Another day, another stupid creationist argument. This time, it’s some pastor whining that biologists don’t understand how animals survive the winter. We don’t?
These insects are not the only ones that hibernate – there are several others butterflies, insects, and even frog that make antifreeze in the fall and hibernate through the winter. Insects in all stages of life – eggs, pupa, and adult (CHECK THIS) – have been programmed to make various versions of antifreeze chemicals in order to survive freezing weather. How did the first Mourning Cloak butterfly learn to make anti-freeze? If it failed even once, the result was death – an evolutionary dead-end. God designed this butterfly to survive the brutal winter as an adult butterfly. The next time you see a butterfly very early in the spring – chances are it is a butterfly that knows how to make antifreeze!
How many attempts to survive the winter did the woolly bear caterpillar try? When did a certain caterpillar “get it right” and survive? Remember there had to be both male and female surviving to produce eggs and continue the species. The original Arctic woolly-bear caterpillar had to make this antifreeze so that its cells would freeze without rupturing for not just one winter…but 13 times for 13 winter freezes…always remembering to produce the antifreeze only just before winter arrived. Then it had to learn to completely rearrange its body structure to turn into a moth on the 14th spring.
How do evolutionists explain this? They don’t! The Arctic woolly-bear caterpillar, the Mourning Cloak butterfly, and a myriad of other creatures were designed to survive through the freezing winter. When you see design, there must be a Designer and that Designer is God. Those who wish to deny God’s existence see this marvelous design and say evolution did it – random mutational changes filtered by natural selection caused all this marvelous design to happen…but this is just storytelling and hand waving – it explains nothing.
Gosh, what a surprise — an ignorant creationist. Actually, we do. Winters aren’t all-or-nothing — look at a globe, and we have these things called latitudes, where we can see variation in the intensity of winters. Minnesota gets rather cold in January, while Nebraska is milder, and Texas is milder still. That means it’s trivial to find animals with a range that spreads from mild to cold environments, and that natural selection can have both variation and different selection regimes to operate. This isn’t difficult at all.
Furthermore, anti-freezes aren’t hard to generate: these are just small molecules that lower the freezing point or bind nascent ice crystals to suppress ice formation. These things evolve all the time by chance! Ask Sean Carroll.
Insects have evolved a variety of cryoprotective substances. As winter approaches, many freeze-tolerant insects produce high concentrations of glycerol and other kinds of alcohol molecules. These substances don’t prevent freezing, but they slow ice formation and allow the fluids surrounding cells to freeze in a more controlled manner while the contents of the cells remain unfrozen.
For maximum protection, some Arctic insects use a combination of such cryoprotectants and antifreezes to control ice formation, to protect cells and to prevent refreezing as they thaw. Indeed, a new kind of antifreeze was recently discovered in the Upis beetle by a team of researchers from the University of Notre Dame and the University of Alaska-Fairbanks. Unlike the protein antifreezes of other beetles, snow fleas and moths, the Upis antifreeze is a complex sugar called xylomannan that is as effective at suppressing ice growth as the most active insect protein antifreezes.
The necessity of avoiding freezing has truly been the mother of a great number of evolutionary inventions. This new finding raises the likelihood that there are more chemical tricks to discover about how insects cope with extreme cold.
Carroll has written a book, The Making of the Fittest: DNA and the Ultimate Forensic Record of Evolution, that explains in detail how the antarctic icefish antifreeze evolved. It’s a truncated pancreatic enzyme; a copy of the enzyme gene acquired a mutation that reduced it to a short 3-amino-acid long fragment (and which was subsequently expanded by duplication to multiple repeated copies) that has chemical properties that suppress ice formation. The blood of the icefish is saturated with this peptide, and it’s produced by the pancreas, just like the original enzyme, secreted into the intestine, just like the original enzyme, and then transported into the circulatory system. The genome of the icefish also contains pseudogenes, copies of original natural ‘experiments’ in the expansion of the antifreeze gene, that provide a record of its molecular history.
Meanwhile, arctic cod also carry an antifreeze protein…but it’s different and of independent origin from the one found in antarctic notothenioid fish.
So, actually, this creationist is completely wrong. Not only can we explain the evolution of antifreezes in animals, we do so in explicit detail, with step-by-step analyses of the molecular events behind them. If you want to see “storytelling and handwaving” that “explains nothing”, you’ll have to go to the loons who say “God did it.”