Epigenetics Evolution Evolutionary biology Genetics

Species: Changing Allele Frequencies?

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A new study is out here. They were studying epigenetic effects in planaria flatworms. Same planaria, three different “species”-level “heads” were regenerated.

Of course, everything must have an “evoltuion-did-it” explanation; so, for the record, here it is:

The ease with which a particular shape could be coaxed from a G. dorotocephala worm was proportional to the proximity of the target worm on the evolutionary timeline. The closer the two species were related, the easier it was to effect the change. This observation strengthens the connection to evolutionary history, suggesting that modulation of physiological circuits may be one more tool exploited by evolution to alter animal body plans.

However, there is more to mull over:

Working with Girardia dorotocephala – free-living planarian flatworms, which have remarkable regenerative capacity – researchers were able to induce the development of different species-specific head shapes by interrupting gap junctions, which are protein channels that enable cells to communicate with each other by passing electrical signals back and forth. The changes were more than skin deep; they included not only the overall shape of the head but also the shape of the brain and the distribution of the worm’s adult stem cells.

Further:

The finding that head shape is not hard-wired by the genome but can be overridden by manipulating electrical synapses in the body suggests that differences in species could be determined in part by the activity of bioelectrical networks.

The difference here between “species” is not due to “changing allele frequencies” brought about by some kind of genetic isolation, as per “neutral genetic drift,” which suggests that “alleles” are “lost” (or gained?) in the process of “speciation”.

Something completely different is going on. Something is really amiss here in evolutionary understanding.

From the pdf file:

Based on these results, we conclude that discrete, species-specific head shapes can be achieved by manipulating the connectivity of physiological networks in the planarian flatworm during head regeneration.

Something is rotten in the state of population genetics.

One Reply to “Species: Changing Allele Frequencies?

  1. 1
    bornagain says:

    related notes,

    Not in the Genes: Embryonic Electric Fields – Jonathan Wells – December 2011
    Excerpt: although the molecular components of individual sodium-potassium channels may be encoded in DNA sequences, the three-dimensional arrangement of those channels — which determines the form of the endogenous electric field — constitutes an independent source of information in the developing embryo.
    http://www.evolutionnews.org/2.....54071.html

    podcast – Jonathan Wells: Is There Biological Information Outside of the DNA?, pt. 3 – Bioelectric code
    http://intelligentdesign.podom.....5_52-07_00

    “Experiments have shown that electromagnetic fields have “morphogenetic” effects—in other words, effects that influence the form of a developing organism. In particular, some experiments have shown that the targeted disturbance of these electric fields disrupts normal development in ways that suggest the fields are controlling morphogenesis.22 Artificially applied electric fields can induce and guide cell migration. There is also evidence that direct current can affect gene expression, meaning internally generated electric fields can provide spatial coordinates that guide embryogenesis.23 Although the ion channels that generate the fields consist of proteins that may be encoded by DNA (just as microtubules consist of subunits encoded by DNA), their pattern in the membrane is not. Thus, in addition to the information in DNA that encodes morphogenetic proteins, the spatial arrangement and distribution of these ion channels influences the development of the animal.”
    Stephen Meyer on electromagnetic fields; “Darwin’s Doubt”, ch.14, ‘Epigenetic Revolution’, ‘Beyond Genes’, ‘Ion Channels and Electromagnetic Fields’.

    The (Electric) Face of a Frog – video
    https://www.youtube.com/watch?v=0VULjzX__OM

    Timelapse Video Reveals Electric Face in Embryonic Tadpole – July 2011
    Excerpt: “When a frog embryo is just developing, before it gets a face, a pattern for that face lights up on the surface of the embryo. We believe this is the first time such patterning has been reported for an entire structure, not just for a single organ. I would never have predicted anything like it. It’s a jaw dropper.”
    http://www.sciencespacerobots......ole-718111

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