Evolutionists
are a curious lot. As I've engaged them over the years, it has
always been my sincere hope that I can help them see the truth. Many
times, I've raised points that are so blatantly obvious that I'm
surprised they can deny them with straight faces. Yet they do deny
them. When they deny them, it's usually through their conscious
effort; that is, evolutionists stubbornly object to reasonable points
because they are committed to their worldview and therefore will
patently reject listening to anything that might contradict it.
However, there have been a few occasions when evolutionists come so
close to seeing the truth that I think they could stumble right into it – even without my help.
I
came across an article online that talked about Darwin's
Finches.
Here is a paragraph from the article talking about speciation.
“[I]ndividual
organisms having a phenotype characteristic providing an advantage in
staying alive to successfully reproduce will pass their phenotype
traits more frequently to the next generation. Over time and
generations the traits providing reproductive advantage become more
common within the population. Darwin called this process "descent
with modification". Adaptive radiation, as observed by Charles
Darwin in Galapagos finches, is a consequence of allopatric
speciation among island populations.”
I
believe this may be the best summary of natural selection that I've
ever read from an evolutionist. The only suggestion I would make to
improve it would be to change, “descent with modification” to
“natural selection.” I could even almost live with “descent
with modification” except that the term has been too closely
identified with “evolution” for too long. Of course, the author
was quoting Darwin's description of the process so I can understand
why it's written the way it is.
Organisms
adapt to their environment. Natural selection occurs by “nature”
sifting through traits present in a population and eliminating those
which are not conducive to that environment. Eventually, all the
individuals within a population will begin to look alike and could be
called a “species.”
What
really struck me by this evolutionist is the next paragraph:
Darwin
also correctly understood that the variability allowing adaptation
already existed in the finch population, though its genetic
(genotype) reason was not yet known by science at the time. Nature
was NOT "producing" the variation within the finch
populations - it already existed. Rather, nature "selected"
from among the population variation the traits that better fostered
survival and reproduction, a process known as "natural
selection".
Wow!
This evolutionist has nailed it. Natural selection can only act
upon traits already present
in the population. In other words, natural selection can make
several species from a single kind, but it cannot create novel
features for the kind. Natural selection – at best – is only a mechanism that can rearrange already existing traits. Using one of my favorite animals, bears, as
an example, natural selection can shuffle existing bear-kind fur
color to make different combinations – like all black, all brown,
all white, black/white, and black/brown. However, natural selection
cannot add new fur colors – like green or blue.
At
last, here is an evolutionist that seems to get it. However, he
fails to grasp the obvious problem this presents for evolution. If
natural selection can only select from existing traits, the obvious
implication is that all the potential for variation must have already
been present in the ancestor. That comports well with creation; it's
the opposite of evolution.
The
theory of evolution is supposed to be a progression of simple to
complex. The supposed
common-ancestor-of-all-things did not have fur. Neither did it have
scales or feathers or even skin. It didn't have bones or blood or
organs of any kind. Evolution, therefore, requires that organisms
acquire new traits. You can't get from an amoeba to a man without
adding new features every step of the way and natural selection simply can't do that.
If
you want to promote the story of evolution as history, you need to be
talking about a mechanism besides natural selection. If I were an
evolutionist, I would be talking non-stop about trait adding
mutations. Mutation is the only
mechanism that makes evolution seem viable. However, trait adding
mutations are exceedingly rare – if any exist at all. Therefore,
evolutionists dishonestly conflate natural selection and evolution
like they are the same thing. They trumpet any example of “change”
as though it's evidence for common descent. Shame on them!
In
the end, this evolutionist, who was so close to the truth that he
could touch it, walked right by without seeing it. He went on to
say, “The
process [of natural selection] guides evolution across the entire
Tree-of Life.”
Natural
selection did not turn fins to feet nor feet to wings. It's rather
dastardly to talk about the beaks of birds and turn it into a
discussion of molecules and men.
I'm not sure what you would count as a "trait-adding mutation." There is, for example, an experiment in which a strain of Chlorella vulgaris (a single-celled eukaryote) was cultured, and then had a predator introduced into the culture. Soon, a new variant of Chlorella appeared: balls of multiple cells, which were too big for the predator to eat, and which quickly replaced the original single-celled form. This multicellular form persisted for several generations after the predator had been removed, strongly suggesting that this was a genetic variant, introduced by mutation, that was favored by an environment containing the predator. Obviously, if you need to go from single-celled organisms to multicellular ones, a multicellular colonial form is an obvious first step, and would seem to count as a "trait-adding mutation:" something has happened to the cell walls to enable them to stick together.
ReplyDeleteNow, to get something more complicated than a ball of cells, you need some way to differentiate cells. Organisms with many tissue types and organs do this with chemical gradients, which cause cells with a high level of the chemical to develop one way, while cells exposed to a lower level develop another.
Known sorts of mutations include single-nucleotide substitutions (the most common sort), duplication or deletion of one or more nucleotides (up to duplication of entire genes -- or the entire genome), translocations of segments of the genome from one locus to another, and insertions of foreign DNA (e.g. from retroviruses). Now, such mutations, in sequence, can alter any genome to any other genome (and note that there are many different pathways by which any large-scale change can take place).
So on the face of it, mutations must be able to "add traits," assuming that traits are produced or caused by genes. Now, one obvious impediment to this is that some alterations to the genome might result in an organism that is nonviable or unfit in any plausible environment. But given that, as noted, there are myriad possible strings of mutations connecting any two genomes, I think it implausible that different "kinds" are on islands in genetic space completely isolated from one another, so that an evolutionary tree connecting them is impossible.
Steven J,
ReplyDeleteYou said, “I'm not sure what you would count as a "trait-adding mutation."”
I admit it's hard to hard to objectively define the term. I talked about it on my blog before:
http://rkbentley.blogspot.com/2012/06/trait-adding-mutations-ill-show-you-why.html
You said, “There is, for example, an experiment in which a strain of Chlorella vulgaris(a single-celled eukaryote) was cultured, and then had a predator introduced into the culture. Soon, a new variant of Chlorella appeared: balls of multiple cells, which were too big for the predator to eat, and which quickly replaced the original single-celled form.”
I've been hearing your example more and more frequently so I think I'm going to add it as a 4th example to the 3 I usually hear from evolutionists. Congratulations, your team has increased the number of possible trait-adding examples by 33%!
You said, “This multicellular form persisted for several generations after the predator had been removed, strongly suggesting that this was a genetic variant, introduced by mutation, that was favored by an environment containing the predator. Obviously, if you need to go from single-celled organisms to multicellular ones, a multicellular colonial form is an obvious first step, and would seem to count as a "trait-adding mutation:" something has happened to the cell walls to enable them to stick together.
It's difficult to determine if this trait was novel to the bacteria or if already existed in their genes and merely became expressed when the predator was introduced. I strongly suspect the latter. If the experiment could be repeated, then it would almost prove the latter.
I'm going to snip the rest of your post because it will take too much space to address and I'm not interested in making this a 2 part reply. It's all a little off subject anyway. My point was that this evolutionist seems to understand that natural selection can only act upon existing traits, yet still trumpets natural selection as the process by which bacteria became biologists.
Don't you agree that the same process by which nature selects from among an existing variety of finch beaks could never add feet to fish or feathers to dinos? If natural selection cannot create new features, how can it be the process that allowed all present biodiversity (the “Tree of Life” mentioned in the article) to have descended from a single ancestor? It's painfully dishonest.
Thanks for your comments. God bless!!
RKBentley
I don't see your point about repeating the experiment. Experiments on penicillin resistance have been done many times on E. coli, and resistant bacteria (with various mutations for resistance) have arisen in experiment after experiment. In a large enough population over enough time, a given mutation can occur more than once (this is true both for beneficial mutations such as some forms of antibiotic resistance in E. coli, and harmful ones such as hemophilia in humans).
ReplyDeleteThat the behavior persisted after the need for it was removed suggests to me that it was a genetic change, albeit one that was less fit in an environment without predators (so a back-mutation that removed it was subsequently favored).
Richard Prum has studied the development of feathers in embryonic birds, comparing it to the development of scales, and identified several steps where mutations altering the development of the latter could lead through useful stages to the development of the former. The existing mix of traits in a population will, itself, change over time as mutations arise to replace variants weeded out by natural selection or genetic drift, and as the environment and the population's interactions with it change. The same applies to modifying fish fins to limbs: the intermediate stages exist in fossils, and it does not strike me as absurd that mutations could accumulate to gradually modify one state to the other.
Steven J,
ReplyDeleteYou said, “I don't see your point about repeating the experiment.”
If we repeat the experiment with different bacteria and the same thing happened, the most reasonable conclusion I would draw from it is that the trait was likely not the result of a random mutation but rather was a defense mechanism already present in the population that became expressed when the predator was introduced.
You said, “That the behavior persisted after the need for it was removed suggests to me that it was a genetic change, albeit one that was less fit in an environment without predators (so a back-mutation that removed it was subsequently favored).”
“Back-mutation”? Really? I think it's a phenomenon similar to what was seen in the peppered moth. The population began as mostly light. When soot on the trees killed the lichens, the population became mostly dark. When the soot was cleaned up, the population returned to mostly light. There was no “mutation” then “back-mutation” involved. It was natural selection acting on traits already present in the species.
You said, “Richard Prum has studied the development of feathers in embryonic birds, comparing it to the development of scales, and identified several steps where mutations altering the development of the latter could lead through useful stages to the development of the former. The existing mix of traits in a population will, itself, change over time as mutations arise to replace variants weeded out by natural selection or genetic drift, and as the environment and the population's interactions with it change. The same applies to modifying fish fins to limbs: the intermediate stages exist in fossils, and it does not strike me as absurd that mutations could accumulate to gradually modify one state to the other.”
Yes, I'm familiar with the story of evolution; I'm just a little skeptical of the “science” being used. You're telling me how it “could have happened” but, of course, we didn't see it happen. I want to OBSERVE some of these trait adding mutations happening in a population. Like I've said, if evolution has occurred, there must have been a billions-of-generations long parade of trait adding mutations. Trait adding mutations would have to occur with a fair amount of regularity. We shouldn't be able to turn on the light in a lab without seeing another example. However, after a century of scrutinizing the theory of evolution, all we have is a handful of suspect examples of and a lot of stories.
Thanks for your comments. God bless!!
RKBentley