In his hypothesis, “Cope’s Rule,” the 19th century’s paleontologist, Edward Drinker Cope, had claimed that as species of animals evolve, they tend to obtain a bigger body size. Although the theory he proposed was alleged to be wrong many times, he remained infallible. He carried out an analysis that involved examples of the evolution history of animals from the dawn of animal life on Earth. Cole’s Rule has recently been proved right by a couple of paleontologists at the Stanford University.


Scientists recently conducted the most comprehensive test of Cole’s Rule. The study involved 17,208 varied groups of marine animals. These life forms were studied for their evolution history over the last 542 million years. The study helps in proving Cole’s Rule right as these animals demonstrated a unique trend of bigger size over time.

The paleontologists to have conducted the test are Professor Jonathan Payne and Noel Heim from the Standard University. Their research addresses the question that why evolution favors a bigger size. They explained the survival is easier for the bigger animals. If an animal is large, it can easily feed on the smaller ones while avoid the risk of getting eaten itself.

In the case of marine animals, a bigger size means a more active animal because of more mass as compared to the surface area. This helps them feel ‘drag’ lesser than smaller animals. Apart from this, bigger animals also have increased metabolic rate that allows for a more active lifestyle.

The scientists claimed that evolution demands an increase in size due to the increased diversification and the fact that bigger animals have increased chances of survival. In their research, Payne and Heim found that the trend of an increase in size is carried on with the evolution of a new species from their ancestors, as opposed to the same animal increasing in size over time.

One Response

  1. carmi2

    Ah, so this explains why people are getting so big. We eat everything: cows, bison, deer, etc. Why the huge obese people we see today have evolved that way so the cows won’t eat them!


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