EVOLUTION OF GAINT
TORTOISES BY
NATURAL SELECTION
Myat Noe Kyi Phyu 9B
(30.3.2022)
Arrival of Giant Tortoises on
the Galapagos islands
The Galapagos Islands are home to a
number of famous animals, including giant
tortoises. Two to three million years ago,
giant tortoises first arrived in Galapagos
from mainland South America, where they
evolved into 15 species with distinct
morphology and distribution. In any case,
three of them are now extinct, and scientists
are currently striving to save the remaining
species as well.
S
E
IS
O
T
R
O
T
T
N
IA
G
F
O
S
N
IO
ADAPTAT
TO THEIR ENVIRONMENTS
The giant tortoises’ shell size and shape
and
subspecies
between
vary
populations. On islands with humid
highlands, the tortoises are larger, with
domed shells and short necks whereas
on islands with dry lowlands, the
tortoises are smaller, with "saddleback"
ve
ha
s
se
oi
rt
to
e
Th
s.
ck
ne
ng
lo
d
an
ls
el
sh
many adaptations that help them
survive, such as large, protective scales
on their shells that insulate them from
injury. Also, they dig dens, tunnels, or
holes in the ground in order to hide
from predators and preserve their
energy during the cold winter months.
Domed
tortoise
Saddlebacked
tortoise
y
b
s
n
io
t
a
t
p
a
d
a
’
s
e
is
o
t
r
o
t
t
n
ia
g
f
o
y
r
e
v
o
c
is
d
’s
Darwin
natural selection
as
w
in
rw
Da
,
ica
er
Am
h
ut
So
in
ds
an
isl
s
go
On the Galapa
nt
re
ffe
di
at
th
ed
tic
no
he
d
an
s
se
oi
rt
to
t
an
gi
e
th
by
d
impresse
He
.
ts
en
nm
ro
vi
en
nt
re
ffe
di
ith
w
ds
an
isl
on
ed
liv
tortoise species
in
e
liv
to
em
th
ed
w
lo
al
at
th
ts
ai
tr
d
ha
s
se
realized that the tortoi
s,
se
oi
rt
to
e
m
so
e,
pl
am
ex
r
Fo
.
ts
en
nm
ro
vi
en
their particular
ey
th
ch
hi
w
in
ls
el
sh
ck
ba
le
dd
sa
ve
ha
,
ge
or
including Lonesome Ge
to
d
an
us
ct
ca
ee
tr
t
ea
to
gh
hi
s
ad
he
r
ei
th
t
lif
are more able to
do
ey
th
ch
hi
w
s,
ce
ur
so
re
od
fo
d
ite
lim
er
ov
es
ut
resolve disp
l
cia
so
g
rin
du
le
ib
ss
po
as
gh
hi
as
s
ad
he
r
ei
through raising th
s
ck
ne
er
ng
lo
ith
w
s
se
oi
rt
to
t
an
gi
e
es
th
interactions. Which is why
by
n
io
ut
ol
ev
of
ry
eo
th
's
in
rw
Da
of
e
pl
am
ex
were selected as an
natural selection.
The END!!
Thank you for your ATTENTION!!