- Education and Science»
- Life Sciences
Three Examples of Evidence for Evolution
The science of evolution is well established among biologists and geologists. The facts that support it are numerous, and well documented. Here are three examples from an article in Nature ("15 Evolutionary Gems", by Henry Gee, Rory Howlett, and Philip Campbell, January 2009) to support the theory.
One example of an organism developing a resistance to a toxin is penicillin. Once considered the standard drug treatment for many illness, it is now less reliable for some illnesses. The virus strain has adjusted to the drug and become more resistant to it.
An article by Manda Clair Jost et al. ("Toxin-resistant Sodium Channels: Parallel Adaptive Evolution Across a Complete Gene Family", Molecular Biology and Evolution, June 2008) mentions an earlier study showing that garter snakes have evolved a resistance to the neurotoxin used by their newt prey.
Jost et al. showed that four taxonomically diverse species of pufferfishes each evolved resistance to the toxins tetrodotoxin (TTX) and saxitoxin (STX). The authors mention that in wild insect populations such as flies, and cockroaches, there was the evolution of pyrethroid and DDT resistance within a few decades of insecticide exposure.
Predator and Prey Co-Evolution
Another way that evolution occurs is by two competing species, a predator and prey evolving side by side. As the prey adapts to make it harder for predator to kill the prey, the predator adapts to make it easier to get to the prey. This is co-evolution where organisms evolve together, and in competition.
Consider the case of water fleas, called the Daphnia, and the microscopic parasites that infest them. As the water fleas, the prey, become better at evading parasites, which are the predator, the parasites become better at infecting them. But over the long run, neither has an advantage over the other; rather a balance exists in their environment.
Another example involves the detection of bat signals by moths and crickets to evade detection. Bats are very good at making sonar signals that allow them to detect prey. But simultaneously the prey have developed sensory mechanisms that allow them to pick up on the signal and
The Journey From Land to Sea
One of the prevailing beliefs was that all life formed in the sea, and that life moved unidirectionally from the sea to land, not the other way around. But there is evolutionary evidence that life did develop from land to sea, at least in the case of whales.
Whales, as mammals, are now fully adapted to life in the water, and have been there for millions of years. They give birth to offspring; they breathe air. So how is it that they developed these mammal qualities in the sea? They did not; in fact there is evidence that mammals originally evolved on land. So whales' distant ancestors, which were land-based, must have gone to water at some point.
To show this, there are hybrid fossils that have dual characteristics, such as the crocodile-like amphibious Ambulocetus and the first known whale ancestor, the Pakicetus. These include ear anatomy, which is now seen only in whales, and they also have limbs like those of the land living mammals from which they derived. The evolutionary scientist, Stepeh Gould claimed, in Natural History magazine 1994 that the Ambolecetus is the very animal that the [intelligent designers] said could not be developed.
These three examples of evolution are but a tiny fraction of the evidence available. While the scientific process of evolution is well established, the facts supporting the theory are numerous. In fact there is more evidence to support Evolution, than General Relativity.
Predator and Prey Co-Evolution
The Journey from Land to Sea