Evolution: Artificial Selection
1. Evolution: Artificial SelectionLearning Objective
18.104.22.168 Explore ways to improve agricultural plants and animals using the methods of breeding.
Define hybrid, inbreeding and outbreeding
Identify two plants and explain how they have been bred to increase certain traits (mustard plant –
cauliflower – flowers, and stems celery)
Identify two animals and explain how they have been bred to increase certain traits (cow – milk,
Artificial (Selective) Selection
Non Random Mating
Inbreeding –within population
Outbreeding-outside of population
8. Non-Random Mating – small population have less gene flow, less randomness to mate, this can cause a decrease in frequency ofallele in a population.
-Only certain individual organisms
gene pool is small due to
these organisms producing
more offspring with only their
-less alleles in a population gene
-less chance for evolutionary
-more chance of extinction
is the process of crossing genetically
different individuals to produce offspring
is the crossing of two closely related
parents (genetically the same), or close
relatives, who share very similar alleles.
• increases the heterozygous alleles
• two different species are involved
• Alleles of offspring are much different
that their parents
• Less probability of genetic mutations
• Post-zygotic hybrid problems
• increases the amount of homozygous
• One species involved
• Alleles of offspring are very similar to
• High probability of genetic mutations
is the crossing of two parents that are not related and have very different alleles.
• increases the amount of heterozygous alleles.
• One species involved
• Alleles of offspring are very different to parents
• Low probability of genetic mutations
10. Steps of Artificial Selection1. Humans decide trait or characteristic of interest.
2. Breed the choices together
3. Choose offspring with ideal characteristics to
4. Repeat for many generations
5. The allelic frequency for the characteristic
6. Decide what type of selection is occurring in the
• Selective, Directional, Disruptive
13. Artificial Selection – hybrid Banana’s that have been bred until they have no seeds. All bananas are CLONES! Low geneticvariation less success…..
In contrast to natural
selection artificial selection
is intentional breeding or organisms for
certain favorable traits, or combination
From this plant.
Cabbage: selection for
the terminal bud (head
In contrast to natural selection this is the
intentional breeding or organisms for
certain favorable traits, or ombination of
Kale: selection is for
little to no seeds
familiaris are created through artificial selection
Notice any differences?
21. Belgian Blue cattle ... they have a mutation that creates twice the muscle tissue. Calves are so big that Caesarian births arestandard.
2. Is it an improvement that the cow would be ‘selected’ for if
released into the wild?
3. Reproductive success?
in this cow?
1. Define hybrid, inbreeding and outbreeding
2. Identify two plants and explain how they
have been bred to increase certain traits
(mustard plant , corn)
3. Identify two animals and explain how they
have been bred to increase certain traits (cow –
25. Choose One to Investigate22.214.171.124 Explore ways to improve agricultural plants and animals using the methods of breeding
Choose One to Investigate
investigates artificial selection
You are investigating inbreeding and hybrids as method of artificial
selection, not genetic engineering or Genetically Modified
√ Name the trait that was selected.
√ Tell why the trait was selected
√ Clear use of terminology explaining the mechanism.
√ Picture of before artificial selection and after artificial
Work shows understanding of differences between the two
types of artificial selection.