Tag Archives: Darwinism

Polemics

Are endogenous virus genes evidence for common descent?

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Investigation in progress
Investigation in progress

This is a guest post by JoeCoder.

It’s often argued that when two or more organisms share viral genes in the same place, it is evidence those organisms evolved from a common ancestor.  Wikipedia’s Evidence for Common Descent page frames it as follows:

Endogenous retroviruses (or ERVs) are remnant sequences in the genome left from ancient viral infections in an organism. The retroviruses (or virogenes) are always passed on to the next generation of that organism that received the infection. This leaves the virogene left in the genome. Because this event is rare and random, finding identical chromosomal positions of a virogene in two different species suggests common ancestry.

This argument presupposes that the viruses inserted themselves into genomes randomly and stick around as junk DNA baggage, rather than genomes originally being designed with viral-like genes that perform useful functions.  However this argument has unraveled as we’ve discovered useful functions for many viral-like genes, including functions that specifically require a viral-like sequence.  Some examples among many:

  1. ERV sequences protect against viral infection through interference–a matching-but-opposite strand of RNA is created to bind to and disable RNA from a virus.
  2. Likewise, ERV’s seem to function “during embryo implantation to help prevent immune recognition by the mother’s immune system”
  3. In worms, an ERV has been observed to create actual viruses that transfer DNA from somatic cells (skin/brain/heart/etc.) to germline (sperm/egg) cells whenever the worm is exposed to too much heat, allowing them to rewrite their own DNA for future generations.
  4. Viral envelopes from ERV transcripts attach to cell membranes in the placenta and causes them to fuse as a normal part of development: “The HERV-W [a human ERV] envelope glycoprotein named syncytin 1 is expressed in all trophoblastic [part of the placenta] cells and directly involved in human trophoblast fusion and differentiation [cells taking on specialized roles]”

These aren’t isolated cases of function.   Phys.org interviewed one researcher:  “When we investigated public data from embryonic cells, we found that many RNAs originated from regions in the human genome that are ERVs.  We did not only observe isolated events, but systematic activation of these ERVs. Every cell type showed transcription of specific classes, something that is very unlikely to occur by chance”.

Those cases all involve RNA viruses and that’s old news.  But two weeks ago, a single-celled eukaryote called Cafeteria roenbergensis was found to harbor maviruses within its own DNA that remain dormant until it is attacked by a large virus known as CroV.  When this happens the maviruses activate to form an attack fleet, as NewScientist reports:

A voracious marine predator plagued by a giant virus has a defence system we’ve never seen before – it fights back by making its very own virus… Rather than waiting for maviruses to arrive by chance when CroVs attack, it actually carries the genes that code for mavirus inside its own genome.  These genes are usually dormant, but they get turned on when Cafeteria is invaded by CroV. “It acts as an inducible antiviral defence system,” write Fischer and his colleague Thomas Hackl in a new preprint paper.

This process kills the Cafeteria roenbergensis cell, but is useful in defending other members of its own species.  In this experiment maviruses were deliberately inserted into the Cafeteria roenbergensis genome (see the original paper), but more interestingly, sequences similar to the Cafeteria roenbergensis viral genes have been found in a wide range of animals:

A wide range of animals, from sea anemones to crocodiles, harbour genetic elements called Maverick transposons that closely resemble the mavirus genes. It’s possible that some of these organisms can also unleash viruses that attack giant viruses.

In spite of this, New Scientist still argues “our genomes are littered with the mutant remains of viruses and genetic parasites.”  But these discoveries reveal this as a rapidly-shrinking argument of the gaps. 

Save this for the next time someone insists that viral genes are useless junk DNA and therefore evidence of common descent.

Videos

Stephen C. Meyer lectures on intelligent design and the origin of life

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Christianity and the progress of science
Christianity and the progress of science

A MUST-SEE lecture based on Dr. Stephen C. Meyer’s book “Signature in the Cell“.

You can get an MP3 of the lecture here. (30 MB)

I highly recommend watching the lecture, and looking at the slides. The quality of the video and the content is first class. There is some Q&A (9 minutes) at the end of the lecture.

Topics:

  • intelligent design is concerned with measuring the information-creating capabilities of natural forces like mutation and selection
  • Darwinists think that random mutations and natural selection can explain the origin and diversification of living systems
  • Darwinian mechanisms are capable of explaining small-scale adaptive changes within types of organisms
  • but there is skepticism, even among naturalists, that Darwinian mechanisms can explain the origin of animal designs
  • even if you concede that Darwinism can account for all of the basic animal body plans, there is still the problem of life’s origin
  • can Darwinian mechanisms explain the origin of the first life? Is there a good naturalistic hypothesis to explain it?
  • there are at least two places in the history of life where new information is needed: origin of life, and Cambrian explosion
  • overview of the structure of DNA and protein synthesis (he has helpful pictures and he uses the snap lock blocks, too)
  • the DNA molecule is composed of a sequence of bases that code for proteins, and the sequence is carefully selected to have biological function
  • meaningful sequences of things like computer code, English sentences, etc. require an adequate cause
  • it is very hard to arrive at a meaningful sequence of a non-trivial length by randomly picking symbols/letters
  • although any random sequence of letters is improbable, the vast majority of sequences are gibberish/non-compiling code
  • similarly, most random sequences of amino acids are lab-proven (Doug Axe’s work) to be non-functional gibberish
  • the research showing this was conducted at Cambridge University and published in the Journal of Molecular Biology
  • so, random mutation cannot explain the origin of the first living cell
  • however, even natural selection coupled with random mutation cannot explain the first living cell
  • there must already be replication in order for mutation and selection to work, so they can’t explain the first replicator
  • but the origin of life is the origin of the first replicator – there is no replication prior to the first replicator
  • the information in the first replicator cannot be explained by law, such as by chemical bonding affinities
  • the amino acids are attached like magnetic letters on a refrigerator
  • the magnetic force sticks the letters ON the fridge, but they don’t determine the specific sequence of the letters
  • if laws did determine the sequence of letters, then the sequences would be repetitive
  • the three materialist explanations – chance alone, chance and law, law alone – are not adequate to explain the effect
  • the best explanation is that an intelligent cause is responsible for the biological explanation in the first replicator
  • we know that intelligent causes can produce functional sequences of information, e.g. – English, Java code
  • the structure and design of DNA matches up nicely with the design patterns used by software engineers (like WK!)

There are some very good tips in this lecture so that you will be able to explain intelligent design to others in simple ways, using everyday household items and children’s toys to symbolize the amino acids, proteins, sugar phosphate backbones, etc.

Proteins are constructed from a sequence of amino acids:

A sequence of amino acids forming a protein
A sequence of amino acids forming a protein

Proteins sticking onto the double helix structure of DNA:

Some proteins sticking onto the sugar phosphate backbone
Some proteins sticking onto the sugar phosphate backbone

I highly, highly recommend this lecture. You will be delighted and you will learn something.

Here is an article that gives a general overview of how intelligent design challenges. If you want to read something more detailed about the material that he is covering in the lecture above related to the origin of life, there is a pretty good article here.

There is a good breakdown of some of the slides with helpful flow charts here on Uncommon Descent.

Positive arguments for Christian theism

Polemics

Mark D. Linville: does Darwinian evolution make morality rational?

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A conflict of worldviews
A conflict of worldviews

Have you ever heard an atheist tell you that naturalistic evolution is an answer to the moral argument? I have. And I found a good reply to this challenge in the book “Contending With Christianity’s Critics“. The chapter that responds to the challenge is authored by Dr. Mark D. Linville. It is only 13 pages long. I have a link to the PDF at the bottom of this post.

First, a bit about the author:

Blog: The Tavern at the End of the World
Current positions:

  • PhD Research Fellow
  • Tutoring Fellow in Philosophy

Education:

  • PhD in Philosophy with a minor in South Asian Studies and a specialization in Philosophy of Religion, University of Wisconsin-Madison
  • MA in Philosophy, University of Wisconsin-Madison
  • MA in Philosophy of Religion, Trinity Evangelical Divinity School
  • MA in Theology, Cincinnati Christian Seminary
  • BA in Biblical Studies, Florida Christian College

Here is his thesis of the essay:

Darwin’s account of the origins of human morality is at once elegant, ingenious, and, I shall argue, woefully inadequate. In particular, that account, on its standard interpretation, does not explain morality, but, rather, explains it away . We learn from Darwin not how there could be objective moral facts, but how we could have come to believe—perhaps erroneously—that there are.

Further, the naturalist, who does not believe that there is such a personal being as God, is in principle committed to Darwinism, including a Darwinian account of the basic contours of human moral psychology. I’ll use the term evolutionary naturalism to refer to this combination of naturalism and Darwinism. And so the naturalist is saddled with a view that explains morality away. Whatever reason we have for believing in moral facts is also a reason for thinking naturalism is false. I conclude the essay with a brief account of a theistic conception of morality, and argue that the theist is in a better position to affirm the objectivity of morality.

And here’s a sample to get your attention:

But even if we are assured that a “normal” person will be prompted by the social instincts and that those instincts are typically flanked and reinforced by a set of moral emotions, we still do not have a truly normative account of moral obligation. There is nothing in Darwin’s own account to indicate that the ensuing sense of guilt—a guilty feeling—is indicative of actual moral guilt resulting from the violation of an objective moral law. The revenge taken by one’s own conscience amounts to a sort of second-order propensity to feel a certain way given one’s past relation to conflicting first-order propensities (e.g., the father’s impulse to save his child versus his impulse to save himself). Unless we import normative considerations from some other source, it seems that, whether it is a first or second-order inclination,one’s being prompted by it is more readily understood as a descriptive feature of one’s own psychology than material for a normative assessment of one’s behavior or character. And, assuming that there is anything to this observation, an ascent into even higher levels of propensities (“I feel guilty for not having felt guilty for not being remorseful over not obeying my social instincts…”) introduces nothing of normative import. Suppose you encounter a man who neither feels the pull of social, paternal or familial instincts nor is in the least bit concerned over his apparent lack of conscience. What, from a strictly Darwinian perspective, can one say to him that is of any serious moral import? “You are not moved to action by the impulses that move most of us.” Right. So?

The problem afflicts contemporary construals of an evolutionary account of human morality. Consider Michael Shermer’s explanation for the evolution of a moral sense—the “science of good and evil.” He explains,

By a moral sense, I mean a moral feeling or emotion generated by actions. For example, positive emotions such as righteousness and pride are experienced as the psychological feeling of doing “good.” These moral emotions likely evolved out of behaviors that were reinforced as being good either for the individual or for the group.2

Shermer goes on to compare such moral emotions to other emotions and sensations that are universally experienced, such as hunger and the sexual urge. He then addresses the question of moral motivation.

In this evolutionary theory of morality, asking “Why should we be moral?” is like asking “Why should we be hungry?” or “Why should we be horny?” For that matter, we could ask, “Why should we be jealous?” or “Why should we fall in love?” The answer is that it is as much a part of human nature to be moral as it is to be hungry, horny, jealous, and in love.3

Thus, according to Shermer, given an evolutionary account, such a question is simply a non-starter. Moral motivation is a given as it is wired in as one of our basic drives. Of course, one might point out that Shermer’s “moral emotions” often do need encouragement in a way that, say, “horniness,” does not. More importantly, Shermer apparently fails to notice that if asking “Why should I be moral?” is like asking, “Why should I be horny?” then asserting, “You ought to be moral” is like asserting, “You ought to be horny.” As goes the interrogative, so goes the imperative. But if the latter seems out of place, then, on Shermer’s view, so is the former.

One might thus observe that if morality is anything at all, it is irreducibly normative in nature. But the Darwinian account winds up reducing morality to descriptive features of human psychology. Like the libido, either the moral sense is present and active or it is not. If it is, then we might expect one to behave accordingly. If not, why, then, as a famous blues man once put it, “the boogie woogie just ain’t in me.” And so the resulting “morality” is that in name only.

In light of such considerations, it is tempting to conclude with C. S. Lewis that, if the naturalist remembered his philosophy out of school, he would recognize that any claim to the effect that “I ought” is on a par with “I itch,” in that it is nothing more than a descriptive piece of autobiography with no essential reference to any actual obligations.

When it comes to morality, we are not interested in mere descriptions of behavior. We want to know about prescriptions of behavior, and whether why we should care about following those prescriptions. We are interested in what grounds our sense of moral obligation in reality. What underwrites our sense of moral obligation? If it is just rooted in feelings, then why should we obey our moral sense when obeying it goes against out self-interest? Feelings are subjective things, and doing the right thing in a real objective state of affairs requires more than just feelings. There has to be a real objective state of affairs that makes it rational for us to do the right thing, even when the right thing is against our own self-interest. That’s what morality is – objective moral obligations overriding subjective feelings. I wouldn’t trust someone to be moral if it were just based on their feelings.

The PDF is right here for downloading, with the permission of the author.