(1) Genetic Variation
• Genetic Variation / Diversity Organisms inherit different variations of traits, giving them different strengths and weaknesses.
• Genetic Variation allows for some individuals to succeed + survive.
(2) The Struggle for Existence
• Living things are always competing to stay alive AND pass on their genes:– There is limited food, water, shelter.– There are changes in climate, disease
transmission, etc.
• Those who can survive and reproduce during tough times are best suited/adapted to their environment.
(3) What does it mean to Adapt?
• To have the traits necessary to remain living and sexually attractive during times of change.
• It does NOT mean:To change/grow body parts so that you can survive that moment.
(4) Evolution
• A change in the allele frequency of a population of living things, over a period of time.– “Allele Frequency” = How often a certain trait
shows up in the population.
(5) NOT Evolution
• Sudden, quick physical changes to individuals so that they can survive.
• Change in populations so that only the “more perfect” versions live on.
• Humans “coming from” monkeys.
(6) What causes/drives Evolution?
• Genetic variation in a population.
• Changes in the environment/resources.
• Changes in sexual preference.
• The dying/extinction of certain populations.
(7) Evolution Mechanisms (EM)
• All evolutionary changes and mechanisms are still driven by natural selection.
• But there are different types of events that can drive evolution.
• End Result is ALWAYS the same:– There will be a change in the allele frequencies in the
population.
– Could produce a new species (a group of organisms that can only reproduce with each other).
(8) Natural Selection
• As the environment changes, certain characteristics amongst living things will help them to survive (Survival of the Fittest).
• If you don’t have these characteristics, you will not reproduce, or will die.
(9) Genetic Drift
• The random removal of certain traits (alleles) from a population.
• “Wrong Place, Wrong Time.”
(10) Genetic Migration
• When organisms with different traits move into new regions and populations, and reproduce with the original organisms.
(11) Geographic Isolation
• When a diverse population is separated and isolated by some geographic barrier (land, water, climate).
Natural Selection video
Hummingbirds YouTube Video
Now Let’s Watch This Video…