Phylogenetics of Coronaviruses


 
CoronavirusThree years into the pandemic, the origin of COVID-19 is still controversial. Two leading theories are under investigation: natural selection process or genetically engineered – each with vastly different implications. The phylogenetics of coronaviruses is the key to the COVID-19 origin dilemma and gaining insights into the theory of evolution.

Coronaviruses are RNA, not DNA viruses. RNA viruses are associated with causing the common cold, influenza,  mumps, and measles; coronaviruses in humans can cause respiratory tract infections ranging from no symptoms, mild symptoms to a cytokine storm resulting in organ failure and death in humans.

 

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Platypus Paradox Dilemma


 
Platypus (Ornithorhynchus anatinus) diving, Tasmania, Australia

The platypus puzzles naturalists and scientists alike. While its bizarre characteristics seem to defy a natural explanation, the platypus may be a classic transitional link. Like a reptile, it lays eggs, yet, it nurses with milk without nipples. As one of the least understood living mammals, and unlike any other known species, it has ten sex chromosomes. The platypus produces venom, like a reptile, and uses electroreception, like a shark – a puzzle known as the platypus paradox dilemma.

That’s not all; the list of oddities goes on. To gain an understanding of this evolution icon, scientists have long-awaited insights from its genome. This January’s journal Nature reports on the most comprehensive investigation of the platypus genome ever performed.

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Darwin’s Tree Got Tangled. What Happened?


 
Within just months of returning from a 5-year voyage on the HMS Beagle, Charles Darwin was quick to start working on a new theory in what he called his “notebooks.” The year was 1837. Etched in a leathery notebook with the letter “B” on the cover, now known as Notebook B, with Darwin’s tree diagram. Starting with “1” at the tree trunk, the twigs and branches represent relationships between species, like a family tree. Species were indicated with sequential letters; simple enough.

Scientists, however, have become increasingly skeptical of Darwin’s tree metaphor to explain how biology works. “Evolution is trickier, far more intricate, than we had realized,” David Quammen explains in his new book entitled The Tangled Tree (2018). Somehow, Darwin’s tree got tangled. What happened?

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Behavioral Evolution in the Red Fire Ant

 

The behavioral evolution in the red fire ant species with the two different types of colonies, one with a single queen and one with multiple queens, has long puzzled biologists. An invisible border seems to exist between the two. Queen ants happening to wander between colonies are quickly destroyed by the male ants. To understand what evolutionary mechanisms might be at play, molecular scientists have recently turned to the genome.

At the Queen Mary University of London, a team of biochemists led by Rodrigo Pracana (pictured below) sequenced the whole genome in both colony types to examine the genetic difference between the two types of colonies – SB and Sb. Surprisingly, rather than finding “slight, successive changes” as predicted by Charles Darwin’s theory of evolution, they discovered the two genes to be “highly divergent” from each other.

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Origin of Bioluminescence


 
JellyfishBioluminescence (pictured left) has fueled folklore legends for thousands of years. From the eight-century Japanese Hotaru firefly legend to the Apache Indian firefly origin of fire celebration, the origin of bioluminescence continues to inspire awe and wonder.

Describing myths and legends with a natural explanation is what drives scientists. “Researchers have long wondered how bioluminescence came to be,” science writer Steph Yin noted in the article “In the Deep, Clues to How Life Makes Light,” published in the Quanta Magazine.

Matthew Davis, evolution biologist at St. Cloud State University, Minnesota, investigated the origin of bioluminescence across ray-finned fishes using new genetic evidence. Published in PLoS One (2016) and entitled “Repeated and Widespread Evolution of Bioluminescence in Marine Fishes,” Davis explains –

“Our objectives in this study were to determine the number of independent evolutionary origins of bioluminescence in ray-finned fishes.”

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