organisms were to theirs. I've only asserted that it is not a nonsensical question. The fact that we keep coming back to the argument that 'environments are constantly changing therefore organisms are always trying to catch up with the changes' implies that, in fact, organisms could end up better adapted to their environments. Implicit in your statement '...environment that 'shapes' them also changes through time.' is that if the environment didn't change through time that we would see a trend towards organisms that were better adapted for their environment. If that's true, then why would we assume that somehow the changes in the environments occur at a rate that is perfectly synchronized with the rate at which a population evolves and so how well organisms are adapted to their environment stays constant? That just seems extraordinarily coincidental. What I could believe is that at different times in history organisms have been more or less adapted to their environments but on average they are no better adapted today than they were in the past. But. I can't see that there is anything that necessarily makes that true. Best, Jeff H. ________________________________________ From: Mitch Cruzan [cru...@pdx.edu] Sent: December 7, 2012 3:03 AM To: Jeff Houlahan Cc: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: [ECOLOG-L] Discussion Panel Topic Suggestions Hi Jeff, Joey, and all the rest. I think several people have expressed a core principle of the misunderstanding of evolution - I will try to explain. Some 3 billion years ago the Earth was occupied by organisms that were certainly simpler than many extant species, but they were also just as well adapted to their environments as anything existing today. The confusion, I think, comes from equating complexity with improvement, but that is not the case. As others have stated, some of the most successful organisms are also some of the least complex. So where does complexity get us? The answer is - probably just to novel ways of resource acquisition. In a Precambrian world (the time that Jeff referred to), the main difference compared to later was that the number of trophic levels was limited. There were photosynthetic autotrophs and "herbivores" that fed off of them, but the evolution of larger "predators" required an increase in complexity. The important thing is that all of the species from that time period were subjected to strong selection so they were as "adapted" to their environments as anything you would find today. The problem is the meaning of "better" - not a word in the evolutionary vernacular. In evolution different species can't be compared as better or worse - they just succeed or they are replaced by others. No species will persist forever - the ultimate fate of any lineage - even Homo sapiens - is extinction. At least 99% of all species that have ever existed are now extinct, and not because they were replaced by improved species - it was often just by chance. The process of species turnover through time is generally not as dramatic as mass extinctions in response to global disasters, but more often it is a replacement - things change until they are eventually different enough that they could not have reproduced with their ancestors. I know you are going to say "what about cockroaches or cycads, haven't then been the same for 100's of millions of years?" No, not really - only superficial based on what we can tell from fossils, but the cockroach of old ages is not the same as the ones we have today. On the other hand, it is important to realize that species are not adapted to their environments because there are many forces constraining them. These include: 1. Environments change in unpredictable ways. Studies of selection in nature often show that is changes from one season to the next - species are chasing (actually, being pushed towards) a moving target. 2. Gene flow from other populations. The effects of selection can be swamped are at least constrained by dispersal of individuals and spores (pollen) from populations that are subjected to different selection regimes. 3. Random effects of genetic drift - do not underestimate the power of drift to overcome selection and gene flow. 4. Evolutionary constraints - genetic correlations among traits due to developmental pathways, life history tradeoffs, and physical constraints may prevent a population from responding to selection. 5. Lack of adequate variation - the right mutations or combinations of alleles at different loci may not have appeared just yet, or not in the right combination in any individual. The upshot is that populations and species are never adapted to their environments. It is important to remember that these environs that we view as stable - these habitats we try to "conserve" - are dynamic. They are destined to undergo change and attempting to constrain them from that would create unnatural conditions. The world has changed a lot in the last 10,000 years and most species have not had a chance to catch up - probably never will because things continue to change. My advice to all who wish to engage in this panel is to head to your nearest used textbook outlet and pick up an older edition of any introductory evolution textbook. The classic is the one by Doug Futuyma, but there are many new versions by other authors as well. For anyone with a few years of biology under their belts including introductory genetics, cell biology, molecular biology, and intro ecology, this subject material should be pretty accessible. Mitch Cruzan On 12/6/2012 5:17 PM, Jeff Houlahan wrote: > Hi Joey, I am not arguing that evolution has led to progress on some axis - > that's an empirical question. I am only arguing that it is not a > misunderstanding of evolution by natural selection to suggest that it is > possible. You've stated conclusively that evolution by natural selection > cannot lead to progress. So, if I could provide empirical evidence that, on > average, current organisms are better adapted to their environments than > organisms were 3,000,000,0000 years ago would you still deny that was > progress? I'm OK with that but it's just a semantic issue then - something > that I would be willing to call progress you wouldn't be willing. On the > other hand, if you're saying that it's not possible that over time time > organisms have become better adapted to their environments then our > difference of opinion is more fundamental. But, keep in mind - this is not a > debate about whether evolution by natural selection HAS resulted in progress, > it is about whether it's reasonable to ask the question, has evolution > resulted in progress? Just because the answer might be no doesn't mean the > question doesn't make sense. > And what about the example from Lenski's work - he has absolutely > demonstrated in his population of E. coli that later generations were more > fit than earlier generations. The population that had been around longer > was better adapted. Why would it be possible over 75,000 generations of > E.coli but not possible as a general rule? > The problem I have is not that you believe that evolution by natural > selection has not resulted in better adapted organisms - it's that you > believe that anybody who suggests it's possible, misunderstands evolution by > natural selection. Best, Jeff Houlahan > > > ________________________________________ > From: Ecological Society of America: grants, jobs, news > [ECOLOG-L@LISTSERV.UMD.EDU] on behalf of Joey Smokey > [northwestbird...@gmail.com] > Sent: December 6, 2012 7:24 PM > To: ECOLOG-L@LISTSERV.UMD.EDU > Subject: Re: [ECOLOG-L] Discussion Panel Topic Suggestions > > Ecolog: > > I would like to commend Wayne for his devil's advocate approach to > suggesting the third question and starting this discussion. It seems my > original interpretation was correct: the whole purpose of the question was > to dispel the misconceptions around the semantics of evolution. > > I find it interesting how several of you use the word "progress" in > different contexts, and I especially like the idea of defining progress > along some sort of axis, such as increasing complexity. This all being > said, I do have some retorts. Firstly, if the argument is to be made that > evolution leads to increasingly complex life forms, it should be noted that > this has happened many times in evolutionary history. Adaptive radiations > and mass extinctions produce a cycle of "simple-to-diverse" organisms over > millenia. However, at the end of every mass extinction, the diversification > of organisms and their niches is eliminated, and complexity of life is > severely reduced. So, given our idea of progress, however you want to > define it, you still cannot use it. If organisms did in fact progress over > whatever axis you'd like to use, then despite mass extinctions they would > continue to become more and more advanced. We are currently in the middle > of an anthropogenic mass extinction, whether or not some folks want to > accept that, and at the end of it, the complexity of life as we know it > will vanish. Fact: prokaryotes have remained simple unicellular organisms > for billions of years for a reason. :) > > To the point of evolution of individuals, populations, and communities: > Individuals and communities do not evolve. I think the idea of community > evolution has been sufficiently put the rest already. To use semantics > correctly: natural selection acts on individuals and has consequences on > allelic frequencies in populations. One individual organism cannot evolve, > because its allelic frequency never changes throughout its life. But, > natural selection can cause it to influence the allelic frequency of future > generations in the population, and that -is- evolution. Also, when folks > use the terms of "fittest" and "survival of the fittest", etc., that should > be avoided. The four postulates of natural selection lead to relative > fitness. In other words, one individual can only have a slightly higher > fitness than another. Liz already alluded to this; and I also quite like > her noting that even our own species is by no means "perfect." > > Recapping: Evolution is not directional. Evolution is not perfect. And > evolution does not lead to the good of the species (example: infanticide). > Evolution leads to organisms being well-adapted to their environment at a > specific time. Temporal environmental changes (i.e. climate change) lead to > organisms no longer being well-adapted to their environment, and they must > either adapt or face extinction. > > Regards, > > Joey Smokey > WSU Vancouver > > > On Thu, Dec 6, 2012 at 12:31 PM, Jeff Houlahan <jeffh...@unb.ca> wrote: > >> Hi all, admittedly evolution by natural selection has no goal - it just >> happens. But, the logical outcome of natural selection is a population >> containing fitter organisms. Richard Lenski's experiments have shown >> conclusively that the E. coli in his cultures that have evolved for longer >> are fitter (using competitive ability as an index of fitness). If we can't >> call that 'progress' then we've put some pretty narrow constraints on the >> word progress and presumably progress can only be used in human contexts >> where there are explicit and clearly defined goals. OK. But that just >> means we need to rephrase the question to avoid the use of the word >> progress (although it's the same question, I think) - as we move from the >> first living organisms to the current group of living organisms, have >> living organisms, on average, become better adapted to their environments? >> I don't know if this is a testable question but it doesn't seem like an >> illogical one. And I have to confess, I see it as semantic hairsplitting >> to be unwilling to talk about 'better adapted to their environment' as >> progress. Best, Jeff Houlahan. >> >> >> ________________________________________ >> From: Ecological Society of America: grants, jobs, news [ >> ECOLOG-L@LISTSERV.UMD.EDU] on behalf of Rachel Bolus [r...@bio.umass.edu] >> Sent: December 6, 2012 2:15 PM >> To: ECOLOG-L@LISTSERV.UMD.EDU >> Subject: Re: [ECOLOG-L] Discussion Panel Topic Suggestions >> >> Hello >> I think that the interesting debate generated by the issue of >> "evolutionary progress" is exactly why it's a good topic for this panel. >> It makes people think carefully about definitions and the processes. I >> also think that Chris Edge just hit the nail on the head about our >> misuse of the word "progress." "Progress" or "advancement" suggests >> teleology, which has been largely rejected by evolutionary biologists. >> >> One of the reasons why we stumble over the question, "Do organisms >> advance over time?" is that we confuse complexity with progress. Yes, on >> average, organisms become more complex over time, because the process of >> evolution is the accumulation of changes in traits of individuals in >> populations over time. Although losses are part of this process, gains >> are added on top of previous gains, resulting in more complexity >> (especially in the multi-celled organisms that more frequently catch our >> eye). >> >> Is complexity progress? As humans, our intuition tell us, "yes" because >> we like shiny complex things (perception bias, perhaps?). If we are >> handed two tablets, one that is a chalkboard and one that is an iPad, we >> know which one we think is better. But when the flood comes, which one >> is still functional afterwards? Adaptation results in organisms fitting >> their environment better, but the more adapted we are to a particular >> environment, the less flexible we are to change. In a large time scale, >> flexibility should trump complexity. Sometimes more complex things are >> better able to adjust to changes in the environment, sometimes they >> aren't. In a "stable" environment (if it exists) what organism is best >> able to survive and reproduce may be complex or may be simple. >> >> What is "better" is largely subjective- is it complexity, adaptation >> (resistant microbes!), size (currently, blue whales!), intelligence >> (humans!), ability to produce the most offspring and biomass possible >> (fungi!), ability to persist relatively unchanged across epochs >> (sponges!)... ? >> >> As an interrelated topic (the previous one is mostly evolutionary, with >> ecology included as part of the process of adaptation), it might be fun >> to include the changing ideas of forest succession (getting back to the >> issue of "Do communities evolve?"). Previously, it was thought that >> forest communities progressed towards climax stages, but now we realize >> how patchwork, stochastic, and cyclical this process is. >> >> Rachel Bolus >> Ph.D. Candidate >> Organismic & Evolutionary Biology >> University of Massachusetts Amherst >> >> On 12/6/2012 10:03 AM, Chris B. Edge wrote: >>> Hello all, >>> I have spent some time thinking about this topic over the last several >>> years. As a relatively 'green' evolutionary ecologist I rarely enter >> these >>> debates in public forums. >>> My opinion's are heavily influenced by Jared Diamond's writing on the >>> topic. In not as eloquent words 'progress' implies that there is a goal >> or >>> target that evolution is moving towards. Of course we can define the goal >>> or target post hoc, complexity, invasion of terrestrial habitats, etc. >> and >>> conclude that evolution has made progress. However non of these >>> goals/targets apply to all organisms or habitats, and non of them can be >>> defined a priori. >>> 'Progress' may capture the essence of the message we want to get across >> it >>> is not a good word to use to describe major evolutionary trajectories >>> unless the statement it is used in also includes the axis or scale >> progress >>> is to be measured on. Instead major trajectories should be described as >>> they are, observed trajectories/trends. For example, consider these two >>> statements; 1) 'evolution has resulted in a trend of increasing >>> complexity', and 2) 'evolution has made progress towards increasing >>> complexity'. The two statements convey the same message, but statement 2 >>> implies that complexity is always good. In my opinion statement 1 is much >>> better. >>> Regards, >>> Chris Edge >>> >>> On Wed, Dec 5, 2012 at 11:40 PM, Wayne Tyson <landr...@cox.net> wrote: >>> >>>> Ecolog: >>>> >>>> Pryde is right on. But the reality is that evolution is misunderstood >> by a >>>> lot of people, and clarity on this subject would go a long way toward >>>> resolving some of the conflict arising therefrom. That will require >> clear >>>> statements from evolutionary biologists for starters, and perhaps a lot >> of >>>> article-writing and TV production that not only is more careful about >> the >>>> semantics used,* but actually getting the ball rolling toward rolling >> back >>>> the misconceptions. >>>> >>>> But first, you catch the rabbit--and even make the stew. Then serve it >>>> until it is found delicious. (As long as it's not bushmeat.) That is, >> get >>>> this matter thoroughly discussed by evolutionary biologists and others >> who >>>> understand the merits and deficiencies of the two "sides," then "make it >>>> news." >>>> >>>> WT >>>> >>>> *advancement, progress . . . >>>> ----- Original Message ----- >>>> From: Liz Pryde >>>> To: Wayne Tyson >>>> Cc: ECOLOG-L@LISTSERV.UMD.EDU >>>> Sent: Wednesday, December 05, 2012 9:00 PM >>>> Subject: Re: [ECOLOG-L] Discussion Panel Topic Suggestions >>>> >>>> >>>> In Darwin's "Origin" the theory was one of adaptation, not >> advancement. >>>> Unfortunately Spencer coined the "fittest" remark and that was a >> popular >>>> mode of thinking at the time - when people were rather >> self-congratulatory >>>> about their scientific understandings of the natural world (how >> clever!). >>>> So, evolution was originally meant as an adaptation to the chance >>>> environment. It may or may not have been 'better' than the previous >> model, >>>> but it survived through chance, and we assume, advantage. This doesn't >>>> necessarily make it advantageous throughout time. >>>> >>>> >>>> I'm sure we can all come up with improvements to the human body ;). >>>> Liz >>>> >>>> >>>> >>>> >>>> >>>> >>>> On 06/12/2012, at 2:47 PM, Wayne Tyson <landr...@cox.net> wrote: >>>> >>>> >>>> Joey and Ecolog >>>> >>>> I am the author of question 3, and the point is exactly the one >> made >>>> by Smokey, with which I fully agree. There do seem to be people who >> seem to >>>> be of the opinion that evolution IS progress, however. I posted this >>>> question to a well-known evolutionary biology forum and Richard Dawkins >>>> replied in the affirmative; when I asked for further clarification, >> there >>>> was no response (except one which agreed with my point; several others >> were >>>> outraged, and I ended up having to issue an "apology." David >> Attenborough, >>>> in one of his excellent TV programs used the term "advance," in >> discussing >>>> the matter with one of the world's top paleontologists, whom I emailed >> the >>>> raw question; he responded in the affirmative, that the creatures he was >>>> most famous for studying did "advance." When I responded by asking if he >>>> would then conclude that the genus Homo would then be an example of >>>> "evolutionary advance," the correspondence was terminated. >>>> >>>> My straw polling amongst "the public" tilts strongly in favor of >>>> "progress" or "advancement" with time, and while I'm not sure of all the >>>> sources that have contributed to this impression, the Time-Life book >> "Human >>>> Evolution," with its famous/infamous "March of Progress" illustration >>>> beginning with a quadruped ape and ending with an upright, apparently >> Aryan >>>> male. I know of no studies that have been done on this issue, and >>>> attempting to raise the discussion on respected websites causes more >>>> blowback than the kind of clarity that Smokey's concise statement >> brings to >>>> the discussion. >>>> >>>> Ecolog is a respected and large listserv. Will there be further >>>> comments, either in support or in refutation of Smokey's explanation, >> or is >>>> this subject one of those academic "third rails" that no one dare touch? >>>> Those who fear posting their comments here could send Smokey and me >> their >>>> comments directly if they want to avoid reprisals (the subject of >> reprisals >>>> for posts reared its ugly head several months ago, and believe it or >> not, >>>> the emails I received were not limited to students; I got several from >>>> professors). >>>> >>>> On the other hand, if this subject is considered unimportant, >> "proper" >>>> actions can be taken, eh? >>>> >>>> WT >>>> >>>> ----- Original Message ----- From: "Joey Smokey" < >>>> northwestbird...@gmail.com> >>>> To: <ECOLOG-L@LISTSERV.UMD.EDU> >>>> Sent: Tuesday, December 04, 2012 1:51 PM >>>> Subject: Re: [ECOLOG-L] Discussion Panel Topic Suggestions >>>> >>>> >>>> >>>> Jason, >>>> >>>> I strongly advise against the third question. Evolution is not >>>> directional, >>>> and the question is worded to suggest that it is. If the point >> of the >>>> question is to dispel the idea of evolution being directional, >> then >>>> it >>>> would be fine. >>>> >>>> There are many common misconceptions of organisms "progressing" >>>> through >>>> evolution. The most common is the typical classroom image of >> human >>>> evolution moving from ape-like toward human-like over time. >>>> Transition >>>> species in the fossil record do not suggest a progressive change >>>> from one >>>> type of body form into another. The transition to terrestrial >> life >>>> is the >>>> same way; transition species such as Tiktaalik, Eusthenopteron, >> and >>>> Ichthyostega did not "march along" until they were well-adapted >> for >>>> life on >>>> land. Evolution does not craft "improved" species or "advanced" >>>> species. It >>>> simply results in organisms being well-adapted for their >> environment >>>> at a >>>> given time. >>>> >>>> In regards to the fourth question, ecological time refers to >>>> immediate >>>> interactions between organisms and their environment. It does >> lead >>>> into >>>> evolutionary time and the change in allelic frequencies through >>>> generations. So, ecological interactions can and do have >> meaningful >>>> impact >>>> on evolutionary trajectories of species. >>>> >>>> I think the first two questions will lead into some good >> discussion. >>>> Best of luck on your discussion panel, >>>> >>>> Joey Smokey >>>> WSU Vancouver >>>> >>>> >>>> On Tue, Dec 4, 2012 at 8:37 AM, jason.strickland < >>>> jason.strickl...@knights.ucf.edu> wrote: >>>> >>>> >>>> Dear group, >>>> >>>> I have compiled some of the ideas that were given to me about >> my >>>> discussion panel. The response was much lower than I expected >> so >>>> if you >>>> have any ideas, feel free to share those as well. Thank you to >> all >>>> those >>>> that contributed. >>>> >>>> >>>> 1. Will most organisms be capable of adapting quickly >> enough >>>> to >>>> respond to climate change/sea level rise to be evolutionarily >>>> relevant? >>>> >>>> 2. What impact will Genetically Modified Organisms have >> on >>>> the >>>> ecology and evolution of the modified species and other >> species? >>>> 3. Do organisms progress/improve/advance through >> evolution? >>>> 4. Do ecological processes/interactions last long enough >> to >>>> have any >>>> meaningful impact on the evolutionary trajectory of a species? >>>> >>>> Please share your thoughts on these topics or suggest others. >>>> >>>> Cheers, >>>> Jason Strickland >>>> jason.strickl...@knights.ucf.edu >>>> >>>> From: jason.strickland >>>> Sent: Tuesday, October 30, 2012 3:59 PM >>>> To: ECOLOG-L@LISTSERV.UMD.EDU >>>> Subject: Discussion Panel Topic Suggestions >>>> >>>> Dear group, >>>> >>>> I am currently working on forming a discussion panel that will >>>> include two >>>> ecologists and two evolutionary biologists to discuss topics >> that >>>> involve >>>> merging ecology and evolution. The discussion will be in front >> of >>>> 150-200 >>>> students ranging from undergraduates to post-docs (all in >>>> biology). The >>>> panel will happen on a Saturday morning so it needs to be an >>>> exciting >>>> discussion to hold the audience's interest and cause them to >> ask >>>> questions. >>>> >>>> I am looking for topics/questions that the two fields do not >>>> completely >>>> agree on. The goal is to have the panel disagree on topics to >>>> allow the >>>> students to learn and be entertained. If anyone can suggest >> topics >>>> or >>>> questions that ecologists and evolutionary biologists have >>>> different >>>> viewpoints on, they would be greatly appreciated. I have a few >>>> topics >>>> already, but wanted to ask a larger audience to suggest topics >> to >>>> determine >>>> if there are certain topics/questions that come up frequently. >>>> Feel free to >>>> email me directly (jason.strickl...@knights.ucf.edu<mailto: >>>> jason.strickl...@knights.ucf.edu>) or respond to this post >> with >>>> your >>>> suggestions. >>>> >>>> Thank you in advance for your help, >>>> >>>> Jason Strickland >>>> jason.strickl...@knights.ucf.edu<mailto: >>>> jason.strickl...@knights.ucf.edu> >>>> >>>> >>>> >>>> >>>> ----- >>>> No virus found in this message. >>>> Checked by AVG - www.avg.com >>>> Version: 10.0.1427 / Virus Database: 2634/5436 - Release Date: >>>> 12/04/12 >>>> >>>> >>>> >>>> Liz Pryde >>>> PhD Candidate (off-campus @ The University of Melbourne) >>>> School of Earth and Environmental Sciences >>>> James Cook University, QLD >>>> >>>> elizabethpr...@gmail.com >>>> epr...@unimelb.edu.au >>>> >>>> >>>> >>>> >>>> >>>> >>>> >> ------------------------------------------------------------------------------ >>>> No virus found in this message. >>>> Checked by AVG - www.avg.com >>>> Version: 10.0.1427 / Virus Database: 2634/5438 - Release Date: >> 12/05/12 >> >> -- >> Ph.D. Candidate >> Organismic & Evolutionary Biology >> University of Massachusetts Amherst >> 219 Morrill Science Center South >> Amherst, MA 01003 >>
