An ID hypothesis: Front-loaded Evolution

Hi, Genomicus.Welcome to EvC!It's nice to see an IDist who's taken some time and put some good thought and reasoning into his work.For my post, I want to focus on this bit: Since front-loading predicts biases in the trajectory of evolution, shouldn't we be able to detect these biases by examining patterns in evolutionary trajectories across multiple lineages? For example, if the front-loaders intended to promote the emergence of a certain characteristic, wouldn't we predict that multiple lineages of descendant organisms would evolve that characteristic? Isn't this what "biased evolutionary trajectories" means?Based on this, wouldn't it be reasonable to argue that characteristics that only emerged once in Earth's evolutionary history probably were not front-loaded into the original propagule? Any technique that biases evolution toward a certain trajectory, yet only results in one out of millions of lineages following that trajectory, was either a very ineffective technique, or an astonishingly complex algorithm that surely even you don't believe was encoded into a single prokaryotic propagule.Edited by Bluejay, : A redundant redundancy

Hi, Jon. So... the first animal was front-loaded?What about the first prokaryotic progenitor of all life? Why did only one sub-sub-lineage of its descendants manifest these front-loaded characteristics?Edited by Bluejay, : Rewording

Hi, Genomicus. No sweat: IDists frequently get swamped here. Nobody will mind if you take a long time to write a high-quality response.Just so you know, if you start to get too far behind, I intend to yield the floor to others. That will help focus the debate better. And, I consider Mr Jack and Bluegenes superior debaters and superior representatives for the positions I would argue, anyway.Any threads of discussion you choose not to follow (including mine) can always be revisited some other time.

Hi, Genomicus.Thanks for the reply. Thanks for the clarification: though, I already figured you for someone wouldn't make this argument. Well, I wasn't trying to put forward an example yet: I was trying to establish a conceptual principle whereby we could test the predictions of FLE.And, yes, there are indeed many lineages of multicellular organisms. As the article you cited mentioned, there are probably at least 5 independent emergences of "true" multicellularity. And, depending on how we define "multicellularity," there are also prokaryotes that can count as multicellular (some cyanobacteria, for instance).So, based only the single criterion I proposed, I would regard multicellularity as potentially consistent with the front-loaded evolution hypothesis. My concern with the specific example here (eyes) is that the bias in trajectory only emerges in one "later branch" of the Tree of Life (Metazoa). So, it seems that the capacity to develop eyes isn't rooted at the base of the Tree of Life, but at the base of the animal branch of the Tree of Life.Unless FLE allows for front-loading within individual branches of the tree, and not exclusively at the base of the tree, I think the proper conclusion is that eyes probably were not front-loaded. Please observe the parallels between your argument here and a specific statement you made in the OP: I will accept your "deep-time" argument if you withdraw your objections to the similar argument in relation to sub-optimal genetic codes.Edited by Bluejay, : No reason given.Edited by Bluejay, : No reason given.Edited by Bluejay, : last time: I swear

Hi, Genomicus.Like everybody else, I don't think there's any rush to respond to me. I'll still be here whenever you get around to responding. The more specific the objective, the less likely the objective is to be met at all using a crude technique like front-loading. I find it highly dubious to suggest that something as specific as an eye could feasibly be front-loaded at all for this exact reason.Unfortunately, I think this is going to leave you in a conundrum: only the most basic, fundamental characteristics that have broad utility for a wide diversity of organisms could be front-loaded. But, the prevalence of those characteristics is expected under anybody's model of the origin and history of life. So front-loading without specific objectives would make no unique predictions, and would thus be untestable. Why not? Otherwise, you've got a gene that has to persist for a very long time with minimal change due to mutation, while not fulfilling its eye-related functions. If you suggest that it could fill another function in the interim, you'd have to accept that it would be undergoing selection for that other function, which leaves no guarantee that it would still be serviceable in eye development once an organism capable of using it to develop eyes evolved.Surely we have to accept that front-loaded eyes are a dubious proposition. But only the animals seem able to actually evolve eyes, because they evolved them several times, and no other group did. Doesn't this suggest that the capacity doesn't exist at the base of the tree?

Hi, Trixie. Can there even be such a thing as a "structural homolog"?