Spying on Whales: The Past, Present and Future of Earth’s Most Awesome Creatures, by Nick Pyenson

Category: Non-Fiction;  Rating: 3 out of 5;  Tags: Whales, Biology, Fossils, Paleontology

The facts about whales are anything but dry.  Whales evolved on land 40 to 50 million years ago, starting out the size of a large dog, with four legs, teeth, a nose in the usual place (on the tip of the snout instead of on the back of the head), and perhaps fur.  Blue whales are the most massive animals ever to have lived.  That’s ever, in the history of life on the planet.  Some whales can live more than twice as long as humans do now.  They communicate in whale song, but we can’t understand what they’re saying.  We almost never see them, except when they surface to breathe.  They hunt cooperatively.  They have multi-chambered stomachs, like cows, and are most closely related to hippos (among living animals).  They have belly buttons.  More than three million whales were killed in the 20th century.

The facts and statistics don’t convey the thrill of examining not just one, but dozens of fantastically preserved, complete fossil whale skeletons in Chile, and then figuring out why numerous whales were beached in the same place at least four separate times over thousands of years.  The numbers don’t give you the ache in your back that you get from measuring fossil whale bones using ladders, forklifts, and movers’ straps.  And they don’t fill your nose with the odour of a dead whale taken apart on the deck of an Icelandic whaling boat, while you study still-mysterious parts of whale anatomy.

Nick Pyenson has given us a glimpse into his life as curator of marine mammal fossils at the Smithsonian, showing us something of what it’s like to be a paleontologist specializing in whales.  Whales and fossils are both pretty cool; a book about fossilized whales is doubly so.

Gathering Moss: A Natural and Cultural History of Mosses, by Robin Wall Kimmerer

Category: Non-Fiction;  Rating: 4 out of 5;  Tags: Moss, Nature, Biology, Environment

We walk along the forest trail in cool shade.  Suddenly, our leader stops, bending close to the surface of a boulder, and identifies several species of moss.  Who knew there were so many different kinds?  I always thought of it as just moss.  I knew there were different kinds, like Spanish moss…but wait, that’s not really a moss at all.  A member of our group asks about a lichen on a tree branch, eliciting a sniff from our leader.  “That’s not a plant,” he says.

Mosses seem so insignificant, they are easy to overlook.  Yet to those willing to take the time to get down on their knees and examine these tiny plants, they are fascinating.  With no roots or vascular system, the leaves are just one cell thick, and must be in direct contact with water to absorb moisture.  Largely adapted to cool, shaded places, they are also remarkably drought tolerant – specimens have been revived after spending 40 years in a cabinet.  Propagation in mosses varies from cloning (most mosses can generate new plants from fragments of leaves and stems) to specialized sexual reproduction.  Some varieties, like Splachnum ampullulaceum, are ridiculously specialized.  This moss only occurs in bogs,  “…in one, and only one, place in the bog.  On deer droppings.  On white-tailed deer droppings.  On white-tailed deer droppings which have lain on the peat for four weeks.  In July.”

Mosses play a significant ecological role, their miniature forests hosting a collection of critters like waterbears, springtails, rotifers, nematodes, mites and fly larvae.  Mosses act as a water reservoir, their tissues, both living and dead, absorbing the liquid when it rains and slowly releasing it when things are dry, regulating humidity and temperature and contributing to the health of the forests in which they live.  They are small plants, but have a large impact.

The Hidden Life of Trees: The Illustrated Edition, by Peter Wohlleben, Translation by Jane Billinghurst

Category: Non-Fiction;  Rating: 3 out of 5;  Tags: Biology, Environment, Forests, Nature, Trees

Lavishly illustrated with beautiful colour photographs, The Hidden Life of Trees shares the author’s love of trees and forests.  A former forester, he now runs an environmentally friendly forest and advocates for the return of large, old forests.

Forests are not simply collections of trees.  In a group, trees behave differently.  They communicate with one another through airborne chemicals, and share nutrients via interconnected root systems.  Fungi connect trees with thin, underground filaments, transmitting information from tree to tree and helping the trees absorb water and nutrients.  By sharing nutrients, trees support weaker members of the forest, providing all with protection from wind and hot sun.  Seedlings grow more slowly in a forest, where they are deprived of the light required for fast growth.  Slow growth when young helps a tree live longer, making their wood more dense and resistant to insects, fungi and wind.

The benefits of forests go beyond providing homes for animals and peaceful places for people.  Forests moderate the climate on a continental scale, as long as there are intact coastal forests and a network of forests into the interior.  They absorb CO2, and trees grow fastest when they’re old.  Old forests are healthier – the understory is cool and moist, the soil is deep and rich.

If we want the world to remain a place in which we enjoy living, we should let our forests grow large and old.

The Sixth Extinction: An Unnatural History, by Elizabeth Kolbert

There was a time when people did not know about extinctions. Before the theory of evolution, before it was understood what fossils represented, it was thought that all forms of life that ever existed still existed; they could still be found somewhere on the planet.  Eventually the fossil evidence became overwhelming, and it was recognized that many forms of life had died out.  There are no more mastodons, mammoths, saber-toothed tigers, or dinosaurs.  No more trilobites or ammonites.

Usually the process of extinction is gradual, but five times in the more than 5 billion years of Earth’s fossil record, it has been sudden, drastic, and catastrophic.  The first of these mass extinctions, at the end of the Ordovician around 444 million years ago, saw the end of about 85% of all marine species.  Most life was still confined to the ocean, so this was a huge bottleneck in the evolutionary tree.  Another, bigger bottleneck occurred at the end of the Permian, when 90% of all life died off.  The asteroid that ended the Cretaceous period 65 million years ago killed around three-quarters of all species.

The causes of these mass extinctions are varied.  Global glaciation or other climate change, (either from astronomical variations or changes in biological activity), ocean acidification, massive volcanic eruptions, and asteroid impact have all been implicated.

Kolbert makes the case that we are in the midst of the sixth great extinction in Earth’s history, and that humans are causing it.  There is a proposal before the International Commission on Stratigraphy to define the current epoch as the Anthropocene, the age of humans.  We have altered the earth at a geologically significant scale.  We have transformed a third to half of the planet’s land surface, most major rivers have been dammed or diverted, artificial fertilizer production exceeds natural fixing of nitrogen, and species numbers are in decline.  We are altering the composition of the atmosphere.  According to one study, only 22% of available land can be counted as wild, and even these wildlands are cut by pipelines, seismic lines, power lines and forest roads.  “Every wild place has, to one degree or another, been cut into and cut off.”

Usually said to have begun with the industrial revolution, the Anthropocene may have started much earlier, when early humans began spreading across the earth.  People seem to have driven to extinction the mega-fauna they encountered, killing off the large animals faster than they could reproduce.  Now, we are seeing the disappearance or endangerment of many species, including frogs, corals, and bats; tropical birds, trees and insects; and, if ocean acidification continues to increase with increased atmospheric CO2, any marine organism with a calcium carbonate shell.

After each extinction event, surviving life forms have evolved, diversified into new species.  But adaptation to new conditions takes time, and the rate of change caused by humans is unprecedented, too fast for some species, leading to a world with far less bio-diversity.  We don’t have a very good record of sustainable development.  We have a long history of entering a new area, cutting down too many trees, killing too many animals, and ruining the land for future use.  The changes we ourselves have caused may lead to our own great extinction.