The Truth About New Biological Information (Continued)

In a previous post (The Reality of Biological Information), I discussed some of the many mechanisms that allow for the production of NEW genetic information without getting into specific examples. In this post I will cite several examples of new genetic information resulting from mutations during evolution. This is a tiny fraction of the total number of such mutations that are known to have produced new information during evolutionary history.

  1. New genes that arose at the origin of vertebrates

When the first vertebrates emerged more than 500 Ma [million years ago], a great deal of new genetic information was created that allowed for many biological novelties, such as the neural crest. Recent genome-wide analyses has provided convincing evidence of two rounds of whole-genome duplication (WGD) early in vertebrate evolution. This led to the presence of 2, 3, or 4 orthologous [ similar] genes for every single invertebrate proto-ortholog. Subsequent evolution was able to utilize the abundance of genetic raw material for further diversification, which led to the emergence of several vertebrate novelties, such as a well-organized brain compartment. Please note that all of this information is based on experimental data.

Many new genes were derived from the additional copies of existing genes after the WGD events. Other genes arose de novo at the base of vertebrate evolution. The ENC gene family (involved in the formation of the vertebrate brain cortex) are among a group of genes that experienced saltatory [“sudden jump”] evolution at the emergence of vertebrates.

  1. The Globin genes

The well-known blood proteins (globins) that vertebrates use to carry oxygen, hemoglobin ( Hb), myoglobin, and cytoglobin  also trace their origins to the whole-genome duplication events in the origin of vertebrates

In the Hb gene lineage, a tandem gene duplication gave rise to the proto a- and b-globin genes, which permitted the formation of multimeric Hbs composed of unlike subunits (a2b2). The evolution of this heteromeric quaternary structure was central to the emergence of Hb as a specialized oxygen-transport protein because it provided a mechanism for cooperative oxygen-binding and allosteric regulatory control. The new composite protein eventually allowed for warm-blooded animals like birds and mammals.

  1. The gene for language: FOXP2.

The FOXP2 gene is known to play an important role in the development of speech and language. The FOXP2 protein sequence is very strongly conserved in mammalian evolution generally, but human FOXP2 differs by two amino acids from that of chimpanzees, gorillas, and macaques, all of which have identical sequences. These two differences in the human protein are due to point mutations in the seventh exon of the gene’s DNA sequence. Further genetic analysis of the gene indicates that this mutated version of the FOXP2 gene had undergone positive selection in human evolution. The genetic data suggest that this highly valuable new protein resulting from mutation occurred around the time of the appearance of modern Homo sapiens and is related to the ability to produce the orofacial movements required for speech.

  1. Other Human Specific Genes.

Researchers have found a large number of new genes that have mutated to produce new information found only in humans, and not in Neanderthals or Denisovans. These are structural genes that code for proteins and enzymes used in cells. There is an even larger group of new human genes that change the way other genes are expressed.  Some examples of new genetic information, all arising from mutations, are given below.

The primate-specific ASPM gene is related to increased brain size and/or other features of human brain. KRTH is a gene for hair keratin. In humans a single  base pair mutation leads to differences in the pattern of hair growth between humans and apes. MAOA (Monoamine oxidase A) is a critical synaptic protein that mediates nerve transmission. In humans a mutation caused a single amino acid change that led to alteration of the protein structure and binding properties. This could be involved in difference in neurological function between humans and other primates. The COX gene family, which code for mitochondria cytochrome oxidase subunits, has undergone rapid evolution in hominids. Specifically, in humans the COX5A gene allows for enhanced oxidative phosphorylation, which could support increased brain energy consumption

I do not expect any “creation scientists” to be swayed by any of this material, since their entire view of science is so distorted that it is not possible to discuss actual scientific ideas or data with them. I post this for the sake of people who have been unduly influenced by their pseudoscientific claims, in particular the constantly repeated central claim that evolution has not and cannot produce new or useful genetic information. This claim is simply false and I hope that the examples above will convince those truly seeking the truth about God’s creation to see that lie for what it is.

REFERENCES

Feiner N, Murakami Y, Breithut L, Mazan S, Meyer A, Kuraku S. Saltatory Evolution of the Ectodermal Neural Cortex Gene Family at the Vertebrate Origin. Genome Biology and Evolution. 5:1485-1502 2013

http://abc.cbi.pku.edu.cn/reference/storz-jf-mpe-2012-globin.pdf  Molecular Phylogenetics and Evolution

http://www.rawstory.com/2013/12/scientists-list-the-specific-genes-that-make-us-human/

http://genome.cshlp.org/content/15/12/1746/T3.expansion

Preuss TM. Human brain evolution: From gene discovery to phenotype discovery. Proc Natl Acad Sci U S A. 2012 Jun 26; 109(Suppl 1): 10709–10716

http://www.sciencedaily.com/releases/2011/10/111019182044.htm

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2 Responses to The Truth About New Biological Information (Continued)

  1. SheilaDeeth says:

    I wish I understood this better, but i’m glad you didn’t dumb it down for those of us who’ve forgotten more than we knew (and probably knew less than we thought we knew, and thought less than we should). I plan to reread it a few times so I’ll have better answers when I’m next asked why I “believe in” evolution, as if it were just a badly chosen fable.

  2. Almost Iowa says:

    I will never understand why creationists continue to argue science. It is a losing battle that puts their faith at risk. Why not simply say, “this is what I believe. I can not explain it – but I believe it.”

    I think we all have elements of faith that are probably wrong – it is the humility to admit that and recognize when we are wrong that makes our faith strong. Faith, like life, should evolve.

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