How does scientific method relate to evolution?

Answer 1

The theory of evolution and inheritance of traits was worked out using the scientific method. The initial work in this area was done in the 1800's by a priest named Gregor Johann Mendel who worked with peas. He worked out the laws governing the espression of dominant and recessive genes, although at the time he didn't know what was responsible.

Evolution is simply a process of natural selection of traits that have some sort of advantage. In hot climates with lots of sunshine, dark skin has an advantage. In nothern climates, light skin has an advantage because in nature, sunlight makes us manufacture vitimin D. If a dark skinned person moved from Africa to Norway, and didn't eat the correct foods, they would suffer from a vitimin D deficiency because their skin color reduced the affect of sunlight on their ability to produce vitimin D. So in a northern climate, light skin is and advantage and left undisturbed for a few centuries, the population would tend to become fair skinned blonds.

In Africa, fair skin is a problem because it sinburns easily and light skinned people tend to develop skin cancer if they do not protect themselves. So in equatorial climates, dark skin is an advantage and left undesturbed for a few centuries, a population would tend to become dark skinned and dark haired.

This is the way evolution typically works. In some cases, there are changes in the genetic makup of an individual that makes him/her more successful. This is called a mutation. Most mutations are fatal but some are advantageous. For example, humans have a mutation that reduces the strength of our muscles compared to our other primate relatives. If we had very strong muscles like chimps and gorillas, we would need a bonny crest on the top of our skull to anchor our jaw muscles. Since our jaw muscles are weak, we can anchor them to the side of our skull and this allows for a larger brain case. This is an advantage and the individual that first had that mutation now has decendants everywhere on earth. Other mutations make it possible for some groups to eat diary foods while others cannot. A mutation that provides protection from malaria to black people is also responsible for cicle cell enimia - and example of a mutation that offers both and advantage and a disadvantage.

The scientific method relates to evolution because that is how the natural laws were discovered. In the scientific method, we look at evidence and we come up with a theory to explain it. Then we look for things that the theory predicts but which we have not yet observed. If these things are found, then the confidence in the theory is strengthened. If these things are not found or if things that the theory says cannot happen are observed, then the theory is wrong and we come up with a new one that explains the new observations as well. When we come to a point where we have a theory that fits all of the data and isn't contradicted by evidence, then we use that theory as if it were true. In some cases it is and in some cases it isn't. For example, Newtons laws work for objects that are not moving very fast relative to each other but we know that the these laws are not true because they break down at high speeds approaching the speed of light. We have much better theory that explains the observations made at high speeds called relativity. The same applies to evolution.