Flexible beetle brains found according to National Geographic 24 August 2015, PhysOrg 25 August 2015 and PNAS doi: 10.1073/pnas.1501272112, 24 August 2015. Dung beetles are well known for collecting pieces of animal droppings, rolling them into a ball and then rapidly and purposely rolling the ball in a straight line to their nest, where they bury the dung. To do this they have to navigate across variable terrain, so before rolling their dung ball away they climb on top of it, look around and get orientated. Previous experiments have shown that beetles get navigation clues from the position of the sun and moon, from polarised light, and even from the position of the Milky Way galaxy.
A group of scientists in Sweden and South Africa have studied the brains of beetles to see how they respond to these navigational clues. They studied two kinds of beetles – diurnal beetles that are mainly active during the daylight hours, and nocturnal beetles who mostly carry out their dung rolling activities at night. By using various experiments with mirrors they worked out that diurnal beetles used the position of the sun and moon to navigate, but the nocturnal beetles used the sun by day but switched to using the pattern of polarised light in the sky at night. Polarised light results from sun or moon light being scattered as it bumps into atoms in the atmosphere with the end result being that the light waves vibrate in only one plane.
The researchers then studied the neurones (brain cells) of the beetles under various light conditions and found that the nocturnal beetles’ brain cells responded to the position of the sun by day, but in low light conditions they switched to responding to polarised light. The brain cells of diurnal (daytime) beetles did not make this switch.
The research team wrote in their summary: “This flexible neural tuning in the nocturnal species provides a simple mechanism that allows it to use the most reliable available orientation cue”. The scientists suggested the nocturnal beetles adapted to the low light conditions by switching from relying on the sun and moon to using polarised light.
Editorial Comment: Adaptation simply means the ability to cope with changes in the environment or with changes in activity. Therefore, when the nocturnal beetles change from orientation by the sun in daylight to orientation by polarised light after it gets dark, that is an adaptation, but it has nothing to do with evolution. It only works if the necessary means to make the change already exists. The daytime dung beetles do not have the ability to use polarised light, so their brain cells don’t make the change, and they never will unless an outside creator adds the necessary information and reprograms the cells.
If any change has occurred in dung beetle brain cells it is more likely that the daytime beetles lost the ability to adapt at night, and therefore prefer to work during the day. The ‘polarising detector mode’ won’t evolve by itself in beetles that didn’t have it in the first place, since the presence of polarised light will never add anything to the beetles’ brain cells.
These studies reveal the genius of the Creator, who knew the world needed dung beetles to be at work all the time, so we wouldn’t always be putting our foot in it, so He built in the required abilities in the beetles’ brain cells. (Ref. neurology, navigation, arthropods, ecology)
Evidence News vol. 15 No.17
23 September 2015
Creation Research Australia