Download How Does Evolution Really Work?

How Does Evolution
Really Work?
Tyler Kendall
Justin Spackman
Genetic Variation
 The characteristics that help an individual to survive
 This happens by genetic mutations
 Example: a hummingbird having a longer beak to be able to get more
nectar
Overproduction of Offspring
 The Animal species have more offspring than what the environment can
support
 This creates a struggle for survival
 Example: a turtle laying 100 eggs, but only 4 survive because of the struggle
for survival
Struggle for Existence
 Struggle for existence leads to competition within a species
 Natural selection will favor those with better traits
 Example: Rocky Mountain Bighorn Sheep fighting for a mate to create
offspring
Differential Survival and Reproduction
 Organisms evolve to fit their environment
 This helps them to survive better
 Example: Giraffes having longer necks in an environment with tall trees so
the giraffes can eat more of the leaves
Response and Questions
 We learned that evolution occurs from natural selection
 And natural selection is composed of four things, genetic variation,
overproduction of offspring, struggle for existence, differential survival and
reproduction.
 Question we still have are could different species of animals evolve through
natural selection into the same species?