A truly comprehensive and unsettling book. Amoebas, protozoans, and insects capable of bringing whole nations to their knees. I'm always fascinated toA truly comprehensive and unsettling book. Amoebas, protozoans, and insects capable of bringing whole nations to their knees. I'm always fascinated to hear about the ways natural organisms find to survive and reproduce. It is difficult to keep the risks in proportion, but it is important to know about the risks of drinking unfiltered water or traveling far away places. I would rather know about the guinea worm that may be eradicated by changing human behavior. I was troubled to hear about the round worm carried by raccoons. Much to think about as you scratch that itch.
I just finished reading "Parasites: Tales of Humanity's Most Unwelcome Guests". It had lots of interesting stories like how the hook worm was imported with slaves from Africa. The hookworms crawl no more than five feet away from the bushes used as a latrine and burrow in through bare feet. It turns out that they don't have much effect on people from Africa, but caused white southerners to become anemic. You might say that the hook worm is the cause of the stereotype of "po' white trash". For hundreds of years, no one could guess the cause. You might also say that the hook worm, imported because of slavery, contributed to its downfall by weakening the troops whose job it was to defend it.
Another story was about an endosymbiont bacteria called Wolbachia that produces certain nutrients needed by nematodes to survive and reproduce. There is a terrible disease called Onchocerciasis or river blindness. A nematode roundworm called O. volvulus is transferred to humans via the bite of a blackfly in the genus Simulium, and has infected thirty-seven million people in Africa. Numerous methods have been used to eradicate this disease which is the second highest infectious cause of blindness. Merck came up with an anti-parasitic drug called ivermectin. It doesn't kill the worms, but causes temporary infertility. Unfortunately the adult worms can live for 10 to 15 years, so the treatments need to be treated annually. Not only that, the black flies can spread the disease to new hosts. Resistance to ivermectin has appeared, with some females able to reproduce a few months after treatment. It turns out that the bacteria Wolbachia spp. live inside the cells and embryos of O.volvulus and other nematodes. The human disease is actually caused by the immune response to Wobachia which are exposed when the nematode dies. One useful approach may be to go after the Wolbachia with antibiotics. So far research hasn't revealed an antibiotic that will clear Wolbachia bacteria in human cases of onchocerciasis with less than three weeks of treatment.
Another round worm, B. procyonis, is picked up from the feces of raccoons. Studies reveal that raccoon infection with B. procyonis is rare, but the following is a cautionary note implying that raccoon presence around small children should be avoided. Adult worms live in raccoon intestines and may generate a hundred thousand eggs a day. Eggs enter the environment in raccoon droppings and mature in moist soil. Raccoons defecate in communal latrines such as the tops of stumps, large horizontal branches, and fallen trees. Small animals such as mice, rabbits, and birds may forage a raccoon latrine and incidentally swallow eggs of B procyonis. In these animals, the infection is deadly. Mature eggs hatch in the intestines and the larvae migrate through tissues into the bloodstream. The majority encyst near the head. A small percentage of the larvae invade the brain causing mice to "jump, run, and spin". Infected animals may fall prey to a hungry raccoon and thus pass the larvae on. Once swallowed, larvae develop into adult worms inside the raccoon intestine.
The people who get caught in the life cycle of B. procyonis are almost invariably small children, those most likely to stumble across a raccoon latrine and transfer eggs from hands to mouths. Immediate preventive treatment with antiparasitic drugs can avert disaster, but by the time the diagnosis is made, it is usually too late. Many victims die and the remainder are left with permanent brain damage. Migrating larvae may cause a rash on the face and trunk, respiratory symptoms, and enlarged liver. The patient develops a fever, with loss of coordination, sleepiness, and irritability. The illness progresses to seizures and coma.
The tough eggs of B. proconis remain infective for years, making a contaminated lawn almost impossible to clean up.
The book is full of similar stories, including a chapter on imaginary infections, so don't get too spooked by these samples stories....more
If you like books about origins or how things got this way, you will love this book. Our ancestors spent hundreds of thousands of years in the hunterIf you like books about origins or how things got this way, you will love this book. Our ancestors spent hundreds of thousands of years in the hunter gatherer mode. Human kind were totally transformed by the introduction of agriculture during the neolithic era about 10,000 years ago. Instead of isolated bands barely holding on to existence, population took off and human society became a possibility. That possibility is eroding as population has increased exponentially during our lifetimes. ...more
I found it in my local library and was not disappointed. When "fair and balanced" counter balances the discoveries of science against the views of those with a profit motive, we are all the poorer. It saddens me that so many americans, including some cherished family members, have no idea of what goes into establishing a justified, true belief. The corporate control of our news outlets make it easy for tobacco companies and oil and coal companies to have their propaganda accepted uncritically. Progress seems hopeless, but the truth has a way of winning out. The book gives me hope and explains how these doubts are funded. Should be required reading for every one who wishes not to be duped by conmen....more
I loved this book. There were many unsettling passages, but documenting the categorization phase of our understanding of life on earth is one of the rI loved this book. There were many unsettling passages, but documenting the categorization phase of our understanding of life on earth is one of the reasons I can't get enough of natural history museums.
Something I learned from this book was that pre-Darwinian collectors tended to find one or a few examples of each species because the prevailing theory was that creation was recent, and Noah's flood was even more so. Once Darwin and Wallace presented the theory of natural selection, it was realized that variations existed from island to island and around each bend in the river, something which primitive hunters had never lost touch with.
Something I rediscovered from this book had to do with Carroll and Lear's nonsense verse. In his twenties, Alfred Wallace had spent a few years collecting butterflies and other species in South America. When he finally set sail for home, the small ship he was on caught fire. The lifeboats were in such bad shape that the cook was ordered to bring cork from the galley to help patch them. Though eventually saved, the leaky lifeboats may have inspired "The Jumblies":
"Their heads were green, and their hands were blue, and they went to sea in a sieve."
I have reconnected with that wonderful Nonesuch album!...more
I found this book to be extremely engrossing. I didn't know that John Muir was considered one of Ralph Waldo Emerson's men. The author, Donald WorsterI found this book to be extremely engrossing. I didn't know that John Muir was considered one of Ralph Waldo Emerson's men. The author, Donald Worster, has a good grasp on the delicate balance between appealing to the people to break out of the rat race to appreciate natural wonders and appealing to the powerful such as Theodore Roosevelt and the railroad magnate, Harriman. John Muir's life was an amazing force that helped establish national parks and monuments all over the western US. He was unafraid to wax poetic to inspire his countrymen to do the right thing. He was in the right place at the right time. It was lovely to read how the views of Darwin transformed his Calvanist views. It was heart breaking to see how the forces of "progress" stacked up against him in the failed attempt to keep Yosemites twin, the Hetch Hetchy valley, from falling under the developer's hammer. (Couldn't they have built that dam closer to SF?)
The book makes me want to do two things: read John Muir's first book "The Mountains of California" written in 1894. I also need to get to Yosemite to take in it's primordial beauty for myself....more