Whales are truly the most awe-inspiring animals of our Anthropocene age. Hunted as a source of oil for lighting, whales have, more or less, recovered from the whaling industry of the last several centuries.
Many whale species have gone extinct over the millennia. Those that have survived, Nick Pyenson argues, have evolved various characteristics that favor their survival. They have proven to be the right size to survive, neither too big nor too small. They have survived because they are one of the ocean’s greatest predators, and not picky eater. They have accommodated themselves to feeding on krill, zooplankton found on the water column. They occupy the first rung of the ocean’s food chain. Whales have stayed global – adopting migratory behavior that provides insurance against regional calamities. And whales have acquired a resiliency by evolving a “culture” within their pod.
Whales are hardly ever seen, remaining at the bottom of the ocean for long periods of time. They are able to dive to impressive depths because they can reduce the amount of oxygen in their blood by holding their breath and thereby reducing their buoyancy. Pyenson has obtained measurements of over 135 minutes without gulping any intake of oxygen.
Rather than teeth, many whale species have a substance called baleen, plates of bone on the upper jaw. Baleen is commonly found in land animals as well, forming hooves, feathers, claws, and finger nails. The fossil remains of whales suggest, however, that some of these species, at least, once had teeth.
Whales, like large land animals, elephants, for example, are characterized by what paleontologists call gigantism, greater size resulting from their global presence. This gigantism operates in much the same way that island environments have led to dwarfism.
Part of the reason that we don’t see a lot of the whales is because they were harvested for decades from the North Atlantic. Many of the whalers were from the Basque country of Spain and France. They mined right whales, bowhead whales, and other whale species they found along the Labrador Coast. The Basque whalers dominated the industry for five centuries. Remnants of that economy can still be seen in the abandoned warehouses in the Antarctic and lining the shore of salt-water habitats in the cold regions of the European continent.
There is good evidence from archeological sites that indigenous peoples have hunted these giant mammals for thousands of years. Fragments from New Zealand suggest a very old date for a whaling industry, one of the earliest industries known to humans. DNA bone fragments suggest that many different whale species were hunted.
The Anthropocene has, generally, not been kind to whales and whale populations. They were hunted down for their oil (blubber) that, when refined, was used for illumination. In the twentieth century alone some 325,000 blue whales were processed in whaling stations that lined Norwegian and other northern European shores. Fleets of factory ships once roamed the oceans in search of whales and whale-oil. Diesel-powered whalers have replaced the sailing ships of old. And they are much more efficient. The International Whaling Commission has attempted to regulate the industry with some success in reducing the numbers of whales that are harvested. But tourists can still view the remnants of this whaling industry on South Georgia and Antarctica.
Like horses, whales have grown larger and then smaller, at one time the size of a large domestic dog. Judging from their fossilized remains some extinct whale species once had four legs. During their sojourns on land, the whale’s closest relatives were the descendants of African hippos. Some whale species have transitioned from the sea and saltwater to fresh water habitats over the millennia.
Nick Pyenson explains that there are two hundred bones in a single whale skeleton, often scattered over the ocean floor, hence difficult to reconstruct. The best hunting for the fossil remains of these earlier whales is in Egypt.
Perhaps the most fascinating aspect of whale life is the whale song. Some whales use echolocation for hunting and navigation. The whale song consists of a repertoire of clicks and high-pitched sounds. The songs seem to be a unique pattern shared by “families’, or as Nick Pyenson calls them “acoustic clans.”
Whale evolution provides a fascinating example of the phenomenon of animal evolution. And the adversity caused by human interventions.