Evolution Genomics

Dinoflagellate genome structure is unique

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Ceratium hirundinella.jpg
Ceratium hirundinella, a dinoflagellate (public domain)

Or, as the title of the story puts it, “unlike any other known”.: One of the main components of plankton in the oceans, dinoflagellates can be parasites or symbionts and include bioluminescent species, photosynthetic species, and species that produce a “red tide.” The species sequenced was Symbiodinium microadriaticum, an important symbiont of corals:

While the updated genome confirms some of what has been suggested by previous work, an unusual relationship between DNA transcription and the shape and organization of their chromosomes reveals that dinoflagellates harbor some of the strangest genomes in the eukaryotic world, according to findings published April 29 in Nature Genetics.

Rather than the flexible, X-shaped chromosomes familiar to humans, dinoflagellates organize their genetic material in orderly blocks along rigid, rod-shaped chromosomes. Genes within blocks are consistently transcribed in one direction and rarely interact with others outside their immediate vicinity. This odd arrangement, the authors found, influences the three-dimensional structure of the entire chromosome.

Amanda Heidt, “Dinoflagellate Genome Structure Unlike Any Other Known” at The Scientist

The paper is open access.

So, in other words, these plankton evolved (randomly, so we are told) a highly successful genome that’s entirely different from the type that most life forms have. Well, if you are skeptical of Darwinian claims that it all happened randomly but just once, how about (at least) twice? Increasingly, Darwinism – or whatever it is that they want to call that stuff nowadays – is for true believers.

See also: Giraffe genome points to maybe four species but it is “not evolutionary”If a big survey of the giraffe genome can’t tell us the answers to the most puzzling questions about one of the most remarkable animals, where should we look for answers next?

5 Replies to “Dinoflagellate genome structure is unique

  1. 1
    paige says:

    So, in other words, these plankton evolved (randomly, so we are told) a highly successful genome that’s entirely different from the type that most life forms have.

    Maybe I am wrong, but I don’t remember anyone saying that evolution was random.

  2. 2
    polistra says:

    Interesting structure. Reminds me of pages in a ledger, where the Dr and Cr on this page interact to reach a balance without affecting other pages. Nature always got there first!

  3. 3
    pspruett says:

    Another interesting thing in the source article is this:
    “dinoflagellates may organize their genes like bacterial operons, clusters of related genes that are under the control of the same regulatory machinery and therefore expressed together. The team also identified an unusual pattern within each chromosome of ‘alternating unidirectional blocks’ of genes, the authors write in the paper. Two blocks sitting next to each other on a chromosome make up what the researchers called a domain, and genes within a domain frequently interact with one another and rarely with those in other domains.”

    Genes are often organized and regulated as operons, which are grouped together in the DNA. This means two things: multiple genes that must function together as a group, and that group is intimately located and controlled. It’s hard enough to explain where solitary new gene information came from. It’s even harder to explain how the mutations that deliver them occur in such well-organized, inter-dependent forms.

  4. 4
    pspruett says:

    Paige, perhaps you are thinking that “natural selection” is the whole of evolution. It is the mechanism that delivers the *change*, that is available to select, which is the random part.

  5. 5
    Belfast says:

    “Chance alone is at the source of every innovation, of all creation in the biosphere. Pure chance, absolutely free but blind, at the very root of the stupendous edifice of evolution: this central concept of modern biology is no longer one among other possible or even conceivable hypotheses. It is today the sole conceivable hypothesis, the only one that squares with observed and tested fact. And nothing warrants the supposition—or the hope—that on this score our position is likely ever to be revised.” Nobel Laureate, Jacques Monod.
    “Mutation merely provides the raw material of evolution; it is a random affair and takes place in all directions. … in all cases they are random in relation to evolution. Their effects are not related to the needs of the organisms; “ Julian Huxley

    Where y’been, Paige?

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