chapter 2 Flashcards
Vitalism
life processes in all organisms are driven by some immeasurable force
variable
something that can vary
scientific control
an experiment or observation designed to minimize the effects of variables other than the single independent variable( variable being tested)
why use a control
- gives you a baseline to which you can compare the rest of the results
- to check for failures in an experience
- controls give more confidence in the results
controlled experiemnt
a scientific investigation in whcih both the control group and experimental group(s) are kept under similar conditions (matched variables) except the factor under study (independent variable) so that the effect or influence of that factor can be identified or determined
hypothesis
proposed explaination for an observable phenomenon - educated guess
2 features of a good experimental design
an independent variable that is carefully manipulated
other variables that could affect the experiment are matched across all test subjects
Theory
a major unifying idea with far reaching implications that has been extensively tested and attempts to disprove it have failed
evolution
the change in a population or species over time; can be directly observed over a short time period
Natural selection
the process that results in the survival and reproductive success of individuals best adapted to their environment; important mechanism in driving evolution, but is not the only mechanism
sexual selection
form of natural selection that ocmes about through preference by one sex for particular characteristics in individuals of the other sex; leads to non- random mating
Genetic Drift
change in genetic makeup of a population due to random events; populations can evolve through drift
mechanisms causing evolution
1) genetic mutations
2) natural selection
3) non-random mating
4) drift
5) migrations
