L9 - The BIG issues Flashcards
Misconception and Correction, Misconception - evolution is a theory about the evolution of life?
Correction - Evolutionary theory does encompass ideas and evidence regarding life’s origins, but this is not the central focus of evolutionary theory. Most of evolutionary biology deals with how life changed after its origin. Regardless of how life started, afterwards it branched and diversified, and most studies of evolution are focused on those processes.
Misconception and Correction, Misconception - evolutionary theory implies that life evolved (and continues to evolve) randomly, or by chance?
Correction - Chance and randomness do factor into evolution and the history of life in many different way; however, some important mechanisms of evolution are non-random and these make the overall process non-random. Adaptations do not therefore come about ‘by chance’. They evolved via a combination of random and non-random processes. The process of mutation, which generates genetic variation is random, but selection is non-random.
Misconception and Correction, Misconception - evolution results in progress; organisms are always getting better through evolution?
Correction - One important mechanism of evolution, natural selection, does result in the evolution of improved abilities to survive and reproduce; however, this does not mean that evolution is progressive.
Misconception and Correction, Misconception - Natural selection gives organisms what they need?
Natural selection acts on the genetic variation in a population, and this genetic variation is generated by random mutation - a process that is unaffected by what the organisms in the population need. If a population happens to have genetic variation that allows some individuals to survive a challenge better than others or reproduce more than others, then those individuals will have more offspring in the next generation, and the population will evolve.
Misconception and Correction, Misconception - Natural selection produces organisms perfectly suited to their environments?
There are many reasons that natural selection cannot produce perfectly-engineered traits. For example, living things are made up of traits resulting from a complicated set of trade-offs - changing one feature for the better may mean changing another for the worse. Future evolution is often constrained by traits they have already evolved.
Misconception and Correction, Misconception - evolution and religion are incompatible?
Of course, some religious beliefs explicitly contradict science (e.g. the belief that the world and all life on it was created in six literal days does contradict with evolutionary theory); but the idea that one always has to choose between science and religion is incorrect. People of many different faiths and levels of scientific expertise see no contradiction at all between science and religion.
Misconception and Correction, Misconception - all traits of organisms are adaptations?
Now, what’s that for? While some traits are adaptive, its important to keep in mind that many traits are not adaptations at all. There’s no reason that having red blood is any better than having green blood or blue blood. Blood’s redness is a by-product of its chemistry, which causes it to reflect red light. The Chemistry of blood may be an adaptation, but bloods colour is not an adaptation.
