Mechanisms of Evolution Flashcards
Jean Lamark
-Evolution occurs through the use and disuse of physical features. -features will increase by use or decrease by disuse . -these traits are then passed down to their offspring. -Through evolution happens during a life time.
Charles Darwin
-Characteristics among members of a species vary. -Only individuals with the characteristics suited to the environmental will survive to reproduce. -Overtime those characteristics will increase in population.
Process of Natural Selection
Process by which populations (not individuals) change in response to their environments.
4 requirements
Genetic Variation Overproduction of offspring Struggle for existence Survival of the fittest.
Genetic Variation
Exists in a population through… Meiosis- Genetic variation can be increased during crossing over and independent assortment. Mutations- Can be beneficial Genetic Recombination- Organisms pass on traits to offspring.
Overpopulation/overproduction
-when conditions are favorable organisms tend to produce more offspring than the environment can support. -Resources are no longer abundant enough to support every individual in a population competition occurs.
Struggle for Existence
-Every organism must constantly fight for limited resources and escape from predators in order to survive long enough to reproduce.
Survival of the Fittest
-individuals best suited/adapted to their environment have the best chances for survival. -reproduce more often and pass those good traits on to their offspring. -increased frequency of best traits
Fitness def
The ability to survive and reproduce in a particular movement.
Selective pressure
The environment factor that effects an organisms ability to survive and/ or reproduce in an environment.