Does biology need the theory that all life shares a common ancestor?

Agreed! It is true that there is a direct line of descent between me (for example) and one of the “bug-like” ancestors of all modern bugs (root of the large pink branch). Your characterization of a ladder is correct in that respect.

A side note is that evolution works on the population level, so I tend to think of it as a line of descent between, e.g., the bug-like ancestral population and the human population. When considering entire populations, lines of descent become rather fuzzy because there can be varying degrees of mixing between populations before they diverge.

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@Dredge,

Where in the Bible does it say that genealogical results are prohibited from looking like a ladder.

Secondly, by “bug”, what do you mean? Do you mean a member of the Insect family? Or are you referring to a one-celled creature similar to what are called Protists?

For goodness sake, George - don’t you know what a “bug” is yet? But seriously, I meant a single-cell organism similar to what are called - what? - Protists? … yeah, ok, that sounds good.

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@Dredge

So, with bugs defined, and ladder in view, Christian Evolutionists can contentedly conclude that God created the bugs, and the ladder belongs to Three owners!

Ecclesiastes 3:18-21
18 I also said to myself, “As for humans, God tests them so that they may see that they are like the animals. 19 Surely the fate of human beings is like that of the animals; the same fate awaits them both: As one dies, so dies the other. All have the same breath[c]; humans have no advantage over animals. Everything is meaningless. 20 All go to the same place; all come from dust, and to dust all return. 21 Who knows if the human spirit rises upward and if the spirit of the animal goes down into the earth?”

God created all that is visible and invisible – even I guess the heavenly beings and they cannot create as God does. So there is even something that exists that is beyond even creation, something even more fundamental than our minds can fathom or let alone imagine.

Somehow, God made a distinction with the human race (or maybe it was somewhere in the hominid chain), perhaps it was a blessing somewhere, I don’t know. Although still “physical”, maybe by analogy consider what happens in IT. When you move to a new flat, typically the apartment/house has the wiring for internet but no service. To get the service, you typically pay some “construction fee” and at some time in the day, suddenly it works. Yet no one actually came to your place to do any “construction”, someone somewhere types in some numbers into a computer. In this respect, absolutely nothing has changed in the hardware or the software of the entire network, yet now you can use the internet whereas before you could not. If God is even beyond creation, then maybe also we are perfectly natural and indistinguishable from any other creature in “hardware” and “software” (call it “wet-ware”), yet we still differ in some very subtle way.

What is different? Well, we can have this personal relationship with God, we have this awareness of God, we have this sense that there are things right and things wrong and that they are eternal somehow. In the same chapter, the Teacher writes “He has made everything beautiful in its time. He has also set eternity in the human heart; yet[a] no one can fathom what God has done from beginning to end.” (Ecc 3:11). I think you would agree that every bit of this is true. Somehow, we are not just like dogs who look to us, we are not like cats who think we worship them, we have the capacity for a relationship with this eternal God who is the alpha and omega and the source of all being. Is there something more than existence? I would say that even from our poor understanding of this universe (or maybe multiverse) existence, yes. At least if there is this God beyond “creation” (material) and even “being” (existence).

However, we are also of this world. It seems that God also wants us to remember that we are dust, we are mortal. The bugs and ourselves come from the same dirt. However, we are not ruled by dirt, we are ruled by a sovereign God. Like dirt, we can ignore God and live like the world (like the dirt), or we can chose to have that relationship with God who is beyond “creation” and even beyond “being”. Truly, this is a far bigger God than our tiny minds can fathom. Yet even in our hopelessly vast ignorance, we still grasp that God is there somehow. Isn’t that amazing? Why should such a God so unfathomable even care about us at all?

Psalm 8
3 When I consider your heavens,
the work of your fingers,
the moon and the stars,
which you have set in place,
4 what is mankind that you are mindful of them,
human beings that you care for them?[c]
(emphasis mine)

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Correct. And of the combined 97% of the DNA that is shared between humans and chimps, ~98% of the bases are the same. When they say that DNA is shared they are saying that it is orthologous, not that it is 100% the same at every base. So let’s go back to the original sequence:

AGGTAGTCCATACTTAG AGCTAGT--ATACTTAG

Those sequences share 15 bases, with an additional 2 bases that aren’t shared. Of the 15 bases that are shared, 14 are the same.

Yes, I know – I’m one of the authors of the paper in question. (Except it’s ~99% identity, not 98%.) This has nothing to do with my point. Take two genomes, each 1000 bp in length. They are identical in a 985 bp stretch, while genome A has a unique 15 bp segment at the 5’ end while genome B has a unique 15 bp stretch at the 3’ end. To me, it’s only reasonable to say that these are two 1 kb genomes that share 98.5% of their DNA. But when we have the analogous situation with humans and chimpanzees, you appear to be saying that they share 97% of their DNA, since you offered 96% as the overall similarity.

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“sfs”?

I would also agree that they share 98.5% of the DNA.

I guess it comes down to the semantics of “shared”. I’m not sure what the actual number is, but let’s say that 90% of human genes have an ortholog in mice. Scientists might say that we share 90% of our genes with mice. Does this mean that those genes we share have 100% identity? No.

You are right in trying to separate shared DNA from sequence identity, which is what I was clumsily discussing before.

That is me.

The question is curious and I would re-phrase it as, “does the theory (or theories) of evolution need a common ancestor, going back to the beginnings of life?”

I say this is curious as I cannot find any paper on evolution that even asks this as a straightforward question - instead we are often presented with nice pictures of tree, bush, and even a forest, as descriptors of how it all has come to be what it is. This interpretive approach may enable the creation of semantics needed for an ideology (and politically) but has little scientific credulity - we shift from assumptions, to it must be right, to you come up with a better explanation. I asked before, if anyone can show a direct connection between the genotype (and all such similarity in DNA) and the phenotype (the species we observe) and I have yet to find a straightforward answer. Yet it all seems so straightforward and perhaps simple as a % figure, some scheme, and presto, by some type of magic, we have a proven answer to one of the most complex and difficult questions in science.

I understand that many are averse to considering ToE within the philosophy of science, but insights from this can be instructive to scientists who value science. One comment is from Fuller, and I provide the bulk of his abstract on this subject:

"…a reflection on the shift in the role of philosophers
vis-à-vis scientists from ‘philosophers of science’ to ‘philosophers for science’,
what I have called the ‘underlabourer syndrome’. One consequence of this
syndrome in the case of Neo-Darwinism is that the theory has become rife with
internal interpretive tensions, which philosophers have tolerated by loosening
their own criteria for a good scientific theory. This shift in philosophical
standards probably reflects the strong cultural standing of Neo-Darwinism.
Intelligent design theory, in its quest to achieve intellectual respectability as an
opponent to Neo-Darwinism, has somewhat mimicked its opponent by adopting
a conception of ‘intelligent designer’ just as open as that of the Neo-Darwinist
conception of ‘evolution’."

[quote=“GJDS, post:241, topic:35756”]
I say this is curious as I cannot find any paper on evolution that even asks this as a straightforward question - [/quote] Why would anyone ask such a question? Can you show me chemistry paper in which someone asks a question like, “does theory X need assumption Y”?

Do you realize that the trees from sequence data are mathematical descriptions of the evidence? You keep pretending that there’s no math in biology, but you’re pretending the the product of the math is a mere assumption.

Again, for sequence data, the trees are not mere interpretations. Do you understand the math underlying these analyses?

[quote] I asked before, if anyone can show a direct connection between the genotype (and all such similarity in DNA) and the phenotype (the species we observe) and I have yet to find a straightforward answer.
[/quote]It’s not a straightforward question, as “genotype” and “phenotype” do not have the definitions you followed each with in parentheses.

Perhaps you’d be less frustrated if you used terms as they are actually used in the literature of those scientific fields?

Steve Fuller sure doesn’t know the basics:

“‘Anything new in science comes when scientific work comes up with something new, and this is unpredictable. At the time that Linus Pauling gambled that the genetic material would be a protein, he knew that it was a gamble and that experimental work would decide it.’ But your own example shows that Pauling DID predict correctly, and there’s nothing mysterious about that, since he made an educated guess about where the relevant science was going.”
http://www.michaelberube.com/index.php/weblog/comments/783/
Scroll down to comment #60.

Of course, this is unintentionally hilarious because Pauling was wrong–the genetic material isn’t protein.

This discussion stems from the question “all life shares a common ancestor”. You have gone of in a tangent - the papers I have seen (all by biology evolutionists) argue on flimsy data on how they think life began (no chemist can believe this), and than from that I have seen “roots” (a tree like structure with numerous roots indicating some of multiplicity of beginnings), which than becomes some of the schemes you seem to refer. No amount of maths can possibly provide a rigorous treatment of such an outlook.

You claim that analysis of the genome provides conclusive proof of, for example, of the (cousin for want of a better term) between a chimp and a human - each of these are described in the literature as “phenotype”. Now I find some remarks extraordinary (since this is central to arguments on common ancestry), that a 98.5% similarity cannot lead to a similar result for the two “phenotypes”. Perhaps there is much more to this than the schemes proposed?

Before we go on a wild exertion into what you think you know and all that you think I may fail to understand, let me close this exchange by referring to the question posed for this thread - does biology need the theory …?

When I first read this pleading in Benkirk’s posting, my immediate assumption is that it was another sophistic question by some recently arrived antagonist. I was very surprised that a question like this is being raised by a veteran of these pages.

I think veterans and newcomers will benefit quite a bit by dipping into the discipline of “Comparative Genomics”!

Behold this concise summary - - and be amazed. It is the answer to the question in another thread, how does Evolutionary theory help medicine …how does Evolutionary theory help science?

"Similarity of related genomes is the basis of comparative genomics. If two creatures have a recent common ancestor, the differences between the two species genomes are evolved from the ancestors’ genome. The closer the relationship between two organisms, the higher the similarities between their genomes. If there is close relationship between them, then their genome will display a linear behaviour (synteny), namely some or all of the genetic sequences are conserved. Thus, the genome sequences can be used to identify gene function, by analyzing their homology (sequence similarity) to genes of known function."

“Comparative genomics exploits both similarities and differences in the proteins, RNA, and regulatory regions of different organisms to infer how selection has acted upon these elements. Those elements that are responsible for similarities between different species should be conserved through time (stabilizing selection)…”

“… while those elements responsible for differences among species should be divergent (positive selection).”

“… Finally, those elements that are unimportant to the evolutionary success of the organism will be unconserved (selection is neutral).”

“One of the important goals of the field is the identification of the mechanisms of eukaryotic genome evolution. It is however often complicated by the multiplicity of events that have taken place throughout the history of individual lineages, leaving only distorted and superimposed traces in the genome of each living organism.”

" For this reason comparative genomics studies of small model organisms (for example the model Caenorhabditis elegans and closely related Caenorhabditis briggsae) are of great importance to advance our understanding of general mechanisms of evolution."
Sources:
Stein, L.D.; et al. (2003). “The genome sequence of Caenorhabditis briggsae: a platform for comparative genomics”. PLoS Biology. 1 (2): E45. doi:10.1371/journal.pbio.0000045. PMC 261899 Freely accessible. PMID 14624247. open access publication – free to read : The Genome Sequence of Caenorhabditis briggsae: A Platform for Comparative Genomics - PMC

“Newly Sequenced Worm a Boon for Worm Biologists”. PLoS Biology. 1 (2): e4–e4. 2003. doi:10.1371/journal.pbio.0000044. : The Genome Sequence of Caenorhabditis briggsae: A Platform for Comparative Genomics

As to the original question, one might imagine that there is not a lot of difference in phenotype differences visible in 8 closely related taxa of bacteria. So what does a comparison of the 8 genomes look like? Are they virtually identical? Ha!

Take a look at a “benchmark” comparison for 8 single celled organisms that are known to be closely related:

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If a Lion and Tiger (very different looking felines) can be more closely related than leopards vs. leopard-like cats in the Asian groupings, is there any point in expecting a consistent relationship between phenotype and genotype? To find a consistent relationship, genes have to be correlated to “phenotypes” at virtually the organ or even cellular level ! - - rather than the more noticeable differences in size, shape and feeding patterns.
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I guess I asked for it - show us how evolution has “helped” medicine - and btw evolution is a theory of one of the natural sciences, and not the helper of science.

@GJDS

And why would a scientist of your caliber consider these two aspects to be mutually exclusive?
From one George to another George, sometimes baby steps are necessary.

We have readers in this audience who don’t consider Evolution a science at all. And they refuse to believe Evolution could ever be considered a science if nobody shows them how Evolutionary concepts help us understand how sections of a genome function (for making medicines, as well as for determining the history of a group of related life forms).

Sincerely,

The Other George

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I think the staff at Biologos are capable and I do not comment on this site to be pro-, or anti-biologos. My interest is to encourage Christians to see the harmony between well established science and faith. Within this context I believe that speculation and a waring mentality that seems to be almost unique to evolution has bedevilled evangelicals and related sections of Christianity. I cannot see how such a crude semantic theory could have such an impact - it is just not that important. The best outlook I can suggest is to regard it as a theory that is inadequate, and to wait for a significant progress in biology - at that time we may have serious science(ToE)-faith discussions.

Anyone want to take a stab at translating the First George’s statement? I have no idea what he is trying to say:

“I believe that speculation and a waring mentality that seems to be almost unique to evolution has bedevilled evangelicals and related sections of Christianity. I cannot see how such a crude semantic theory could have such an impact - it is just not that important.”

But I do agree with him that evangelicals do seem bedeviled. Nothing could be simpler than acknowledging that a six day creation was an allegory to support the 7th day Sabbath (day of rest) - - a Sabbath covenant which is apparently no longer necessary since the eternal covenant for the Sabbath has been replaced by covenant with Jesus.

[quote=“GJDS, post:243, topic:35756”]
This discussion stems from the question “all life shares a common ancestor”.[/quote]

That would be a hypothesis, and biology doesn’t need it, to address the title. There’s clearly a common ancestor for all of the organisms that evolution deniers care about; before that, there could have been multiple origins.

You may have seen them, but nothing you write suggests that you read them.

If that’s the case, you’d cite such papers, but you never do. Why is that?

Again, you keep making claims about what’s in the literature, but you never cite any. Why is that?

And I don’t. So where does that leave us? Why wouldn’t you quote and cite these alleged remarks instead of making vague accusations?

Your bluster is the same this year and last year - I have seen your posts for about 2 years, and if you displayed a fraction of the attention you seek from others, you would know that I sited many papers - your manners remain as boorish as ever.

I agree with you that @benkirk could have and should have phrased his response more congenially.

I agree with the substance of @benkirk’s concern, though. I have not read widely in litetature, but I have the impression that what it says, on the one hand, and what you say it says, on the other, are not in agreement. So I would be interested in which specific sources you have in mind. Perhaps your reading has lagged behind a bit and missed some important developments? I know you are very busy with the chemistry work that God has called you to, so it would be no crime to have missed something.

Grace and peace,
Chris

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