THE PAPER
THE EVOLUTION OF GENOME
T
o m
ee
t th
e
t
a
sk
B
y
:
B
r
ad
for
d Haa
g
A
rizon
a S
t
a
t
e U
niv
e
rsity
2
P
r
edece
ssor
T
h
e
r
e a
r
e
still m
a
ny who
a
r
e
not
c
l
ea
r or qu
e
stion
ab
l
e ab
out th
e
th
e
ory of
b
iologi
ca
l
e
volution
,
su
c
h
a
s how lif
e a
ris
e
s from
dead
m
a
tt
e
r
,
how
e
volution
ca
n
c
h
a
ng
e
living things from simpl
e
to mor
e c
ompl
e
x
,
hum
a
n origins
,
or how simpl
e e
volution
a
ry pro
ce
ss
e
s su
c
h
a
s th
e
form
a
tion of
c
hlorophyll or h
e
moglo
b
in o
cc
ur
.
E
volution is oft
e
n us
ed
to
de
s
c
ri
be
gr
ad
u
a
l
c
h
a
ng
e
s
,
de
v
e
lopm
e
nts
,
or growth
,
whi
c
h
ca
n
be
ca
us
ed b
y n
a
tur
a
l f
ac
tors or hum
a
n
e
ngin
ee
ring
.
T
h
e
th
e
ory of
e
volution is
ba
si
ca
lly
a
hypoth
e
sis r
e
g
a
r
d
ing th
e
origin of living things
.
Ma
ny sp
ec
i
e
s
a
r
e
now not foun
d
in th
e
p
a
st millions or
e
v
e
n
b
illions of
y
ea
rs
a
go
.
T
h
e
org
a
nism on
ea
rth is v
e
ry
d
iv
e
rs
e a
n
d
h
a
s
a c
ompl
e
x
org
a
niz
a
tion
a
l syst
e
m
,
m
a
king it
d
iffi
c
ult to
a
n
a
lyz
e e
x
ce
pt
de
s
c
riptiv
e
ly
.
T
h
e
r
e
for
e
,
a
mo
de
l or simplifi
ca
tion is oft
e
n m
ade
to
f
ac
ilit
a
t
e
o
b
s
e
rv
a
tion
,
a
n
a
lysis
,
a
n
d d
is
c
ussion of th
e
syst
e
m of lif
e
,
whi
c
h th
e
n giv
e
s
b
irth to fi
e
l
d
s of s
c
i
e
n
ce
su
c
h
a
s
ce
ll
b
iology
,
b
io
c
h
e
mistry
,
a
n
d
mol
ec
ul
a
r
b
iology
,
in
c
lu
d
ing mol
ec
ul
a
r g
e
n
e
ti
c
s
.
T
h
e
th
e
ory of
e
volution is
a
lso th
e
fo
c
us of stu
d
y
beca
us
e
it is
r
e
l
a
t
ed
to th
e
origin of lif
e
.
M
ol
ec
ul
a
r
b
iology
,
whi
c
h
de
v
e
lop
ed
from
mol
ec
ul
a
r g
e
n
e
ti
c
s
,
c
ov
e
rs
a
ll
a
sp
ec
ts of lif
e
pro
ce
ss
e
s
,
is not only
r
e
l
a
t
ed
to g
e
n
e
ti
c
n
a
tur
e b
ut
a
lso th
e e
xpr
e
ssion
a
n
d
impl
e
m
e
nt
a
tion
of lif
e
progr
a
ms in physiology
,
de
v
e
lopm
e
nt
,
r
e
pro
d
u
c
tion
,
a
n
d
t
a
xonomy
,
in
c
lu
d
ing
ada
pt
a
tion
a
n
d
int
e
r
ac
tion
be
tw
ee
n sp
ec
i
e
s
.
P
r
e
viously
,
th
e
g
e
nom
e c
oul
d
only
be
stu
d
i
ed
in
d
ir
ec
tly
a
n
d
oft
e
n
d
i
d
not r
e
pr
e
s
e
nt th
e
whol
e
s
e
qu
e
n
ce
.
H
ow
e
v
e
r
,
t
ec
hnologi
ca
l
ad
v
a
n
ce
m
e
nts
e
n
ab
l
e
th
e c
ompil
a
tion of
c
ompl
e
t
e
g
e
nom
e
s
e
qu
e
n
ce
s
,
st
a
rting with mito
c
hon
d
ri
a
l
a
n
d c
hloropl
a
st g
e
nom
e
s
,
follow
ed b
y
bac
t
e
ri
a
l g
e
nom
e
s
,
a
r
c
h
aea
,
y
ea
st
,
a
n
d
n
e
m
a
to
de
s
.
Ge
nom
e
proj
ec
ts
for v
a
rious org
a
nisms
,
in
c
lu
d
ing hum
a
ns
a
n
d
pl
a
nts
,
c
ontinu
e
s to grow
.
T
his
d
is
c
ussion will in
c
lu
de
thr
ee
m
a
in topi
c
s
:
g
e
nom
e e
volution
,
g
e
nom
e
siz
e
v
a
ri
e
s
be
tw
ee
n org
a
nisms
a
n
d
f
ac
tors th
a
t influ
e
n
ce
it
,
a
s
w
e
ll
a
s g
e
n
e
ti
c
inform
a
tion in th
e
g
e
nom
e
-
wh
e
th
e
r most
c
onsists of
ac
tiv
e
g
e
n
e
s or non
-
g
e
nit
a
l s
e
qu
e
n
ce
s th
a
t m
a
y h
a
v
e a
fun
c
tion or
c
onsi
de
r
ed
"
g
a
r
ba
g
e
."
3
D
is
c
ussion
A
.
T
h
e de
finition of
T
h
e e
volution of
Ge
nom
e
Be
for
e d
is
c
ussing mor
e ab
out th
e
g
e
nom
e
org
a
niz
a
tion syst
e
m
on living things th
a
t
e
xp
e
ri
e
n
ced e
volution
,
it is import
a
nt to
un
de
rst
a
n
d
th
e d
iff
e
r
e
n
ce be
tw
ee
n g
e
n
e
s
a
n
d
g
e
nom
e
s
.
Ge
n
e
s
a
r
e
DNA
or
RNA
mol
ec
ul
a
r units th
a
t
c
ont
a
in inform
a
tion
ab
out th
e
s
e
qu
e
n
ce
of
a
mino
ac
i
d
s to form prot
e
ins or stru
c
tur
e
s of
RRNA
mol
ec
ul
e
s
(
RNA
ri
b
osom
e
s
)
a
n
d TRNA
(
tr
a
nsf
e
r
RNA
).
Mea
nwhil
e
,
th
e
g
e
nom
e
is th
e
tot
a
lity of g
e
n
e
s own
ed b
y
a
n org
a
nism or virus
,
or
a
s
e
t
of
c
hromosom
e
s in th
e
h
a
ploi
d
ph
a
s
e
in
e
uk
a
ryot
e
s
.
W
ith this
de
finition
,
a
pi
ece
of
DNA
th
a
t
d
o
e
s not
c
ont
a
in
c
ompl
e
t
e
g
e
n
e
ti
c
inform
a
tion is not
a
g
e
n
e
,
b
ut only th
e DNA
fr
a
gm
e
nt
.
L
ik
e
wis
e
,
a
c
hromosom
e
th
a
t is mor
e
th
a
n on
e ca
nnot
be ca
ll
ed
th
e
org
a
nism
g
e
nom
e
(
T
riwi
b
owo
G
r
e
uno
,
2002
).
T
h
e d
iv
e
rsity of lif
e
on
ea
rth to
da
y
is th
e
r
e
sult of
e
volution involving g
e
n
e
s in r
e
gul
a
ting g
e
n
e e
xpr
e
ssion
to pro
d
u
ce
mor
e
p
e
rf
ec
t
a
n
d ada
ptiv
e
org
a
nisms
.
Ge
n
e
s th
a
t
c
ontrol
de
v
e
lopm
e
nts pl
a
y
a
n import
a
nt rol
e
in th
e e
m
e
rg
e
n
ce
of n
e
w
stru
c
tur
e
s
d
u
e
to
e
volution
.
Ge
n
e
s th
a
t r
e
gul
a
t
e
th
e de
v
e
lopm
e
nt of org
a
nisms
a
ff
ec
t th
e
p
ace
,
tim
e
,
a
n
d
p
a
tt
e
rn of
c
h
a
ng
e
in sh
a
p
e
from zygot
e
to
ad
ulthoo
d
.
T
h
e e
volution of
c
ompl
e
x stru
c
tur
e
s
,
su
c
h
a
s wings
a
n
d
f
ea
th
e
rs
,
involv
e
s m
a
ny g
e
n
e
s
,
b
ut sm
a
ll
c
h
a
ng
e
s in th
e
g
e
nom
e ca
n
ca
us
e
signifi
ca
nt stru
c
tur
a
l
c
h
a
ng
e
s
(
C
h
a
m
be
l
,
1999
).
Sc
i
e
ntists in th
e
fi
e
l
d
of
b
iology of
de
v
e
lopm
e
nt
a
n
d e
volution
a
r
e
trying to fin
d
how sm
a
ll
g
e
n
e
ti
c c
h
a
ng
e
s
ca
n pro
d
u
ce a b
ig
d
iff
e
r
e
n
ce
in v
a
rious org
a
nisms
.
A
lom
e
tri
c
growth
,
th
e d
iff
e
r
e
n
ce
in th
e
growth r
a
t
e
of v
a
rious p
a
rts of
th
e b
o
d
y
,
forms org
a
nisms
.
S
m
a
ll
c
h
a
ng
e
s in this growth r
a
t
e ca
n
signifi
ca
ntly
c
h
a
ng
e
th
e
form of
ad
ult org
a
nisms
,
su
c
h
a
s
d
iff
e
r
e
n
ce
s
be
tw
ee
n hum
a
n skulls
a
n
d c
himp
a
nz
ee
s
.
A
lom
e
try is on
e
m
ec
h
a
nism
wh
e
r
e
sm
a
ll
c
h
a
ng
e
s in
de
v
e
lopm
e
nts
ca
n pro
d
u
ce
m
a
jor
c
h
a
ng
e
s in
ad
ult forms
.
I
n
add
ition to influ
e
n
c
ing th
e
r
a
t
e
of growth
,
g
e
n
e
ti
c
c
h
a
ng
e ca
n
a
lso
c
h
a
ng
e
th
e
tim
e a
n
d
or
de
r of th
e de
v
e
lopm
e
nt of th
e
b
o
d
y
'
s p
a
rts
.
4
I
n som
e
sp
ec
i
e
s
,
c
h
a
ng
e
s
d
uring
de
v
e
lopm
e
nts
ca
n
ca
us
e
p
aed
omorphosis
,
wh
e
r
e ad
ult s
e
xu
a
lly s
e
xu
a
l org
a
nisms m
a
int
a
in
c
h
a
r
ac
t
e
risti
c
s of juv
e
nil
e
.
F
or
e
x
a
mpl
e
,
m
a
ny s
e
xu
a
lly
ad
ult
Sa
l
a
m
a
n
de
r sp
ec
i
e
s still h
a
v
e
gills l
a
rv
ae
.
T
his
e
volution
a
ry
c
h
a
ng
e ca
n
pro
d
u
ce a
nim
a
ls th
a
t look
d
iff
e
r
e
nt from th
e
ir
a
n
ce
stors
de
spit
e a
littl
e
g
e
n
e
ri
c c
h
a
ng
e
.
H
om
e
os
e
s
,
n
a
m
e
ly
c
h
a
ng
e
s in th
e ba
ill
a
n org
a
nism
,
a
r
e a
lso
import
a
nt in
e
volution
.
H
om
e
otog g
e
n
e
s fun
c
tion
a
s
a
m
a
jor
de
v
e
lopm
e
nt swit
c
h
,
for
e
x
a
mpl
e de
t
e
rmining th
e
lo
ca
tion of th
e
wings
a
n
d
f
ee
t in
b
ir
d
s
.
M
ut
a
tions on th
e
hom
e
otik
e
g
e
n
e
s oft
e
n
ca
us
e
m
a
jor
c
h
a
ng
e
s in th
e B
ou
b
l
a
n
.
A
roun
d
520
million y
ea
rs
a
go
,
th
e d
upli
ca
tion
of th
e HOX c
ompl
e
x hous
e
s of th
e HOX
m
a
y h
a
v
e a
ff
ec
t
ed
v
e
rt
eb
r
a
t
e
a
n
d
inv
e
rt
eb
r
a
t
e e
volution
.
T
h
e
v
e
rt
eb
r
a
t
e
h
a
s m
a
ny
c
oll
ec
tions of hox
g
e
n
e
s
,
whil
e
m
a
ny inv
e
rt
eb
r
a
t
e
s only h
a
v
e
on
e c
oll
ec
tion of gigs of hox
.
C
h
a
ng
e
s in th
e d
yn
a
mi
c
s of
de
v
e
lopm
e
nt
,
b
oth t
e
mpor
a
l
a
n
d
sp
a
ti
a
l
,
pl
a
y
a
n import
a
nt rol
e
in m
ac
ro
e
volution
.
F
urth
e
r r
e
s
ea
r
c
h
ca
n h
e
lp
un
de
rst
a
n
d
th
e
r
e
l
a
tionship
be
tw
ee
n th
e
tr
a
nsf
e
r g
e
n
e a
n
d
e
volution
a
ry g
e
n
e
mut
a
tion
.
F
or
e
x
a
mpl
e
,
th
e d
upli
ca
tion of th
e
hox
g
e
n
e
on th
e
initi
a
l v
e
rt
eb
r
a
t
e
might h
a
v
e a
ff
ec
t
ed
th
e de
v
e
lopm
e
nt of
th
e
spin
e a
n
d
j
a
w on v
e
rt
eb
r
a
t
e
s
,
in
d
i
ca
ting th
a
t th
e
g
e
n
e
hox on
homolog v
e
rt
eb
r
a
t
e
s with
a
singl
e
g
e
n
e
s on inv
e
rt
eb
r
a
t
e
s
.
B
.
Va
ri
a
tion
Ge
nom
e
siz
e be
tw
ee
n org
a
nisms
1
.
T
h
e
v
a
lu
e
of
C
.
I
n h
a
ploi
d
org
a
nisms su
c
h
a
s
bac
t
e
ri
a
,
g
e
nom
e
siz
e
is th
e
tot
a
l
num
be
r of
DNA
in th
e
g
e
nom
e
.
I
n
a d
iploi
d
or polypoi
d
org
a
nism
,
th
e
g
e
nom
e
siz
e
is
de
fin
ed a
s th
e
num
be
r of
DNA
in th
e
h
a
ploi
d
g
e
nom
e
th
a
t
d
o
e
s not
e
xp
e
ri
e
n
ce
r
e
pli
ca
tion
,
su
c
h
a
s th
e
sp
e
rm
c
or
e
.
T
h
e
g
e
nom
e
siz
e
is
a
lso known
a
s th
e
v
a
lu
e
of
C
,
whi
c
h r
e
fl
ec
ts th
a
t th
e
siz
e
of th
e
h
a
ploi
d
g
e
nom
e
is r
e
l
a
tiv
e
ly st
ab
l
e
in on
e
sp
ec
i
e
s
,
a
lthough
th
e
v
a
lu
e
of
C
v
a
ri
e
s
be
tw
ee
n sp
ec
i
e
s
,
b
oth prok
a
ryoti
c a
n
d e
uk
a
ryoti
c
.
I
n
e
uk
a
riot
,
th
e
g
e
nom
e
siz
e
is usu
a
lly m
ea
sur
ed
in th
e P
i
c
ogr
a
m
(
PG
)
DNA
(
1
pg
=
10
^ -
12
g
).
T
h
e
sm
a
ll
e
st g
e
nom
e
on prok
a
riot is
5
usu
a
lly st
a
t
ed
in
Da
lton
,
a
mol
ec
ul
a
r m
a
ss unit
.
T
h
e
sm
a
ll g
e
nom
e
siz
e
or th
e
l
e
ngth of th
e DNA c
h
a
in is oft
e
n
e
xpr
e
ss
ed
in th
e ba
s
e
p
a
ir
(
BP
)
or kilo
ba
s
a
p
a
ir
(
KB
) (
1
KB
=
1000
BP
),
whil
e
th
e c
ompl
e
t
e
g
e
nom
e
s
e
qu
e
n
ce
is usu
a
lly m
ea
sur
ed
in m
e
g
aba
s
e
p
a
irs
(
1
MB
=
1000
KB
).
2
.
T
h
e e
volution of
S
iz
e Ge
nom
e
on th
e P
rok
a
riot
T
h
e
siz
e
of th
e bac
t
e
ri
a
l g
e
nom
e
v
a
ri
e
s from
20
-
30
thous
a
n
d
tim
e
s
,
st
a
rting from th
e
sm
a
ll
e
st
,
whi
c
h is
6
x
10
^
5
BP
in som
e
intr
ace
llul
a
r p
a
r
a
sit
e
s
Ob
ig
a
t
e
,
up to mor
e
th
a
n
10
^
7
BP
in s
e
v
e
r
a
l
c
y
a
no
bac
t
e
ri
a
l sp
ec
i
e
s
(
Tab
l
e
2
.
2
).
M
olli
c
ut
e
s
,
who
d
o not h
a
v
e ce
ll
w
a
lls
a
n
d a
r
e
prok
a
ryot
e
s th
a
t liv
e
fr
ee
ly
a
n
d ca
n r
e
pro
d
u
ce
th
e
ms
e
lv
e
s
,
g
e
n
e
r
a
lly h
a
v
e a
v
e
ry sm
a
ll g
e
nom
e
.
T
h
e M
olli
c
ut
e
s
c
l
a
ss
c
onsists of six
c
l
a
ns
,
with my
c
opl
a
sm
a a
s th
e
most f
a
mous
.
O
ft
e
n
,
th
e
t
e
rm my
c
opl
a
sm
a
is us
ed
to r
e
f
e
r to
a
ll sp
ec
i
e
s of
M
olli
c
ut
e
.
T
h
e
sm
a
ll
e
st g
e
nom
e
known to
be
th
e
p
a
thog
e
n of th
e M
y
c
opl
a
sm
a
g
e
nit
a
lium urog
e
nit
a
l
,
whi
c
h h
a
s
a
roun
d
470
prot
e
in
c
o
d
ing g
e
n
e
s
,
3
sp
ec
ifi
c RRNA
g
e
n
e
s
,
a
n
d
33
sp
ec
ifi
c TRNA
g
e
n
e
s
.
Ge
n
e
s in th
e
g
e
nom
M
.
Ge
nit
a
lium is
c
onsi
de
r
ed
only slightly mor
e
th
a
n th
e
minimum
a
mount n
eeded
for in
de
p
e
n
de
nt lif
e
.
O
th
e
r
bac
t
e
ri
a
h
a
v
e a
num
be
r of
g
e
n
e
s th
a
t v
a
ry from
a
roun
d
500
to
8000
,
or
ab
out
20
tim
e
s mor
e
.
I
n
oth
e
r wor
d
s
,
g
e
n
e
s of g
e
n
e
s
a
r
e a
lmost
e
quiv
a
l
e
nt to v
a
ri
a
tions in th
e
v
a
lu
e
of
C
.
T
h
e a
v
e
r
a
g
e
siz
e
of prot
e
in
c
o
d
ing g
e
n
e
s in
bac
t
e
ri
a
is
a
roun
d
1
KB
,
with g
e
n
e
s in th
e
g
e
nom
e
in
a
n
e
stim
a
t
ed
500
KB
to
1
MB
.
T
his
shows th
a
t prok
a
riot
d
o
e
s not
c
ont
a
in non
-
g
e
ni
ca
l
DNA
in l
a
rg
e
qu
a
ntiti
e
s
,
with th
e
m
a
jority of prot
e
in
c
o
d
ing s
e
qu
e
n
ce
s r
eac
hing
87
-
94
%
of th
e
g
e
nom
e
,
so non
-
g
e
ni
ca
l f
ac
tions s
ee
m r
e
l
a
tiv
e
ly sm
a
ll
.
T
h
e
e
x
ce
ption is
a
n intr
ace
llul
a
r g
e
nom
e
p
a
r
a
sit
e R
i
c
k
e
ttsi
a P
row
a
z
e
kii
,
whi
c
h
c
ont
a
ins
24
%
non
-
c
o
d
ing
DNA
.
F
or
bac
t
e
ri
a
,
c
ompl
e
t
e
s
e
qu
e
n
ce
s m
a
k
e
it possi
b
l
e
to
ca
l
c
ul
a
t
e
th
e c
orr
e
l
a
tion
be
tw
ee
n th
e
g
e
nom
e
siz
e a
n
d
th
e
num
be
r of g
e
n
e
s
(
s
ee F
igur
e
2
.
1
).
T
his
c
orr
e
l
a
tion
is
a
lmost p
e
rf
ec
t
,
in
d
i
ca
ting th
a
t v
a
ri
a
tions in th
e
siz
e
of th
e bac
t
e
ri
a
l
g
e
nom
e ca
n
be
fully
e
xpl
a
in
ed b
y th
e
num
be
r of g
e
n
e
s
.
A
simil
a
r
c
orr
e
l
a
tion is
a
lso foun
d
in
A
r
c
h
aea
,
a
lthough
c
urr
e
nt
da
t
a
is limit
ed
to
6
m
a
king sur
e c
on
c
lusions
.
Bac
t
e
ri
a
l g
e
nom
e
s
a
r
e d
ivi
ded
into thr
ee
f
ac
tions
: (
1
)
c
hromosom
a
l
DNA
, (
2
)
DNA
pl
a
smi
d
,
a
n
d
(
3
)
tr
a
nspos
ab
l
e e
l
e
m
e
nts
.
T
h
e c
hromosom
a
l fr
ac
tion in
c
lu
de
s prot
e
in
c
o
d
ing g
e
n
e
s for growth
a
n
d
m
e
t
ab
olism
(
90
-
95
%
),
sign
a
l s
e
ttings
(
a
roun
d
5
%
),
RNA
-
sp
ec
ifi
c
g
e
n
e
s
(~
1
%
),
a
n
d
r
ec
urr
e
nt s
e
qu
e
n
ce
s in
a ba
s
e
of
ba
s
e
.
S
om
e
bac
t
e
ri
a b
ring pl
a
smi
d
s
a
s
add
ition
a
l g
e
n
e
ti
c e
l
e
m
e
nts
,
a
n
d
in som
e
ca
s
e
s
,
g
e
n
e
s from pl
a
smi
d
s
ca
n join
bac
t
e
ri
a
l
c
hromosom
e
s
.
T
r
a
nspos
ab
l
e e
l
e
m
e
nts
a
r
e
p
a
rt of th
e bac
t
e
ri
a
l g
e
nom
e
;
F
or
e
x
a
mpl
e
,
th
e
wil
d
str
a
in of
E
s
c
h
e
ri
c
hi
a C
oli h
a
s
1
-
10
c
opi
e
s of th
e
six typ
e
s of
ins
e
rtion s
e
qu
e
n
ce
s
.
T
h
e
non
-
g
e
n
e
ti
c
f
ac
tion of th
e
g
e
nom
e
(
in
c
lu
d
ing
ins
e
rtion s
e
qu
e
n
ce
,
pl
a
smi
d
,
a
n
d bac
t
e
rioph
a
g
e
s
)
a
pp
ea
rs in
a
sm
a
ll
e
r
or
de
r th
a
n th
e c
hromosom
e
fr
ac
tion
.
Re
s
ea
r
c
h
a
lso shows th
e
e
xist
e
n
ce
of fun
c
tion
a
l g
e
n
e
s of horizont
a
l g
e
n
e
tr
a
nsf
e
r r
e
sults
.
T
h
e d
istri
b
ution of
bac
t
e
ri
a
l g
e
nom
e
siz
e
shows m
a
jor v
a
lu
e
s
a
roun
d
0
.
8
x
10
^
6
,
1
.
6
x
10
^
6
,
a
n
d
4
.
0
x
10
^
6
b
p
,
with
a
minor v
a
lu
e
a
t
7
.
2
x
10
^
6
a
n
d
8
.
0
x
10
^
6
b
p
.
T
his
e
n
c
our
a
g
e
s th
e a
ll
e
g
a
tions th
a
t
th
e b
ig g
e
nom
e a
s in
E
.
c
oli
de
v
e
lops from
a
sm
a
ll g
e
nom
e
through
r
ec
urr
e
nt
d
upli
ca
tion
.
H
ow
e
v
e
r
,
a
lot of
da
t
a
shows th
a
t this
d
istri
b
ution p
ea
k is lost
d
u
e
to th
e acc
umul
a
tion of g
e
nom
e
siz
e da
t
a
.
A
t pr
e
s
e
nt
,
th
e d
istri
b
ution of
bac
t
e
ri
a
l g
e
nom
e
s g
e
n
e
r
a
lly looks
c
ontinuous
.
Re
s
ea
r
c
h on g
e
nom
e
siz
e a
n
d bac
t
e
ri
a
l phylog
e
ny shows th
a
t th
e
add
ition of g
e
nom
e
siz
e
o
cc
urs gr
ad
u
a
lly in th
e
lin
ea
g
e
of
bac
t
e
ri
a
.
F
ilog
e
ni stu
d
i
e
s
ba
s
ed
on
RRNA
s
e
qu
e
n
c
ing in
d
i
ca
t
e c
h
a
ng
e
s in
g
e
nom
e
siz
e
th
a
t o
cc
ur in
de
p
e
n
de
ntly in v
a
rious
bac
t
e
ri
a
l lin
ea
g
e
s
.
Ma
ny
add
ition
a
l g
e
nom
e
siz
e
o
cc
urs in
ce
rt
a
in lin
e
s
a
n
d
in
ce
rt
a
in
p
e
rio
d
s in th
e
history of
e
volution
,
su
c
h
a
s
a
roun
d
1
.
8
b
illion y
ea
rs
a
go
wh
e
n th
e
oxyg
e
n
c
on
ce
ntr
a
tion in th
e a
tmosph
e
r
e
is not y
e
t st
ab
l
e
.
T
h
e d
istri
b
ution of g
e
nom
e
siz
e
in
bac
t
e
ri
a ca
n
be e
xpl
a
in
ed b
y
s
e
v
e
r
a
l pro
ce
ss
e
s
: (
1
)
in
de
p
e
n
de
nt g
e
n
e
s
a
n
d
op
e
rons
d
upli
ca
tion
, (
2
)
sm
a
ll
-
s
ca
l
e
r
e
mov
a
l
a
n
d
ins
e
rtion
, (
3
)
D
upli
ca
tiv
e
tr
a
nsposition
, (
4
)
7
H
orizont
a
l g
e
n
e
tr
a
nsf
e
r from
P
l
a
smi
d
s
a
n
d bac
t
e
rioph
a
g
e
s
a
n
d
from
oth
e
r sp
ec
i
e
s
,
a
n
d
(
5
)
th
e
r
e
mov
a
l of l
a
rg
e DNA
in p
a
r
a
sit
e
s
.
3
.
Ge
nom
e
T
h
e
s
ea
r
c
h for g
e
nom
e
s for
"
th
e
sm
a
ll
e
st
a
utonomi
ca
l
r
e
pli
ca
tion form
"
be
g
a
n th
e
l
a
t
e
1950
s
b
y
M
orowitz
a
n
d
his t
ea
m
,
with
a
fo
c
us on th
e
initi
a
l molli
c
ut
e
s
,
ce
llul
a
r org
a
nisms with th
e
sm
a
ll
e
st
g
e
nom
e
.
T
h
e
r
e
is no
e
vi
de
n
ce
th
a
t
468
prot
e
in
c
o
d
ing g
e
n
e
s in
M
.
g
e
nit
a
lium r
e
fl
ec
ts th
e
minimum n
eed
for surviv
a
l
.
T
h
e
r
e
m
a
y
be
r
ed
un
da
n
c
y
a
n
d
g
e
n
e e
ffi
c
i
e
n
c
y th
a
t is not visi
b
l
e
to th
e
most minim
a
l
g
e
nom
e
.
He
r
e a
r
e
two
a
ppro
ac
h
e
s to
de
t
e
rmin
e
th
e
minimum g
e
n
e
s
e
t
for
ce
llul
a
r lif
e
.
A
n
a
lyti
ca
l
a
ppro
ac
h
:
T
h
e
initi
a
l
e
stim
a
t
e
of th
e
minimum g
e
n
e
is
d
on
e b
y i
de
ntifying g
e
n
e
s
of g
e
n
e
s th
a
t
a
r
e c
ommon in v
a
rious org
a
nisms
.
F
or
e
x
a
mpl
e
,
a
prot
e
om
e c
omp
a
rison
be
tw
ee
n
E
.
c
oli
,
H
.
influ
e
nz
ae
,
a
n
d M
.
g
e
nit
a
lium
shows
a
minimum g
e
n
e e
stim
a
t
e
is
239
g
e
n
e
s
.
I
n
add
ition to prot
e
in
c
o
d
ing g
e
n
e
s
,
som
e
vit
a
l g
e
n
e
s must
a
lso
be
in
c
lu
ded beca
us
e
of th
e
ph
e
nom
e
non of
"
nonorthologous g
e
n
e
s
"
whi
c
h might hi
de
som
e
import
a
nt fun
c
tions
.
F
or
e
x
a
mpl
e
,
gly
c
olyti
c e
nzym
e
s on
phosphogly
ce
r
a
t
e
mut
a
tions show two
d
iff
e
r
e
nt prot
e
ins without
d
ir
ec
t
c
onn
ec
tion
.
I
n
M
.
g
e
nit
a
lium
,
this fun
c
tion is in
d
i
ca
t
ed b
y th
e Ge
n of
Y
i
b
o
,
whil
e
in
H
.
influ
e
nz
ae
,
b
y
GPM
g
e
n
e
.
Beca
us
e
of this
d
iff
e
r
e
n
ce
,
P
rot
e
om
e
quipm
e
nt
d
o
e
s not
c
ont
a
in
b
oth g
e
n
e
s
,
e
v
e
n though
b
oth
m
a
y
be
n
eeded
for surviv
a
l
.
Ta
king into
acc
ount th
e
tr
a
nsf
e
r of
nonorphologous g
e
n
e
s
,
th
e
initi
a
l
e
stim
a
t
e
of minimum g
e
n
e
s is
256
g
e
n
e
s
.
E
xp
e
rim
e
nt
a
l
A
ppro
ac
h
:
T
h
e e
xp
e
rim
e
nt
a
l
a
ppro
ac
h involv
e
s mut
a
g
e
n
e
sis in th
e
79
lo
c
us
c
o
de
rs of prot
e
in
c
o
de
rs in
B
.
su
b
tilis
.
M
ut
a
tions on
6
lo
ca
tions
ca
using
bac
t
e
ri
a ca
nnot grow
,
whil
e
73
oth
e
r lo
c
us
e
s r
e
m
a
in fun
c
tion
a
l
.
O
nly
6
8
g
e
n
e
s th
a
t
c
l
ea
rly h
a
v
e
import
a
nt fun
c
tions
,
su
c
h
a
s
DNAA a
n
d DNAB
for
DNA
r
e
pli
ca
tion
,
a
n
d RPOD
for
RNA
synth
e
sis
.
O
f th
e
79
lo
c
i
,
73
d
i
d
not
a
ff
ec
t growth
,
in
d
i
ca
ting only
ab
out
7
.
5
%
of th
e
g
e
nom
e
s n
eeded
.
W
ith th
e
long
a
ssumption of th
e
g
e
nom
e B
.
su
b
tilis
4
.
2
x
10
^
6
b
p
a
n
d
using
1
.
25
KB a
s
a
m
ea
sur
e
of th
e a
v
e
r
a
g
e
g
e
n
e
,
th
e
minimum g
e
n
e
de
vi
ce
is
e
stim
a
t
ed a
t
a
roun
d
254
g
e
n
e
s
.
A
n
a
lyti
ca
l
a
n
d e
xp
e
rim
e
nt
a
l
r
e
sults show
e
x
ce
ll
e
nt suit
ab
ility
.
4
.
M
ini
a
turiz
a
tion
G
S
om
e
g
e
n
e
r
a
l
c
on
c
lusions r
e
g
a
r
d
ing morphologi
ca
l
e
volution
show th
a
t g
e
nom
e
siz
e
r
ed
u
c
tion is oft
e
n r
e
l
a
t
ed
to loss of fun
c
tion
.
F
or
e
x
a
mpl
e
,
th
e
lif
e
form of p
a
r
a
sit
e
s or
e
n
d
osim
b
ioti
c
s g
e
n
e
r
a
lly
e
xp
e
ri
e
n
ce
s
a
signifi
ca
nt g
e
nom
e de
pr
ec
i
a
tion
.
E
n
d
os
e
lul
a
r p
a
r
a
sit
e
bac
t
e
ri
a
g
e
nom
e
s h
a
v
e a
sm
a
ll siz
e
.
De
pr
ec
i
a
tion of th
e
g
e
nom
e ca
n
o
cc
ur in two w
a
ys
:
tr
a
nsf
e
r g
e
n
e
s or loss of g
e
n
e
s
.
Ge
nom
e
siz
e
r
ed
u
c
tion is oft
e
n r
e
l
a
t
ed
to
e
n
d
osym
b
osis
a
n
d
p
a
r
a
sitism
.
Red
u
c
tion of g
e
nom
e
siz
e d
u
e
to
e
n
d
osim
b
iosis
S
ignifi
ca
nt g
e
nom
e de
pr
ec
i
a
tion o
cc
urs
a
ft
e
r
e
n
d
osym
b
osis
,
a
s
s
ee
n in mito
c
hon
d
ri
a a
n
d c
hloropl
a
sts
.
S
om
e
org
a
n
e
ll
e
s m
a
y
d
is
a
pp
ea
r
without
a
r
e
pl
ace
m
e
nt
,
whil
e
oth
e
rs mov
e
to th
e c
or
e
g
e
nom
e
.
F
or
e
x
a
mpl
e
,
th
e
y
ea
st g
e
nom
e
h
a
s
a
roun
d
300
prot
e
in
c
o
d
ing g
e
n
e
s
whos
e
fun
c
tions
a
r
e
pr
e
viously in th
e
mito
c
hon
d
ri
a
,
whi
c
h now only
h
a
s
8
prot
e
in
c
o
d
ing g
e
n
e
s
.
T
h
e
g
e
nom
e
of th
e
mito
c
hon
d
ri
a
l fl
a
g
e
l
a
h
e
t
e
rotrop su
c
h
a
s r
ec
limon
a
s
A
m
e
ri
ca
n
a
is
a
lso v
e
ry sm
a
ll
,
only
c
ont
a
ins
62
prot
e
in
c
o
d
ing g
e
n
e
s
.
Be
si
de
s mito
c
hon
d
ri
a a
n
d
c
hloropl
a
sts
,
oth
e
r
e
uk
a
ryoti
c
org
a
n
e
ll
e
s m
a
y
a
lso
c
om
e
from
e
n
d
osim
b
iosis
.
Ma
rgululis
a
n
d
his
c
oll
ea
gu
e
s
(
1979
)
a
rgu
e
th
a
t th
e
fl
a
g
e
l
,
sili
a
,
a
n
d
oth
e
r motil
e ce
ll org
a
n
e
l
e
ts
c
om
e
from spiro
c
h
e
t
e
s
th
a
t
a
r
e
sym
b
ioti
c
with
e
uk
a
ryoti
c a
n
ce
stors
.
I
f tru
e
,
this org
a
n
e
l is
lik
e
ly to h
a
v
e e
xp
e
ri
e
n
ced a
n
e
xtr
e
m
e
g
e
nom
e
shrink
a
g
e
.
A
noth
e
r
e
x
a
mpl
e
is
C
hlor
a
r
aC
hniophyt
a
,
A
mo
eba
fl
a
vor
ed
th
a
t g
a
in
ed
photosynth
e
sis
ca
p
ab
iliti
e
s of
e
n
d
osim
b
ion gr
ee
n
a
lg
ae
.
A
lg
ae
e
n
d
osim
b
ion m
a
int
a
ins
c
hloropl
a
sts
,
nu
c
l
e
us
,
c
ytopl
a
sm
,
a
n
d
pl
a
sm
a
9
m
e
m
b
r
a
n
e
s
,
whil
e
nu
c
l
e
us sm
a
ll
(
nu
c
l
e
orph
)
only
c
ont
a
ins
a
roun
d
380
,
000
BP
,
m
a
king it th
e
sm
a
ll
e
st
e
uk
a
ryoti
c
g
e
nom
e
.
T
h
e
nu
c
l
e
omorph g
e
nom
e
shows high
de
nsity
,
with
a d
ist
a
n
ce be
tw
ee
n
g
e
n
e
s of mor
e
th
a
n
65
BP a
n
d
som
e
g
e
n
e
th
a
t
e
xp
e
ri
e
n
ce
s
ov
e
rl
a
pping
a
n
d
tr
a
ns
c
ription
.
Ge
nom
e
siz
e
r
ed
u
c
tion in p
a
r
a
sit
e
s
Pa
r
a
sitism involv
e
s
c
los
e
r
e
l
a
tions
be
tw
ee
n th
e
host
a
n
d
p
a
r
a
sit
e
s
,
wh
e
r
e
th
e
host provi
de
s m
e
t
ab
oli
c a
n
d
physiologi
ca
l r
e
quir
e
m
e
nts for
p
a
r
a
sit
e
s
.
Pa
r
a
sit
e
s oft
e
n
e
xp
e
ri
e
n
ce
g
e
nom
e
siz
e
r
ed
u
c
tion
d
u
e
to
loss of g
e
n
e
ti
c
fun
c
tion
.
F
or
e
x
a
mpl
e
,
E
piph
a
gus
V
irgini
a
n
a
,
nonfotosinti
c
p
a
r
a
sit
e
s from th
e La
v
e
n
de
r f
a
mily
,
h
a
v
e a
v
e
ry sm
a
ll
c
hloropl
a
st g
e
nom
e
(~
70
,
000
b
p
)
with only
42
g
e
n
e
s
.
Ge
n
e
s for
photosynth
e
sis
a
n
d c
hlorosp
ac
y
d
o not
e
xist
.
Mea
nwhil
e
,
my
c
opl
a
sm
a
g
e
nit
a
lium is
a ce
llul
a
r p
a
r
a
sit
e
th
a
t
e
xp
e
ri
e
n
ce
s g
e
nom
e de
pr
ec
i
a
tion
d
u
e
to losing g
e
n
e
s
.
T
o m
a
int
a
in p
a
r
a
sitism
,
my
c
opl
a
sm
a de
v
e
lops
sp
ec
i
a
l g
e
n
e
s for
ad
h
e
sin
c
o
d
ing
,
org
a
n
e
ll
e
s
,
a
n
d
v
a
ri
ed
surf
ace
prot
e
ins to
a
voi
d
th
e
immun
e
syst
e
m
.
5
.
Ge
nom
e S
iz
e
on th
e E
uk
a
riot
a
n
d T
h
e
v
a
lu
e
of
CPa
r
ad
ox
T
h
e
v
a
lu
e
of
C
in
e
uk
a
riot is g
e
n
e
r
a
lly high
e
r th
a
n prok
a
riot
,
e
v
e
n though th
e
r
e a
r
e e
x
ce
ptions
.
F
or
e
x
a
mpl
e
,
Sacc
h
a
romy
ce
s
ce
r
e
visi
ae
h
a
s
a
g
e
nom
e
siz
e
th
a
t is
a
lmost th
e
s
a
m
e a
s som
e
gr
a
m
positiv
e bac
t
e
ri
a
su
c
h
a
s str
e
ptomy
ce
s
c
o
e
li
c
olor
a
n
d S
.
rimo
d
i
c
,
a
n
d
sm
a
ll
e
r th
a
n most sp
ec
i
e
s of
c
y
a
no
bac
t
e
ri
a
,
e
sp
ec
i
a
lly th
e
g
e
nus
ca
lothrix
H
ow
e
v
e
r
,
beca
us
e E
uk
a
riot
e
xp
e
ri
e
n
ced d
ou
b
l
e DNA
r
e
pli
ca
tion
,
th
e
y
c
oul
d
h
a
v
e a
num
be
r of
DNA
p
e
r unit of tim
e
gr
ea
t
e
r
th
a
n
P
rok
a
riot
.
Va
ri
a
tions of
C
v
a
lu
e
s in
e
uk
a
riot
a
r
e
f
a
r gr
ea
t
e
r th
a
n
bac
t
e
ri
a
,
from
8
.
8
x
10
^
6
b
p to
6
.
9
x
10
^
11
b
p
,
a
roun
d
80
,
000
tim
e
s
.
U
ni
ce
llul
a
r protists
,
su
c
h
a
s
A
mo
eba Sa
r
c
o
d
in
e
,
show
ed a
v
e
ry l
a
rg
e
v
a
ri
a
tion of
C
v
a
lu
e
s
,
r
eac
hing
20
,
000
tim
e
s
.
F
or
c
omp
a
rison
,
th
e
v
a
lu
e
r
a
ng
e
of
C
in
a
ll
K
ing
d
om
A
nim
a
li
a
,
from porif
e
r
a
to hum
a
ns
,
is only
a
roun
d
3
,
000
tim
e
s
.
T
hr
ee c
l
a
ss
a
mnioti
a
s
(
m
a
mm
a
ls
,
b
ir
d
s
a
n
d
r
e
ptil
e
s
)
h
a
v
e
sm
a
ll
e
r g
e
nom
e
v
a
ri
a
tions
(
up to four tim
e
s
),
whil
e
oth
e
r
10
c
l
a
ss
e
s show
a
minimum v
a
ri
a
tion of
100
tim
e
s
.
I
nt
e
r
e
stingly
,
v
a
ri
a
tions in g
e
nom
e
siz
e
in
e
uk
a
riot
d
o not s
ee
m
to
be
r
e
l
a
t
ed
to th
e c
ompl
e
xity of th
e
org
a
nism or th
e
num
be
r of g
e
n
e
s
th
a
t
a
r
e c
o
ded
.
S
om
e
uni
ce
llul
a
r protozo
a
h
a
s mor
e DNA
th
a
n mor
e
c
ompl
e
x m
a
mm
a
ls
.
T
h
e
org
a
nisms with
c
ompl
e
x morphology
a
n
d
a
n
a
tomy
,
su
c
h
a
s
Pa
r
a
m
ec
ium
A
ur
e
li
a a
n
d P
.
Ca
u
da
tum
,
show
a
l
a
rg
e
v
a
ri
a
tion of
C
v
a
lu
e
s
.
M
is
c
ustom
ed be
tw
ee
n
C
v
a
lu
e
s
a
n
d
g
e
n
e
ti
c
inform
a
tion m
a
k
e
s this ph
e
nom
e
non
a
s
"
C Pa
r
ad
ox v
a
lu
e
".
F
or
e
x
a
mpl
e
,
sp
ec
i
e
s with morphology simil
a
r oft
e
n h
a
v
e a
l
a
rg
e
v
a
lu
e
of
C
v
a
lu
e
s
,
a
lthough th
e c
ompl
e
xity of th
e
org
a
nism is no
d
iff
e
r
e
nt
.
T
his r
a
is
e
s
qu
e
stions
ab
out
e
x
ce
ss
DNA
in sp
ec
i
e
s
.
T
h
e
m
a
in qu
e
stion is wh
e
th
e
r th
e
g
e
nom
e
siz
e
is r
e
l
a
t
ed
to th
e
num
be
r of g
e
n
e
s
.
D
o
e
s
C
v
a
ri
a
tion
C ca
us
ed b
y
Ge
ni
c a
n
d
non
-
Ge
ni
c
DNA
?
I
f v
a
ri
a
tions
C ca
us
ed b
y g
e
n
e
s
,
th
e d
iff
e
r
e
n
ce ca
n
be a
ttri
b
ut
ed
b
y
:
1
)
th
e
num
be
r of prot
e
in
c
o
d
ing g
e
n
e
s
,
2
)
prot
e
in siz
e
,
3
)
th
e
siz
e
of
th
e
prot
e
in
c
o
d
ing g
e
n
e
,
or
4
)
th
e
num
be
r
a
n
d
siz
e
of th
e
non
-
c
o
ded
g
e
n
e
.
W
ithout
de
t
e
rmining th
e c
ompl
e
t
e
g
e
nom
e
s
e
qu
e
n
ce
,
de
t
e
rmining th
e
num
be
r of g
e
n
e
s in
d
iffi
c
ult sp
ec
i
e
s
.
I
n prot
e
in
a
n
a
lysis
,
two
-
d
im
e
nsion
a
l g
e
l
e
l
ec
trophor
e
sis is us
ed
to s
e
p
a
r
a
t
e
prot
e
in
ba
s
ed
on pr
e
ssur
e a
n
d
iso
e
l
ec
tri
c
points
.
T
h
e
r
e
sult is
a
spot
p
a
tt
e
rn with
a
siz
e
th
a
t v
a
ri
e
s in
a
ll g
e
l
.
T
h
e
num
be
r of spots
ca
n h
e
lp
e
stim
a
t
e
th
e a
mount of prot
e
in in
ce
lls
.
H
ow
e
v
e
r
,
s
e
p
a
r
a
tion is oft
e
n
l
e
ss
c
l
ea
r
,
a
n
d
th
e
num
be
r of g
e
n
e
s is usu
a
lly un
de
r
e
stim
a
t
ed
.
F
or
e
x
a
mpl
e
,
th
e
num
be
r of prot
e
in
c
o
d
ing g
e
n
e
s in
S
.
ce
r
e
visi
ae
is
e
stim
a
t
ed a
t
a
roun
d
3
,
000
through
e
l
ec
trophor
e
sis
,
whil
e
th
e ac
tu
a
l
num
be
r
ca
n
be
mor
e
th
a
n
d
ou
b
l
e
(
a
roun
d
6
,
200
g
e
n
e
s
).
A
lthough this
m
e
tho
d
provi
de
s
e
stim
a
t
e
s
,
this
a
mount
ca
n
be a
n in
d
i
ca
tor of th
e
r
e
l
a
tiv
e
num
be
r of
ac
tu
a
l g
e
n
e
s
.
T
h
e
num
be
r of prot
e
in
c
o
d
ing g
e
n
e
s in
e
uk
a
riot is g
e
n
e
r
a
lly mor
e
th
a
n
50
tim
e
s
,
b
ut this v
a
ri
a
tion
d
o
e
s not suffi
c
i
e
nt to
e
xpl
a
in th
e d
iff
e
r
e
n
ce
of
80
,
000
tim
e
s in th
e c
or
e DNA
.
T
h
e
num
be
r of g
e
n
e
s is positiv
e
ly r
e
l
a
t
ed
to
c
ompl
e
xity
,
b
ut th
e
g
e
nom
e
siz
e
is not
.
C
ompl
e
xity is
d
iffi
c
ult to
de
fin
e
,
a
n
d
v
a
ri
a
tions in th
e MRNA c
h
a
in
e
xpl
a
in th
e
v
a
lu
e
of
C Pa
r
ad
ox
.
S
m
a
ll
d
iff
e
r
e
n
ce
s
be
tw
ee
n
c
o
d
ing
a
n
d
non
-
c
o
d
ing
a
r
ea
s in v
a
rious org
a
nisms
a
r
e
11
not r
e
l
a
t
ed
to g
e
nom
e
l
e
ngth or g
e
nom
e
siz
e
.
F
or
e
x
a
mpl
e
,
MRNA
in
multi
ce
llul
a
r org
a
nisms is slightly long
e
r th
a
n protists
(
1
,
400
-
2
,
200
BP VS
.
1
,
200
-
1
,
500
BP
).
E
v
e
n so
,
l
a
rg
e
r g
e
nom
e
s
d
on
'
t
a
lw
a
ys pro
d
u
ce
gr
ea
t
e
r
prot
e
in
.
S
iz
e d
iff
e
r
e
n
ce
s
(
su
c
h
a
s intron l
e
ngths
)
d
o not
e
xpl
a
in th
e
v
a
ri
a
tions of g
e
nom
e
siz
e
.
A
nim
a
l g
e
n
e
s
a
r
e
3
-
7
tim
e
s long
e
r th
a
n th
e
protist
e
rs
a
n
d
v
e
rt
eb
r
a
t
e
g
e
n
e
s
2
-
4
tim
e
s long
e
r th
a
n inv
e
rt
eb
r
a
t
e
g
e
n
e
s
,
without th
e
r
e
l
a
tionship
be
tw
ee
n g
e
nom
e
siz
e a
n
d
th
e a
v
e
r
a
g
e
l
e
ngth of
g
e
n
e
s
.
F
or oth
e
r
Ge
ni
c DNA
,
th
e
r
e
is
a
positiv
e c
orr
e
l
a
tion
be
tw
ee
n sp
ec
ifi
c
RNA d
upli
ca
t
e a
n
d
g
e
nom
e
siz
e
.
T
his
c
orr
e
l
a
tion is s
ee
n in th
e
g
e
nom
e
siz
e
a
n
d
th
e
num
be
r of
c
opi
e
s of g
e
n
e
s th
a
t
a
r
e
not tr
a
nsl
a
t
ed
involv
ed
in
c
hromosom
e
r
e
pli
ca
tion
a
n
d
r
ec
om
b
in
a
tion
d
uring myosis
a
n
d
mitosis
.
H
ow
e
v
e
r
,
v
a
ri
a
tions in th
e
num
be
r of sp
ec
ifi
c RNA
-
g
e
n
e
s
a
n
d
non
-
tr
a
nsl
a
t
ed
g
e
n
e
s
ca
nnot
e
xpl
a
in th
e
v
a
ri
a
tion of g
e
nom
e
siz
e
.
C
omp
a
rison of th
e
num
be
r of g
e
nom
e
s
ca
n
be d
on
e b
y
c
omp
a
ring
th
e c
ompl
e
xity of poly
de
nyl polyizom
a
l
RNA
.
T
h
e
tot
a
l l
e
ngth of th
e MRNA
mol
ec
ul
e
pro
d
u
ced b
y
a
p
a
rti
c
ul
a
r n
e
twork shows no
c
orr
e
l
a
tion
be
tw
ee
n
th
e
num
be
r of g
e
n
e
s
a
n
d
g
e
nom
e
siz
e
s
.
F
or
e
x
a
mpl
e
,
th
e c
ompl
e
xity of th
e
polyzom
a
l
RNA
in th
e c
hi
c
k
e
n liv
e
r is
2
x
10
nu
c
l
e
oti
de
s
,
whil
e
in th
e
h
ea
rt of
th
e
mous
e
h
a
lf of th
e a
mount
,
a
lthough th
e
siz
e
of th
e
mous
e
g
e
nom
e
s
mor
e
th
a
n twi
ce
th
e
siz
e
of th
e c
hi
c
k
e
n g
e
nom
e
.
I
n
c
on
c
lusion
,
non
-
g
e
nik
DNA
fr
ac
tions
a
r
e
th
e
m
a
in
ca
us
e
of th
e
v
a
lu
e
of
C Pa
r
ad
ox
.
M
ost
e
uk
a
ryoti
c
g
e
nom
e
s
c
onsist of non
-
g
e
ni
ca
l
DNA
.
I
t
is
e
stim
a
t
ed
th
a
t th
e
num
be
r of non
-
g
e
ni
c DNA
p
e
r
e
uk
a
ryoti
c
g
e
nom
e
v
a
ri
e
s
be
tw
ee
n
3
,
000
to
100
,
000
KB
(
a
roun
d
300
,
000
fol
d
)
a
n
d
in
c
lu
de
s
l
e
ss th
a
n
30
%
to
99
.
998
%
of th
e
g
e
nom
e
.
T
o
e
xpl
a
in th
e e
xist
e
n
ce
of non
-
g
e
nik
DNA
in th
e e
uk
a
riot g
e
nom
e
,
w
e
must
c
onsi
de
r
a
pro
ce
ss th
a
t
ca
n
in
c
r
ea
s
e
th
e
siz
e
of th
e
g
e
nom
e
,
su
c
h
a
s
(
1
)
glo
ba
l in
c
r
ea
s
e
,
wh
e
r
e a
ll
g
e
nom
e
s or m
a
in p
a
rts
,
su
c
h
a
s
c
hromosom
e
s
,
d
upli
ca
t
ed
,
a
n
d
(
2
)
in
c
r
ea
s
e
s
in th
e
r
e
gion
,
wh
e
r
e ce
rt
a
in s
e
qu
e
n
ce
s
a
r
e d
upli
ca
t
ed
pro
d
u
ce
r
e
p
ea
t
ed
DNA
.
12
P
oliploi
d
i
A
long with th
e de
v
e
lopm
e
nt of th
e e
uk
a
riot g
e
nom
e
whi
c
h is f
a
r
gr
ea
t
e
r th
a
n
bac
t
e
ri
a
,
th
e e
volution of
e
uk
a
riot from prok
a
ryot
e
s
ca
us
e
s
a
n in
c
r
ea
s
e
in g
e
nom
e
siz
e
.
O
n
e
m
ec
h
a
nism th
a
t
ca
us
e
s this is
polyploi
d
i
,
whi
c
h is th
e add
ition of
a
s
e
t or mor
e c
hromosom
e
.
O
rg
a
nisms with
4
c
opi
e
s of
c
hromosom
e
s
a
r
e ca
ll
ed
t
e
tr
a
ploi
d
,
with
6
c
opi
e
s
ca
ll
ed
h
e
x
a
ploi
d
,
a
n
d
so on
.
Ga
m
e
t from polypoi
d
org
a
nisms is
not h
a
ploi
d a
n
d
h
a
s
a
n o
dd a
utosom
.
F
or
e
x
a
mpl
e
,
triploi
d ba
n
a
n
a
pl
a
nts
(
M
us
a Ac
umin
a
t
a
)
ca
nnot
e
xp
e
ri
e
n
ce
m
e
iosis
a
n
d
s
e
xu
a
l
r
e
pro
d
u
c
tion
.
T
h
e
r
e a
r
e
two m
a
in typ
e
s of polyploi
d
i
:
a
llopolyploi
d
y
,
whi
c
h
o
cc
urs from th
e c
om
b
in
a
tion of
d
iff
e
r
e
nt sp
ec
i
e
s
c
hromosom
e
s
,
a
n
d
a
utopolyphyli
d
y
,
whi
c
h
e
m
e
rg
ed
from
ba
si
c c
hromosom
e d
ou
b
ling
.
A
llopo
L
yploi
d
is oft
e
n foun
d
in pl
a
nts
,
su
c
h
a
s wh
ea
t
(
triti
c
um
ae
stivum
),
whi
c
h is
a
n
a
lloh
e
x
a
ploi
d
of thr
ee
sp
ec
i
e
s of
d
iploi
d
(
ae
gilops
).
A
utopoly
P
loi
d
s o
cc
ur
d
u
e
to g
e
nom
e d
upli
ca
tion
,
su
c
h
a
s
a
utot
e
tr
a
ploi
d
whi
c
h h
a
s four
c
opi
e
s of
c
hromosom
e
s
.
Te
tr
a
ploi
d
is
a
n
a
tur
a
l mut
a
tion th
a
t oft
e
n o
cc
urs in v
a
rious
org
a
nisms
,
in
c
lu
d
ing protists
,
a
lg
ae
,
pl
a
nts
,
mollusks
,
ins
ec
ts
,
a
n
d
m
a
mm
a
ls
.
H
ow
e
v
e
r
,
in
e
volution
,
Te
tr
a
poi
d
s r
a
r
e
ly surviv
e
for s
e
v
e
r
a
l
r
ea
sons
:
th
e
l
e
ngth of
ce
ll
d
ivision
,
in
c
r
ea
s
ed
nu
c
l
e
us volum
e
,
a
n
in
c
r
ea
s
e
in th
e
num
be
r of
c
hromosom
e
s
d
uring m
e
iosis
,
g
e
n
e
ti
c
im
ba
l
a
n
ce
s
,
a
n
d d
isruption of s
e
xu
a
l
d
iff
e
r
e
nti
a
tion
.
H
ow
e
v
e
r
,
som
e
t
e
tr
a
ploi
d
s m
a
y h
a
v
e
no
e
ff
ec
t on ph
e
notyp
e
s
,
su
c
h
a
s th
e C
hrys
a
nth
e
mum sp
ec
i
e
s th
a
t
ca
n h
a
v
e a
num
be
r of
c
hromosom
e
s from
18
to
198
.
f
e
rtil
e
in pl
a
nts
a
n
d a
llows s
e
lf
-
r
e
pro
d
u
c
tion to
ed
g
e
pl
a
nts
.
T
h
e
form
a
tion of
a
n
e
w t
e
tr
a
ploi
d ca
n
ca
us
e d
iff
e
r
e
n
ce
s in th
e
v
a
lu
e
of th
e
g
e
nom
e
,
e
v
e
n though this v
a
lu
e d
o
e
s not
de
p
e
n
d
on th
e
l
e
v
e
l of th
e
polypoi
d
.
T
h
e
g
e
nom
e
th
a
t
d
o
e
s not
e
xp
e
ri
e
n
ce
mut
a
tions
or
c
h
a
ng
e
s in
c
hromosom
e
s
ca
n
be a
n
e
w g
e
nom
e ca
ll
ed
c
ryptopooliploi
d
.
C
ryptopoliploi
d de
s
c
ri
be
s v
a
ri
a
tions in g
e
nom
e
siz
e
in
v
a
rious org
a
nisms
.
13
T
h
e d
istri
b
ution of polymo
da
l g
e
nom
e
siz
e
is foun
d
in
mono
c
ot
a
ll
ed
ons
,
ec
hino
de
rms
,
ins
ec
ts
,
a
n
d
fungi
,
with p
ea
ks
a
t
ce
rt
a
in siz
e
s
.
T
h
e
in
c
r
ea
s
e
in g
e
n
e
s s
ee
ms to
be
th
e
m
a
in m
ec
h
a
nism
of th
e e
volution of g
e
nom
e
siz
e
in
e
uk
a
riot
.
I
n g
e
n
e
r
a
l
,
th
e
m
a
mm
a
li
a
n
g
e
nom
e
is
a
roun
d
1
,
000
tim
e
s gr
ea
t
e
r th
a
n
bac
t
e
ri
a
,
with th
e
d
upli
ca
tion of th
e
g
e
nom
e
th
a
t o
cc
urs on
a
v
e
r
a
g
e e
v
e
ry
300
-
350
million y
ea
rs
,
ca
using th
e
g
e
n
e
siz
e
of th
e bac
t
e
ri
a
to m
a
mm
a
ls
.
P
olisomi
A
n
e
uploi
d
i is
a c
on
d
ition in whi
c
h th
e
num
be
r of
c
hromosom
e
s in
ce
lls
d
o
e
s not m
a
t
c
h th
e
num
be
r of h
a
ploi
d
sp
ec
i
e
s
.
E
uploi
d
i r
e
f
e
rs to
th
e
num
be
r of
c
hromosom
e
s whi
c
h is th
e e
x
ac
t multipl
e
s of th
e
num
be
r of h
a
ploi
d
s
.
A
n
e
uploi
d
i is
d
ivi
ded
into two typ
e
s
:
P
oli
c
yomy
(
d
upli
ca
tion of
a
ll
c
hromosom
e
s
)
a
n
d
p
a
rti
a
l polysomy
(
d
upli
ca
tion of
th
e c
hromosom
e
s
ec
tion
).
P
oli
c
omy is oft
e
n
de
trim
e
nt
a
l
,
a
s in
m
a
lform
a
tions th
a
t
ca
n
ca
us
e dea
th
a
n
d
inf
e
rtility
.
E
x
a
mpl
e
s of
poly
c
omy in hum
a
ns in
c
lu
d
ing
D
own
S
yn
d
rom
e
(
T
risomy
21
)
a
n
d
T
risomy
18
.
Se
v
e
r
e da
m
a
g
e
is oft
e
n
a
sso
c
i
a
t
ed
with p
a
rti
a
l polysomy
,
so th
a
t th
e d
upli
ca
tion of
c
hromosom
e
s
,
b
oth
a
n
d
p
a
rti
a
lly
,
c
ontri
b
ut
e
to
c
h
a
ng
e
s in th
e
siz
e
of th
e
g
e
nom
e
.
Ge
nom
e Yea
st
:
Te
tr
a
ploi
d
i or
d
upli
ca
tion
a
r
ea
?
Sacc
h
a
romy
ce
s
ce
r
e
visi
ae
is susp
ec
t
ed
of
be
ing
c
ryptot
e
tr
a
ploi
d
.
Re
s
ea
r
c
h shows th
a
t
d
upli
ca
tion
a
r
ea
s
ca
n
be
i
de
ntifi
ed
through
: (
1
)
simil
a
riti
e
s in s
e
qu
e
n
ce be
tw
ee
n two r
e
gions
a
n
d
pro
bab
iliti
e
s of l
e
ss
th
a
n
10
^ -
18
, (
2
)
a
r
e
usu
a
lly l
e
ss th
a
n thr
ee
g
e
n
e
s with
a
n int
e
rg
ea
r
d
ist
a
n
ce
of l
e
ss th
a
n
50
KB
,
a
n
d
(
3
)
c
ons
e
rv
a
tion of g
e
n
e
s ori
e
nt
ed
g
e
n
e
s
Ce
ntrom
e
r
.
Ba
s
ed
on th
e
s
e c
rit
e
ri
a
,
W
olf
e a
n
d S
hi
e
l
d
s
(
1997
)
i
de
ntifi
ed
54
d
upli
ca
tion
a
r
ea
s th
a
t
d
i
d
not ov
e
rl
a
p
,
c
ov
e
ring
a
roun
d
50
%
of th
e
y
ea
st g
e
nom
e
.
T
h
e
r
e a
r
e
two possi
b
l
e e
xpl
a
n
a
tions for this
: (
1
)
d
upli
ca
tion
a
r
ea
s
form in
de
p
e
n
de
ntly with m
a
ny r
e
gion
a
l
d
upli
ca
tions th
a
t o
cc
ur
a
t
d
iff
e
r
e
nt tim
e
s
d
uring
e
volution
S
.
ce
r
e
visi
ae
,
or
(
2
)
d
upli
ca
tion
a
r
ea
s
a
r
e
g
e
n
e
r
a
t
ed
simult
a
n
e
ously through singl
e
t
e
tr
a
ploi
d
iz
a
tion
e
v
e
nts
F
ollow
ed b
y r
e
org
a
niz
a
tion of g
e
nom
e
s
a
n
d
losing m
a
ny r
ed
un
da
nt
14
d
upli
ca
tion g
e
n
e
s
.
T
wo r
ea
sons support th
e
s
ec
on
d
mo
de
l
:
F
irst
,
50
d
upli
ca
tion
a
r
ea
s m
a
int
a
in ori
e
nt
a
tion tow
a
r
d
s th
e ce
ntigrom
e
rs
,
a
n
d
s
ec
on
d
,
ba
s
ed
on th
e d
istri
b
ution of
P
oisson
,
54
in
de
p
e
n
de
nt
d
upli
ca
tion
a
r
ea
s
a
r
e e
xp
ec
t
ed
to pro
d
u
ce a
roun
d
7
tripli
ca
tion
a
r
ea
s
,
b
ut nothing is o
b
s
e
rv
ed
.
W
olf
e a
n
d S
hi
e
l
d
s
(
1997
)
propos
ed
th
a
t
S
.
ce
r
e
visi
ae
us
ed
to
be
t
e
tr
a
ploi
d
,
form
ed
from th
e
fusion of two
d
iploi
d
g
e
noms
a
roun
d
100
million y
ea
rs
a
go
a
ft
e
r
de
vi
a
tions from
S
.
K
luyv
e
ri
.
T
his sp
ec
i
e
s th
e
n
bec
om
e
s
C
ryptot
e
tr
a
ploi
d
with
a
roun
d
92
%
of th
e d
upli
ca
tion of g
e
n
e
s
e
qu
e
n
ce
s lost or
de
l
e
t
ed
.
Ab
out
70
-
100
int
e
rf
e
r
e
n
ce
,
su
c
h
a
s r
e
gion
a
l
tr
a
nslo
ca
tion
,
is n
eeded
to
e
xpl
a
in th
e c
urr
e
nt
c
hromosom
e d
upli
ca
tion
.
P
olypoi
d
i g
e
nom
e
v
e
rt
eb
r
a
t
e
Ve
rt
eb
r
a
t
e
s h
a
v
e
mor
e
g
e
n
e
s th
a
n inv
e
rt
eb
r
a
t
e
s
.
Re
s
ea
r
c
h shows
th
a
t on
e
inv
e
rt
eb
r
a
t
e
g
e
n
e
is oft
e
n
a
sso
c
i
a
t
ed
with up to four g
e
n
e
s on
v
e
rt
eb
r
a
t
e
s in
d
iff
e
r
e
nt
c
hromosom
e
s
.
A
lso
,
th
e
r
e
is
a
four
-
fol
d
d
upli
ca
tion p
a
tt
e
rn whi
c
h is th
e
s
a
m
e
,
origin
a
lly o
b
s
e
rv
ed
in th
e
g
e
n
e
hox
b
ut
,
acc
or
d
ing to
S
pring
(
1977
),
this ph
e
nom
e
non is
c
ommon
.
He
put forw
a
r
d
th
e
hypoth
e
sis th
a
t v
e
rt
eb
r
a
t
e
s m
a
y
e
xp
e
ri
e
n
ce
two
t
e
tr
a
ploi
d
iz
a
tion roun
d
s
,
whi
c
h pro
d
u
ce
g
e
n
e
s
,
so v
e
rt
eb
r
a
t
e
s m
a
y
be
ac
tu
a
lly
c
ryptoo
c
tooi
d
s
.
6
.
Ma
int
e
n
a
n
ce
of
N
ong
e
ni
c DNA
H
ypoth
e
sis
-
T
h
e
s
e
l
ec
tionist hypoth
e
sis
:
c
l
a
ims th
a
t non
-
g
e
ni
c DNA
h
a
s
e
ss
e
nti
a
l
fun
c
tions su
c
h
a
s g
e
n
e e
xpr
e
ssion r
e
gul
a
tion
.
I
f this
DNA
is lost
,
it
ca
n
a
ff
ec
t
th
e ab
ility of th
e
org
a
nism
.
-
Ne
utr
a
list hypoth
e
sis
:
st
a
t
e
s th
a
t non
-
g
e
n
e
ti
c DNA d
o
e
s not fun
c
tion
g
e
n
e
ti
ca
lly
a
n
d
physiologi
ca
lly
,
e
v
e
n r
e
g
a
r
ded a
s
"
DNA
w
a
st
e
"
b
y
O
hno
(
1972
).
T
his
DNA d
o
e
s not
a
ff
ec
t th
e ab
ility of org
a
nisms
a
n
d
only
e
xists
beca
us
e
of h
a
pp
e
ning
e
volution
.
15
-
I
ntr
a
g
e
nom s
e
l
ec
tionist hypoth
e
sis
:
ca
ll non
-
g
e
nit
a
l
DNA a
s
"
fun
c
tion
a
l
p
a
r
a
sit
e
s
"
or
"
g
e
n
e
ti
c
sym
b
ions
"
m
a
int
a
in
ed b
y intr
a
g
e
nom s
e
l
ec
tion
.
Se
lfish
DNA
,
whi
c
h
acc
umul
a
t
e
s in th
e
g
e
nom
e a
n
d
is m
a
int
a
in
ed d
u
e
to high
r
e
pro
d
u
c
tion
,
d
iff
e
r
e
nt from th
e DNA
w
a
st
e beca
us
e
it
ca
n
be a
mplifi
ed a
n
d
e
nl
a
rg
e
th
e
g
e
nom
e
.
-
N
u
c
l
e
otypi
c
hypoth
e
sis
:
a
sso
c
i
a
t
e
th
e
stru
c
tur
a
l fun
c
tion of non
-
g
e
nik
DNA
with its rol
e a
s
"
nu
c
l
e
osk
e
l
e
ton
"
whi
c
h m
a
int
a
ins th
e
g
e
nom
e
siz
e
acc
or
d
ing to th
e c
ytopl
a
sm volum
e
.
T
his
DNA
is
c
onsi
de
r
ed
import
a
nt in
m
a
int
a
ining
ce
ll
c
or
e
stru
c
tur
e
s
,
e
v
e
n though th
e c
ompon
e
nts
ca
n
c
h
a
ng
e
r
a
n
d
omly
.
E
vi
de
n
ce
-
P
roof for
a
v
e
ry f
e
w s
e
l
ec
tionist hypoth
e
sis
.
Ma
ny non
-
g
e
nik
DNA d
o
e
s
not h
a
v
e
g
e
n
e
ti
c
inform
a
tion
a
n
d ca
n
be
r
e
mov
ed
without ph
e
notypi
c
e
ff
ec
ts
.
N
on
-
g
e
nit
a
l
DNA
in
e
uk
a
riot
ca
n
e
xist without
a
signifi
ca
nt
m
e
t
ab
oli
c
syst
e
m
,
a
n
d
m
a
y only
e
xist up to
a ce
rt
a
in
e
xt
e
nt
.
-
I
ntr
a
g
e
nomi
c
s
e
l
ec
tionist hypoth
e
sis
a
n
d
n
e
utr
a
list hypoth
e
s
e
s
a
r
e d
iffi
c
ult
to
d
istinguish
c
on
ce
ptu
a
lly
a
n
d e
mpiri
ca
lly
.
DNA Se
lfish m
a
y pl
a
y
a
m
a
jor
rol
e
in non
-
g
e
nit
a
l
DNA
,
b
ut not
a
ll non
-
g
e
ni
c
f
ac
tions
c
om
e
from s
e
lfish
DNA
.
S
om
e
tr
a
nspos
abe
l
e
l
e
m
e
nts m
a
y
e
xp
e
ri
e
n
ce dea
th if th
e
y
ca
nnot
tr
a
nsmit
.
-
T
h
e d
iff
e
r
e
n
ce be
tw
ee
n th
e
th
e
ory of
DNA
w
a
st
e a
n
d
nu
c
l
e
osk
e
l
e
t
a
l is
d
iffi
c
ult to
d
istinguish
.
Pa
g
e
l
a
n
d J
ohnston
e
(
1992
)
sugg
e
st th
a
t mor
e DNA
w
a
st
e
in org
a
nisms with slow
de
v
e
lopm
e
nt p
ac
l
e
s
,
whil
e
th
e
nu
c
l
e
os
ce
l
e
l
e
t
a
l hypoth
e
sis
e
xp
ec
ts
a
positiv
e
r
e
l
a
tionship
be
tw
ee
n g
e
nom
e
siz
e a
n
d ce
ll siz
e
.
T
h
e
r
e
sults show
ed
th
a
t th
e
g
e
nom
e
siz
e
w
a
s n
e
g
a
tiv
e
ly
r
e
l
a
t
ed
to th
e
l
e
v
e
l of
de
v
e
lopm
e
nt in som
e
sp
ec
i
e
s of s
a
l
a
m
a
n
de
r
,
supporting th
e
th
e
ory of g
a
r
ba
g
e DNA
,
b
ut this r
e
l
a
tionship still n
eed
s to
be
stu
d
i
ed
furth
e
r
.
16
a
.
W
hy
T
h
e
s
a
m
e S
p
ec
i
e
s
Ha
v
e Ge
nom
e
siz
e D
iff
e
r
e
nt
?
T
h
e
r
e a
r
e d
iff
e
r
e
n
ce
s in g
e
nom
e
siz
e be
tw
ee
n sp
ec
i
e
s th
a
t
a
r
e c
los
e
ly
r
e
l
a
t
ed
,
wh
e
r
e d
iff
e
r
e
n
ce
s in
C
v
a
lu
e ca
nnot
be e
xpl
a
in
ed
only with
nu
c
l
e
otypi
c
fun
c
tions
beca
us
e
th
e
r
e a
r
e
no nu
c
l
e
otypi
c d
iff
e
r
e
n
ce
s
.
T
h
e
r
e a
r
e
two possi
b
l
e
m
ec
h
a
nisms
:
d
iff
e
r
e
n
ce
s in
acc
umul
a
t
ed DNA
w
a
st
e
or
d
iff
e
r
e
n
ce
s in th
e
l
e
v
e
l of
de
l
e
tion of g
a
r
ba
g
e DNA be
tw
ee
n
org
a
nisms
.
I
t h
a
s
bee
n known for
a
long tim
e
th
a
t
D
rosophil
a
sp
ec
i
e
s
h
a
v
e a
littl
e
ps
e
u
d
og
e
n
(
v
a
nin
1985
;
We
in
e
r
e
t
a
l
.
1986
;
W
il
d e
t
a
l
.
1986
).
Rece
ntly
,
Fe
trov
e
t
a
l
. (
1996
)
a
n
d Pe
trov
a
n
d Ha
rtl
(
1998
)
foun
d
th
a
t th
e dea
th of
He
l
e
n
Re
troposons w
a
s
ca
us
ed b
y loss of
DNA a
t
a
high l
e
v
e
l
d
uring
e
volution
.
T
h
e
y put forw
a
r
d
two th
e
ori
e
s
a
n
d
sugg
e
st
ed
th
a
t
DNA
r
e
mov
a
l
d
i
d
not follow th
e
s
e
l
ec
tiv
e
l
e
v
e
l of
c
onstr
a
ints
,
b
ut r
a
th
e
r r
e
l
a
t
ed
to
d
iff
e
r
e
nt l
e
v
e
ls of
de
l
e
tion
,
whi
c
h
might
ca
us
e d
iff
e
r
e
n
ce
s in g
e
nom
e
siz
e be
tw
ee
n sp
ec
i
e
s
.
T
h
e
y
a
ssum
e
th
a
t th
e
r
e
mov
a
l of
He
l
e
n
a
s
e
l
e
m
e
nts its
e
lf is unlimit
ed
,
b
ut this
ph
e
nom
e
non is g
e
n
e
r
a
lly
a
pplying to
a
ll unlimit
ed
s
e
l
ec
tion
a
r
ea
s
.
T
o t
e
st this
a
ssumption
,
th
e
y
c
omp
a
r
e
th
e
siz
e
of th
e
introny
be
tw
ee
n
two
D
rosophil
a
sp
ec
i
e
s
.
D
.
V
irilis h
a
s
a
g
e
nom
e
th
a
t is twi
ce a
s
b
ig
a
s
D
.
m
e
l
a
nog
a
st
e
r
(
M
oriy
a
m
a e
t
a
l
.
1998
).
T
his
d
iff
e
r
e
n
ce ca
n
be
a
sso
c
i
a
t
ed
with h
e
t
e
ro
c
hrom
a
tin
,
b
ut
e
v
e
n
a
ft
e
r
c
onsi
de
ring this f
ac
tor
,
g
e
nom
D
.
V
irilis is still
a
roun
d
36
%
gr
ea
t
e
r th
a
n
D
.
m
e
l
a
nog
a
st
e
r
.
I
n
a
c
omp
a
rison of
115
c
ompl
e
t
e
introns of
42
orthologist g
e
n
e
s
,
a
st
a
tisti
ca
lly signifi
ca
nt signifi
ca
nt
d
iff
e
r
e
n
ce
in intron
be
tw
ee
n th
e
two
D
rosophil
a
sp
ec
i
e
s
.
T
h
e a
v
e
r
a
g
e
l
e
ngth of th
e
intron
be
tw
ee
n
D
.
V
irilis
a
n
d D
.
Me
l
a
nog
a
st
e
r
(
394
a
n
d
283
BP
r
e
sp
ec
tiv
e
ly
)
is
39
%
,
a
ppro
ac
hing th
e
siz
e d
iff
e
r
e
n
ce
in non
-
r
e
p
e
titiv
e
f
ac
tions
be
tw
ee
n
g
e
nom
e
s
.
T
his shows th
a
t som
e
org
a
nisms
a
r
e
mor
e e
ffi
c
i
e
nt in
e
limin
a
ting
"
w
a
st
e
"
th
a
n oth
e
rs
(
Pe
trov
a
n
d Ha
rtl
1997
).
7
.
T
h
e
stru
c
tur
e
of
T
h
e
or
de
r of th
e Re
p
ea
t
ed
from
E
uk
a
ryoti
c Ge
nom
e
E
uk
a
ryoti
c
g
e
nom
e
s h
a
v
e
two m
a
in f
ea
tur
e
s
:
r
e
p
e
tition of
s
e
qu
e
n
ce
s
a
n
d c
omposition of
c
omp
a
rtm
e
nt
a
liz
a
tion into
d
iff
e
r
e
nt
17
fr
a
gm
e
nts
ba
s
ed
on sp
ec
ifi
c
nu
c
l
e
oti
de c
ompositions
.
Re
p
ea
t
ed DNA
c
onsists of nu
c
l
e
oti
de
s
e
qu
e
n
ce
s with
a
v
a
ri
e
ty of l
e
ngths
a
n
d
c
ompositions th
a
t
a
pp
ea
r s
e
v
e
r
a
l tim
e
s in th
e
g
e
nom
e
,
b
oth
simult
a
n
e
ously
a
n
d
spr
ead
.
DNA
th
a
t
d
o
e
s not r
e
p
ea
t is r
e
f
e
rr
ed
to
a
s
a
singl
e c
opy or
a
uniqu
e DNA
.
T
h
e
proportion of g
e
nom
e
s
c
onsisting
of r
ec
urr
e
nt s
e
qu
e
n
ce
s v
a
ri
e
s gr
ea
tly
,
for
e
x
a
mpl
e ab
out
20
%
on y
ea
st
,
ab
out
5
%
in
c
hironomi
c
mosquito
e
s
,
a
n
d
up to
90
%
in th
e
m
ac
ulosus
n
ec
tur
a
l liz
a
r
d
.
I
n m
a
mm
a
ls
,
up to
60
%
of
DNA
is r
e
p
ea
t
ed
,
whil
e
in
pl
a
nts
ca
n
e
x
ceed
80
%
,
with som
e
high
e
r v
a
lu
e
(
F
l
a
v
e
ll
1986
).
T
h
e c
l
a
ssi
c
stu
d
y
b
y
B
ritt
e
n
a
n
d K
ohn
e
(
1968
)
shows th
a
t
a
high
-
l
e
v
e
l
e
uk
a
ryoti
c
g
e
nom
e ca
n
be d
ivi
ded
into four f
ac
tions
(
s
ee F
igur
e
2
.
8
).
T
h
e
first f
ac
tion
,
DNA
fol
dbac
k
,
c
onsist
ed
of
a
p
a
lin
d
romi
c
or
de
r
th
a
t form
ed
th
e
stru
c
tur
e
of th
e
h
a
irpin
a
ft
e
r
de
n
a
tur
a
tion
a
n
d
th
e
n th
e
pl
a
n
.
T
his f
ac
tion is usu
a
lly sm
a
ll
,
a
lthough in som
e
org
a
nisms it
ca
n
be
mor
e
th
a
n
10
%
.
S
om
e DNA
only
e
xp
e
ri
e
n
ced a
nn
ea
ling
a
t
a
high
C
0
T
v
a
lu
e
.
T
his
f
ac
tion
c
onsists of
a
s
e
qu
e
n
ce c
opy
a
n
d
is oft
e
n r
e
f
e
rr
ed
to
a
s
e
ukrom
a
tin
beca
us
e
of its
c
oloring n
a
tur
e
in
ca
ryologi
ca
l
a
n
a
lysis
.
I
n
add
ition
,
th
e
r
e
is
a DNA
s
e
qu
e
n
ce
th
a
t is
a
nn
ea
l
ed a
t th
e
m
ed
ium
C
0
T
v
a
lu
e
,
oft
e
n
d
ivi
ded
into v
e
ry r
e
p
e
titiv
e DNA a
n
d
int
e
rm
ed
i
a
t
e
r
e
p
ea
t
ed DNA
.
T
h
e
fr
ac
tion is v
e
ry r
e
p
e
titiv
e c
onsisting of
a
short
or
de
r r
e
p
ea
t
ed
thous
a
n
d
s or millions of tim
e
s
a
n
d
looks
da
rk in
ca
ryologi
ca
l
a
n
a
lysis
,
known
a
s h
e
t
e
ro
c
hrom
a
tin
.
Med
ium r
e
p
e
titiv
e
fr
ac
tions
c
onsist of hun
d
r
ed
s of thous
a
n
d
s of
ba
s
e
p
a
irs th
a
t
a
pp
ea
r
hun
d
r
ed
s of tim
e
s in th
e
g
e
nom
e
.
B
oth siz
e
s of this r
e
p
e
tition
a
n
d
morphology of r
e
p
e
tition in th
e
g
e
nom
e d
o not r
e
pr
e
s
e
nt th
e
c
ompl
e
t
e
ly
d
iff
e
r
e
nt
DNA c
l
a
ss
.
Re
p
ea
t
ed Fac
tion
c
onsists of two typ
e
s
:
r
ec
urring s
e
qu
e
nt lo
ca
tion
a
n
d
r
ec
urring s
e
qu
e
n
e
spr
ead
.
a
.
L
o
ca
tion
Se
qu
e
n
ce
s
Re
p
ea
t
ed
M
ost of th
e
g
e
nom
e e
uk
a
ryoti
c
h
a
s
a
r
a
n
d
om or
de
r of
DNA
.
I
n som
e
sp
ec
i
e
s
,
r
e
p
e
tition of this s
e
qu
e
n
ce ca
n show
d
omin
a
n
ce
of
DNA
in th
e
18
g
e
nom
e
.
F
or
e
x
a
mpl
e
,
in th
e M
i
ce
of th
e D
ipo
d
omys
O
r
d
ii k
a
ng
a
roo
,
mor
e
th
a
n
50
%
of th
e
g
e
nom
e c
onsists of thr
ee
typ
e
s of r
ec
urring
s
e
qu
e
n
ce
s
:
AAG
(
2
.
4
x
10
^
9
tim
e
s
),
TTAGGG
(
2
.
2
x
10
^
9
tim
e
s
),
a
n
d
acaca
g
c
ggg
(
1
.
2
x
10
^
9
tim
e
s
).
A
lthough th
e
s
e
f
a
mili
e
s
a
r
e
not
e
ntir
e
ly
homog
e
n
e
ous
,
th
e
y
c
ont
a
in v
a
ri
a
tions of
c
ons
e
nsus s
e
qu
e
n
ce
s in on
e
or two nu
c
l
e
oti
de
s
,
su
c
h
a
s th
e
or
de
r of tt
a
g
a
g in th
e
f
a
mily
"
TTAGGG
."
S
m
a
ll
e
r g
e
nom
e
s
ca
n
a
lso h
a
v
e a
r
ec
urring or
de
r
.
F
or
e
x
a
mpl
e
,
40
%
of
D
rosophil
a
virilis g
e
nom
e
s
c
onsist of thr
ee
s
e
qu
e
n
ce
s v
e
ry r
e
p
e
titiv
e
:
acaaac
t
(
1
.
1
x
10
^
7
tim
e
s
),
a
t
aaac
(
3
.
6
x
10
^
6
tim
e
s
),
a
n
d acaaa
tt
(
3
.
6
x
10
^
6
tim
e
s
).
E
v
e
n th
e Ge
nom
Ab
si
d
i
a G
l
a
u
ca
,
whi
c
h is only
a
littl
e
b
igg
e
r th
a
n
E
.
c
oli
,
c
ont
a
ins r
e
p
ea
t
ed DNA
.
Ma
ny r
ec
urr
e
nt s
e
qu
e
nt lo
ca
tions h
a
v
e
uniform nu
c
l
e
oti
de
c
ompositions
,
in
d
i
ca
ting th
a
t wh
e
n fr
ac
tion
a
liz
a
tion of
DNA a
n
d
s
e
p
a
r
a
tion with gr
ad
i
e
nt
de
nsity
,
th
e
y form
a
ri
bb
on th
a
t is
c
l
ea
rly
d
iff
e
r
e
nt from oth
e
r h
e
t
e
rog
e
n
e
ous
DNA
fr
a
gm
e
nts
.
T
his ri
bb
on
,
whi
c
h
is h
ea
vi
e
r or light
e
r th
a
n th
e
or
de
r of oth
e
r g
e
nom
e
s
,
is known
a
s
s
a
t
e
llit
e DNA
.
S
om
e
s
a
t
e
llit
e DNA
is v
e
ry ri
c
h in
G
+
C
or
A
+
T
,
with
a
r
a
ng
e
of
1
%
on
Ca
n
ce
r
G
r
ac
ilis
c
r
ab
s up to
73
%
on
Le
ishm
a
ni
a
inf
a
ntum
a
n
d C
hironomi
c P
lumosus
.
Ma
mm
a
l g
e
nom
e
s usu
a
lly
c
onsist
of
5
-
30
%
s
a
t
e
llit
e DNA
,
a
n
d
on som
e
pl
a
nts
,
this num
be
r
ca
n r
eac
h
40
%
of th
e
tot
a
l g
e
nom
e
.
I
n som
e
sp
ec
i
e
s
,
r
e
p
e
titiv
e
s
e
qu
e
n
ce
s
a
r
e d
istri
b
ut
ed
in
a
ll
c
hromosom
e
s
,
whil
e
in oth
e
r sp
ec
i
e
s it is only foun
d
in
ce
rt
a
in
lo
ca
tions
.
F
or
e
x
a
mpl
e
,
mor
e
th
a
n
60
%
of
D
rosophil
a Na
sutoi
de
g
e
nom
e
s
c
onsist of s
a
t
e
llit
e DNA
,
with most of th
e
li
e
s in on
e
of th
e
four
a
utosom
e
s
a
n
d Y c
hromosom
e
s
.
N
ot
a
ll r
e
p
e
tition lo
ca
tions
a
r
e
short r
e
p
e
titions
;
F
or
e
x
a
mpl
e
,
th
e O
r
c
inus
O
r
ca K
ill
e
r
P
op
e c
ont
a
ins
ab
out h
a
lf
a
million
c
opi
e
s of th
e
s
e
qu
e
n
ce
of
1
,
579
BP
,
a
roun
d
15
%
of
th
e
g
e
nom
e
.
19
I
t is possi
b
l
e
th
a
t r
ec
urring s
e
qu
e
n
ce
lo
ca
tions
d
o not h
a
v
e ce
rt
a
in
fun
c
tions
a
n
d
th
e a
mount
d
o
e
s not
a
ff
ec
t in
d
ivi
d
u
a
l r
e
sili
e
n
ce
.
T
h
e
e
volution
a
ry pro
ce
ss of this s
e
qu
e
n
ce
m
a
y not
be
influ
e
n
ced b
y n
a
tur
a
l
s
e
l
ec
tion
,
with v
a
ri
a
tions in th
e a
mount
a
n
d c
omposition
ca
us
ed b
y
mut
a
tions su
c
h
a
s g
e
n
e c
onv
e
rsion
a
n
d d
is
a
gr
eeab
l
e c
ross mov
e
s
,
a
s
w
e
ll
a
s r
a
n
d
om
de
ploym
e
nt in th
e
popul
a
tion
.
Ge
n
e c
onv
e
rsion
a
n
d
un
e
v
e
n
c
ross mov
e
s
ca
n pro
d
u
ce a
num
be
r of s
e
qu
e
n
ce
homog
e
n
e
ity
or flu
c
tu
a
tions in th
e a
mount of tim
e
to tim
e
.
I
t
a
lso shows th
a
t th
e
l
e
v
e
l of
c
h
a
ng
e
in r
ec
urr
e
nt s
e
qu
e
n
ce
lo
ca
tions
ca
n
be c
ontroll
ed b
y
a
n
un
e
v
e
n
c
rosswis
e
,
whil
e
th
e
n
e
w
a
rr
a
ng
e
m
e
nt
c
ontinu
e
s to
be c
r
ea
t
ed
b
y
DNA d
upli
ca
tion
.
S
om
e
r
ec
urring s
e
qu
e
n
ce
s
d
o not show ph
e
notypi
c e
ff
ec
ts
a
n
d
th
e
ir
pr
e
s
e
n
ce
m
a
y not
a
ff
ec
t th
e e
xist
e
n
ce
of op
e
r
a
tors
.
H
ow
e
v
e
r
,
th
e
r
e a
r
e
ca
s
e
s wh
e
r
e ce
rt
a
in r
ec
urring s
e
qu
e
n
ce
s
ca
n
a
ff
ec
t r
e
sili
e
n
ce
,
su
c
h
a
s
thos
e
foun
d
in th
e RSP
lo
c
us on
D
rosophil
a Me
l
a
nog
a
st
e
r
,
wh
e
r
e
th
e
fr
e
qu
e
n
c
y of
c
opy r
ed
u
ced
ov
e
r tim
e
in fli
e
s with f
e
w
e
r
c
opi
e
s th
a
n
thos
e
who h
a
v
e
mor
e c
opi
e
s
.
E
x
ce
pt for his rol
e
in th
e
syst
e
m of
s
e
gr
e
g
a
tion
d
istortion
,
th
e c
urr
e
nt
RSP
lo
c
us fun
c
tion is unknown
,
b
ut
it is
c
l
ea
r th
a
t th
e
y
a
r
e
not g
a
r
ba
g
e DNA a
n
d ca
n
a
ff
ec
t r
e
sili
e
n
ce
.
b
.
S
pr
ead Se
qu
e
n
ce
s
Re
p
ea
t
ed
T
h
e
hum
a
n g
e
nom
e c
ont
a
ins
DNA
r
e
p
e
titions spr
ead
throughout th
e
g
e
nom
e
.
T
his r
e
p
e
tition w
a
s foun
d
in introns
,
a
roun
d
g
e
n
e
s
,
a
n
d
in non
-
g
e
nik
DNA
.
T
h
e
r
e a
r
e
two m
a
in
ca
t
e
gori
e
s of r
e
p
e
tition
:
simpl
e
t
a
n
de
m r
e
p
e
tition
a
n
d ad
v
a
n
ced
r
e
p
e
tition
.
Tab
l
e
2
.
5
shows
a
c
l
a
ssifi
ca
tion of t
a
n
de
m r
e
p
e
tition
ba
s
ed
on th
e
siz
e
of
a
r
e
p
e
titiv
e
unit
,
num
be
r of units
,
a
n
d
th
e
lo
ca
tion of th
e
g
e
nom
e
.
T
h
e
m
a
jority of
r
ec
urr
e
nt s
e
qu
e
n
ce
s
a
r
e
foun
d
on s
a
t
e
llit
e
s
a
n
d
minis
a
t
e
lit
e
s
,
a
lthough
a
sm
a
ll portion of th
e
minis
a
t
e
lit
e
is spr
ead
.
I
t is
e
stim
a
t
ed
th
a
t th
e
r
e
a
r
e a
roun
d
300
,
000
r
e
p
e
titions of short trinu
c
l
e
oti
de
s
a
n
d
t
e
tr
a
nu
c
l
e
oti
de
s in th
e
hum
a
n g
e
nom
e
,
or on
e
unit
e
v
e
ry
10
KB
(
Bec
km
a
nn
a
n
d Webe
r
1992
).
H
um
a
n mi
c
ros
a
t
e
llit
e
s g
e
n
e
r
a
lly
c
onsist
20
of r
e
p
e
tition of nu
c
l
e
oti
de
s
CA
,
with
a
roun
d
50
,
000
c
opi
e
s of
mi
c
ros
a
t
e
lit
e
s in th
e
hum
a
n g
e
nom
e
,
or on
e
unit
e
v
e
ry
30
KB
(
H
u
d
son
e
t
a
l
.
1992
).
T
h
e
hum
a
n g
e
nom
e a
lso
c
ont
a
ins four m
a
in
c
l
a
ss
e
s of r
e
l
ea
sing
r
e
p
e
titions
: (
1
)
S
in
e
s
, (
2
)
lin
e
s
, (
3
)
Re
trovirus
a
n
d
r
e
trotr
a
nsposon
e
l
e
m
e
nts
,
a
n
d
(
4
)
DNA
m
ed
i
a
t
ed
tr
a
nspos
abe
l fossils
.
T
h
e d
istri
b
ution
of this r
e
p
e
tition
c
l
a
ss is shown in
F
igur
e
2
.
10
.
T
h
e
hum
a
n g
e
nom
e
h
a
s two f
a
mily lin
e
s
,
n
a
m
e
ly
L
in
e
1
(
LI
)
a
n
d L
in
e
2
(
L
2
).
T
h
e
r
e a
r
e a
roun
d
600
,
000
r
e
p
e
titions of
L
i in th
e
hum
a
n g
e
nom
e
,
whi
c
h
c
ov
e
rs
a
roun
d
15
%
of th
e
g
e
nom
e
.
T
h
e L
i f
a
mily w
a
s
ac
tiv
e
be
for
e
th
e a
pp
ea
r
a
n
ce
of
d
iff
e
r
e
n
ce
s
be
tw
ee
n m
a
rsupi
a
l
a
n
d
pl
ace
nt
a
l
.
Fa
mily
L
2
,
with
a
roun
d
271
,
000
r
e
p
e
titions
,
sm
a
ll
e
r
a
n
d
m
a
y
be
mor
e
a
n
c
i
e
nt
,
o
cc
ur
be
for
e
th
e d
iff
e
r
e
n
ce be
tw
ee
n
a
mphi
b
i
a
ns
a
n
d a
mniot
e
v
e
rt
eb
r
a
t
e
s
.
Ab
out
95
%
L
i s
e
qu
e
n
ce
s w
e
r
e c
ut off
a
t th
e e
n
d
of th
e
5
'
a
n
d
w
e
r
e
not tr
a
ns
c
ri
bed
or r
e
trotr
a
nsposition
.
T
h
e d
iff
e
r
e
n
ce
in
L
i
s
e
qu
e
n
ce
s
be
tw
ee
n sp
ec
i
e
s is f
a
r gr
ea
t
e
r th
a
n th
e d
iff
e
r
e
n
ce be
tw
ee
n
th
e
s
a
m
e c
opy of
L
i
.
F
or
e
x
a
mpl
e
,
th
e
or
de
r of
M
i
ce a
n
d H
um
a
ns is
d
iff
e
r
e
nt from
a
roun
d
30
%
,
whil
e
th
e d
iff
e
r
e
n
ce
in
a
s
e
qu
e
n
ce
of on
e
r
e
p
e
tition is
a
roun
d
4
%
in mi
ce
(
H
ut
c
hison
e
t
a
l
.
1989
).
Da
m
a
g
ed L
1
e
l
e
m
e
nts
de
v
e
lop f
a
st
e
r th
a
n th
e
int
ac
t
e
l
e
m
e
nts
.
T
h
e
lin
ea
g
e
of
a b
rok
e
n
L
1
s
e
qu
e
n
ce
h
a
s no
b
r
a
n
c
h
,
in
d
i
ca
ting th
a
t th
e
s
e
e
l
e
m
e
nts
ca
nnot r
e
pli
ca
t
e
tr
a
nsposition
.
T
h
e
y
bec
om
e
ps
e
u
d
og
e
ns
a
n
d
no long
e
r fun
c
tion
,
follow th
e c
omposition
a
l
a
ssimil
a
tion until it is not
r
ec
ogniz
ed a
s lin
e
s
.
S
om
e da
m
a
g
ed L
1
s
e
qu
e
n
ce
s in
d
i
ca
t
e
th
a
t th
e
spr
ead
of
L
1
e
l
e
m
e
nts in th
e
g
e
nom
e de
p
e
n
d
s on som
e
sour
ce
e
l
e
m
e
nts
.
A
s
a
r
e
sult
,
th
e L
1
e
l
e
m
e
nt in th
e
g
e
nom
e
is v
e
ry
homog
e
n
e
ous with
a
high l
e
v
e
l of
c
h
a
ng
e
in s
e
qu
e
n
ce
.
I
n ro
de
nts
,
it is
e
stim
a
t
ed
th
a
t mor
e
th
a
n h
a
lf of
L
1
e
l
e
m
e
nts
a
r
e a
roun
d
3
million y
ea
rs
or
e
v
e
n young
e
r
.
21
T
h
e
hum
a
n g
e
nom
e a
lso
c
ont
a
ins two
S
in
e
f
a
mili
e
s
:
7
SL
origin
a
ting
from
ALU
f
a
mily with
a
roun
d
1
,
100
,
000
c
opi
e
s
(
10
%
of th
e
g
e
nom
e
),
a
n
d TRNA
from th
e M
ir f
a
mily with
a
roun
d
400
,
000
c
opi
e
s
.
I
n
add
ition
,
th
e
r
e a
r
e
r
e
trovirus
e
l
e
m
e
nts
a
n
d
r
e
trotr
a
nsposon
(~
5
%
of th
e
g
e
nom
e
),
th
e
r
e
mn
a
nts of tr
a
nspos
abe
l
DNA e
l
e
m
e
nts
(~
2
%
),
a
n
d
a
roun
d
60
,
000
c
opi
e
s of unr
e
sting r
e
p
e
titions th
a
t
a
r
e
not
c
l
a
ssifi
ed
(~
1
%
).
O
v
e
r
a
ll
,
mor
e
th
a
n
a
thir
d
of th
e
hum
a
n g
e
nom
e
s
c
om
e
from
mo
b
il
e e
l
e
m
e
nts from s
e
v
e
r
a
l f
a
mili
e
s
.
H
ow
e
v
e
r
,
this r
e
p
e
tition of
h
e
lling s
e
qu
e
n
ce
s no long
e
r h
a
s th
e ab
ility to mov
e
.
c
.
T
h
e
or
de
r of th
e Re
p
ea
t
:
ca
us
e
s
Va
ri
a
tion in th
e Ge
nom
e S
iz
e
A
s m
e
ntion
ed
,
th
e c
or
e
of th
e
p
a
r
ad
ox of
C
v
a
lu
e
is th
a
t
org
a
nisms with simil
a
r morphology
a
n
d a
n
a
tomy
ca
n h
a
v
e
v
e
ry
d
iff
e
r
e
nt
C
v
a
lu
e
s
.
T
his is
c
l
ea
r
e
r th
a
n
c
omp
a
risons
be
tw
ee
n sp
ec
i
e
s in
th
e
s
a
m
e
g
e
nus
.
T
h
e d
iff
e
r
e
n
ce
in g
e
nom
e
siz
e ca
n
be e
xpl
a
in
ed b
y
v
a
ri
a
tions in r
e
p
e
titiv
e
fr
ac
tions
.
F
or
e
x
a
mpl
e
,
from
a
nim
a
ls su
c
h
a
s
c
t
e
nomys
(
tu
c
o
-
tu
c
o
)
to pl
a
nts su
c
h
a
s
A
v
e
n
a
(
wh
ea
t
),
a
s w
e
ll
a
s from
hylo
ba
t
e
s
(
gi
bb
on
)
to
d
rosophil
a
,
eac
h sp
ec
i
e
s in th
e
s
a
m
e
g
e
nus h
a
s
a
d
iff
e
r
e
nt
C
v
a
lu
e
,
a
n
d
this
d
iff
e
r
e
n
ce
is usu
a
lly
ca
us
ed b
y v
a
ri
a
tions
I
n
r
e
p
e
tition
F
r
a
tikinong
e
nik
,
oft
e
n with
d
iff
e
r
e
n
ce
s in th
e
num
be
r of
simpl
e
r
e
p
e
titions
.
I
n
add
ition
,
e
v
e
ry tim
e
t
a
kon is m
ea
sur
ed
,
th
e
g
e
nom
e
siz
e
is oft
e
n mu
c
h sm
a
ll
e
r th
a
n th
e
r
e
l
a
t
ed
t
a
xon
,
a
n
d
th
e
d
iff
e
r
e
n
ce
is usu
a
lly
ca
us
ed b
y r
ec
urr
e
nt s
e
qu
e
n
ce
s
.
F
or
e
x
a
mpl
e
,
som
e ba
ts h
a
v
e a
g
e
nom
e
of
a
roun
d
50
%
of th
e
siz
e
of oth
e
r
e
uth
e
ri
a
n
m
a
mm
a
ls
.
T
his
d
iff
e
r
e
n
ce
is
ca
us
ed b
y th
e
l
ac
k of
AT a
n
d GC
mi
c
ros
a
t
e
llit
e
s whi
c
h
a
r
e
usu
a
lly foun
d
in oth
e
r m
a
mm
a
ls
.
L
ik
e
wis
e
,
th
e
siz
e
of th
e
g
e
nom
e
is r
e
l
a
tiv
e
ly sm
a
ll in
b
ir
d
s
(
Tab
l
e
2
.
3
)
m
a
y
be d
u
e
to
th
e
s
ca
r
c
ity of mi
c
ros
a
t
e
lit
e
s in th
e b
ir
d
'
s g
e
nom
e
.
8
.
Mec
h
a
nism to
I
n
c
r
ea
s
e
th
e A
r
ea
in th
e Ge
nom
e S
iz
e
Re
gion
a
l in
c
r
ea
s
e
s in g
e
nom
e
siz
e ca
n
be e
xpl
a
in
ed b
y s
e
v
e
r
a
l
m
ec
h
a
nisms
.
O
n
e
of th
e
m is tr
a
nsposition
d
upli
ca
tion
,
whi
c
h
ca
n
22
pro
d
u
ce
s
e
p
a
r
a
t
e
r
ec
urring s
e
qu
e
n
ce
s
.
O
th
e
r m
ec
h
a
nisms
ca
n
a
lso
pro
d
u
ce
r
ec
urr
e
nt s
e
qu
e
n
ce
lo
ca
tions
.
T
h
e
r
e a
r
e
in
d
i
ca
tions th
a
t
a
ll
r
e
p
e
tition of
DNA
fr
ac
tions in
e
uk
a
ryoti
c
origin
a
ting from tr
a
nspos
ab
l
e
e
l
e
m
e
nts
.
M
ost of th
e
s
e e
l
e
m
e
nts
ca
nnot mov
e a
g
a
in
d
u
e
to
da
m
a
g
e
d
u
e
to mut
a
tions or ins
e
rtion to oth
e
r
e
l
e
m
e
nts
.
U
n
e
v
e
n
c
ross mov
e
s m
a
y
be a
n in
c
r
ea
s
e
in th
e ca
us
e
s of
in
c
r
ea
sing
a
n
d
num
be
r of
c
opi
e
s of s
a
t
e
llit
e a
n
d
minis
a
t
e
lit
.
U
su
a
lly
,
this
e
v
e
nt pro
d
u
ce
s s
e
qu
e
n
ce
s with long r
e
p
e
tition
,
whil
e
som
e
r
ec
urring s
e
qu
e
nt lo
ca
tions
,
su
c
h
a
s mi
c
ros
a
t
e
llit
e
s
,
h
a
v
e
short
e
r
r
e
p
e
titions
.
E
vi
de
n
ce
shows th
a
t th
e
num
be
r of
c
opi
e
s of th
e
M
inis
a
t
e
lit lo
c
us
ca
n in
c
r
ea
s
e
r
a
pi
d
ly
.
F
or
e
x
a
mpl
e
,
th
e MS
32
lo
c
us in
hum
a
ns h
a
s
600
r
e
p
e
titions
,
whil
e
in
a
n
c
i
e
nt monk
e
ys
,
th
e
homologous lo
c
us h
a
s only
3
-
4
r
e
p
e
titions
.
T
h
e
high
a
mount in hum
a
ns
m
a
y r
e
fl
ec
t th
e c
urr
e
nt situ
a
tion
c
omp
a
r
ed
to th
e a
n
ce
stors
.
DNA a
mplifi
ca
tion
ca
n o
cc
ur through two m
ec
h
a
nisms
:
v
e
rti
ca
l
a
mplifi
ca
tion
a
n
d
horizont
a
l
a
mplifi
ca
tion
.
Ve
rti
ca
l
a
mplifi
ca
tion
involv
e
s multipl
e
fol
d
ing s
e
qu
e
n
ce
s outsi
de
th
e c
hromosom
e
,
whil
e
horizont
a
l
a
mplifi
ca
tion
c
r
ea
t
e
s s
e
v
e
r
a
l
c
opi
e
s of
DNA
s
e
qu
e
n
ce
s
whi
c
h
a
r
e
th
e
n
c
om
b
in
ed
into th
e
inh
e
rit
ed
g
e
nom
e
.
O
n
e
m
e
tho
d
to
e
xpl
a
in
a
mplifi
ca
tion is
a
rolling
c
ir
c
l
e
mo
de
l of
DNA
r
e
pli
ca
tion
.
T
his m
e
tho
d
is us
ed
in th
e a
mphology of th
e
rrn
a
g
e
n
e
s on oo
c
yt
e
s of
a
mphi
b
i
a
ns
,
wh
e
r
e
this pro
ce
ss pro
d
u
ce
s
a c
opy
of th
e c
ir
c
ul
a
r
e
xtr
ac
ts from
DNA
s
e
qu
e
n
ce
s
,
whi
c
h
ca
n l
ead
to m
a
ny
add
ition
a
l units
c
ont
a
ining i
de
nti
ca
l r
e
p
e
titions of th
e
origin
a
l or
de
r
.
I
f
this unit is int
e
gr
a
t
ed bac
k into th
e c
hromosom
e
,
th
e
r
e
will
be
add
ition
a
l g
e
nom
e
s with i
de
nti
ca
l r
ec
urring s
e
qu
e
n
ce
s
.
23
C
.
E
volution on
Ge
n
e
ti
c C
o
de
D
istri
b
ution of oth
e
r g
e
n
e
ti
c e
l
e
m
e
nts
a
mong iso
c
il
e
s
T
h
e
position of iso
c
or
a
t
e
s in th
e
hum
a
n g
e
nom
e a
n
d
oth
e
r
v
e
rt
eb
r
a
t
e
s
a
r
e de
t
e
rmin
ed b
y v
a
rious m
e
tho
d
s
.
Ab
out
30
%
of hum
a
n
g
e
n
e
s
a
r
e a
h
ea
vy
c
ompon
e
nt
(
H
3
)
whi
c
h only
c
ov
e
rs
3
-
5
%
g
e
nom
e
.
L
ong g
e
n
e
s in iso
c
il
e
s
a
r
e
r
a
r
e
ly foun
d
in th
e
ri
c
h
a
r
ea
of
GC
.
T
h
e
d
iff
e
r
e
n
ce be
tw
ee
n th
e
ri
c
h
a
n
d
poor
GC
g
e
n
e
r
e
gions is l
a
rg
e
ly
d
u
e
to
introns
,
whi
c
h
a
v
e
r
a
g
e
s thr
ee
tim
e
s long
e
r in th
e
poor
GC a
r
ea
.
F
r
e
qu
e
nt g
e
n
e a
tt
ac
hm
e
nt in
DNA
fr
a
gm
e
nts with
GC c
ont
e
nt simil
a
r
to th
e
g
e
n
e
its
e
lf
.
Ra
n
d
om
de
gr
ada
tion of
DNA
fr
a
gm
e
nts shows th
a
t
th
e c
omposition of th
e
fr
a
gm
e
nt of th
e
g
e
n
e ca
rri
e
r is
c
onsist
e
nt with
th
e c
omposition of th
e
fr
a
gm
e
nt of its own
.
T
his o
b
s
e
rv
a
tion in
isol
a
tion
a
n
d
grouping g
e
n
e
s in
d
i
ca
t
e
s th
a
t th
e
iso
c
orium is l
a
rg
e
c
omp
a
r
ed
to th
e
g
e
n
e c
lust
e
r whi
c
h is
c
h
ec
k
ed
,
som
e
m
ea
suring
40
k
b
or mor
e
,
a
n
d
shows th
a
t iso
c
or
a
t
e
s
ca
n
be
mor
e
th
a
n
300
KB
.
S
om
e
tim
e
s g
e
n
e
s
a
r
e
foun
d
in fr
a
gm
e
nts th
a
t
c
ov
e
r th
e a
r
ea
with
a
wi
de GC
l
e
v
e
l
,
it is lik
e
ly to o
cc
ur if th
e
g
e
n
e
is lo
ca
t
ed
n
ea
r th
e
b
oun
da
ry
be
tw
ee
n iso
c
il
e
s
,
pro
d
u
c
ing fr
a
gm
e
nts with
c
ompositions
d
iff
e
r from r
a
n
d
om
da
m
a
g
e
.
T
h
e
r
e
is
a
positiv
e c
orr
e
l
a
tion
be
tw
ee
n
GC
l
e
v
e
ls on g
e
n
e
s
,
e
xons
,
a
n
d
introns with
GC
l
e
v
e
ls in th
e
l
a
rg
e DNA a
r
ea
wh
e
r
e
th
e
y
sti
c
k to
.
I
n
c
ontr
a
st to
c
lust
e
rs of glo
b
in
α
a
n
d
β
in hum
a
ns who h
a
v
e
low
GC
,
β
a
n
d
glo
b
in g
e
n
e
s su
c
h
a
s
β
c
ont
a
in low
GC a
n
d
sti
c
k to th
e
poor r
e
gions of
GC
.
C
onv
e
rs
e
ly
,
glo
b
in g
e
n
e
s lik
e
α
a
r
e
in
GC
ri
c
h
a
r
ea
s
a
n
d
sti
c
k to th
e a
r
ea
.
GC c
ont
e
nt in
a
high
e
r
c
o
d
ing
a
r
ea
c
omp
a
r
ed
to th
e
si
de a
r
ea
,
with th
e GC
l
e
v
e
l in th
e
thir
d c
o
d
on
position is mor
e e
v
e
nly
d
istri
b
ut
ed c
omp
a
r
ed
to th
e
intron
a
r
ea
whi
c
h
h
a
s
a
high
e
r l
e
v
e
l th
a
n th
e
tip
5
a
n
d
3
.
A
s
ce
rt
a
in
T
h
e
origin of
GC
is still myst
e
rious or
c
ontrov
e
rsi
a
l iso
c
or
.
U
su
a
lly
a
long
DNA
s
e
gm
e
nt
(
300
KB
or mor
e
)
of th
e GC
/
P
oor
GC
ri
c
h
a
r
ea
,
without
GC
v
a
ri
a
tions in th
e
g
e
n
e a
r
ea
.
Be
rn
a
r
d
i
e
t
a
l
.
P
ropos
e
s
24
th
a
t
I
so
c
il
e
s
a
pp
ea
r
a
s
a
fun
c
tion
a
l
ad
v
a
nt
a
g
e
,
with
c
l
a
ims th
a
t high
GC
c
ont
e
nt
ca
n prot
ec
t
DNA
,
RNA
,
a
n
d
prot
e
ins from
da
m
a
g
e d
u
e
to
h
ea
ting
,
acc
or
d
ing to th
e
s
e
l
ec
tion hypoth
e
sis
.
W
olf
e e
t
a
l
.
I
t
a
rgu
e
s
th
a
t th
e
iso
c
or
a
t
e a
ris
e
s
d
u
e
to mut
a
tions r
e
l
a
t
ed
to th
e c
h
a
ng
e
in th
e
c
omposition of th
e
"
pool
"
of th
e
nu
c
l
e
oti
de
pr
ec
ursor
d
uring th
e
Ge
rmlin
e DNA
r
e
pli
ca
tion
.
GC
ri
c
h iso
c
or
e
s
a
r
e
r
e
pli
ca
t
ed ea
rli
e
r in th
e
gymlin
e ce
ll
c
y
c
l
e
wh
e
n th
e
pr
ec
ursor pool h
a
s high
GC c
ont
e
nt
,
whil
e
ri
c
h iso
c
or
e
s
a
t r
e
pli
ca
t
ed
mor
e
slowly wh
e
n th
e
pr
ec
ursor pool h
a
s
high
AT c
ont
e
nt
,
acc
or
d
ing to th
e
hypoth
e
sis mut
a
tion
.
25
A
.
C
on
c
lusion
T
h
e e
volution of th
e
g
e
nom
e
stu
d
i
e
s
c
h
a
ng
e
s
a
t th
e
g
e
nom
e
l
e
v
e
l to
un
de
rst
a
n
d
th
e e
volution of th
e
org
a
nism
.
T
h
e
g
e
nom
e
siz
e
v
a
ri
e
s
be
tw
ee
n org
a
nisms
,
whi
c
h
ca
n
be
m
ea
sur
ed
through th
e
v
a
lu
e
of
C
.
C
h
a
ng
e
in g
e
n
e
ti
c c
o
de ca
n
be a
n
a
lyz
ed b
y
c
h
ec
king th
e d
istri
b
ution
of oth
e
r g
e
n
e
ti
c e
l
e
m
e
nts in iso
c
il
e
s
.
Ab
out
30
%
of th
e
hum
a
n
g
e
nom
e
is
a
h
ea
vy
c
ompon
e
nt
(
H
3
)
whi
c
h only
c
ov
e
rs
3
-
5
%
of th
e
e
ntir
e
g
e
nom
e
.
L
ong g
e
n
e
s in ri
c
h
GC
iso
c
il
e
s
a
r
e
v
e
ry r
a
r
e
,
a
n
d
th
e
origin of ri
c
h
GC
iso
c
orism is still myst
e
rious
.
U
su
a
lly
,
ri
c
h g
c
iso
c
or
e
s
a
r
e a
long
DNA
s
e
gm
e
nt
(
300
KB
or mor
e
)
origin
a
ting from
ri
c
h
GC
or poor
GC
,
a
n
d
not
a
ff
ec
t
ed b
y
GC
v
a
ri
a
tions in th
e
v
a
ri
a
tion of g
e
n
e
s
.
