Misunderstandings regarding evolution
Following on from the previous topic of universals and parochials, another important distinction which needs to be made when discussing evolution (and any debate really) is that of general and specific. It may sound obvious but you would be surprised at how many arguments are caused by people with opinions at different levels. This is also where a lot of misunderstanding about evolution comes in. You could almost say that natural selection works on individuals and evolution works on a species as a whole. For example, someone might argue that the survival of the fittest theory is wrong since a strong individual might be killed by accident or simply doesn't get the chance to mate. This is too specific. Looking at the population as a whole, statistically, the fittest will survive.
Another problem comes from the term: survival of the fittest. It is the meaning of the word "fittest" that leads to misunderstanding. In normal daily life, "fit" usually means physically fit: stong, heallthy, atheletic, whereas in evolution, it means "most suitable". Often, people will look at specific examples in nature, and argue that it is not the strongest that are selected. We should say survival of the most suitable. A peackock with a ridiculously long tail may not be as fast or as agile as one with a short tail, but weighing up the danger of a long tail against the chance of attracting a mate, and we find that long-tailed individuals are "fitter" in general.
Many people believe evolution happens over millions of years and is therefore unobservable in one's lifetime, or indeed a civilisation's lifetime. This is not true. There are many examples of evolution being witnessed and tracked by biologists, from viruses and moths, to fish and dogs. We can also track evolutionary changes in the fossil records for many species.
One of the most annoying misunderstandings comes in the form of: "if we evolved from monkeys, why are there still monkeys around?" The key to this misuderstanding is the term "monkeys". We didn't evolve from monkeys, we evolved from a common ancestor with monkeys. It is just that we evolved more drastically, probably due to less hospitable or fluctuating environments. Imagine this: a species of primate live in a lush green forest. Then the forest (and primate population) gets split in half by an uncrossable river, and that one half turns onto barren plains while the other remains lush and green. The population half in the plains now have to evolve in response to new dangers, more limited resources and fierce competition while the other half can continue being perfectly adapted to their surrounding. This is how new species originate. And the reason for a lack of missing links? The evolution to adapt to the harsh new environment will be pretty quick, and since that half of the population is evolving together, there is no room or resources for part of that population to remain static. That is, unless the new species is split further, which is exactly what happens and is why we see so many species in the world.
Another problem phrase is: giraffes evolved long necks in order to reach tall trees. The problem here is the "in order to" part. What we should say is: giraffes evolved long necks in response to tall trees. While this difference may seem trivial and pedantic, it is an extremely important distinction in evolution. There is no higher intelligence guiding evolution, it has no goal or purpose. The giraffe population does not want long necks. It is simply that giraffes with slightly longer necks had, in general, more food and were therefore better fed and stronger, favoured by natural selection, and ultimately leading to more offspring with inherited long necks. The giraffes were competing not only against each other and other grazers, but presumably with the tree itself, which probably evolved taller in reponse to the evolution of the giraffe. If you still don't understand the distinction from my short explanation I suggest you go away and think about it a lot and do more reading, because it is the basis for understanding evolution.
We will evolve huge foreheads and lose our little fingers in the future. No, we won't! I will discuss the future of human evolution later.
Another problem comes from the term: survival of the fittest. It is the meaning of the word "fittest" that leads to misunderstanding. In normal daily life, "fit" usually means physically fit: stong, heallthy, atheletic, whereas in evolution, it means "most suitable". Often, people will look at specific examples in nature, and argue that it is not the strongest that are selected. We should say survival of the most suitable. A peackock with a ridiculously long tail may not be as fast or as agile as one with a short tail, but weighing up the danger of a long tail against the chance of attracting a mate, and we find that long-tailed individuals are "fitter" in general.
Many people believe evolution happens over millions of years and is therefore unobservable in one's lifetime, or indeed a civilisation's lifetime. This is not true. There are many examples of evolution being witnessed and tracked by biologists, from viruses and moths, to fish and dogs. We can also track evolutionary changes in the fossil records for many species.
One of the most annoying misunderstandings comes in the form of: "if we evolved from monkeys, why are there still monkeys around?" The key to this misuderstanding is the term "monkeys". We didn't evolve from monkeys, we evolved from a common ancestor with monkeys. It is just that we evolved more drastically, probably due to less hospitable or fluctuating environments. Imagine this: a species of primate live in a lush green forest. Then the forest (and primate population) gets split in half by an uncrossable river, and that one half turns onto barren plains while the other remains lush and green. The population half in the plains now have to evolve in response to new dangers, more limited resources and fierce competition while the other half can continue being perfectly adapted to their surrounding. This is how new species originate. And the reason for a lack of missing links? The evolution to adapt to the harsh new environment will be pretty quick, and since that half of the population is evolving together, there is no room or resources for part of that population to remain static. That is, unless the new species is split further, which is exactly what happens and is why we see so many species in the world.
Another problem phrase is: giraffes evolved long necks in order to reach tall trees. The problem here is the "in order to" part. What we should say is: giraffes evolved long necks in response to tall trees. While this difference may seem trivial and pedantic, it is an extremely important distinction in evolution. There is no higher intelligence guiding evolution, it has no goal or purpose. The giraffe population does not want long necks. It is simply that giraffes with slightly longer necks had, in general, more food and were therefore better fed and stronger, favoured by natural selection, and ultimately leading to more offspring with inherited long necks. The giraffes were competing not only against each other and other grazers, but presumably with the tree itself, which probably evolved taller in reponse to the evolution of the giraffe. If you still don't understand the distinction from my short explanation I suggest you go away and think about it a lot and do more reading, because it is the basis for understanding evolution.
We will evolve huge foreheads and lose our little fingers in the future. No, we won't! I will discuss the future of human evolution later.
posted by Daley Paley at 5:13 PM
0 Comments:
Post a Comment
<< Home