Adaptation, Variations, Mutations, and Selective Advantage (7.1)
Adaptations: Is a structure, behaviour, or physiological course of action that increases an
organism’s skill to survive and reproduce.
Behavioural Adaptations
- Affects the way an organism acts, concerning hunting, hibernating, mating rituals,
etc.
Structural Adaptations
- Affect a specific feature of an organisms body
Physiological Adaptations
- special features of an organism that allows it to perform specialized functions
Mimicry: a special type of adaptation that mimics an adaptation to another organism
-
Some species develop adaptations that give an lead, like being venomous, or
savor ghastly
Other species extend a way to show as if they have these variations
Genetic Variation
- the number of possible genes in an offspring can inherit from their parent can
result in genetic variation
Mutations: in DNA to a variation of traits within many individuals of a species. This
variation of traits will allow some individuals to better adapt to the challenges passed by
the environment. Those organisms that are better suited to their environment will survive
to reproduce and pass on their traits.
-
A change in the content of genetic information
An alteration in the genetic identity of an organism
Can be a positive, negative or neutral change
As environments change , having mutations can allow an organism continue life
in that environment (selective advantage)
Mutations are the only resource of genetic variation
Selective advantages is a genetic advantage of one organism over its opponent
It will assist an organism carry on the challenges of its environments to reproduce
Selective Advantage: A genetic advantage that improves an organism’s chance of
survival, usually in a changing environment.
-
the genetic advantage of one organism over its competitors
improves an organism life
mutation giving organisms an advantage over other organisms in environment
over time, those with an advantage increase in population
variation that serves organism well
mutation that makes species more genetically diverse
Hardy-Weinberg Mathematical Model
Description: The frequency of all the dominant R and recessive r alleles equals the
total frequency and adds up to 1.0 or 100% of the alleles present. (In other words,
remains constant)
The equation:
(p + q) 2
=
Frequency of allele types
combinations
p = frequency of dominant allele A
(homozygous dominant)
q = frequency of recessive allele a
p2 + 2pq + q2
=1
Frequency of allele
p2 = frequency of AA
q2 = frequency of aa (homozygous recessive)
2pq = frequency of Aa
(heterozygous)
Helpful tips:
1. In most populations, the frequency of two alleles is calculated from the proportion of
homozygous recessives (q2), since it is the only identifiable genotype directly from its
phenotype. If only the dominant phenotype is known, q2 may be calculated (1-frequency
of dominant phenotype).
2. All calculations must be carried out using proportions, not percentages.