New study: DNA requires maintenance from surrounding cell

Christianity and the progress of science
Christianity and the progress of science

My friend Bruce shared this post from Reasons to Believe about some recent research on DNA.

Naturalists like to argue that DNA somehow came into existence randomly, but it turns out that not only is DNA marvelously improbable for even the simplest living organism, but it also requires a lot of support from other areas of the cell in order to remain stable.

It says:

In 2015, three scientists won the Nobel Prize in Chemistry for decades of research into DNA—research that reinforces the idea that evolution is mythology and makes the modern evolutionary theory of abiogenesis seem more and more indefensible. It turns out that DNA is inherently unstable, and the preservation of genetic information requires a complex symbiotic relationship between the cell and DNA that is so interdependent that neither could have arisen independently of the other.

DNA (deoxyribonucleic acid) is the giant organic molecule which carries and preserves an organism’s genetic information. DNA is essential to the growth and reproduction of life-forms because precise copying and self-replication of DNA is a critical part of the process of cell division.

Tomas Lindahl, the first Nobel laureate, has demonstrated that the rate at which DNA decays should have made the development of life on Earth impossible.1 The Nobel Committee expresses this on a personal level: “you ought to have been a chemical chaos long before you even developed into a foetus.”2

So why doesn’t our genetic material disintegrate into complete chemical chaos? It is because of molecular repair mechanisms within the cell. The three Nobel laureates “mapped, at a molecular level, how cells repair damaged DNA and safeguard the genetic information.”3 They found that a multitude of molecular systems constantly monitor the genome and repair any damage.

One such mechanism discovered by Lindahl is base excision repair, which explains why our DNA doesn’t collapse. A base of a nucleotide often loses an amino group and becomes unable to form a base pair, thus breaking the DNA chain. But an enzymedetects the error, and other enzymes repair it so that the DNA can replicate properly.

Paul Modrich, the second laureate, discovered another molecular mechanism calledmismatch repair. Replication errors often occur as the DNA is copied, but Modrich found that enzymes continually detect most of these errors, and other enzymes repair them. The Nobel Committee says this “reduces the error frequency during DNA replication by about a thousandfold.”4

One further issue that DNA must contend with is mutations, caused by DNA damage due to radiation and a variety of mutagenic substances. For example, radiation might make two base pairs bind to one another incorrectly. But the third laureate, Aziz Sancar, discovered that through a mechanism called nucleotide excision repair, enzymes will cut out, remove, and replace a damaged DNA strand.

We have long known that the cell could not reproduce without DNA, but we now know that DNA would self-destruct without the cell. It is this complex symbiotic relationship between a cell and its DNA that makes the modern evolutionary theory more difficult to defend.

[…]This research shows that for abiogenesis to occur, undirected, random processes must have anticipated the inherent instability of DNA and assembled the cell with the variety of enzymes necessary to prevent the self-destruction of DNA. Additionally, the cell’s chemistry, the self-preservation instinct, and anticipatory DNA repair mechanisms must have all come together at the same instant in time within only 1 billion years; otherwise, any nascent life could not have survived. If the probability barrier to evolution seemed like climbing Mount Improbable before, it has now become climbing Mount Impossible.

Could simple single-celled life-forms emerge and evolve into more complex life? Single-celled life-forms are not so simple. For example, the genome of an aerobic hyper-thermophilic crenarchaeon (a thermophilic archaea, a type of bacteria) consists of 1.7 billion base pairs, which is almost 60 percent of the 2.9 billion base pairs in thehuman genome.5

So, not only is it fantastically improbably to 1) get the building blocks of life, and 2) build the sequence of base pairs in DNA, but 3) you also have to have supporting systems to maintain the DNA in the cell: even more specified complexity.

2 thoughts on “New study: DNA requires maintenance from surrounding cell”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s