lismore said:
You have observed people evolving into something else?
Can you share what these observations are?
Haha, seeing people evolving into something else would be silly, especially since our lifetimes severely limit what we are capable of observing in the moment. However, we can
very easily watch a bacterial culture replicate, adapt, die and procreate in response to the environment it resides in. This is how viruses evolve, and why many months of each year are spent by scientists devising new vaccines to the recently-mutated flu virus.
However, if evolution were confined to viruses it would be one thing. It is, of course, used by all living creatures. Did you know that you are actually living testimony to one of the two parts of evolutionary theory? When you were born, and as your DNA was formed from the recombination of your parents' genetic structures, mutations occured. You are not simply the average of your parents' DNA, but are in fact a completely new sort of creature, with traits of both parents as well as a smattering of random mutations that make you wholly unique as well. Mutations happen every time a new DNA sequence is formed.
I mentioned that mutation is one of two parts, the other being natural selection, of course. Natural selection states that those organisms best adapted to their environment are more likely to survive, and thus pass along their adaptations. What this means is that when a mutation occurs, it is either neutral (most of the time), detrimental (rarely) or beneficial (rarely). Organisms with detrimental mutations don't do as well as those with neutral or beneficial mutations, so their detrimental genes tend not to get passed along (they often die before they reproduce). Those with beneficial mutations, on the other hand, tend to do better than other organisms, and have a higher likelihood of surviving to pass along their beneficial genes. The end result, of course, is that populations of organisms tend to adapt better and better to the environment they live in through a continued process of mutation and natural selection.
A few things to note about mutation and natural selection: mutation, as far as we can tell, is basically random. Most mutations are neutral, but there's no way to predict whether an organism will be created with beneficial or detrimental mutations. Natural selection is
not random. It has a direction - that of increasingly more well-adapted and able organisms. This means that evolution as a whole is also not random. The end result of the process of evolution is the production of better-adapted organisms.
Did you get a chance to read the link on what scientific theories are? They also mentioned a few notes on what facts are. Natural selection and mutation are both
facts. They are observations we have made. We have observed that mutations occur in DNA recombination, and we have observed that creatures better adapted to their environment tend to pass along their genes more reliably. Evolution is both
theory and
fact. As mutation and natural selection are both
facts, so is evolution as it is simply a combination of the two. It is also a
theory, as there exists a set of explanations as to why evolution occurs. These explanations do a good job of making predictions and have not yet been falsified, which means as of this moment, evolutionary theory is a good theory.
If you have any questions about this topic, feel free to ask!