June 5, 2019 | David F. Coppedge

Mammals With Super Senses

These mammals are very different from each other except in how they put human technology to shame.

Bats

Bats have an ambulance in their ears (Virginia Tech). Echolocating bats have a challenge. They need to be able to follow moths through foliage by sound alone. While they dart through bushes and trees after their prey, bats hear reflected noise from leaves and other objects, each with their own doppler shifts. Researchers at Virginia Tech found that bats perform a trick that filters out the “bad doppler” noise from the “good doppler” of the prey.

The animals move their ears fast enough so that sound waves that impinge on the ears are transformed by the motion of the ear surfaces and shifted to higher or lower frequencies,” said Mueller. “In fact, the bat species studied (horseshoe bats and Old World Roundleaf bats) can move their ears so fast that Doppler shifts of around 350 Hz can be created. This is about seven times larger than the smallest Doppler shift the animals haven been shown to be able to detect.

So how does this ear motion actually help them on the hunt?

“The solution these two types of bats have come up with has been to tune in on the Doppler shifts that are produced by the wing beat motion of their prey,” Mueller explained. “These ‘good Doppler shifts’ serve as a unique identifying feature that sets prey apart from static distractors, such as leaves in foliage.”

By imitating this trick, the researchers believe it “could give rise to new sensory principles that could enable small, yet powerful sensors,” for instance in “drones that can operate in dense foliage or autonomous underwater vehicles navigating near complex underwater structures.”

Evolutionary theory did not help the research. The paper in PNAS says,

These species were thought to be evolutionarily tuned to Doppler shifts generated by a prey’s wing beat. Self-generated Doppler shifts from the bat’s own flight motion were, for the most part, considered a nuisance that the bats compensate for. Our findings indicate that these Doppler-based biosonar systems may be more complicated than previously thought because the animals can actively inject Doppler shifts into their input signals.

Elephants

Elephants can judge the quantity of hidden food just by using smell (New Scientist). Put two buckets of food in front of an elephant, one with more than the other. Without being able to see the food, an elephant will most often pick the bucket with more. Double-blind experiments in Thailand showed that elephant olfaction is more complicated than scientists had thought:

Elephants have more brain real estate dedicated to smell than other animals do, which may be related to the fact that their primary concerns are finding food and interacting with other elephants.

“For a lot of large mammals, especially herbivorous ones, we don’t really understand what goes into the food finding process, whether it’s quality or quantity,” says Melissa Schmitt at the University of California, Santa Barbara. “This is some of the first evidence of how elephants choose food based on quantity alone, and using olfaction.

Narwhals

Narwhals have endured a million years with low genetic diversity, and they’re thriving (Science Daily). Those arctic whales with long tooth tusks sported by the males know more about genetics than scientists. Usually, scientists consider the amount of genetic diversity as a measure of population health. Danish scientists, however, were surprised that narwhals have low genetic diversity yet are doing well. This is contrary to evolutionary expectations, says the article:

Low genetic diversity has historically been viewed as a species’ death sentence because it was thought that when members of a species have less DNA variation for natural selection to act on, they would struggle to adapt to changes in their surroundings. But this research suggests it might be more complicated than that.

“There’s this notion that in order to survive and be resilient to changes, you need to have high genetic diversity, but then you have this species that for the past million [Darwin] years has had low genetic diversity and it’s still around — and is actually relatively abundant,” says Eline Lorenzen, an associate professor and curator at the Natural History Museum of Denmark.

In each of these articles, evolutionary theory was either useless or wrong, sometimes wrong for decades. The scientists were surprised in each case, by how complicated the observations were.

Darwinism is the most useless, simplistic, and wrong theory in the history of science. Can we ditch it and move into the 21st century now?

 

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