Download Evolution - Hannah E. Styron

Evolution
Holt Environmental Science
Chpt 4.2
Evolution by natural
selection
 A change in the genetic characteristics of a
population from one generation to the next is
known as evolution
Evolution by natural
selection
 Natural selection: the process by which
individuals that are better adapted to their
environment survive and reproduce more
successfully than less well adapted individuals do
 Proposed by Charles Darwin
Darwin observed differences among
island species.
 Variation is a difference in a physical trait.
 An adaptation is a feature that allow an
organism to better survive in its environment.
– Species are able to adapt to their environment.
– Adaptations can lead to genetic change in a
population.
Coevolution
 The process of two species evolving in response
to long-term interactions with each other is
called coevolution
Evolution by Artificial Selection
 Artificial selection is the process by which
humans select traits through breeding.
Genetically Modified Crops
A genetically modified organism (GMO) is an
organism whose genetic material has been altered
using genetic engineering techniques.
Evolution of Resistance
 Resistance is the ability of one or more organisms
to tolerate a particular chemical designed to kill
it
Evolution caused by pollution
 During the industrial revolution, factories in
England polluted the air with tons of soot which
coated the trees. This caused dark colored moths
to increase in population and the light colored
moths to decline because dark colored moths
were more suited for survival.