n*e
2 楼
在精子形成的最后一步减数分裂，男性两个染色体X和Y分离。如果带有Y染色体的精子
与卵子结合就是男孩，X染色体精子生女孩。一个卵子被X还是Y受孕，看起来应该是随
机事件。
但是，在生活中我们可以注意到，如果一对夫妻第一个生的是男孩，第二个也多半是男
孩。反过来也一样。也就是是说，同性别孩子家庭多于杂性别孩子家庭。这种现象就意
味着生男生女并不是随机事件。
如果大样本调查支持这种现象。生男生女的奥秘可能还是中医说对了。不是随机的。
与卵子结合就是男孩，X染色体精子生女孩。一个卵子被X还是Y受孕，看起来应该是随
机事件。
但是，在生活中我们可以注意到，如果一对夫妻第一个生的是男孩，第二个也多半是男
孩。反过来也一样。也就是是说，同性别孩子家庭多于杂性别孩子家庭。这种现象就意
味着生男生女并不是随机事件。
如果大样本调查支持这种现象。生男生女的奥秘可能还是中医说对了。不是随机的。
r*e
3 楼
感觉像是很爽的晒太阳
【在 c*******7 的大作中提到】
: 哦也
【在 c*******7 的大作中提到】
: 哦也
D*a
4 楼
你自己看吧
1
00:00:01,200 --> 00:00:03,130
Hello, and welcome back to Animal
Behavior.
2
00:00:04,590 --> 00:00:06,189
When sexually reproducing animals
produce
3
00:00:06,189 --> 00:00:08,330
their offspring, they have a choice.
4
00:00:08,330 --> 00:00:13,030
They can produce either a son or a
daughter in any given reproductive event.
5
00:00:13,030 --> 00:00:15,730
In this lecture, we'll look at the
question of whether in certain
6
00:00:15,730 --> 00:00:17,330
circumstances it might pay parents to
7
00:00:17,330 --> 00:00:21,210
preferentially produce either a son or
daughter.
8
00:00:21,210 --> 00:00:23,300
Now for a long time it was assumed
9
00:00:23,300 --> 00:00:26,207
that in species with genetic sex
determination - animals like
10
00:00:26,207 --> 00:00:30,100
birds or mammals - that sex determination
was pretty random -
11
00:00:30,100 --> 00:00:32,960
that it couldn't really be influenced by
the parents.
12
00:00:32,960 --> 00:00:35,552
But we now know that a huge variety of
organisms, including birds
13
00:00:35,552 --> 00:00:40,240
and mammals are capable of
manipulating the sex of their offspring.
14
00:00:40,240 --> 00:00:43,159
And manipulating the sex in ways that
increase their fitness.
15
00:00:45,280 --> 00:00:47,968
To understand interesting patterns of sex
allocation we
16
00:00:47,968 --> 00:00:51,926
first have to understand why from an
evolutionary perspective,
17
00:00:51,926 --> 00:00:56,062
we expect investment in the two sexes to
be equal at the population level.
18
00:00:56,062 --> 00:00:58,862
Now at first, this seems rather counter-
intuitive. After all, if the
19
00:00:58,862 --> 00:01:03,030
sperm of a single male can fertilize lots
of different females,
20
00:01:03,030 --> 00:01:06,570
why not produce a sex ratio of say, 1 male
for every 10 females.
21
00:01:07,900 --> 00:01:10,930
Now we can see why that wouldn't work by
doing a thought experiment.
22
00:01:12,190 --> 00:01:16,450
Suppose we had a population in which there
were ten times as many females as males.
23
00:01:18,170 --> 00:01:23,240
Such a female bias sex ratio can't be
evolutionarily stable. Why?
24
00:01:23,240 --> 00:01:27,465
Well, because any parent that produces a
rare male will gain about ten times as
25
00:01:27,465 --> 00:01:33,880
much reproductive success
as any individual that produces a female.
26
00:01:33,880 --> 00:01:37,219
That's because this male can potentially
mate with on average,
27
00:01:37,219 --> 00:01:38,588
10 females,
28
00:01:38,588 --> 00:01:42,660
whereas each of these females can only
mate with this one male.
29
00:01:44,040 --> 00:01:45,967
As a consequence, any gene that causes
parents to
30
00:01:45,967 --> 00:01:49,152
produce a son, will rapidly spread through
the population,
31
00:01:49,152 --> 00:01:53,110
and the proportion of sons will steadily
increase to more than one in ten.
32
00:01:57,080 --> 00:01:59,690
But the converse is equally unstable.
33
00:01:59,690 --> 00:02:04,171
If there are ten males all competing to
fertilize the eggs of a single female,
34
00:02:04,171 --> 00:02:06,280
then daughters are going to have an
enormous
35
00:02:06,280 --> 00:02:09,860
fitness advantage because only one of
these ten males.
36
00:02:09,860 --> 00:02:13,685
Can fertilize the offspring that's
produced by this female.
37
00:02:13,685 --> 00:02:17,585
So even though this female can only
produce one offspring, each of these males
38
00:02:17,585 --> 00:02:22,460
has only a one in ten chance of being the
father of that offspring.
39
00:02:22,460 --> 00:02:24,568
So again, there's a ten fold advantage in
40
00:02:24,568 --> 00:02:28,235
terms of reproduction to females in this
situation.
41
00:02:28,235 --> 00:02:31,384
Both sexes will only have the same
reproductive success
42
00:02:31,384 --> 00:02:36,090
when the population sex ratio is exactly
one to one.
43
00:02:36,090 --> 00:02:39,058
Even tiny deviations from that ratio are
going to provide fitness
44
00:02:39,058 --> 00:02:43,770
advantages that'll favor bias towards the
sex that returns better fitness.
45
00:02:45,520 --> 00:02:47,518
This insight, that persistent sex ratio
bias
46
00:02:47,518 --> 00:02:50,450
of the population can't be stable,
47
00:02:50,450 --> 00:02:53,320
came from a famous theoretician by the
name of Ronald Fisher.
48
00:02:53,320 --> 00:02:55,814
And the way that Fisher expressed it was
that "the sex
49
00:02:55,814 --> 00:03:00,507
ratio will so adjust itself, under the
influence of natural selection,
50
00:03:00,507 --> 00:03:02,885
that the total parental expenditure
incurred in
51
00:03:02,885 --> 00:03:06,000
respect of children of each sex will be
equal.
52
00:03:07,890 --> 00:03:10,374
A nice way to test Fisher's theory is to
experimentally
53
00:03:10,374 --> 00:03:12,642
push the sex ratio away from parity and
then try and
54
00:03:12,642 --> 00:03:16,460
observe whether it evolves back to that
point.
55
00:03:16,460 --> 00:03:18,566
And you can do that in species that have
unusual
56
00:03:18,566 --> 00:03:23,570
forms of sex determination by manipulating
the frequency of the sex alleles.
57
00:03:23,570 --> 00:03:26,540
And this little fish for example, which is
called a Southern Platyfish,
58
00:03:26,540 --> 00:03:31,130
sex is determined by a single
genetic locus that has three alleles.
59
00:03:31,130 --> 00:03:36,580
There are three female genotypes and there
are two male genotypes.
60
00:03:38,010 --> 00:03:38,505
Alexandra Basolo showed
61
00:03:38,505 --> 00:03:41,420
that if the relative frequency of those alleles
62
00:03:41,420 --> 00:03:46,403
is changed - by setting up populations
with biased sex ratio -
63
00:03:46,403 --> 00:03:48,704
selection will favor the rarer sex, and
within
64
00:03:48,704 --> 00:03:53,090
a few generations the ratio swings back to
parity.
65
00:03:53,090 --> 00:03:57,713
So in this case here, if we start off with
a population that is female biased, that
66
00:03:57,713 --> 00:04:03,822
has a relatively low proportion of males.
As we go through the generations,
67
00:04:03,822 --> 00:04:07,630
the sex ratio quickly swings back to
parity.
68
00:04:09,600 --> 00:04:14,120
The same is true if we start with a
population that is quite male biased.
69
00:04:14,120 --> 00:04:16,457
So here we have a high proportion of
males, again,
70
00:04:16,457 --> 00:04:20,944
as we move through just a couple of
generations of reproduction,
71
00:04:20,944 --> 00:04:24,500
we end up with a population that
ends up back at parity.
72
00:04:26,080 --> 00:04:28,870
We can refine Fisher's argument by
rephrasing it in terms of the resources
73
00:04:28,870 --> 00:04:32,066
that are invested.
So far, we've implicitly assumed
74
00:04:32,066 --> 00:04:32,457
75
00:04:32,457 --> 00:04:35,760
that daughters and sons are equally costly to
produce.
76
00:04:35,760 --> 00:04:37,416
But what if we imagine that sons are twice
as
77
00:04:37,416 --> 00:04:41,120
costly as daughters to produce, because
they're twice as big,
78
00:04:41,120 --> 00:04:43,030
and eat twice as much food while they're
developing?
79
00:04:44,470 --> 00:04:46,268
Now, when the sex ratio is one to one, a
80
00:04:46,268 --> 00:04:49,800
son has the same number of children as a
daughter.
81
00:04:49,800 --> 00:04:51,714
But because the sons are twice as costly
82
00:04:51,714 --> 00:04:55,620
to make, they're a bad investment for a
parent.
83
00:04:55,620 --> 00:04:57,720
Because each of the grandchildren that's
84
00:04:57,720 --> 00:04:59,700
produced here, is twice as expensive as
85
00:04:59,700 --> 00:05:03,585
the grandchildren that are produced by a
daughter.
86
00:05:03,585 --> 00:05:07,890
It should therefore pay parents to produce
daughters instead.
87
00:05:09,510 --> 00:05:12,575
We expect the sex ratio to swing toward
the female bias.
88
00:05:12,575 --> 00:05:17,440
And as that happens, the expected
reproductive success of a son will go up.
89
00:05:17,440 --> 00:05:19,378
Until the average son produces twice the
90
00:05:19,378 --> 00:05:22,680
number of grand offspring as the average
daughter.
91
00:05:22,680 --> 00:05:27,620
At that point, sons and daughters will
give exactly the same return per unit of
92
00:05:27,620 --> 00:05:33,077
investment.
Because even though a son costs twice as
93
00:05:33,077 --> 00:05:39,370
much, he provides twice as many offspring
as a daughter does.
94
00:05:42,690 --> 00:05:45,919
What this means is that when the sexes
differ in their costs,
95
00:05:45,919 --> 00:05:48,051
the stable strategy for parents is not to
produce
96
00:05:48,051 --> 00:05:51,920
equal numbers of the two sexes, but to
invest equally.
97
00:05:51,920 --> 00:05:56,250
If males are twice as costly as females,
parents should only produce half as many.
98
00:05:59,800 --> 00:06:01,440
Now to test this prediction, all we need
to do is to
99
00:06:01,440 --> 00:06:04,990
find a study system where the costs of
producing sons and daughters differs.
100
00:06:06,230 --> 00:06:10,060
And a nice example of this comes from two
closely related wasp species.
101
00:06:11,570 --> 00:06:16,050
Polistes variatus is a species where males
and females are equal in size.
102
00:06:17,490 --> 00:06:20,087
A closely related species, Polistes
metricus, has females
103
00:06:20,087 --> 00:06:22,199
that are half the size of males.
104
00:06:24,340 --> 00:06:27,092
Now, in metricus female wasps produce
twice as many
105
00:06:27,092 --> 00:06:31,960
females as in males amd variatis equal
numbers are produced.
106
00:06:31,960 --> 00:06:34,816
So, exactly as predicted by Fisher, when
males cost
107
00:06:34,816 --> 00:06:39,060
twice as much as females, half as many are
produced.
108
00:06:40,760 --> 00:06:42,828
So, the take home message from this
lecture is that at the
109
00:06:42,828 --> 00:06:47,040
population level we expect sex ratios to
be pretty near parity.
110
00:06:47,040 --> 00:06:49,432
A parent should invest in sons and
daughters near
111
00:06:49,432 --> 00:06:53,670
equally, based on how many are produced
and what they cost to produce.
112
00:06:55,030 --> 00:06:58,038
However, we'll see in the next lecture
that there are some contexts that might
113
00:06:58,038 --> 00:07:02,460
favor a bias in production of sons and
daughters at the level of the individual.
1
00:00:01,200 --> 00:00:03,130
Hello, and welcome back to Animal
Behavior.
2
00:00:04,590 --> 00:00:06,189
When sexually reproducing animals
produce
3
00:00:06,189 --> 00:00:08,330
their offspring, they have a choice.
4
00:00:08,330 --> 00:00:13,030
They can produce either a son or a
daughter in any given reproductive event.
5
00:00:13,030 --> 00:00:15,730
In this lecture, we'll look at the
question of whether in certain
6
00:00:15,730 --> 00:00:17,330
circumstances it might pay parents to
7
00:00:17,330 --> 00:00:21,210
preferentially produce either a son or
daughter.
8
00:00:21,210 --> 00:00:23,300
Now for a long time it was assumed
9
00:00:23,300 --> 00:00:26,207
that in species with genetic sex
determination - animals like
10
00:00:26,207 --> 00:00:30,100
birds or mammals - that sex determination
was pretty random -
11
00:00:30,100 --> 00:00:32,960
that it couldn't really be influenced by
the parents.
12
00:00:32,960 --> 00:00:35,552
But we now know that a huge variety of
organisms, including birds
13
00:00:35,552 --> 00:00:40,240
and mammals are capable of
manipulating the sex of their offspring.
14
00:00:40,240 --> 00:00:43,159
And manipulating the sex in ways that
increase their fitness.
15
00:00:45,280 --> 00:00:47,968
To understand interesting patterns of sex
allocation we
16
00:00:47,968 --> 00:00:51,926
first have to understand why from an
evolutionary perspective,
17
00:00:51,926 --> 00:00:56,062
we expect investment in the two sexes to
be equal at the population level.
18
00:00:56,062 --> 00:00:58,862
Now at first, this seems rather counter-
intuitive. After all, if the
19
00:00:58,862 --> 00:01:03,030
sperm of a single male can fertilize lots
of different females,
20
00:01:03,030 --> 00:01:06,570
why not produce a sex ratio of say, 1 male
for every 10 females.
21
00:01:07,900 --> 00:01:10,930
Now we can see why that wouldn't work by
doing a thought experiment.
22
00:01:12,190 --> 00:01:16,450
Suppose we had a population in which there
were ten times as many females as males.
23
00:01:18,170 --> 00:01:23,240
Such a female bias sex ratio can't be
evolutionarily stable. Why?
24
00:01:23,240 --> 00:01:27,465
Well, because any parent that produces a
rare male will gain about ten times as
25
00:01:27,465 --> 00:01:33,880
much reproductive success
as any individual that produces a female.
26
00:01:33,880 --> 00:01:37,219
That's because this male can potentially
mate with on average,
27
00:01:37,219 --> 00:01:38,588
10 females,
28
00:01:38,588 --> 00:01:42,660
whereas each of these females can only
mate with this one male.
29
00:01:44,040 --> 00:01:45,967
As a consequence, any gene that causes
parents to
30
00:01:45,967 --> 00:01:49,152
produce a son, will rapidly spread through
the population,
31
00:01:49,152 --> 00:01:53,110
and the proportion of sons will steadily
increase to more than one in ten.
32
00:01:57,080 --> 00:01:59,690
But the converse is equally unstable.
33
00:01:59,690 --> 00:02:04,171
If there are ten males all competing to
fertilize the eggs of a single female,
34
00:02:04,171 --> 00:02:06,280
then daughters are going to have an
enormous
35
00:02:06,280 --> 00:02:09,860
fitness advantage because only one of
these ten males.
36
00:02:09,860 --> 00:02:13,685
Can fertilize the offspring that's
produced by this female.
37
00:02:13,685 --> 00:02:17,585
So even though this female can only
produce one offspring, each of these males
38
00:02:17,585 --> 00:02:22,460
has only a one in ten chance of being the
father of that offspring.
39
00:02:22,460 --> 00:02:24,568
So again, there's a ten fold advantage in
40
00:02:24,568 --> 00:02:28,235
terms of reproduction to females in this
situation.
41
00:02:28,235 --> 00:02:31,384
Both sexes will only have the same
reproductive success
42
00:02:31,384 --> 00:02:36,090
when the population sex ratio is exactly
one to one.
43
00:02:36,090 --> 00:02:39,058
Even tiny deviations from that ratio are
going to provide fitness
44
00:02:39,058 --> 00:02:43,770
advantages that'll favor bias towards the
sex that returns better fitness.
45
00:02:45,520 --> 00:02:47,518
This insight, that persistent sex ratio
bias
46
00:02:47,518 --> 00:02:50,450
of the population can't be stable,
47
00:02:50,450 --> 00:02:53,320
came from a famous theoretician by the
name of Ronald Fisher.
48
00:02:53,320 --> 00:02:55,814
And the way that Fisher expressed it was
that "the sex
49
00:02:55,814 --> 00:03:00,507
ratio will so adjust itself, under the
influence of natural selection,
50
00:03:00,507 --> 00:03:02,885
that the total parental expenditure
incurred in
51
00:03:02,885 --> 00:03:06,000
respect of children of each sex will be
equal.
52
00:03:07,890 --> 00:03:10,374
A nice way to test Fisher's theory is to
experimentally
53
00:03:10,374 --> 00:03:12,642
push the sex ratio away from parity and
then try and
54
00:03:12,642 --> 00:03:16,460
observe whether it evolves back to that
point.
55
00:03:16,460 --> 00:03:18,566
And you can do that in species that have
unusual
56
00:03:18,566 --> 00:03:23,570
forms of sex determination by manipulating
the frequency of the sex alleles.
57
00:03:23,570 --> 00:03:26,540
And this little fish for example, which is
called a Southern Platyfish,
58
00:03:26,540 --> 00:03:31,130
sex is determined by a single
genetic locus that has three alleles.
59
00:03:31,130 --> 00:03:36,580
There are three female genotypes and there
are two male genotypes.
60
00:03:38,010 --> 00:03:38,505
Alexandra Basolo showed
61
00:03:38,505 --> 00:03:41,420
that if the relative frequency of those alleles
62
00:03:41,420 --> 00:03:46,403
is changed - by setting up populations
with biased sex ratio -
63
00:03:46,403 --> 00:03:48,704
selection will favor the rarer sex, and
within
64
00:03:48,704 --> 00:03:53,090
a few generations the ratio swings back to
parity.
65
00:03:53,090 --> 00:03:57,713
So in this case here, if we start off with
a population that is female biased, that
66
00:03:57,713 --> 00:04:03,822
has a relatively low proportion of males.
As we go through the generations,
67
00:04:03,822 --> 00:04:07,630
the sex ratio quickly swings back to
parity.
68
00:04:09,600 --> 00:04:14,120
The same is true if we start with a
population that is quite male biased.
69
00:04:14,120 --> 00:04:16,457
So here we have a high proportion of
males, again,
70
00:04:16,457 --> 00:04:20,944
as we move through just a couple of
generations of reproduction,
71
00:04:20,944 --> 00:04:24,500
we end up with a population that
ends up back at parity.
72
00:04:26,080 --> 00:04:28,870
We can refine Fisher's argument by
rephrasing it in terms of the resources
73
00:04:28,870 --> 00:04:32,066
that are invested.
So far, we've implicitly assumed
74
00:04:32,066 --> 00:04:32,457
75
00:04:32,457 --> 00:04:35,760
that daughters and sons are equally costly to
produce.
76
00:04:35,760 --> 00:04:37,416
But what if we imagine that sons are twice
as
77
00:04:37,416 --> 00:04:41,120
costly as daughters to produce, because
they're twice as big,
78
00:04:41,120 --> 00:04:43,030
and eat twice as much food while they're
developing?
79
00:04:44,470 --> 00:04:46,268
Now, when the sex ratio is one to one, a
80
00:04:46,268 --> 00:04:49,800
son has the same number of children as a
daughter.
81
00:04:49,800 --> 00:04:51,714
But because the sons are twice as costly
82
00:04:51,714 --> 00:04:55,620
to make, they're a bad investment for a
parent.
83
00:04:55,620 --> 00:04:57,720
Because each of the grandchildren that's
84
00:04:57,720 --> 00:04:59,700
produced here, is twice as expensive as
85
00:04:59,700 --> 00:05:03,585
the grandchildren that are produced by a
daughter.
86
00:05:03,585 --> 00:05:07,890
It should therefore pay parents to produce
daughters instead.
87
00:05:09,510 --> 00:05:12,575
We expect the sex ratio to swing toward
the female bias.
88
00:05:12,575 --> 00:05:17,440
And as that happens, the expected
reproductive success of a son will go up.
89
00:05:17,440 --> 00:05:19,378
Until the average son produces twice the
90
00:05:19,378 --> 00:05:22,680
number of grand offspring as the average
daughter.
91
00:05:22,680 --> 00:05:27,620
At that point, sons and daughters will
give exactly the same return per unit of
92
00:05:27,620 --> 00:05:33,077
investment.
Because even though a son costs twice as
93
00:05:33,077 --> 00:05:39,370
much, he provides twice as many offspring
as a daughter does.
94
00:05:42,690 --> 00:05:45,919
What this means is that when the sexes
differ in their costs,
95
00:05:45,919 --> 00:05:48,051
the stable strategy for parents is not to
produce
96
00:05:48,051 --> 00:05:51,920
equal numbers of the two sexes, but to
invest equally.
97
00:05:51,920 --> 00:05:56,250
If males are twice as costly as females,
parents should only produce half as many.
98
00:05:59,800 --> 00:06:01,440
Now to test this prediction, all we need
to do is to
99
00:06:01,440 --> 00:06:04,990
find a study system where the costs of
producing sons and daughters differs.
100
00:06:06,230 --> 00:06:10,060
And a nice example of this comes from two
closely related wasp species.
101
00:06:11,570 --> 00:06:16,050
Polistes variatus is a species where males
and females are equal in size.
102
00:06:17,490 --> 00:06:20,087
A closely related species, Polistes
metricus, has females
103
00:06:20,087 --> 00:06:22,199
that are half the size of males.
104
00:06:24,340 --> 00:06:27,092
Now, in metricus female wasps produce
twice as many
105
00:06:27,092 --> 00:06:31,960
females as in males amd variatis equal
numbers are produced.
106
00:06:31,960 --> 00:06:34,816
So, exactly as predicted by Fisher, when
males cost
107
00:06:34,816 --> 00:06:39,060
twice as much as females, half as many are
produced.
108
00:06:40,760 --> 00:06:42,828
So, the take home message from this
lecture is that at the
109
00:06:42,828 --> 00:06:47,040
population level we expect sex ratios to
be pretty near parity.
110
00:06:47,040 --> 00:06:49,432
A parent should invest in sons and
daughters near
111
00:06:49,432 --> 00:06:53,670
equally, based on how many are produced
and what they cost to produce.
112
00:06:55,030 --> 00:06:58,038
However, we'll see in the next lecture
that there are some contexts that might
113
00:06:58,038 --> 00:07:02,460
favor a bias in production of sons and
daughters at the level of the individual.
T*u
5 楼
哈哈，第一张很优雅，低二张很高兴。
n*e
6 楼
幸好没拷贝大英百科全书。
【在 D*a 的大作中提到】
: 你自己看吧
: 1
: 00:00:01,200 --> 00:00:03,130
: Hello, and welcome back to Animal
: Behavior.
: 2
: 00:00:04,590 --> 00:00:06,189
: When sexually reproducing animals
: produce
: 3
【在 D*a 的大作中提到】
: 你自己看吧
: 1
: 00:00:01,200 --> 00:00:03,130
: Hello, and welcome back to Animal
: Behavior.
: 2
: 00:00:04,590 --> 00:00:06,189
: When sexually reproducing animals
: produce
: 3
B*e
7 楼
男的女的？
D*a
8 楼
七分钟的视频而已..论坛传不了，我有么办法
【在 n**e 的大作中提到】
: 幸好没拷贝大英百科全书。
【在 n**e 的大作中提到】
: 幸好没拷贝大英百科全书。
i*l
9 楼
今天周末 有几秒钟，就回一个：
班门弄斧
班门弄斧
n*e
10 楼
能简明表达观点吗？随机或非随机。
【在 D*a 的大作中提到】
: 七分钟的视频而已..论坛传不了，我有么办法
【在 D*a 的大作中提到】
: 七分钟的视频而已..论坛传不了，我有么办法
D*a
11 楼
简明了就不准了。
要准的话：随机和非随机都作用于男女（雌雄）比例
【在 n**e 的大作中提到】
: 能简明表达观点吗？随机或非随机。
要准的话：随机和非随机都作用于男女（雌雄）比例
【在 n**e 的大作中提到】
: 能简明表达观点吗？随机或非随机。
n*e
12 楼
看来你还是将道理的。一般而言，如果有非随机的因素存在。我们就不能说一个事件是
随机发生的。所以随机非随机存在内在排斥，不可同时有理。
【在 D*a 的大作中提到】
: 简明了就不准了。
: 要准的话：随机和非随机都作用于男女（雌雄）比例
随机发生的。所以随机非随机存在内在排斥，不可同时有理。
【在 D*a 的大作中提到】
: 简明了就不准了。
: 要准的话：随机和非随机都作用于男女（雌雄）比例
D*a
13 楼
也对也不对。
非随机是大量统计的结果，是指整体的一个种群而言，但是具体到某一家/某一窝，还
是不能预测的。
你可以看看这篇，http://www.guokr.com/post/502618/
讲的不如我这个视频细，但是也差不多
【在 n**e 的大作中提到】
: 看来你还是将道理的。一般而言，如果有非随机的因素存在。我们就不能说一个事件是
: 随机发生的。所以随机非随机存在内在排斥，不可同时有理。
非随机是大量统计的结果，是指整体的一个种群而言，但是具体到某一家/某一窝，还
是不能预测的。
你可以看看这篇，http://www.guokr.com/post/502618/
讲的不如我这个视频细，但是也差不多
【在 n**e 的大作中提到】
: 看来你还是将道理的。一般而言，如果有非随机的因素存在。我们就不能说一个事件是
: 随机发生的。所以随机非随机存在内在排斥，不可同时有理。
n*e
14 楼
Genetics 课本上说其实北美白人初级性别比（出生比）男：女大约1.06:1也就是出生
男孩多。其解释是因动量定理Y精子速度更快，我也觉得这个很扯，不过是个可能的假
设。然后考察整个人群（男女老少都考察）的次级性别比就发现男比女无限接近1:1了
。原因是男婴多病早夭（X染色体剂量效应相关，女人2份X屏蔽一份且随机（理论上）
，男人没这好处），而且男人死得早。
男孩多。其解释是因动量定理Y精子速度更快，我也觉得这个很扯，不过是个可能的假
设。然后考察整个人群（男女老少都考察）的次级性别比就发现男比女无限接近1:1了
。原因是男婴多病早夭（X染色体剂量效应相关，女人2份X屏蔽一份且随机（理论上）
，男人没这好处），而且男人死得早。
v*e
15 楼
还是随机事件，只不过有相关性。楼主显然没搞明白什么叫做随机什么叫做不随机。另
外说一句，随机不随机，都和旧医没关系。
外说一句，随机不随机，都和旧医没关系。
a*n
16 楼
这个不好说，不过某些人精神分裂注册马甲化妆成普通网友来吹捧自己
肯定不是随机的，估计是手机信号辐射太多，造成的生理病变
【在 n**e 的大作中提到】
: 在精子形成的最后一步减数分裂，男性两个染色体X和Y分离。如果带有Y染色体的精子
: 与卵子结合就是男孩，X染色体精子生女孩。一个卵子被X还是Y受孕，看起来应该是随
: 机事件。
: 但是，在生活中我们可以注意到，如果一对夫妻第一个生的是男孩，第二个也多半是男
: 孩。反过来也一样。也就是是说，同性别孩子家庭多于杂性别孩子家庭。这种现象就意
: 味着生男生女并不是随机事件。
: 如果大样本调查支持这种现象。生男生女的奥秘可能还是中医说对了。不是随机的。
肯定不是随机的，估计是手机信号辐射太多，造成的生理病变
【在 n**e 的大作中提到】
: 在精子形成的最后一步减数分裂，男性两个染色体X和Y分离。如果带有Y染色体的精子
: 与卵子结合就是男孩，X染色体精子生女孩。一个卵子被X还是Y受孕，看起来应该是随
: 机事件。
: 但是，在生活中我们可以注意到，如果一对夫妻第一个生的是男孩，第二个也多半是男
: 孩。反过来也一样。也就是是说，同性别孩子家庭多于杂性别孩子家庭。这种现象就意
: 味着生男生女并不是随机事件。
: 如果大样本调查支持这种现象。生男生女的奥秘可能还是中医说对了。不是随机的。
l*z
17 楼
哈哈, 笑坏了.
【在 a***n 的大作中提到】
: 这个不好说，不过某些人精神分裂注册马甲化妆成普通网友来吹捧自己
: 肯定不是随机的，估计是手机信号辐射太多，造成的生理病变
【在 a***n 的大作中提到】
: 这个不好说，不过某些人精神分裂注册马甲化妆成普通网友来吹捧自己
: 肯定不是随机的，估计是手机信号辐射太多，造成的生理病变
n*e
18 楼
你错了，随机是大量统计的结果。男女比非常接近1：1（在没有任意堕胎的国家）。现
在我质疑的就是这一点。具体到每一家就可以发现有优先生男或者优先生女的趋势。这
当然是局部经验。要得出结论需要大样本统计。
我先假定一下调查统计的结果。如果。如果。在两个孩子的家庭，单性别明显多于杂性
别。在三个孩子家庭，前两个孩子单性别明显多于杂性别。在四个孩子家庭，前三个孩
子单性别明显多于杂性别。你就必须承认，生男生女不是随机事件。
所以不要用大量统计男女均衡的结果来反驳我的观点。应该证明即使nile假设的结果是
事实，也不能表明生男生女不是随机的。
【在 D*a 的大作中提到】
: 也对也不对。
: 非随机是大量统计的结果，是指整体的一个种群而言，但是具体到某一家/某一窝，还
: 是不能预测的。
: 你可以看看这篇，http://www.guokr.com/post/502618/
: 讲的不如我这个视频细，但是也差不多
在我质疑的就是这一点。具体到每一家就可以发现有优先生男或者优先生女的趋势。这
当然是局部经验。要得出结论需要大样本统计。
我先假定一下调查统计的结果。如果。如果。在两个孩子的家庭，单性别明显多于杂性
别。在三个孩子家庭，前两个孩子单性别明显多于杂性别。在四个孩子家庭，前三个孩
子单性别明显多于杂性别。你就必须承认，生男生女不是随机事件。
所以不要用大量统计男女均衡的结果来反驳我的观点。应该证明即使nile假设的结果是
事实，也不能表明生男生女不是随机的。
【在 D*a 的大作中提到】
: 也对也不对。
: 非随机是大量统计的结果，是指整体的一个种群而言，但是具体到某一家/某一窝，还
: 是不能预测的。
: 你可以看看这篇，http://www.guokr.com/post/502618/
: 讲的不如我这个视频细，但是也差不多
n*e
19 楼
随机事件，特征是结果不可预测，可能性各半。
我在原帖中就表明了这两个特征：在精子形成的最后一步减数分裂，男性两个染色体X
和Y分离。如果带有Y染色体的精子与卵子结合就是男孩，X染色体精子生女孩。一个卵
子被X还是Y受孕，看起来应该是随机事件。
请问我怎么“没搞明白什么叫做随机什么叫做不随机”。
你认为是随机不是随机都可以。关键不是你的观点。而是你为观点提供的论据。
另外说一句。中医不认为生男生女是随机的。只是中医关于这方面的理论，你根本就没
有读过。不要讨论你没有知识的事务。那会显得你很无知。
【在 v*******e 的大作中提到】
: 还是随机事件，只不过有相关性。楼主显然没搞明白什么叫做随机什么叫做不随机。另
: 外说一句，随机不随机，都和旧医没关系。
我在原帖中就表明了这两个特征：在精子形成的最后一步减数分裂，男性两个染色体X
和Y分离。如果带有Y染色体的精子与卵子结合就是男孩，X染色体精子生女孩。一个卵
子被X还是Y受孕，看起来应该是随机事件。
请问我怎么“没搞明白什么叫做随机什么叫做不随机”。
你认为是随机不是随机都可以。关键不是你的观点。而是你为观点提供的论据。
另外说一句。中医不认为生男生女是随机的。只是中医关于这方面的理论，你根本就没
有读过。不要讨论你没有知识的事务。那会显得你很无知。
【在 v*******e 的大作中提到】
: 还是随机事件，只不过有相关性。楼主显然没搞明白什么叫做随机什么叫做不随机。另
: 外说一句，随机不随机，都和旧医没关系。
v*e
20 楼
可能性1/4：3/4的也是随机事件。不光是1/2:1/2。
【在 n**e 的大作中提到】
: 随机事件，特征是结果不可预测，可能性各半。
: 我在原帖中就表明了这两个特征：在精子形成的最后一步减数分裂，男性两个染色体X
: 和Y分离。如果带有Y染色体的精子与卵子结合就是男孩，X染色体精子生女孩。一个卵
: 子被X还是Y受孕，看起来应该是随机事件。
: 请问我怎么“没搞明白什么叫做随机什么叫做不随机”。
: 你认为是随机不是随机都可以。关键不是你的观点。而是你为观点提供的论据。
: 另外说一句。中医不认为生男生女是随机的。只是中医关于这方面的理论，你根本就没
: 有读过。不要讨论你没有知识的事务。那会显得你很无知。
n*e
21 楼
有些公认的东西就不必抠字眼了。精子只有带X 和带Y的两种，所以这里的随机事件只
需考虑一半对一半的。
【在 v*******e 的大作中提到】
:
: 可能性1/4：3/4的也是随机事件。不光是1/2:1/2。
需考虑一半对一半的。
【在 v*******e 的大作中提到】
:
: 可能性1/4：3/4的也是随机事件。不光是1/2:1/2。
n*e
22 楼
网络无赖们的特征是用语言暴力人身攻击代替对客观事物的讨论。一大嗜好就是强行给
人戴上精神病的帽子。这一点与世界各国的暴君对待政敌的手法极为相似。所以爱因斯
坦有句名言：天才的暴君总是由无赖来继承。
最近网络无赖们把强制精神病的诊断水平发挥到了新的高度。有人声称精神病根本原因
是大脑前列腺受损。根据他理解的医学科学知识，他的大脑应该是长在比邻膀胱和直肠
的地方，而他脖子上的球状物体唯一的功能就是用来排泄肮脏的语言。这种人类罕见的
畸形只有家族遗传性基因缺陷才可以解释。
不过这位畸形儿对佛法颇有悟性。知道“诳语”死后是要割舌下地狱的。他说“微镜”
就是nile的马甲。Nile用马甲吹捧自己就是“诳语”。
“诳语”比较正式的用词是妄语，属于佛家基本戒律之一。首要内容就是不能撒谎，也
就是不能伪造事实歪曲事实。nile没说过的话硬要说他就是这么说的。Nile没有伪造任
何人的言论硬说nile伪造。人与马吸收植物蛋白的能力基本相同，硬要说有巨大不同。
不是生物专家，硬要冒充生物专家。这就是妄语，按佛家的说法，死后是要割舌下地狱
的。
回到微镜是不是nile的马甲问题上，标准还是事实。本人对这种指控一直采取的态度是
不加回应。第一个理由是无法出示证据证明微镜不是nile的马甲。也没有义务提供证据
证明微镜是nile的马甲。更重要的理由是那个指控nile用马甲自我吹捧的无赖完全没有
资格对nile的诚信问题作出道德评判。
不论微镜是不是nile的马甲，微镜对nile的评价和对肥版版主封禁nile的评价都是是个
人观点的真实陈述，与“诳语”没有丝毫联系。某人既然指控微镜是nile的马甲，自然
应该用事实证明所言真实不虚。
如果你并不知道微镜是不是nile的马甲，请不要用你从你祖先那里继承下来的长在裤裆
里的“大脑”先去思考，也不要流着满口污秽追着nile问来问去自寻烦恼。等你和诽谤
nile的人一同割舌下地狱的时候，自然有恶鬼告诉你微镜是不是nile的马甲。
人戴上精神病的帽子。这一点与世界各国的暴君对待政敌的手法极为相似。所以爱因斯
坦有句名言：天才的暴君总是由无赖来继承。
最近网络无赖们把强制精神病的诊断水平发挥到了新的高度。有人声称精神病根本原因
是大脑前列腺受损。根据他理解的医学科学知识，他的大脑应该是长在比邻膀胱和直肠
的地方，而他脖子上的球状物体唯一的功能就是用来排泄肮脏的语言。这种人类罕见的
畸形只有家族遗传性基因缺陷才可以解释。
不过这位畸形儿对佛法颇有悟性。知道“诳语”死后是要割舌下地狱的。他说“微镜”
就是nile的马甲。Nile用马甲吹捧自己就是“诳语”。
“诳语”比较正式的用词是妄语，属于佛家基本戒律之一。首要内容就是不能撒谎，也
就是不能伪造事实歪曲事实。nile没说过的话硬要说他就是这么说的。Nile没有伪造任
何人的言论硬说nile伪造。人与马吸收植物蛋白的能力基本相同，硬要说有巨大不同。
不是生物专家，硬要冒充生物专家。这就是妄语，按佛家的说法，死后是要割舌下地狱
的。
回到微镜是不是nile的马甲问题上，标准还是事实。本人对这种指控一直采取的态度是
不加回应。第一个理由是无法出示证据证明微镜不是nile的马甲。也没有义务提供证据
证明微镜是nile的马甲。更重要的理由是那个指控nile用马甲自我吹捧的无赖完全没有
资格对nile的诚信问题作出道德评判。
不论微镜是不是nile的马甲，微镜对nile的评价和对肥版版主封禁nile的评价都是是个
人观点的真实陈述，与“诳语”没有丝毫联系。某人既然指控微镜是nile的马甲，自然
应该用事实证明所言真实不虚。
如果你并不知道微镜是不是nile的马甲，请不要用你从你祖先那里继承下来的长在裤裆
里的“大脑”先去思考，也不要流着满口污秽追着nile问来问去自寻烦恼。等你和诽谤
nile的人一同割舌下地狱的时候，自然有恶鬼告诉你微镜是不是nile的马甲。
a*n
23 楼
你别乱扯，micromirror是不是你马甲，你就说个话
你要是不敢说，就不是男人没种。
给你这样的人说话，要照顾到你的智商，所以我把我的问题简化一下，
来做选择题
micromirror是不是nile的马甲
（A）是
（B）不是
你来选吧，是A还是B
你要是认怂不敢选，以后见了本大侠，就给我规规矩矩的把尾巴夹紧。
【在 n**e 的大作中提到】
: 网络无赖们的特征是用语言暴力人身攻击代替对客观事物的讨论。一大嗜好就是强行给
: 人戴上精神病的帽子。这一点与世界各国的暴君对待政敌的手法极为相似。所以爱因斯
: 坦有句名言：天才的暴君总是由无赖来继承。
: 最近网络无赖们把强制精神病的诊断水平发挥到了新的高度。有人声称精神病根本原因
: 是大脑前列腺受损。根据他理解的医学科学知识，他的大脑应该是长在比邻膀胱和直肠
: 的地方，而他脖子上的球状物体唯一的功能就是用来排泄肮脏的语言。这种人类罕见的
: 畸形只有家族遗传性基因缺陷才可以解释。
: 不过这位畸形儿对佛法颇有悟性。知道“诳语”死后是要割舌下地狱的。他说“微镜”
: 就是nile的马甲。Nile用马甲吹捧自己就是“诳语”。
: “诳语”比较正式的用词是妄语，属于佛家基本戒律之一。首要内容就是不能撒谎，也
你要是不敢说，就不是男人没种。
给你这样的人说话，要照顾到你的智商，所以我把我的问题简化一下，
来做选择题
micromirror是不是nile的马甲
（A）是
（B）不是
你来选吧，是A还是B
你要是认怂不敢选，以后见了本大侠，就给我规规矩矩的把尾巴夹紧。
【在 n**e 的大作中提到】
: 网络无赖们的特征是用语言暴力人身攻击代替对客观事物的讨论。一大嗜好就是强行给
: 人戴上精神病的帽子。这一点与世界各国的暴君对待政敌的手法极为相似。所以爱因斯
: 坦有句名言：天才的暴君总是由无赖来继承。
: 最近网络无赖们把强制精神病的诊断水平发挥到了新的高度。有人声称精神病根本原因
: 是大脑前列腺受损。根据他理解的医学科学知识，他的大脑应该是长在比邻膀胱和直肠
: 的地方，而他脖子上的球状物体唯一的功能就是用来排泄肮脏的语言。这种人类罕见的
: 畸形只有家族遗传性基因缺陷才可以解释。
: 不过这位畸形儿对佛法颇有悟性。知道“诳语”死后是要割舌下地狱的。他说“微镜”
: 就是nile的马甲。Nile用马甲吹捧自己就是“诳语”。
: “诳语”比较正式的用词是妄语，属于佛家基本戒律之一。首要内容就是不能撒谎，也
a*n
24 楼
哈哈哈哈
你看过micrormirror的发帖记录啦？就是我签名档里面的链接。
怎么样，你能猜出来吗
【在 l****z 的大作中提到】
: 哈哈, 笑坏了.
你看过micrormirror的发帖记录啦？就是我签名档里面的链接。
怎么样，你能猜出来吗
【在 l****z 的大作中提到】
: 哈哈, 笑坏了.
x*e
25 楼
精子是只有X和Y，但含X和Y的精子生存率，游动快慢等可以不一样啊
【在 n**e 的大作中提到】
: 有些公认的东西就不必抠字眼了。精子只有带X 和带Y的两种，所以这里的随机事件只
: 需考虑一半对一半的。
【在 n**e 的大作中提到】
: 有些公认的东西就不必抠字眼了。精子只有带X 和带Y的两种，所以这里的随机事件只
: 需考虑一半对一半的。
n*e
26 楼
如果你真的长了个脑袋，应该看出来这里讨论的不是1.06：1的问题吧。
【在 x********e 的大作中提到】
: 精子是只有X和Y，但含X和Y的精子生存率，游动快慢等可以不一样啊
【在 x********e 的大作中提到】
: 精子是只有X和Y，但含X和Y的精子生存率，游动快慢等可以不一样啊
x*e
27 楼
1.06是你拍脑袋臆想出来的吧
【在 n**e 的大作中提到】
: 如果你真的长了个脑袋，应该看出来这里讨论的不是1.06：1的问题吧。
【在 n**e 的大作中提到】
: 如果你真的长了个脑袋，应该看出来这里讨论的不是1.06：1的问题吧。
a*t
28 楼
我盯你很久了。从来就没有看到你说一句实话。
这么说吧。如果你没有M某某是N某某的马甲证据。你就不是人养的。
这个帖子你三番五次说是N某某写的。
同主题阅读：素食给我健康之——素食与腋臭
http://www.mitbbs.com/article_t/Dreamer/34028641.html
如果是你写的，你就是从猪屁股里爬出来的。
【在 a***n 的大作中提到】
: 这个不好说，不过某些人精神分裂注册马甲化妆成普通网友来吹捧自己
: 肯定不是随机的，估计是手机信号辐射太多，造成的生理病变
这么说吧。如果你没有M某某是N某某的马甲证据。你就不是人养的。
这个帖子你三番五次说是N某某写的。
同主题阅读：素食给我健康之——素食与腋臭
http://www.mitbbs.com/article_t/Dreamer/34028641.html
如果是你写的，你就是从猪屁股里爬出来的。
【在 a***n 的大作中提到】
: 这个不好说，不过某些人精神分裂注册马甲化妆成普通网友来吹捧自己
: 肯定不是随机的，估计是手机信号辐射太多，造成的生理病变
n*e
29 楼
智商一个很重要的指标就是看一个人对数字是否敏感。你太差了。不要推脱说你没看过
第一页回帖。千万不要再打脸了。
【在 x********e 的大作中提到】
: 1.06是你拍脑袋臆想出来的吧
第一页回帖。千万不要再打脸了。
【在 x********e 的大作中提到】
: 1.06是你拍脑袋臆想出来的吧
n*e
30 楼
我觉得他应该从猪pp爬回去。
【在 a*********t 的大作中提到】
: 我盯你很久了。从来就没有看到你说一句实话。
: 这么说吧。如果你没有M某某是N某某的马甲证据。你就不是人养的。
: 这个帖子你三番五次说是N某某写的。
: 同主题阅读：素食给我健康之——素食与腋臭
: http://www.mitbbs.com/article_t/Dreamer/34028641.html
: 如果是你写的，你就是从猪屁股里爬出来的。
【在 a*********t 的大作中提到】
: 我盯你很久了。从来就没有看到你说一句实话。
: 这么说吧。如果你没有M某某是N某某的马甲证据。你就不是人养的。
: 这个帖子你三番五次说是N某某写的。
: 同主题阅读：素食给我健康之——素食与腋臭
: http://www.mitbbs.com/article_t/Dreamer/34028641.html
: 如果是你写的，你就是从猪屁股里爬出来的。
h*n
31 楼
你说的这个没有任何依据。 如果有， 请提供链接。
【在 n**e 的大作中提到】
: 我觉得他应该从猪pp爬回去。
【在 n**e 的大作中提到】
: 我觉得他应该从猪pp爬回去。
a*n
32 楼
不要和精神分裂的病人争吵
【在 h********n 的大作中提到】
: 你说的这个没有任何依据。 如果有， 请提供链接。
【在 h********n 的大作中提到】
: 你说的这个没有任何依据。 如果有， 请提供链接。
n*e
33 楼
我反复说过这不是统计结论。是个人经验。你可以提出相反的观点。
【在 h********n 的大作中提到】
: 你说的这个没有任何依据。 如果有， 请提供链接。
【在 h********n 的大作中提到】
: 你说的这个没有任何依据。 如果有， 请提供链接。
h*n
34 楼
我错了。
【在 a***n 的大作中提到】
: 不要和精神分裂的病人争吵
【在 a***n 的大作中提到】
: 不要和精神分裂的病人争吵
n*e
35 楼
你的质疑我本无需回答。因为前面已经回答过。回答是对你表示尊重。不过你不配。所
以送你三个字母 SOB。
【在 h********n 的大作中提到】
: 我错了。
以送你三个字母 SOB。
【在 h********n 的大作中提到】
: 我错了。
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