In the article Humans Evolving? Armed with the Evidence, the Story Breaks Down, Eric H. Anderson goes over a new research finding regarding the median artery:
[…] Science Alert headline was more direct, both about the observation and the implications: “More Humans Are Growing an Extra Artery in Our Arms, Showing We’re Still Evolving.”
Reporting in the Journal of Anatomy, scientists in Australia had uncovered that more adults now possess a “median artery of the forearm,” contrasted with studies over the past two centuries. Specifically, based on a sample of “78 upper limbs dissected at two different Australian Universities,” the researchers analyzed whether a median artery in the forearm was present. They then compared this number to those of prior studies and concluded that “the prevalence of median arteries of forearms” since 1846 had increased from approximately 10 percent to over 30 percent. The authors calculate that if the trend continues, nearly every person born after 2100 will have a median artery.
Setting aside for a moment the small sample size (as the authors acknowledge), let’s assume that the numbers reported in this study and in prior studies back to the mid 1800s are reflective of a genuine trend in the prevalence of the forearm median artery. Let’s further assume that the researchers’ projections for the future increase of this prevalence are spot on and that everyone born after 2100 will carry a median artery. What does this demonstrate about evolution? After all, it isn’t sufficient to simply observe a biological change and then declare that, therefore, humans are “evolving.” We must look at the underlying cause to understand what is really happening.
Regulating Embryonic Development
The authors of the study acknowledge that the cause of this change is unknown, but suggest it is likely the result of a mutation in a regulatory structure. Specifically, the median artery is “an embryonic structure, which normally regresses around the 8th week of gestation.” The median artery is therefore a perfectly normal aspect of human anatomy, present during early embryonic development and then typically fading or disappearing altogether as the radial and ulnar arteries on either side of the forearm develop and take over the job.
If we pause here and consider the facts, we can already see the clear outlines of a rational fact-based answer to the question at hand. The median artery is a normal (presumably essential) part of early embryonic development. After the artery has done its job, the developing embryo shuts down the median artery as it develops the radial and ulnar arteries. This speaks clearly to regulation and control. The kinds of things that are consistent with a planned and purposeful process. Indeed, the authors recognize that a regulated system is at work: “The mechanism for the regression of the median artery is initiated and regulated by specific genes. Persistence of the median artery into adulthood indicates the failure of the expression of these genes” (emphasis added). The researchers go on to suggest that this failure of the regression process “could have resulted from alteration of or damage to genes by mutations,” or perhaps an environmental factor, such as an infection of the mother, could have disrupted the regression process.
In either case, what we have is a carefully controlled process toward a particular outcome that has been disrupted.Humans Evolving? Armed with the Evidence, the Story Breaks Down, by Eric H. Anderson
It’s not that something new is naturally arising: it’s that something is broken.
And sadly, as time goes on, more and more of our genes are going to break down.
We now have a decent handle on biotechnology, and this grip on the science will grow firmer over time. Eventually – this decade, or next century – we will be able to fight the natural (and probably accelerating!) degradation of our bodies and our genes and even of the animals and plants around us: a fight that I believe we will largely win, even before the Second Coming.
No more shall there be in it an infant who lives but a few days, or an old man who does not fill out his days, for the young man shall die a hundred years old, and the sinner a hundred years old shall be accursed.Isaiah 65:60 English Standard Version
But let’s return from future victory, to the needs of the current fight:
Darwin Devolves — Again
First, no new biological structures were observed and there is no evidence that evolution produced any new biological feature. Quite the contrary. A functional structure, necessary for early embryonic development, failed to be removed when it would normally be eliminated in the developmental process. If this counts as “evolution,” as the authors say and the eager headlines proclaim, then it certainly is not evolution as Darwin envisioned it. Evolution needs to explain (and Darwin thought he was explaining) the origin of new biological features, and eventually completely new biological forms. Observing that a pre-existing structure remains on the scene after it was supposed to depart stage left tells us nothing about the structure’s origin.
Instead, what we seem to be observing in the case of the human median artery is a breakdown of a pre-existing system and a failure of a regulatory process to proceed along its pre-programmed lines. In spite of the evolutionary narrative, breakdown of existing systems and disruption of genetic programming is precisely what we can expect from mutations. If it turns out that the persistence of the median artery into adulthood is indeed the result of mutations, then what we will have is yet another example of broken genes and a broken process — another example of loss-of-function mutations, just as Michael Behe argued in Darwin Devolves. Such de-evolutionary changes may be interesting, but they are of no comfort to the evolutionary story. Indeed, they are precisely the opposite of what evolutionary theory has to explain.
Natural Selection to the Rescue?
Second, despite suggestions in the researchers’ paper to the contrary, the persistence of the median artery can hardly be viewed as an example of natural selection acting on variations. If it is, then it seems to be exactly backwards from what the theory states. As already mentioned, potential negative implications for carpal tunnel syndrome are at hand. Additionally, the authors note the disadvantages of the persistent artery in terms of potential “thrombosis, aneurysm, calcification or traumatic rupture,” and acknowledge that “a median artery is usually considered a disadvantage when complications arise due to its presence.” Why then would natural selection aggressively select for the median artery in the course of just a few generations? The best the authors can offer for a selection advantage is that “in rare instances,” the median artery could act as a backup “emergency vessel” if damage to the radial or ulnar arteries occurs.
On balance, the authors’ own cited evidence points to an overarching disadvantage in the persistence of the median artery, suggesting (one might reasonably conclude) that there was a purpose in the first place for the regression of the artery after it had done its job in early embryonic development.Humans Evolving? Armed with the Evidence, the Story Breaks Down, by Eric H. Anderson
Christians are going to have to get to work, to fix the increasing cascade of genetic problems.
And not waste time in occult beliefs on how our bodies & genes breaking down supposedly represents a genetic improvement over the past.