Alternatives to Modern Evolutionary Theory

Science

(T J Runyon) #1

Here lately I’ve been thinking about alternatives to evolutionary theory as it’s currently understood, universal common ancestry and no need to posit an intervening intelligence. Through this thinking I’ve come to the conclusion that there is only one remotely plausible alternative. That is progressive creation with common ancestry within created kinds or basic types. (Example: An original Tyrannosauroid type evolved and diversified into all the other Tyrannosaurs). I don’t feel like too much science wise would change if this model ended up being true. We would still have to determine relationships and how the changes took place, etc. just don’t seeing evolutionary biology changing too much and evolutionary theory would maybe just have to change some definitions around. So on the face of it it seems plausible to me. But I just came across this post on @Joel_Duff blog. And it’s something I haven’t thought about it and it seems to make these separate ancestry models problematic. Eventually the diversity within the basic types will be greater than the diversity between separate types. Unless what? Mutations just stop happening at a certain point? Doesn’t seem to be plausible. I don’t know. And it’s troubling to me that I haven’t really seen anyone from the OEC/ID crowd trying to address these potential problems. Universal common ancestry seems to be the only model that really makes sense of things.

Dodging Darwin: How Ken Ham’s Ark Encounter is Slowly Embracing Evolution – Naturalis Historia


(John Harshman) #2

The problem with that notion is that we would then expect to be able to enumerate the created kinds rather easily, finding no nested hierarchy above that level. And yet there is no such level.

One must agree.


(T J Runyon) #3

Do you think it’s possible, in theory, to find such levels? I know YECs have tried but I’ve seen nothing from OEC/ID. It just seems to be arguing against evolution 95 percent of the time without putting forward models of their own or trying to better our understanding of the world from them. But do you think that’s possible?


(John Harshman) #4

My point is that it would be possible, in fact easy, if they actually existed. The fact that we don’t find them tells us they don’t exist.


(S. Joshua Swamidass) #5

I’m not sure. If they were in the very distant past, would they still be easy to find? What if they were at, say, the phylum level?


(John Harshman) #6

Sure. If they were we would see no connections among phyla. Or kingdoms. No Deuterostomia, no Opisthokonta, no Eukaryota, and so on.


(S. Joshua Swamidass) #7

Can you please unpack this?


(John Harshman) #8

I’m afraid I can’t. I don’t know what needs unpacking. But I’ll say it using more words, if that helps. If the phyla were independently created, we would not expect to see them connected in a nested hierarchy. Thus we would not see Echinodermata, Chordata, and Cephalochordata connected in Deuterostomia. We would not see Metazoa and Fungi connected in Opisthokonta. We would not see all the various eukaryotes connected in a big group. And so on, in a very consistent pattern. The data and connections above the phylum level look no different from the data and connections below the phylum level. No level at which the tree stops.


(S. Joshua Swamidass) #9

Doesn’t the nesting break down at some point from the noise of all that time, recombination, and horizontal gene transfers?


(John Harshman) #10

Turns out that it doesn’t. This isn’t to say that it’s easy to do phylogenetic analysis at a deep level, that you can just get a bunch of sequences and dump them into PAUP (or whatever); it take a bit of work and thought.


(S. Joshua Swamidass) #11

I want to understand this more.


(John Harshman) #12

You might try reading the Methods sections of a bunch of deep phylogeny papers, if that’s what you’re wondering about.


(David MacMillan) #13

Maybe I can shed some light on this by analogy to a completely separate field.

I was at a pretty small college with a really good research program so I had the chance to do my own research (and get published) during undergrad. We were working with lasing phenomena in polymer microspheres. For those not familiar, lasers are created by producing patterns of constructive and deconstructive interference in a lasing medium that “pumps” that medium full of bouncing photons. Once the medium can no longer hold any more energy, it “dumps” the energy in a laser pulse. In sufficiently small microscopic spheres, the internal reflection path of photons is on the order of the wavelength of the photon and so the entire sphere acts as a lasing medium.

Our research was probing the hypothesis that the behavior of light within the medium changed temporarily after releasing a laser pulse. I ran several thousand laser trials and analyzed the spectrum of fluorescence after each trial. We were looking for some signal in the fluorescence behavior that would show up only when the laser had actually fired.

After a LOT of data analysis, I figured out a way to compare the amount of energy trapped inside resonance peaks to the baseline amount of energy being pumped into the sphere. As soon as I charted that ratio, I found a nice, clean, even break in the data. Ran more trials to duplicate, figured out the math to predict it, and submitted for peer review.

All that to say – IF there is actually a “breaking point” in the pattern of common ancestry, it should show up in the data. The creationists should be able to propose a mathematically defined discriminant that will produce a different signal for common and uncommon ancestry. They should be able to plug the genetic code in for any two species and get a clear answer every time. Anything less is foolishness.


(S. Joshua Swamidass) #14

Really? Even if it was very early on? Even if the other lineage died out? Or converged to the same genetic code? Are we really sure about this? For we even get to special creation, can any say with certainty that there was NOT two abiogenesis events on earth that ended up merging, or one dying off? Depending on what we call “life” it might even be likely they there were several events to “cross the line” almost (geologically) simultaneously, even if God was not directly intervening.

I entirely agree that the evidence is overwhelming that, for example, all mammals (including humans) share common ancestry. Doesn’t this inference get less and less certain the farther back we go? Especially before LUCA, I’m not sure how we could know.

@sygarte, thoughts?


(John Harshman) #15

I think we can dispose of the “merging” idea, just on the basis of the single genetic code. But there could definitely be multiple origins of life, provided only one survives.

Incidentally, the term “genetic code” is being used very loosely in the current thread. Let’s recall that it means the mapping between 3-base nucleic acid codons and amino acids and is not a synonym for genomic sequences.


(John Harshman) #16

No, it does not. Some nodes are difficult to resolve, but there are well-resolved nodes all through the tree. One may need to use different data to resolve them, and one may have to analyze them differently, but there’s a lot that’s clear, far below mammals, to the base of Eukaryota at least.


(S. Joshua Swamidass) #17

LUCA is before the first node. How do you know there was not another lineage in the very distant past that eventually died out?


(John Harshman) #18

As I have already agreed, above, there is no way to know.


(David MacMillan) #19

Certainly multiple abiogeneses are possible, very early on. But any claims of “kinds” being specially created are readily falsifiable using the above method.

Notably, 99.999% (+/- 0.1%) of creationists insist on a hard break between humans and chimpanzees. Any non-arbitrary, rigorous discriminant which would place humans and chimps on a separate lineage would also introduce breaks between species which can be demonstrated to have common ancestry via interbreeding.

One of the most disappointing parts of the Ham-Nye debate was when Nye failed to adequately explain the graphic of all the various hominid skulls. The argument is that if you line up all the extant fossil hominid skulls, from most distant relatives to modern humans, creationists are unable to consistently state where the dividing line between human and ape should be placed. If there was an actual break between humans and other apes, there should be a clear clustering, but there is not, and creationist inability to agree on the break is telling testimony.

Nye utterly failed to get that point across.

EDIT:

The graphic in question:


(Bill Cole) #20

I don’t know if you have seen this before. John explained the genes not following ancestral lines by gene loss. Could a claim be made that a large loss of genes could be evidence of special creation?