Answering The Critics
Genetic Entropy Part 4: The Lenski Evolution Experiment
By Steve Hudgik
The Long Term Evolution Experiment (LTEE) has been in progress at Michigan State University since February 1988. Dr. Richard Lenski has been culturing E. coli bacteria through more than 76,000 generations (as of early 2021) and tracking genetic changes. The goal was to learn how evolution works. The long term evolution experiment is now used as one of the major proofs evolution happens. But, does it actually show that?
What Is The Long Term Evolution Experiment?
In 1988 twelve cultures of E. coli bacteria were started in the laboratory. They were cultured in a medium that provided some glucose as a food source, but the amount was limited. That put the E. coli in a stressful situation that would promote "evolution." In addition, citrate was included as a chelating agent. With the E. coli going through more than six generations per day, this was a situation in which, if true, evolution could be observed happening at a high speed. This experiement continues today having gone through over 76,000 generations. What are the results?
Random Mutations Happened and the E. Coli Changed
By the 31,500th generation one of the cultures developed the ability to metabolize citrate as an energy source. Evolution evangelists now claim this proves evolution happens. However, we need to ask a very simple question. What were they to start? (E. coli) And what are they now? (E. coli -- no change). So what happened? Change, but no evolution.
As part of the experiment samples of each culture were taken every 500 generations, frozen, and preserved. This allows scientists to go back and find the genetic changes that resulted in the ability to metabolize citrate. It turns out that E. coli has always had the ability to metabolize citrate under anaerobic conditions, meaning conditions in which oxygen is not available. In E. coli, and people like you, energy comes from combining carbon (from sugar for example) with oxygen. The chemical reaction releases energy. When oxygen is not available, the chemical reaction cannot take place, no energy is produced, and the organism will die. E. coli have the ability to detect when there is no oxygen, and flip a switch that turns on their ability to metabolize citrate, which can be used to make energy without oxygen. It is not as efficient as metabolizing sugar and oxygen, but it keeps the E. coli alive.
What happened in the long term evolution experiment is that the switch that turns on the ability to metabolize citrate broke (a simplistic, but basically accurate description) such that it was always on. In other words, the E. coli's genetic material was damaged and that damage resulted in a benefit for E. coli living in an environment that tended to run short of sugar. So the broken E. coli proliferated, out competing the normal E. coli.
Is This Evolution?
E. coli that has been damaged is not evolution. What the Long Term Evolution Experiment has demonstrated is genetic entropy. The degrading of the genome.
Other changes have been noted in the E. coli. For example, they have grown to be physically larger. It was also noticed that in some instances all twelve cultures mutated in similar ways, and in other cases they mutated in different ways. It is a fact that change in the E. coli happened. No one disputes that organisms change in response to their environment. But is that change evolution?
One of the tests done in the Long Term Evolution Experiment was to take mutated E. coli and culture it together with copies of the original bacteria (retrieved from the freezer). They were cultured in the same medium used throughout the experiment. The mutated E. coli out competed the original bacteria. The claim was then made that this demonstrates the mutated bacteria is fitter... better able to survive. Is that true?
Was There An Increase In Fitness?
By doing a comparison of E. coli, in the same unique environment as used throughout the experiment, it was demonstrated that the E. coli have adapted to that unique environment. However, it demonstrated nothing about an overall increase in fitness. There is a very simple experiment that could have, and should have been done. Culture mutated and original E. coli in a normal environment that, for example, has plenty of glucose. I have no doubt the original E. coli would win.
Does This Experiment Show Evolution Happening?
The Lenski experiment shows that organisms change. That is something we already knew and that no one disputes. The question is: Is that change evolution? For evolution to be demonstrated the E. coli has to become something that is no longer E. coli. That has not happened, even after 76,000 generations. Evolution proponents say that evolution takes much longer than we can observe, even in E. coli. That means we will not see E. coli become something other than E. Coli, but we will see change that will eventually lead to something new. Richard Dawkins famously said:
"Evolution has been observed. It’s just that it hasn’t been observed while it’s happening."
What's missing from this discussion are the answers to two questions: What are the characteristics of changes that would lead to a new type of organism (and evolution)? What is the character of the observed changes in E. coli on the molecular level? These are big questions and the answers fill entire books. For example, I recommend Dr. John Sandford's "Genetic Entropy" and Dr. Michael Behe's "Darwin Devolves."
What are the characteristics of the needed change? Biblical creations often say that change that adds information to the genome is needed. That is true, but we then need to define "information." A change that damages the genome, can add information. To be more specific, the needed change as one that results in new (novel), specified complexity. But there is still a problem.
There are pre-existing mutations that are a part of the original design of our genome. These may appear to be new information... to be novel specified complexity. However, they are not new. Adaptability has been designed into all organisms. However, you should be aware that... particularly at the level of popular articles and videos, the existence of designed mutations is often ignored by evolution proponents.
To define what is needed for evolution to be happening, we need to be able to distinguish between designed, pre-existing "mutations" and random mutations.
Evolution requires novel specific complexity. The human genome is about 1000 times bigger than that of a bacteria. It specifies the greater complexity of a human. Where did all those new instructions come from?
To achieve novel specified complexity requires more than a single mutation. Multiple mutations are required to specify a new characteristics that changes (evolves) the organism into something novel and those mutations (changes) need to occur in a specific order. For example, if you are building a house, the order might be draw plans, then built the fondation, framing, roof, sheetrock, and then paint. If you attempt to build the house in a different order, sheetrock, roof, foundation, painting, draw plans, framing... you don't get a house. And with natural selection removing anything that is not useful, if you start the house by having sheetrock delivered, it will be removed as useless before it can be used.
Notice that I included "draw plans" as a part of the house analogy. Genetics involves a control system. There is more to genetics than simply linearly reading DNA. DNA operates in four dimensions, and the same section of DNA typically has multiple functions. There is a control system that directs what the DNA is to accomplish, and when it is start and stop. That control system (in the analogy it is represented by the house plans) must be in place and fully functional.
The characteristics of evolutionary change are: multiple random mutations, that are selectable so they are preserved by natural selection, and they happen (randomly) in exactly the right order so as to create a functional additive sequence, along with other mutations creating an appropriate control system, such that novel specified complexity results.
What is seen in the Lensky long term evolutionary experiment? Mutations that have characteristics of pre-existing designed mutations (pre-programmed mutations); random mutations of the designed mutations causing distortions of those designed mutations; and random mutations that damage the genome, such as the mutation that enabled E. coli to metabolize citrate.
Bottom Line: The Lenski experiment does not demonstrate evolution happens, nor does it refute genetic entropy. What is shows are the hands of an intelligent designer creating pre-existing mutations, and the powerful forces of random mutation and natural selection driving living organisms downward in fitness.
Next: Genetic Entropy #5: Why Do We Still Have Bacteria?
Bacterial 'Evolution' Is Actually Design in Action (ICR 2012)
Bacteria Evolving in the Lab? (CMI 2008)
Can Mutations Create New Information (CMI 2011)
Evolution's Top Example Topples (ICR 2015)