Evolving Galaxies, Beetles and Humans
CHAPTER 80 Evolutionary Potpourri
Although I plan to talk about evolution later, given my obsession with anything related to space and our universe I have to start with recently reported results from NASA's Cassini spacecraft mission on plumes observed on Saturn's moon Enceladus and Jupiter's moon Europa. Most interesting to me are the results of analyses on material Cassini "sniffed" when it dived into a plume of gas and icy material spewing from Enceladus back in October of 2015. I seem to recall knowing of the dive back then and wondering if there were instruments onboard the spacecraft that could analyze the plume. The answer, finally, is yes!
Using a mass spectrometer, the Cassini team found the plume contained almost 98 percent water, about one percent hydrogen and the rest a mix of carbon dioxide, methane and ammonia. The presence of all these compounds enhance the possibility that there's life of some sort in the ocean beneath the crust of the moon. The hydrogen is believed to form by warm water interacting with rock at the bottom of the moon's ocean. The Cassini team earlier had used its Cosmic Dust Analyzer to suggest water was reacting with rock in the ocean and now that suggestion is confirmed. I'm convinced that these moons with oceans are better targets than a manned mission to Mars if we're to find any form of life evolving in our solar system. Being 89, I won't live to see if NASA does find life there but I can imagine worms or even fishy critters swimming around in the oceans of Europa and/or Enceladus.
Speaking of life evolving, let's go back to a more fundamental question. How did our galaxies evolve? As I'm writing this paragraph, I hear the trucks coming to pick up our materials for recycling that we are required to put out every Thursday. Why mention recycling? In the December 2, 2016 issue of Science, I found an article by B. H. C. Emonts and a host of other authors on the growth of a collection of protocluster galaxies known as the Spiderweb galaxy and it turns out that recycling is involved. The astronomers are looking at the Spiderweb galaxies forming over 10 billion years ago, only 3 billion years after the Big Bang. The interesting thing they are finding is that they are observing big pools of carbon monoxide in the gases from which these early galaxies are forming. Almost all the other gas is hydrogen in one form or another. The key point is that carbon and oxygen must have been formed from exploding stars, where all the heavier elements are formed. Hence the recycling of material from even earlier stars was taking place way back then. As Carl Sagan and now Neil DeGrasse Tyson would say, we are all made of star stuff.
By the way, have you ever wondered how many galaxies there are? A news item in the November 18, 2016 issue of Science cites an estimate made by Conselice et al. in the Journal of Astrophysics of 2.0 plus or minus 0.6 trillion galaxies in the observable universe! As a scientist, I can't recall ever having seen a number with an error bar so large. Even so, if there are only 1,4 trillion galaxies, the number of galaxies is huge and the number of stars and planets must be out of sight.
OK, let's turn to evolutionary topics here on Earth, the tiny speck that it is. This past week Neil DeGrasse Tyson appeared on Stephen Colbert's show and Tyson pointed to a tiny speck in a photo Cassini had taken through Saturn's rings. Tyson took delight in noting that the speck was Earth. In the April issue of National Geographic there's a fascinating article by D. T. Max titled "Beyond Human". The article is a fascinating blend of evolutionary history and a take on what the future might look like, with humans affecting future evolution either deliberately or involuntarily on this tiny speck we call home.
The article is loaded with little icons depicting various mileposts in our own cultural and biological evolution. For example, one of the icons depicts the development of lactose tolerance, the ability to digest milk beyond infancy. This bit of evolution has been of utmost importance to me personally, having been a dedicated milk drinker my entire life. Indeed, I've been called "Uncle Milk" by some of my nieces and nephews on my wife's side. Who knows, has my consumption of about a quart of milk a day contributed to the fact that I've been reasonably healthy up until now with my 90th birthday due at the end of this year? In contrast, I was surprised to see an icon denoting arsenic tolerance. It seems that, in certain areas of Argentina, the populations have evolved a tolerance to high levels of arsenic in their groundwater. Could I have developed a similar tolerance? I did work with arsenic a good bit in my days at Bell Labs, where we often used arsenic to dope our germanium or silicon crystals.
Another interesting evolutionary item in the article was a statement that only some ten thousand years ago the humans living in Europe were still of a color not too different from their cousins in Africa; Europeans still hadn't evolved the white skin color that helps absorb the sunlight to make vitamin D. Just goes to show that the definition of race based on color is a pretty arbitrary thing.
I'm not sure where I first saw this, but an intriguing bit of evolution has occurred in the so-called rove beetle. This beetle, on twelve different occasions, has evolved to look like an army ant. In fact the resemblance is so close that the beetles actually have infiltrated army ant domiciles and enjoy eating baby ants! The beetles sometimes even march with the army ants on occasion. The New Scientist Web site has a long article on the imposters and points out this is a classic case of convergent evolution, in which different populations of a particular critter evolve along a similar path to accomplish the same goal.
Oh, I almost forgot. The most intriguing part of the Geographic article dealt with a cyborg. The author, Mr. Max, describes how in Barcelona he met a 34-year-old gentleman named Neil who was born in Belfast but raised in Spain. The odd thing about the fellow was the antenna that was attached to his skull. The fellow was born with a rare condition called achromatopsia, a condition whereby the afflicted individual cannot perceive color. Everything is in black and white. Neil is a musician and when in his teens he had the idea of trying to "see" colors through sound frequencies. So what did he do but find a surgeon and I presume others with technical expertise that resulted in the implant of a fiber optic sensor and a microchip and whatever else was need to sense the colors around him and convert these colors into different vibrations at the base of his skull!
He can now tell you the color of your sweater and says the world has opened up to him and he now feels that this new feature is more like a sixth sense than either sight or sound. Not only that, but he can "see" colors than we humans cannot. He can see infrared light from infrared lamps and he can also see ultraviolet markings on flowers that show where nectar is located. I'm assuming that bees can see these markings. This opens up the possibility that others may wish to expand their senses. Just looking around, it's clear than the younger population has evolved to a point where they are lost without a smart device in their hand. It wouldn't surprise me that in the future many or even most people would be walking around with antennas implanted on their heads with circuitry allowing them not just to see infrared or ultraviolet colors but to do away with keypads and just "think" commands or questions that could be addressed through your cyborg circuitry.
Finally, after finishing this paragraph, I plan to prepare my version of Kentucky fried dinosaur for dinner. I'm obviously trying to be cute, playing with the fact that chickens and other birds evolved from dinosaurs. However, after reading an article titled "Taking Wing" by Stephen Brusatte in the January 2017 issue of Scientific American I realize that I'm not being cute at all, just stating fact. Brusatte, a paleontologist at the University of Edinburgh in Scotland, begins the article by citing a day back in 2014 when he arrived in Jinzhou, China to meet a famed dinosaur hunter, Junchang Lu (umlaut over the u). Lu had asked Brusatte to come to China to assist him in studying a certain fossil.
Brusatte was stunned when he saw the fossil, embedded in rock, describing it as one of the most beautiful fossils he had ever seen. The fossil, about the size of a donkey, was obviously a close cousin to the Velociraptor but at the same time quite different from that dinosaur portrayed in Jurassic Park. The fossil's bones were light and hollow and it legs were long and skinny, while its body was covered with feathers, including its arms covered with feathers described as quill pens, stacked over each other forming wings. The article goes on at length discussing the evolution of birds as dinosaurs and Brusatte makes the flat out statement that birds are dinosaurs, dinosaurs that did not go extinct when that asteroid slammed into Earth. He makes the point that once those dinosaurs took flight they evolved rapidly until today there are more than ten thousand species of dinosaurs around the globe. I just looked out the window and saw a dinosaur we call a robin, a sign that spring is here!
Next column on or about June 1, hopefully. This column was posted late due to another fall by my wife and subsequent hospital stay.
Allen F. Bortrum