Formation of a New Species
, ~
~insuo
species
to
d
group of orgs that closely resemble each other/closely related + able to breed among themselves (but not wh
any other species) and produce
viable
offspring
·
population
- group of individuals of same species occupying a particular habitat
* natural selection only operates on variation in inherited characteristics
individuals in pop identical natural selection
Genetically
·
.
=
no
must be genetic variation = influences nature of
offspring- environ Conditions can select best adapted indivividuals
·
.
↳ Darwin didn't understand inheritance + thus couldn't prove his theory
↳
Mendel's work published in his lifetime but he was unaware of them
~ou of mention ↑
sexual reproduction happen every Variation
-
all s time to allow max .
1) meiosis
of random of
rearrangement genetic material arrangement homologous chromosomes on equator
·
-
->
crossing-over when bivalents form
·
results in formation of new combo .
of alleles
2) chance fertilization
female fertilisation
genetic material from male gametes recombines
during
·
+
↳ no
choosing which male
gamete fuses =
variety of
genotypes in
offspring
↳ in
altered
genotypes may may not appear Phenotype
3) random
mating
female gamete (with particular genotype) equal fertilised the pop
has chance to be
by every male
gamete in
·
every .
↳ new set of created each time
Completely genes
Mutations
to
d
Sudden alteration in genetic make-up (genetic code) of an org
mutation
only gametic mutations relevant to inheritance - occur in gametes can give rise to
offspring with
·
=
↳ mutations be passed
germ-line
can on
in
eggs /sperm
: =
·
it : 1) changes in base Sequences of DNA -
main
way new alleles created = main source of genetic variation
2) whole chromosomes deleted/duplicated / entire chromosomal compliment multiplied -
polyploidy
beneficial in
small % =
evolutionarily =
result in change phenotype
·
↳ if mutation allows orgs to adapt better to new/unfavourable conditions =
survive + breed
↳ has
natural selection =
eventually whole pop .
new
genotype
species Formed
=
new
, ~
~insuo
species
to
d
group of orgs that closely resemble each other/closely related + able to breed among themselves (but not wh
any other species) and produce
viable
offspring
·
population
- group of individuals of same species occupying a particular habitat
* natural selection only operates on variation in inherited characteristics
individuals in pop identical natural selection
Genetically
·
.
=
no
must be genetic variation = influences nature of
offspring- environ Conditions can select best adapted indivividuals
·
.
↳ Darwin didn't understand inheritance + thus couldn't prove his theory
↳
Mendel's work published in his lifetime but he was unaware of them
~ou of mention ↑
sexual reproduction happen every Variation
-
all s time to allow max .
1) meiosis
of random of
rearrangement genetic material arrangement homologous chromosomes on equator
·
-
->
crossing-over when bivalents form
·
results in formation of new combo .
of alleles
2) chance fertilization
female fertilisation
genetic material from male gametes recombines
during
·
+
↳ no
choosing which male
gamete fuses =
variety of
genotypes in
offspring
↳ in
altered
genotypes may may not appear Phenotype
3) random
mating
female gamete (with particular genotype) equal fertilised the pop
has chance to be
by every male
gamete in
·
every .
↳ new set of created each time
Completely genes
Mutations
to
d
Sudden alteration in genetic make-up (genetic code) of an org
mutation
only gametic mutations relevant to inheritance - occur in gametes can give rise to
offspring with
·
=
↳ mutations be passed
germ-line
can on
in
eggs /sperm
: =
·
it : 1) changes in base Sequences of DNA -
main
way new alleles created = main source of genetic variation
2) whole chromosomes deleted/duplicated / entire chromosomal compliment multiplied -
polyploidy
beneficial in
small % =
evolutionarily =
result in change phenotype
·
↳ if mutation allows orgs to adapt better to new/unfavourable conditions =
survive + breed
↳ has
natural selection =
eventually whole pop .
new
genotype
species Formed
=
new
