The other day I took my to-be-read list to the local library and looked up all the books that were actually currently on the shelf, and checked out the few of them. This was one of them. I had not read any of Fortey’s books before, and the closest thing I can remember reading would be Stephen Jay Gould’s Burgess Shale book – although this subject matter shows up in less concentrated form throughout popular science writing.
My expectations were of a somewhat dry recitation of a list of living fossils, but from the onset chapter on horseshoe crabs I was enthralled. There is biological and geologic nomenclature (with British spellings), but the context is pretty familiar to me, and Fortey brings in his own personal perspective and just enough human story-telling to keep the writing alive. This is NOT a textbook, although sometimes a few more diagrams would have been helpful.
After using horseshoe crabs and velvet worms to introduce the themes and concepts Fortey wants to cover, he does go through the major classifications of survivors – which corresponds nicely to a chronological pass through the history of life on Earth. He spends quite a bit of time on microbial life and its origins before the “Great Oxygenation Event” and “Snowball Earth”, and that was where I learned the most. He ends with a summary that corrects the popular misconceptions of “living fossils” and “survival of the fittest” evolution.
I recently moved from Wisconsin to South Carolina. In case you are unfamiliar, Wisconsin has a geologically very young terrain (the last glacier retreated maybe 10,000 years ago) and the plant and animal life is similarly young. However, I am now here near the South Carolina coast, where I have been exploring the inland salt marshes and tidal zones in my kayak. During the time I was reading this book, besides finding the relatively recently arrived birds (osprey, pelicans, ibis, loons, etc.) and mammals (otters, dolphins, humans, etc.), I encountered Paleozoic-survivor horseshoe crabs and Precambrian-survivor jelly fish for the first time. I see them with a better understanding than I might have.
I highly recommend this book. Fortey’s more popular book “Life: A Natural History of the First Four Billion Years of Life on Earth” is now on my to-be-read list.
Here are my chapter by chapter notes:
1 Old Horseshoes. Horseshoe crabs are not crabs, but arthropods that date from before the Permian Extinction. They are contemporaries of trilobites. They have blue copper-based blood with an amazing ability to coagulate. Recent harvesting for human medical treatments has impacted their numbers. Fortey speculates on trilobite behavior, and wonders about their blood.
2 The Search for the Velvet Worm. Velvet Worms of New Zealand seem related to Cambrian lobopods. The Burgess Shale species Hallucigenia is also related. Fossils are rare because the animals were made only of soft tissues. The newly labeled Ediacaran Era has been carved out of the late Pre-Cambrian.
3 Slimy Mounds. Fortey visits stromatolites of Shark Bay Australia. Built by blue-greens (cyanobacteria) living in colonies on the filmy surface. Prokeryotes are everywhere, but fail to compete effectively with eukeryotes where there are nutrients. Fossil stromatolites on edges of remaining continental shields. Drove the Great Oxygenation Event that enabled later complex life. Plants, Fungi, Animals. (5*)
4 Life in Hot Water. Fortey visits Yellowstone NP, discusses microbial life, survivors from the beginnings (Archaean, 3 billion years ago). Color patterns due to extreme temp sensitivity of many varieties. Life developed on oxygenless Earth. Some survived by embedding symbiotically, such as animal digestion. Three domains of life: Archaea, Bacteria, and Eukarya (which recently includes plants, fungi, animals).
5 An Inveterate Bunch. Invertebrates: Brachiopods, Mollusks, Sponges, Jellies. I did not realize that brachiopods still live (Fortey finds them in Hong Kong. They are eaten by humans.)
6 Greenery. A survey of botanical survivors. Fortey's first fossil find was lepidodendrum bark in the family's coal. Mine too. I still have it. This chapter covers lycopods, liverwort, horsetails, ginkgo, cycad, araucaria, welwitschia, DNA research causing a reorganization of classifications. Previously "related" plants are actually the result of convergent evolution from diverse branches into morphological niches.
7 Of Fishes and Hellbenders. Lamprey, Lungfish, Coelacanth. The adaptation from fish to air breathers. Sharks. Development of the jaw. Almost no amphibian diversity survived the extinctions; all current amphibians are descended from very limited stock. Tuartara not competitive with mammals, but preserved on mammal-free islands near New Zealand. Reptiles, turtles, crocodilians, snakes.
8 Heat in the Blood. Mammals and birds. Specifically, egg-laying mammals (monotremes) such as Echidna, Platypus. Also, early primates, such as tarsier. Land birds (Kiwi, Emu, etc.) have returned to flightlessness; this does not indicate they are at the root of birds. Flying birds developed simultaneously with the later dinosaurs, but survived the extinction, perhaps resembling the South American tinamou.
9 Islands, Ice. Recent (100,000 years) survivors and near-survival extinctions. Survivors more like in isolated pockets protected from competitive incursions. Islands also created by climate limits (poles) and mountain ranges. Midwife toads (ferrera) of Majorca. Homo floresiensis. Polar Bear. North American megafauna extinctions (mammoth, giant sloth) and survivors (bison, musk ox). European (auroch, bison, ibix).
10 Survivors Against the Odds. Review of the great extinction events in the Earth's history. "Living fossil" inaccurate term; survivors continue to evolve. "Survival of the fittest" inaccurate concept; more like athletic event hurdles. Survival of interdependent species in surviving habitats is important. Tendency of long-lived low-reproducing species to survive.
Epilogue. Cockroaches and Humans.
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