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Problems with the Universal Genome Hypothesis

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No sooner did I post about the blog The Deeps of Time than it introduced me to a concept brand-new to me: the Universal Genome. In a nutshell, UG proposes that all animals have a large, and largely shared, genome; the differences between animal species result from different genes being expressed. Click here for a good explanation of the model, which appeared in a paper in the journal Cell Cycle in 2007.

Unlike evolution, UG really does hypothesize that complexity arose all at once — as if a Boeing 767 had appeared fully formed from a junk yard. In the case of UG, the 767 is the genome, not the phenotype (appearance). A better metaphor would be that the genome is a yard full of every kind of mechanical part one could want, and in each species only certain parts are used.

Clearly, UG fits in very well with Intelligent Design and very poorly with the theory of evolution.

Immediately two problems with this hypothesis jump out at me:

1. Life on earth does not consist solely of animals. I don't believe these genomic observations are found in other kingdoms, such as plants, nor in other domains, such as Bacteria and Archaea. Plant genomes are quite different from animal genomes in terms of what they can contain; for example, unlike animals, plants can easily accommodate many copies of large amounts of the genome, as in polyploidy (multiple copies of chromosomes). Universal genome is not a universal hypothesis if it applies only to animals, meaning some other hypothesis is necessary for other kingdoms of life.

2. Convergent evolution can explain at least some of the observations attributed to UG. For example, the paper notes that cubozoans (box jellies) have eyes that are genetically similar to the eyes of chordates, even though the last common ancestor of cubozoans and chordates did not have eyes. If this observation is true, an alternate explanation is that the eye evolved independently in both lineages from the same genes, genes that happened to be the best suited to the changes that could result in eye genes.

The observations cited in the paper in Cell Cycle hardly require the construction of a brand new theory of dubious scientific value to explain them. Good science would require searching for explanations among existing biological models first.

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