All the complexity that appears required for efficient adaptation begs the question, “How would early life on Earth adapt to a changing environment without complex adaptation mechanisms that supposedly evolved much later?” However, there is some evidence that life on earth has always adapted quickly. Life seems to have thrived immediately (~3.8 Ba) after the Earth’s period of heavy bombardment (~4.0 Ba), for instance. The idea that random evolution happened relatively well for 3.5 billion years and then somehow randomly upgraded itself to Evolution 2.0 sometime in the last 500 million years is absurd and a theory that I have never heard openly proposed—though it is the necessary conclusion of the Darwinian perspective of evolution.
This brings me to the main point of this post. A recent study[1] has all but proven the idea of efficient evolution, which in turn strongly implies that the ability for organisms to adapt and evolve is no accident but a designed feature of life. This study has shown that a certain fish able to breath air can adapt to moving across land in its own lifetime! This is not Darwinian evolution. There is no “survival of the fittest” in this example of adaption. You have a fish that learned to “walk” on land without any genetic changes happening.
It appears that there were some epigenetic changes in the fish, though. (Epigenetic changes are non-genetic, chemical changes in the cells that can happen because of environmental factors. Such epigenetic changes often cause genetic switches to be thrown, activating or inactivating genes.) If you’ve been following my blog, you know that I’ve suggested that epigenetic changes are likely the primary driver of macroevolution. Once epigenetic changes happen, genetic loss-of-information can happen over many generations that causes relatively permanent genetic alterations (genetic “fixing”).
For instance, when the first amphibian was evolving some 400 million years ago, it probably started moving on land simply because of new behaviors causing epigenetic changes, or vice versa. These changes would get passed on to several generations activating preexisting genes for leg bones and joints to grow. This would reinforce the behavioral changes and cause the epigenetic changes to continue to be passed on indefinitely. Over many generations, the genetic information for fish fins and gills would be discarded, leaving the all-important genes for legs and air-breathing essentially permanently activated. This would be a one-way street, for the most part, as described in the previous blog post. Evolving back to a fish would eventually be virtually impossible because of the loss of the information needed for living solely under water. (That may be partly why no marine mammals ever readapted to having gills and getting oxygen directly from the water or being cold-blooded.)
Here is what the article about this study said:
“The [bichir fish] did far more
than just survive [on land]. They became better at ‘walking’. They planted
their fins closer to their bodies, lifted their heads higher off the ground and
slipped less than fish raised in water. Even
more remarkably, their skeletons changed too. Their ‘shoulder’ bones lengthened
and developed stronger contacts with the fin bones, making the fish better at
press-ups. The bone attachments to the skull also weakened, allowing the head
to move more. These features are uncannily reminiscent of those that
occurred as our four-legged ancestors evolved from Tiktaalik-like forebears. …
We have long known that our muscles, sinews and bones adapt to cope with whatever we make them do. A growing number of biologists think this kind of plasticity may also play a key role in evolution. Instead of mutating first and adapting later, they argue, animals often adapt first and mutate later. Experiments like Standen's [fish experiment] suggest this process could even play a role in major evolutionary transitions such as fish taking to land and apes starting to walk upright. …
Plastic [non-genetic] changes occur because an environmental trigger affects a developmental pathway in some way. More of a certain hormone may be produced, or produced at a different time, or genes are switched on that normally remain inactive, and so on. The thing is, random mutations can also have similar effects. So in an environment in which a particular plastic response is crucial for survival, only mutations that reinforce this response, or at least do not impede it, can spread through a population. Eventually, the altered developmental pathway will become so firmly stabilised [sic] by a genetic scaffolding that it will occur even without the environmental trigger, making it a permanent hereditary feature.”[1] (Emphasis mine)
We have long known that our muscles, sinews and bones adapt to cope with whatever we make them do. A growing number of biologists think this kind of plasticity may also play a key role in evolution. Instead of mutating first and adapting later, they argue, animals often adapt first and mutate later. Experiments like Standen's [fish experiment] suggest this process could even play a role in major evolutionary transitions such as fish taking to land and apes starting to walk upright. …
Plastic [non-genetic] changes occur because an environmental trigger affects a developmental pathway in some way. More of a certain hormone may be produced, or produced at a different time, or genes are switched on that normally remain inactive, and so on. The thing is, random mutations can also have similar effects. So in an environment in which a particular plastic response is crucial for survival, only mutations that reinforce this response, or at least do not impede it, can spread through a population. Eventually, the altered developmental pathway will become so firmly stabilised [sic] by a genetic scaffolding that it will occur even without the environmental trigger, making it a permanent hereditary feature.”[1] (Emphasis mine)
The article does not mention epigenetic changes, but that is almost certainly
what caused skeletal changes in the fish. Regardless, there is this issue of
complexity and efficiency with the adaptation of the fish. How can the bones
change appropriately to help aid walking without any genetic changes? It seems
like magic, or as if the fish’s body somehow is aware and able to decide how it
needs to change to help the fish better thrive in its new situation. There’s
still a lot about epigenetics that is not understood, but it certainly seems
like a design feature, since it aids in survival in such a dramatic way and appears to be able to create relatively permanent changes in creatures.[2]
In the end, if epigenetics is this efficient, then it makes for the perfect efficient driver of evolution. It shouts design. It is not the work of billions of years of random evolution. If someone wants to argue that it is, I say the burden of proof is on them to show that it did in fact evolve.
In the end, if epigenetics is this efficient, then it makes for the perfect efficient driver of evolution. It shouts design. It is not the work of billions of years of random evolution. If someone wants to argue that it is, I say the burden of proof is on them to show that it did in fact evolve.
References
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