|MadSci Network: Evolution|
Hi Dave, That is a good question, and actually a very old one first posed by a taxonomist named Jean Baptiste Lamarck in about 1809AD. He was an early theorist about the evolution of species, about 40 years before Charles Darwin showed us all(except the Kansas state board of education)that evolution occurs by random mutation and survival of the fittest. By comparison, Lamarck believed that evolution occured by will power. For example, giraffes have long necks, but how did they get that way? Lamarck theorized that early ancestors of the giraffe had short necks, but eventually stretched them out over time tyring to reach the top leaves on tall trees. Not only did they stretched their own necks to accomodate their desire, but were able to pass this new physical trait to their offspring. So in essence he believed that modifications an organism makes during its lifetime are inherited by the offspring. He also proposed that organs that weren't used deteriorated while those that were overused became stronger. Well this last part is pretty true cause muscles get stronger with excessive use and weaker with disuse. However it doesn't hold true that if you are very weak or strong that your kids will turn out the same as you. You can't will yourself to have bigger muscles without taking physical action, or have weak muscles without physical inaction. Now, I think this first part answers your finger question in that no amount of will power will get you a 6th finger on one hand. Can you change yourself mentally? Not really sure what you mean so I'll take a guess. You can't will yourself to change the structure, size or shape of your brain but you can change the way you think. For example, people who are scared of spiders can take steps to rid themselves of this fear, or at least decrease that fear. So I'll sum up using Darwin's theory. When a species evolves, thereby changing it's physical and/or mental abilites, it does so through a series of genetic mutations propagated through generations. That was a tongue twister. Evolution of a 6th finger as a dominant(very common) physical trait will take a very long time, and only if there is a selection for people with this trait. (Selection meaning that there is some life or death need for 6 fingers/ and ability of 6 fingered people to produce more offspring that 5 fingered people). Who knows, maybe a million years from now humans may have very different physical and mental features and abilities than we have now. Too bad you and I will never know but you can imagine. So put your will power to more productive use like developing your imagination. Good luck, Mark Sullivan
Try the links in the MadSci Library for more information on Evolution.