genetic variation within
occurs
a
population
when there is enough
and phenotypes that
stabilising
Autosomal linkage when 2 in
Dihybrid
aresutetotheenvironmentwireproduct larger
cross 9: 3: 3:
genes are close to each other
TG Tg +G +g
in
linked
will be
phenotypically suited to the environment. When an
TG TTGGTTGg TAGG TAGg disruptive
is suited to an environment it will have a survival
organism
Tg TTGg TTgg TtGg Ttgg advantage and pass on its
genes ,
this leads to directional selection. Mi
sex-linkage gene is on the sex If I traits are both advantageous ,
the population will split, this is
↓ G TAGG TAGg +GG
chromosomes (XX female ,
XX-male +Gg disruptive selection.
eg fur length in rabbits
.
If they become so
↓
homozygous or
nemizygos +g different it could lead to speciation
TtGg Ttgg tGg tgg
heterozygous
Speciation
↓
Variation
<
genetic
↓
> mutations
-
substitution
allopatric ,
2 populations sympatric groups , of a
deletion the
meiosis
become population
Epistasis in
S
modifies or geographically same area
-
environmental addition - > an allele
independent
-
-
segregation translocation masks the expression become
separated eg split by reproductiveally
-
.
of homologous
. blood group
eg chromosomes an a p of another
A
dryland or river ect. isolated
.
I
Chiasmata
B-E-bbE---ee eglab coat colour
-
-
random
Edetermines weather
fertilisation 9 : 3 : 4
melanin is deposited at all
Isolating mechanisms
discontinuous variation
B determines how much geographical-river splits population
T purely genetic
·
melanin is deposited
ecological-diff habitats in the same area
walelea
.
temporal -
mating seasons don't align
#
Hardy-Weinberg
ediate
principle
O
continuous variation behavioural-courtship doesn't align
p + q= 1
large population natural selection
E
no mechanical
·
: -
> anatomical differences
ph + 2pq+ q
2
/ no
migration mutation
=
no
gene gametic can't fuse
·
>
gametes
-
j www
Aa Aa an random
mating hybrid sterility > offspring of hybrid
·
cross
-
I a
Fight