Python's [] at least 3x faster than list()?

It appears that using [] around a generator expression (test1) behaves substantially better than putting it inside of list() (test2). The slowdown isn't there when I simply pass a list into list() for shallow copy (test3). Why is this?

Evidence:

from timeit import Timer

t1 = Timer("test1()", "from __main__ import test1")
t2 = Timer("test2()", "from __main__ import test2")
t3 = Timer("test3()", "from __main__ import test3")

x = [34534534, 23423523, 77645645, 345346]

def test1():
    [e for e in x]

print t1.timeit()
#0.552290201187


def test2():
    list(e for e in x)

print t2.timeit()
#2.38739395142

def test3():
    list(x)

print t3.timeit()
#0.515818119049

Machine: 64 bit AMD, Ubuntu 8.04, Python 2.7 (r27:82500)