Theory of evolution by natural selection
Example
How does natural selection work
What is natural selection
key features of evolution by natural selection
what is evolution by natural selection
why is natural selection important for populations
mechanism of evolution
used to account for millions of species that live on earth
states that the most complex organisms occur totally by natural selection
genetic mutations are beneficial to an individual are passed on to reproduction
results in a new generation of organisms that are more likely to survive and reproduce
example
giraffes have evolved to have long necks
shorter necks access less foods which should be unlikely to survive and pass on their genes
individuals have characteristics that give it an increased change of survival where they live
organisms that survive are better adapted
process where populations of living organisms adapt and change
Deer mince
migrated from Nebraska
change from dark brown to light brown
this was a genetic change
helped them hide from predators
occurs when mutations change to an organism DNA are advantageous
allowing them to survive in the environment
Darwin's process of natural selection had four componets
Variation
Inheritance
high rates of population growth
survival and reproduction
favourable traits are passed on to offspring
animals survive and reproduce
variations include: hair, colour, size
more offspring being produced
if the environment rapidly changes
animals might not be able to adapt quickly enough through natural selection
process through populations of living organisms change and adapt
favourable traits are passed on
through generations
natural selection can lead to speciation
one species gives a rise to a new and obesely different species
one of the process that drives evolution and helps explain diversity of life on earth