Carnivores lack taste receptors for sweets - An example of mutation driven devolution
https://www.nih.gov/news-events/nih-research-matters/carnivores-lack-taste-sweets
Excerpt: "Earlier research by Dr. Gary Beauchamp of the Monell Chemical Senses Center in Philadelphia showed that domestic and wild cats showed no preference for sweet-tasting foods. More recently, he and his colleagues reported that these cats have defects in the Tas1r2 gene, which codes for a key portion of the sweet taste receptor. The scientists reasoned that this malfunctioning gene might underlie the cats' reliance on a meat-based diet and indifference to sweeter plant-based foods.
To test this theory on other meat-eating animals, the researchers sequenced Tas1r2 genes from 12 species of non-feline carnivores (order Carnivora). The study was supported by NIH's National Institute on Deafness and Other Communication Disorders (NIDCD).
To test this theory on other meat-eating animals, the researchers sequenced Tas1r2 genes from 12 species of non-feline carnivores (order Carnivora). The study was supported by NIH's National Institute on Deafness and Other Communication Disorders (NIDCD).
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| This was not the original design. |
As reported in the March 12, 2012, online edition of the Proceedings of the National Academy of Sciences, 7 of the 12 tested species had flaws in the Tas1r2 gene. They include the sea lion, fur seal, harbor seal, Asian otter, spotted hyena and 2 cat-like creatures (fossa and banded linsang). All are strict meat eaters. These species, however, have differing mutations that disrupt Tas1r2. The researchers suspect that the gene may have been damaged and lost independently as these carnivores evolved toward exclusive meat-eating diets.
The remaining 5 species—including both omnivores and exclusive meat eaters—all had intact and functional Tas1r2 genes. These species include the spectacled bear, Canadian otter, raccoon, red wolf and aardwolf.
In behavioral tests, the researchers found that the Asian otter, with defective Tas1r2, showed no preference for sweet foods. But the omnivorous spectacled bear, with intact Tas1r2, strongly preferred foods with natural sugar or even no-calorie sweeteners."
A few examples of genetic degradation. Vertebrates lacking the sweet taste receptor:
Sweet
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Sweet
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Tas1r2, Tas1r3, Tas2rs
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https://www.sciencedaily.com/releases/2012/03/120312152639.htm
Excerpt: "The current research raises questions beyond diet choice, as taste receptors have recently been identified in many organs throughout the body, including intestine, pancreas, nose, and lungs. These extra-oral taste receptors are believed to serve many different functions."
My comment: Loss of information, damaged genes, loss of receptors, malfunctioning DNA strands, mutations etc. never result in any kind of evolution. These examples are hard evidence for genetic entropy. They also tell us that earlier in the history, thousands of years ago, these animals were able to eat plant based food. But because genetic degradation is an inevitable phenomenon all over nature, they have lost that ability and turned into carnivores.
Excerpt: "The current research raises questions beyond diet choice, as taste receptors have recently been identified in many organs throughout the body, including intestine, pancreas, nose, and lungs. These extra-oral taste receptors are believed to serve many different functions."
My comment: Loss of information, damaged genes, loss of receptors, malfunctioning DNA strands, mutations etc. never result in any kind of evolution. These examples are hard evidence for genetic entropy. They also tell us that earlier in the history, thousands of years ago, these animals were able to eat plant based food. But because genetic degradation is an inevitable phenomenon all over nature, they have lost that ability and turned into carnivores.
