Lancelet Genome Provides Answers on Evolution

Posted on June 18, 2008  Comments (1)

Lancelet genome shows how genes quadrupled during vertebrate evolution by Robert Sanders

“If you compare the 23 chromosomes of humans with the 19 chromosomes of amphioxus, you find that both genomes can be expressed in terms of 17 ancestral pieces. So, we can say with some confidence that 550 million years ago, the common ancestor of amphioxus and humans had 17 chromosomal elements.”

Each of those 17 ancestral segments was duplicated twice in the evolution of vertebrates, after which most of the routine “housekeeping” genes lost the extra copies. Those left, totaling a couple thousand genes, found new functions that, Putnam said, make us different from all other creatures.

“These few thousand genes have been retooled to make humans more elaborate than their simpler ancestors. They are involved in setting up the body plan of an animal and differentiating different parts of the animal,” he said. “The hypothesis, pretty strongly supported by this data, is that the multiplication of this particular kind of gene and differentiation into different functions was important in the formation of vertebrates as we know them.”

“The most exciting thing that the amphioxus genome does is provide excellent evidence for the idea that Ono proposed in 1970, that the human genome had undergone two rounds of whole-genome duplication with subsequent losses,”

A great example of the scientific method in action. It often isn’t a matter of developing a theory one day, testing it the next and learning the outcome the next. The process can take decades for complex matters.

Related: Opossum Genome Shows ‘Junk’ DNA is Not JunkAmazing Science: Retrovirusesposts on evolution

One Response to “Lancelet Genome Provides Answers on Evolution”

  1. Curious Cat Science Blog » Single-Celled Giant
    November 21st, 2008 @ 5:34 pm

    “I personally think now that the whole Precambrian may have been exclusively the reign of protists,” says Matz. “Our observations open up this possible way of interpreting the Precambrian fossil record.”

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