We Don’t Know Everything About Electric Fish

There are six different lineages of so-called “electric fish,” each of which evolved its potential independently and convergently. The most famous of these is the electric eel, though speaking of convergent evolution that species is not actually an eel. The portion of the body that produces the electric field is called the “electric organ,” and appears to be derived from muscle cells, but are quite different from each other. A recent paper in Science – “Genomic basis for the convergent evolution of electric organs” (pdf, press release) – investigating representatives of four of six lineages determined that, despite their differences, the same underlying genetic and cellular processes have been leveraged (or hijacked) in each case.

Nathaniel Jeanson has an article up today about this paper called “Darwin’s ‘Special Difficulty’ Solved?” His conclusion is, if anything, unusually weak, and it’s difficult to know what to make of it. He begins by quote-mining Darwin, a common tactic but one which the ICR doesn’t seem to often resort: Continue reading

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Convergent Evolution

A Monarch Butterfly caterpillar feedsIt’s official: ICR “news” articles are now called Creation Science Updates. Or rather “Update” – they haven’t really mastered this pluralisation thing. The first article of this brave new era is called How Some Insects Can Eat Poisonous Plants, by Brian Thomas.

The chemicals used by milkweeds (including swan plants) and similar as a poison to deter herbivorous insects are known as cardenolides. They work by blocking the sodium pumps in cell membranes, but a handful of organisms are resistant to its effects. The most famous of these is the monarch butterfly, which was already known to have a amino-acid substitution mutation (referred to as “N122H”) in the gene coding for the pump that contributed to the butterfly’s immunity. A new paper in PNASCommunity-wide convergent evolution in insect adaptation to toxic cardenolides by substitutions in the Na,K-ATPase (pdf) – takes a look at the underlying genetics of all 18 insects known to be resistant, along with a number of their relatives. Continue reading

Not Once, but Twice

For his first trick in Discovery Rewrites Plant Evolution, Brian Thomas will dredge up an old botanical discovery from 2009 which he apparently forgot to comment on at the time:

One of the first lessons in plant evolution is that algae existed for millions of years before the more complicated materials and structures necessary to convert them into woody land plants had ever evolved. This lesson sounded more feasible when evolutionists thought that algae were missing a critical land plant tissue-building chemical. But when secular scientists discovered this very material in algae from the coast of California, they invented new lessons to replace the old. Changing evolutionary lessons illustrate important origins lessons.

is that ”one of the first lessons in plant evolution” (I doubt it)? Has Brian ever conceded that any evolutionary process was ‘feasible’? (In this case he would probably have claimed that not having lignin – the chemical in question – was just one more impossible step.) For that matter, is feasibility even affected here? So many questions in this paragraph alone… Continue reading