Download SBI3U Evolution Biological Changes Over Times Evolution Lesson

SBI3U Evolution Biological Changes Over Times
Evolution Lesson #1
 All species exhibit genetic variation
 Mutations create
mutations (______ in genetic info)
.
3 Types of Mutations
Type
Description
- mut
reproductive
success
- mut is selected
against;
accumulate over
time
-mut selective
advantage or
disadvantage
- in DNA that
may not have
immediate effect
mut reproductive
success
- mut is favoured
overtime;
accumulates over
time
Examples
Question: Bacteria has developed resistance to antibiotics, this is an example of
which type of mutation? Why?
Selective Breeding
 Domestication ( of members of a species to suit human needs through
controlled captive breeding) of animals and plants
Artificial Selection: Directed breeding in which individuals that exhibit a particular
trait are chosen as parents of the next generation. It's used to produce new breeds
or varieties of plants/animals.
Artificial:
Selection:
 Artificial selection is limited by genetic variability within the breeding population.
 Artificial selection can reduce genetic diversity of population loss of
biodiversity
Evidence For Evolution
Biogeography:
 The observed geographic patterns of distribution of organisms (living/fossils)
 Provides compelling evidence that remote islands are populated by species
that evolved from species that had travelled from the closest major land mass
 Examples:
Darwin's Hypotheses
 Patterns of distribution of species (living/extinct) may be evidence of evolution
 Animals brought to island by water/air became established and evolved
 This could explain why isolated islands had many species found nowhere else
and resemble species from nearest continental land mass
Observation from Galapagos Island
Many species of plants, birds, insects,
some reptiles
No native amphibians, few land mammals
Many unique species found nowhere else
Unique species most closely resemble
species on the nearest continental land
mass
Darwin’s Hypothesis regarding remote
islands
These organisms are only able to reach
remote islands by crossing large expanses
of open ocean
Amphibians and most mammals are
unable to cross open ocean so not found
on remote island
Overtime, ancestral species have evolve to
new geographically isolated species
Unique species are descendants of
ancestral species from the nearest
continental land masses and will exhibit
some similarities.
Testing Darwin's Hypothesis
- Hawaiian islands which were formed
that rose from the ocean floor
- Examination of species of the Hawaiian island support the hypothesis:
- Introducing native species may have devastating impact on many native species.
Ex: arrival of Europeans 1778 lead to the extinction of the black mamo birds
- When testing hypothesis its important to consider alternative explanations that
might account for your findings. Maybe Island lack individual group because they
cannot survive in that setting.