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:
The front-loading hypothesis proposes that ... [the intentionally seeded] life forms contained the necessary genomic information to shape future evolution, such that the “course” of evolution was biased in pre-determined trajectories.
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.
I don't mind objective criticism at all, but for the record, for all of you: now that the weekend is over, I won't have that much time to respond to all of you - only one or two responses per day, unless I can muster some more time. This means that I will be only responding to the highest-quality criticisms...
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.
In the first place, I'm not envisioning anything like extreme front-loading, where something as specific as the human species is front-loaded.
Thanks for the clarification: though, I already figured you for someone wouldn't make this argument.
So if I'm understanding you correctly, you're saying that if multicellularity was front-loaded, we should expect multicellular life forms to evolve independently. But this is what is believed to have occurred; that is, that multicellular life forms arose multiple times but many of these lineages went extinct...
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.
And there is good evidence of biased trajectories of important biological features: to name just one example, eyes have evolved independently in different lineages - indicative of a biased trajectory.
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.
Essentially, it would not be reasonable to argue that "characteristics that only emerged once in Earth's evolutionary history probably were not front-loaded into the original," because lineages can be lost through deep time.
Please observe the parallels between your argument here and a specific statement you made in the OP:
Arguing that the sub-optimal codes once did exist early in life’s history, but vanished once the optimal codes came on the scene (i.e., that they were outcompeted), looks awfully ad hoc.
I will accept your "deep-time" argument if you withdraw your objections to the similar argument in relation to sub-optimal genetic codes.
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.
Do note, too, that the more specific the front-loading objective, the less likely it is that that objective will evolve multiple times.
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.
Well, you wouldn't expect eyes in prokaryotes, now would you?
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.
Actually, the capacity for eye development is encoded at the root of the phylogenetic tree of life.
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?