Natural Selection and Artificial Selection
Natural Selection: the process that results when the
______________ of a ____________ of organisms ______ over
many _____________. Individuals with certain ________
___________survive specific local environmental conditions and
_____ on their traits through ____________. For natural selection
to occur you must have ________ within a _______. I.e. peppered
moth
When environment changes it exerts a _________ ___________
on a population. The pressure may result from predators, parasites,
weather etc
The individuals with ________ traits are selected for by their
environment. They __________ the _______ in the environment.
I.e. antibiotic resistant bacteria or plants that survive under dense
trees in forest.
Natural selection is ______________, has no will, purpose or
direction. A trait that was __________ in one environment may not
be if environmental conditions change. Over time the population
numbers of individuals with favourable or unfavourable traits will
change over generations to accommodate the new environment.
Those individuals with the most __________ traits for that
environment will be _________, their numbers will start to
_______ over many generations and they will be considered to be
the _______ or have the best _______ for their environment.
Artificial Selection:
I.e. dog and cat breeders and the use of biotechnology for crops and
plants (food industry)
The difference between natural and artificial selection is in
natural selection the ____________ plays the role that
________ play in artificial selection. In natural selection the
_____ ________ are affected since the individuals with the
best fitness will pass on their traits while the others may die
off or become extinct.
Consequences of Artificial Selection
When humans _____ and choose the ______ for ________,
the individuals that result will not be the most ____ for the
environment (i.e. British Bulldog: respiratory ailments and hip
dysplasia)
Plants that have been ___________ bred lack genetic
diversity. Most agriculture is based on extensive plantings of
the same desired varieties called ____________. What if a
new disease arises or mutation?
To reduce catastrophe gene banks have been assembled: bank
contains populations of early ancestors with vast diversity