Wednesday, October 07, 2015

The latest in my Talk to the Fossils series - Denyse O'Leary

Talk to the Fossils 3.jpg Horizontal gene transfer: Sorry, Darwin, it's not your evolution any more
Horizontal gene transfer (HGT), sometimes called lateral gene transfer (LGT), is a profound recent discovery in genetics: Genome mapping has shown that bacteria can acquire genes from the bacteria around them --that is, horizontally -- rather than from a previous generation (vertical transfer), as when a parent cell divides into two daughter cells. They can transfer multiple segments of DNA at once to fellow species members.
But that was hardly the critical finding. This is: Because bacteria are found everywhere and are comparatively simple, they can move newly acquired genes between life forms in the other domains of life. They can produce heritable changes with no recent common ancestor. …
So we are a long way from when biochemist Christian de Duve (1917-2013), grudgingly admitted the significance of horizontal gene transfer, noting that it "... has been recognized as a major complication when attempting to use molecular data to reconstruct the tree of life."
It certainly has, because where HGT is in play, there just isn't a tree of life. Even popular science writers are beginning to recognize the significance of this fact. More.
Talk to the Fossils 3.jpgEpigenetic change: Lamarck, wake up, you're wanted in the conference room!
To recap, Darwinism entails vertical transfer of genes from a common ancestor to descendants. Horizontal gene transfer means transfer of genes from one organism to another on contact, irrespective of the ancestry of either life form. HGT is a form of evolution, yes. But it drastically weakens the status of Darwinism as the "only known theory." Any Darwinian claim about evolution must first rule out HGT as a possible explanation. And, as we shall shortly see, it must rule out epigenetics as well.
Why does this historic shift in the burden of proof receive comparatively little attention? Probably it's due to the overwhelming acceptance of Darwinism as a cultural metaphor and philosophy of life. One thinks, for example, of Amazon citing "purposeful Darwinism" and taking Darwinian Theory to the max as a defense against a recent exposé of the firm's labor conditions. The concepts Amazon advances are scientifically meaningless but culturally meaningful. And culture drowns out science.
Thus, when talking to fossils (or current living forms), our challenge is to listen to what they have to say, not what the Darwinian interpreters of the fossils (and of almost everything else) have to say.
Which brings us to epigenetics. Jean-Baptiste Lamarck (1744-1829) was an early evolutionist who proposed that life forms could acquire information from their environment and pass it on in their genes. He was dismissed, when not ridiculed, by Darwinists for many decades (though not, as it happens, by Darwin). But the basic thrust of his idea has recently resurfaced in epigenetics.
There is an irony in the way the resurgence came about. A key science achievement of the 1990s was the mapping of the human genome.
Who guessed that the genome, of all things, would be, not Darwinism’s triumph, but its grave?
Talk to the Fossils 3.jpg Devolution: Getting back to the simple life
Most of the time, when we think of evolution, we mean mechanisms for the growth of complex new information. After all, entropy (the tendency for disorder to increase over time) can satisfactorily explain loss of information. Yet, in the history of life, some forms survive while -- or even by -- losing information (devolution). Their history may tell us something useful too.
We all know devolution when we see it -- a jar of pennies becomes a doorstop, a computer becomes a boat anchor, the XYZ volume of the Encyclopedia props up a too-short table leg.
But interest in devolution of life forms spiked with the recent discovery of giant viruses, which a 2014 editorial at The Scientist considered a possible fourth domain of life.
The giant mimivirus for example, unlike conventional viruses, "carries many genes thought to be unique to cellular life, suggesting that it evolved from a cell."
If so, strictly speaking, it "devolved" from a cell. More.
Devolution caused researchers to think Incorrect thoughts. Talk to the Fossils 3.jpgLife continues to ignore what evolution experts say (look, this is becoming a habit!)
Readers may well wonder about the term "mechanism" of evolution, as used here. Consistent with Michael Behe's question, "How, exactly?", it means a process observed to account for inherited change. If a bacterium is observed to absorb antibiotic resistance genes from another bacterium and pass them on during cell division, we will term that a mechanism. It is not a theory about what "must have happened" over vast tracts of time; it is an event we have witnessed, produced by causes we can identify.
But what drives the process? That is, why do living cells attempt to protect themselves in ways that rocks and rotting wood do not? As we shall see, a number of non-Darwinian biologists now focus on the way that cells have changed and do change themselves to respond to challenges in their environment -- natural genetic engineering. More.
Talk to the Fossils 3.jpg Natural genetic engineering? Natural popcorn? Or something more important?
Why does the animal want to live?
We can build machines -- we create them to do what we want -- and then put them out with the trash. But not free-living life forms. They try to survive. To deny this would require us to say, as Barham notes, that purpose is an illusion.
Part of the problem between Barham and Shapiro, which led to an exchange of views, sounds conceptual. What does Dr. Shapiro mean by "natural" processes, as opposed to "more than strictly material" ones, as above? A strictly material process would be a series of events fully explained by material processes (for example, what happens when a loose stone falls off a cliff).
But some entities in nature are not material at all: the number 7 comes to mind. Some philosophers have argued that we can construct a theory of items grouped by sevens without using a concept like 7. But whatever advantages these philosophers' suggestion may offer, it does not represent what people do. We have an immaterial concept of 7 that organizes items and events, instantiated in various media at various times. It is natural without being material in any meaningful way. More.
Talk to the Fossils 3.jpgNatural selection: Could it be the single greatest idea ever invented?
Darwin's theory of evolution (natural selection acting on random mutations) is a cultural icon, like the Big Bang, or e=mc2. One needn't know anything specific about any of these ideas. Indeed, media professionals can be passionately devoted to Darwinism without knowing anything about it at all.
That makes sense. Professed loyalty to Darwin is an admission to good parties. And Darwinism's relationship to modern warfare and eugenics is drowned out by cultural support. True, hillbillies thump the Bible against it, to the groans of the better educated. But what if...?
First, what exactly isDarwin's theory anyway, other than an invite to the approved parties?
Here it is: Information can be created without intelligence. That is, natural selection acting on random mutation explains the order of life we see all around us. What can't survive won't, and that explains how very complex life forms and structures -- including the human mind -- get built up.
True: Things that can't survive don't. But why would that fact alone drive nature to produce anything as simple as a kitten, let alone a math genius?
We've looked earlier at documented ways evolution can really happen -- if all we really want to know is how life forms can change over time. That said, I spent the last fifteen years trying to understand the cultural part. Darwinism isn't just about evolution as such. It is also a way of looking at life. It tries to explain life without assuming that there is any actual mind at all, dispensing with traditional philosophies and religions. More.
And how is that working out? Also, just out of interest, why do so many Christians support it? Talk to the Fossils 3.jpg Can sex explain evolution?
Picture a triplex: Tom, a world class cribbage addict in Apartment A, does no work and has no money (apart from social assistance and charity). Dick, in Apartment B, works eight shifts a week in trucking, so has no trouble paying his bills. Harry, formerly in Apartment C, went off and became a multimillionaire (legally) in packaging and shipping for the software industry.
Does work alone explain Harry's success? Did he work a thousand times harder and more often than Dick? Is that even possible? Or is it all an accident of fate, such that Tom or Dick might have stumbled down the same way and done the same thing?
Most human beings tend to doubt that it is so simple. Also, there are not a billion generations between Tom, Dick, and Harry. Not even one, actually.
And if each of these guys somehow ends up with fertile heirs, is any of them "unfit"?
Very well, so let us now look at Darwin's other theory, sexual selection: More.
Talk to the Fossils 3.jpg Could we all get together and evolve as a group?
No subject apart from religion has vexed Darwin's followers more than why people sacrifice themselves for others. They have embraced the ambiguous term "altruism" because it does not clearly mean "compassion" or "heroism." Rather, it is to be seen as the same natural force that causes worker ants to pass on their genes by serving their queen, who lays lots of eggs, instead of reproducing themselves (kin selection). Maybe this force creates the change we are looking for.
A champion of this proposed mechanism was evolutionary biologist E. O. Wilson.
But then Wilson dramatically abandoned kin selection in 2010 in a Nature paper, "The evolution of eusociality," co-authored with mathematicians. He argued that strict Darwinism (natural selection) "provides an exact framework for interpreting empirical observations," dispensing with the other theories he had promoted for decades. Over 140 leading biologists signed a letter to Nature, attacking the 2010 paper. Some called his new, strictly Darwin model "unscholarly," "transparently wrong," and "misguided."
What? All this is said of a Darwin-only model? More.
Read there, argue here. See the other series:  The cosmology series is here. The origin of life series is here. The human evolution series is here. The human mind series is here. Follow UD News at Twitter!


Peter Black said...

Denyse, your prodigious research and keen insights continue to amaze and provide helpful perspectives on these heady issues. Thank you for your tireless labours in teasing out the fibres in the webbing of what seems to be too glib assumptions. ~~+~~

Glynis said...

Some very interesting thoughts, including Tom, Dick and Harry and devolution. Fascinating - and sometimes confusing because of my less than capable brain - thoughts. Thanks for making me think, Denyse! (once again)

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