4. Several reasons why mutation happens
• DNA fails to copy accurately
• External influences can
create mutations.
• Sex/gender and genetic
shuffling
5. • DNA fails to copy accurately
- DNA are not copied
perfectly.
- There is a small differences
between the original DNA
from that of the copied
DNA sequence
6. • External influences can create
mutations
- Exposure to specific
chemicals or radiation can
caused mutation, DNA may
caused break down.
7. • Sex/Gender & Genetic Shuffling
- A good example is a mother who has
a bushy eyebrows and a father having
a big nose.
- The offspring or child maybe have a
bushy eyebrows and big nose because
of the associated genes that the
parents have.
8. GENE FLOW/ MIGRATION
• Any movement of
individuals and/or the
genetic material they
can carry from one
population to another.
9. • Gene flow can be very
important source of
genetic variation.
• it may happen through the
migration of organisms or
the movement of gametes.
10. Some individuals from a population of
brown beetles might have joined a
population of green which would make
genes for brown coloration more frequent.
11. Genetic Drift
- A random changes in allele
frequencies from one generation to
the next.
- This can occur when a small group of
individuals leaves a population and
establishes a new one in a
geographically isolated region.
12.
13. Random Drift
- Consist of random fluctuations
in the frequency of appearance
of a gene, usually in a small
population.
- The process may caused gene
variants to disappear completely
14. Bottleneck Effect
- An environmental event results in
survival of only few individuals.
- Ex. Earthquakes or Tsunamis,
epidemics that can decimate the
number of individual in the population,
predation or habitat destruction etc.)
15. Populations that go through bottlenecks
loose much of their genetic variation.
16. Founder Effect
- - It is the loss of genetic variation that occurs
when a new population is established by a small
number of individual that cleaved from larger
populations.
- - Some genetic traits are becoming more
prevalent in the population due to small,
geographically and socially isolated community.
17. Shows a predominance of orange circles in the newly
founded population. These orange circles may
correspond to a given allele responsible for the variation
in a trait (for example, specific eyes color). In extreme
cases, founder effect also plays a fundamental role in the
18. Bottleneck Effect Founder Effect
- sudden decline in
population size due to
natural disasters or human-
caused events.
-Small groups starts a
new population on a
location.
- The remaining population
contains less genetic
variability
- the founder of the new
colony is not genetically
representative of the
population they came
from, thus less genetic
variability
Difference of Bottleneck and Founder Effect
19. Ex: With the genetic analysis of Arius
manillensis or Manila sea catfish using
the mitochondrial control region,
evidences confirmed that genetic
bottleneck occurred in the species
(Santos & Quilang, 2012).
Ex: The manila clam (Ruditapes
philippinarum) is now established in
North America and Europe. Studies
conducted revealed the occurrence
of founder effect in the European
population evidenced by its reduced
genetic variability (Cordero,
Delgado, Liu, Ruesink & Saavedra,
2017)
20. NATURAL SELECTION
- - Describes as the survival of the fittest,
elimination of the unfit which is in contrast to
that of the genetic drift but also a part of
explaining diversity in the planet.
- - has something to do with the natural resources and
other organism( Predation, disaster, diseases, climate
change, change in habitat, exposure to chemicals.
