Cumberland Times-News

March 29, 2014

Which species is truly the most successful?

Bob Doyle, Columnist
Cumberland Times-News

— When the question of success is raised, most of us think of lavish homes, sports arenas, cars or stocks owned.

But if we consider all of nature, the number of individuals or their total mass should be considered. Our species (Homo Sapiens) is having problems (especially in the developing countries) in securing clean drinking water and food.

There are only about 7 billion of us. The total human mass is about 350 million tonnes or 350 billion kilograms. One kilogram (kg) weighs 2.2 pounds and a tonne equals 1,000 kg. This makes humanity’s total weight to be 770 billion pounds.

If we divide this number by our population, the average human weighs 110 pounds (includes infants, preschoolers, students and peers, adults and the elderly).

How do we stack up against other species? It is estimated that all plants outweigh all animals by 99 to 1!

If we consider the most numerous living organisms, bacteria have an estimated total mass of 1,300,000 million tonnes. That is 3,700 times the mass of all humans. But should we consider life forms that are not visible to the eye?

Most of the several pounds of bacteria that we carry around in our intestinal track are good, helping us digest our food and converting some of it into vitamins.

Certainly by numbers of individuals, insects have us beat. Insects are creatures with an exoskeleton (on the outside), a head, a thorax, an abdomen, and three pairs of legs. All insects have antennae and compound eyes.

Insects make up about 80 per cent of the world’s known species. The number of individual insects now alive in the world is estimated to be 10 quintillion. A quintillion is 1 followed by 18 zeroes, in other words a billion times a billion. This is roughly 1.4 billion times larger than our human population.

It has been calculated that for every human pound, there are 300 pounds of insects. Of the insects, there is a fight between ants and termites for the honor of having the biggest mass of insects. (I realize that there are many species of both ants and termites, but let’s not make things any more complicated.)

Ants have been estimated to have a total mass of 2,700 million tonnes or nearly eight times the mass of all humans.

 Termites have been accused of producing 30,000 times as much methane as cows because of their faster metabolism. (Methane (CH4) is a potent greenhouse gas whose heat trapping ability is 23 times that of carbon dioxide.)

Why should we be concerned about insects, little critters that sometimes infest our houses or live on our cats and dogs?

It is a matter of resources. Insects are a rich source of protein, without the fat in customary meats (such as beef, pork). Raising grains is water intensive with one ton of grain requiring thousands of tons of water.

The amount of water to raise one pound of beef is even worse, as often cattle are fed with grain and the grass in pastures needs much water to grow.

People in sub-Sahara Africa rely on insects as a protein source. A delicacy in mainland Chinese restaurants is fried scorpions! Raising a pound of insects takes one to two pounds of feed and water.

Insects can be ground up, forming a paste that can be made palatable and a good source of protein. And with the right conditions, insects can be grown in small enclosures, not requiring industrial feedlots (for cattle and pigs) that pollute water and streams.

References used include ‘Infographic History of the World’ and internet sources such as the Smithsonian Encyclopedia.

Sky Sights Ahead: We have our second new moon this month (where moon shifts from the eastern dawn to the western dusk). A slender crescent moon should be easy to spot in the 8:20 p.m. dusk on April 1.

The planet Mars is a conspicuous yellow-orange point of light low in the southeast in late evening. (Tonight Mars rises about 8:30 p.m. On April 8, Mars will be opposite the sun and shining all through the night.

Bob Doyle invites any readers comments and questions. E-mail him at rdoyle@frostburg.edu . He is available as a speaker on his column topics.