2007-03-05 13:32:02 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Biology
Genes are always trying out different combinations to see what works best. If the combo is bad, the animal dies or won't be able to find a mate. If it's a good combo, it gets passed onto the next generation and might give that individual an advantage.
2007-03-05 13:37:06 · answer #1 · answered by Moral Orel 6 · 0⤊ 0⤋
Because of the genetic combination of parents and generations causing mutations. Also b/c of "crossing-over" that occurs in Meiosis genetic variation and possible mutation can occur within the organism not just by reproduction. Mutations can be caused by external factors like chemicals or radiation.
2007-03-05 21:49:34 · answer #2 · answered by rellik_912 1 · 0⤊ 0⤋
Mutations are mistakes. DNA replication doesn't have 100% accuracy, and random errors occur in every generation. The interesting thing is that sometimes the errors are bad for the organism, sometimes they don't matter, and once in a while they help out.
2007-03-05 21:44:51 · answer #3 · answered by Stacy 3 · 0⤊ 0⤋
The real simple answer is "stuff happens".
2007-03-05 21:48:09 · answer #4 · answered by Joan H 6 · 0⤊ 0⤋