If you bring 10,000 embryos on the first ship, and 10,000 on the second ship, you'll run out in the 25th year, and 58th year.
I modified your death rate so that when people hit 70 years old it shot up to 10% per year. As otherwise we had hundreds of 100 year olds.
That link allows you to change the values and they should update the simulation in the output window. I'm sorry its in C++, its the only language I know really well.
- Total 354,102
- Infants 39,882
- Children 53,934
- Teens 49,704
- YoungAdults 79,456
- Adults 91,140
- Seniors 39,986
- Males 181,138
- Females 172,964
In the year 207, there are 16 males and 13 females turning 100 years old. There are 8300 babies born that year.
The year 58 had 6135 females and 1152 males born. Birth rates dropped for the next 100 years, until the year 131, (7600 births).
What would really happen?
Each woman has 12 direct children, the father, grandma, and grandfather are spread to thin to help (they'd have to help raise: 96 children, 240 children, and 9216 children respectively). This is just too much.
They're going to revolt
I'm not a woman so I'm not 100% sure on this, but I have a sneaking suspicion they don't like being used as baby factories and forced to raise 12 kids (essentially alone - remember the "husband" has 8 other women in his polycule). The first generation might be optimistic, but mental health would be a real issue, there'd be anger and resentment, but the second generation, born in the first few years and about to be implanted on their 18th birthday will not share that optimism, and you'll have a suffragette movement around about year 20.
... If a woman refuses to be a baby factory are we really going impregnate her against her will?
There's a whole bunch of LGBT issues also not considered here.
... And starve
Farming is going to be a real issue, take year 15 as an example:
There will be:
- Infants 2682
- Children 6749
- Teens 853 (13 and 14 year old)
- Adults 984 (90 males and 894 females)
Those 900 woman are going to be fully occupied nursing 3 infants each, and yelling discipline at 7 misbehaving children. Assuming all the men are farmers, they're going to need to grow food for 11,000 people, 122 mouths to feed each. With current American tech they can hit 166 mouths fed per farmer. You've regressed tech for this (for the infant mortality figure), so I've got to assume farming has as well. In postwar american, 1 Farmer feeds 73 people. Putting the tweens and children in the field may put starvation off a bit, but they need to be in school, otherwise you're society is going to regress very quickly, and you'll be illiterate within a few generations.
Edit: actually that 1 in 73 assumes theres people refining fuel, making fertilizers and pesticides, making replacmenet parts, and spitting out new machinery at an exponential rate. That's not going to happen as everyone is busy making babies or growing food. You'll regress to 1930s level farm output, which is 1 farmer per 4 mouths.
... and die of exposure
The growth rate in the number of buildings is also extreme.
Each male in the first 60 years has to build 80 houses in their lifetime (one for each of his partners daughters), each house has to hold a family of up to 14 (most 13, but the males need to live somewhere too). That's a lot to build, remember he's making his own nails, cutting his own logs, etc, all while farming food for 122 people.
So slow the implantation down
Embryos can be stored for a while, so no need to implant them ASAP. Changing the requirements to 3 natural children, and 3 embryos (so 6 children total per woman) the population at year 207 is 345,000.
I wrote a calculator for this:
https://godbolt.org/z/zoPYsz

The panel on the left is C++ code, the pannel on the right is the output.
Just change the numbers on the left (eg what years do women have children), and the log will update on the right.
Here's the source if the link goes dead (C++17)
#include <vector>
#include <set>
#include <iostream>
#include <numeric>
int main()
{
// There are 0 children aged 0 to 17 on the first ship
std::vector<size_t> males(18,0);
std::vector<size_t> females(18,0);
// Our initial colonists
males.push_back(120);
females.push_back(1080);
auto survivalRateMaleChild = 0.99;
auto survivalRateFemaleChild = 0.94;
auto survivalRateEveryone = (1000.0 - 12.0) / 1000.0;
auto simulatedYears = 207;
// What years of her life does a given woman have children?
std::set<int> randomChildAt = {19, 25, 35};
std::set<int> femaleChildAt = {21, 22, 23, 24, 26, 27, 28, 29, 30};
// Finite number of embryos
auto embryos = 10000;
for (auto year = 0; year < simulatedYears; year++)
{
// Calculate our births
size_t newMales = 0;
size_t newFemales = 0;
if (embryos > 0)
{
for (auto i : femaleChildAt)
{
if (i >= females.size()) continue;
newFemales += females[i];
}
}
embryos -= newFemales;
if (embryos < 0 && newFemales)
{
std::cout << "Run out of embryos\n";
}
for (auto i : randomChildAt)
{
if (i >= females.size()) continue;
newFemales += females[i] / 2;
newMales += females[i] / 2;
}
males.insert(males.begin(), newMales);
females.insert(females.begin(), newFemales);
// Kill off our infant mortality children (they all die at age 5)
males[5] *= survivalRateMaleChild;
females[5] *= survivalRateFemaleChild;
// Kill of our random death rate. Child infant mortality is
// calcualted seperately, we don't want to double kill them.
for (auto age = 18; age < females.size(); age++)
{
females[age] *= survivalRateEveryone;
males[age] *= survivalRateEveryone;
}
// Kill of our seniors, 10% die per year
for (auto age = 70; age < females.size(); age++)
{
females[age] *= 0.90;
males[age] *= 0.90;
}
// Add the second ship, which is full of 18 year olds.
if (year == 57)
{
males[18] += 120;
females[18] += 1080;
embryos += 10000;
}
// Print some stats
std::cout <<
"Y: " << year << ". "
<< newMales << "m and "
<< newFemales << "f born. Pop: "
<< std::accumulate(males.begin(), males.end(), 0) +
std::accumulate(females.begin(), females.end(), 0) << "\n";
}
std::cout << "At end of simulation: \n";
size_t total = 0;
size_t infants = 0;
size_t children = 0;
size_t teenages = 0;
size_t youngAdults = 0;
size_t adults = 0;
size_t seniors = 0;
size_t male = 0;
size_t female = 0;
for (auto age = 0; age < 100; age++)
{
if (age >= females.size()) continue;
std::cout << age << " yr olds: " << males[age] << " males and " << females[age] << " females.\n";
auto t = males[age] + females[age];
male += males[age];
female += females[age];
if (age < 5) infants += t;
else if (age < 13) children += t;
else if (age < 20) teenages += t;
else if (age < 35) youngAdults += t;
else if (age < 60) adults += t;
else seniors += t;
total += t;
}
std::cout << "Total " << total << "\n";
std::cout << "Infants " << infants << "\n";
std::cout << "Children " << children << "\n";
std::cout << "Teens " << teenages << "\n";
std::cout << "YoungAdults " << youngAdults << "\n";
std::cout << "Adults " << adults << "\n";
std::cout << "Seniors " << seniors << "\n";
std::cout << "Males " << male << "\n";
std::cout << "Females " << female << "\n";
return 0;
}
Year by year running log of births and population
Y: 0. 0m and 0f born. Pop: 1185
Y: 1. 533m and 533f born. Pop: 2236
Y: 2. 0m and 0f born. Pop: 2221
Y: 3. 0m and 1041f born. Pop: 3247
Y: 4. 0m and 1028f born. Pop: 4260
Y: 5. 0m and 1015f born. Pop: 5260
Y: 6. 0m and 1002f born. Pop: 6209
Y: 7. 494m and 494f born. Pop: 7183
Y: 8. 0m and 977f born. Pop: 8083
Y: 9. 0m and 965f born. Pop: 8972
Y: 10. 0m and 953f born. Pop: 9850
Y: 11. 0m and 941f born. Pop: 10716
Y: 12. 0m and 929f born. Pop: 11596
Y: 13. 0m and 0f born. Pop: 11523
Y: 14. 0m and 0f born. Pop: 11452
Y: 15. 0m and 0f born. Pop: 11381
Y: 16. 0m and 0f born. Pop: 11311
Y: 17. 436m and 436f born. Pop: 12114
Y: 18. 0m and 0f born. Pop: 12101
Y: 19. 0m and 0f born. Pop: 12075
Y: 20. 0m and 0f born. Pop: 12050
Y: 21. 244m and 244f born. Pop: 12502
Y: 22. 0m and 0f born. Pop: 12422
Y: 23. 477m and 953f born. Pop: 13793
Y: 24. 471m and 941f born. Pop: 15134
Run out of embryos
Y: 25. 465m and 1859f born. Pop: 17375
Y: 26. 458m and 458f born. Pop: 18178
Y: 27. 452m and 452f born. Pop: 18981
Y: 28. 447m and 447f born. Pop: 19700
Y: 29. 884m and 884f born. Pop: 21284
Y: 30. 872m and 872f born. Pop: 22778
Y: 31. 862m and 862f born. Pop: 24336
Y: 32. 850m and 850f born. Pop: 25870
Y: 33. 208m and 208f born. Pop: 26123
Y: 34. 414m and 414f born. Pop: 26766
Y: 35. 410m and 410f born. Pop: 27391
Y: 36. 404m and 404f born. Pop: 28005
Y: 37. 796m and 796f born. Pop: 29405
Y: 38. 394m and 394f born. Pop: 30047
Y: 39. 389m and 389f born. Pop: 30660
Y: 40. 384m and 384f born. Pop: 31263
Y: 41. 490m and 490f born. Pop: 32061
Y: 42. 374m and 374f born. Pop: 32593
Y: 43. 803m and 803f born. Pop: 33984
Y: 44. 796m and 796f born. Pop: 35349
Y: 45. 1213m and 1213f born. Pop: 37536
Y: 46. 565m and 565f born. Pop: 38408
Y: 47. 660m and 660f born. Pop: 39463
Y: 48. 551m and 551f born. Pop: 40248
Y: 49. 809m and 809f born. Pop: 41531
Y: 50. 798m and 798f born. Pop: 42743
Y: 51. 1186m and 1186f born. Pop: 44722
Y: 52. 582m and 582f born. Pop: 45491
Y: 53. 445m and 445f born. Pop: 45991
Y: 54. 378m and 378f born. Pop: 46338
Y: 55. 562m and 562f born. Pop: 47047
Y: 56. 554m and 554f born. Pop: 47708
Y: 57. 818m and 818f born. Pop: 50134
Y: 58. 541m and 4677f born. Pop: 54932
Run out of embryos
Y: 59. 1152m and 6135f born. Pop: 61797
Y: 60. 701m and 701f born. Pop: 62763
Y: 61. 1095m and 1095f born. Pop: 64500
Y: 62. 507m and 507f born. Pop: 65036
Y: 63. 871m and 871f born. Pop: 66047
Y: 64. 694m and 694f born. Pop: 66606
Y: 65. 1545m and 1545f born. Pop: 69192
Y: 66. 744m and 744f born. Pop: 70142
Y: 67. 830m and 830f born. Pop: 71293
Y: 68. 725m and 725f born. Pop: 72199
Y: 69. 784m and 784f born. Pop: 73214
Y: 70. 856m and 856f born. Pop: 74303
Y: 71. 1209m and 1209f born. Pop: 76098
Y: 72. 653m and 653f born. Pop: 76780
Y: 73. 779m and 779f born. Pop: 77663
Y: 74. 550m and 550f born. Pop: 78045
Y: 75. 1182m and 1182f born. Pop: 79646
Y: 76. 733m and 733f born. Pop: 80237
Y: 77. 1058m and 1058f born. Pop: 81416
Y: 78. 2528m and 2528f born. Pop: 85495
Y: 79. 3300m and 3300f born. Pop: 91098
Y: 80. 777m and 777f born. Pop: 91590
Y: 81. 1193m and 1193f born. Pop: 92929
Y: 82. 675m and 675f born. Pop: 93190
Y: 83. 991m and 991f born. Pop: 93984
Y: 84. 2514m and 2514f born. Pop: 97801
Y: 85. 3625m and 3625f born. Pop: 104035
Y: 86. 935m and 935f born. Pop: 104873
Y: 87. 1289m and 1289f born. Pop: 106431
Y: 88. 761m and 761f born. Pop: 106942
Y: 89. 892m and 892f born. Pop: 107606
Y: 90. 825m and 825f born. Pop: 108071
Y: 91. 1419m and 1419f born. Pop: 109902
Y: 92. 818m and 818f born. Pop: 110519
Y: 93. 1014m and 1014f born. Pop: 111492
Y: 94. 2322m and 2322f born. Pop: 115018
Y: 95. 3188m and 3188f born. Pop: 120184
Y: 96. 959m and 959f born. Pop: 120792
Y: 97. 1408m and 1408f born. Pop: 122265
Y: 98. 1623m and 1623f born. Pop: 124147
Y: 99. 2168m and 2168f born. Pop: 126967
Y: 100. 847m and 847f born. Pop: 127044
Y: 101. 1628m and 1628f born. Pop: 128796
Y: 102. 897m and 897f born. Pop: 128979
Y: 103. 1212m and 1212f born. Pop: 129751
Y: 104. 2498m and 2498f born. Pop: 133069
Y: 105. 3360m and 3360f born. Pop: 138194
Y: 106. 1076m and 1076f born. Pop: 138709
Y: 107. 1549m and 1549f born. Pop: 140200
Y: 108. 875m and 875f born. Pop: 140326
Y: 109. 1118m and 1118f born. Pop: 140784
Y: 110. 1650m and 1650f born. Pop: 142267
Y: 111. 2638m and 2638f born. Pop: 145891
Y: 112. 1043m and 1043f born. Pop: 146277
Y: 113. 1408m and 1408f born. Pop: 147364
Y: 114. 2338m and 2338f born. Pop: 150270
Y: 115. 3084m and 3084f born. Pop: 154552
Y: 116. 1078m and 1078f born. Pop: 154738
Y: 117. 1695m and 1695f born. Pop: 156234
Y: 118. 1340m and 1340f born. Pop: 157007
Y: 119. 1793m and 1793f born. Pop: 158581
Y: 120. 2322m and 2322f born. Pop: 161157
Y: 121. 3470m and 3470f born. Pop: 166111
Y: 122. 1167m and 1167f born. Pop: 166396
Y: 123. 1637m and 1637f born. Pop: 167614
Y: 124. 2118m and 2118f born. Pop: 169794
Y: 125. 2797m and 2797f born. Pop: 173291
Y: 126. 1160m and 1160f born. Pop: 173447
Y: 127. 1934m and 1934f born. Pop: 175290
Y: 128. 1087m and 1087f born. Pop: 175195
Y: 129. 1406m and 1406f born. Pop: 175387
Y: 130. 2693m and 2693f born. Pop: 178162
Y: 131. 3842m and 3842f born. Pop: 183353
Y: 132. 1293m and 1293f born. Pop: 183435
Y: 133. 1831m and 1831f born. Pop: 184628
Y: 134. 2052m and 2052f born. Pop: 186271
Y: 135. 2704m and 2704f born. Pop: 189062
Y: 136. 1512m and 1512f born. Pop: 189424
Y: 137. 2511m and 2511f born. Pop: 191965
Y: 138. 1392m and 1392f born. Pop: 192236
Y: 139. 1875m and 1875f born. Pop: 193417
Y: 140. 2999m and 2999f born. Pop: 196814
Y: 141. 4172m and 4172f born. Pop: 202595
Y: 142. 1395m and 1395f born. Pop: 202764
Y: 143. 2052m and 2052f born. Pop: 204309
Y: 144. 1866m and 1866f born. Pop: 205478
Y: 145. 2463m and 2463f born. Pop: 207728
Y: 146. 2138m and 2138f born. Pop: 209263
Y: 147. 3357m and 3357f born. Pop: 213413
Y: 148. 1382m and 1382f born. Pop: 213376
Y: 149. 1868m and 1868f born. Pop: 214041
Y: 150. 3015m and 3015f born. Pop: 217020
Y: 151. 4115m and 4115f born. Pop: 222220
Y: 152. 1489m and 1489f born. Pop: 222131
Y: 153. 2299m and 2299f born. Pop: 223795
Y: 154. 1903m and 1903f born. Pop: 224499
Y: 155. 2511m and 2511f born. Pop: 226080
Y: 156. 2713m and 2713f born. Pop: 228055
Y: 157. 4096m and 4096f born. Pop: 232993
Y: 158. 1624m and 1624f born. Pop: 232977
Y: 159. 2253m and 2253f born. Pop: 234239
Y: 160. 3044m and 3044f born. Pop: 237092
Y: 161. 4118m and 4118f born. Pop: 242053
Y: 162. 1717m and 1717f born. Pop: 242162
Y: 163. 2737m and 2737f born. Pop: 244489
Y: 164. 1853m and 1853f born. Pop: 244869
Y: 165. 2455m and 2455f born. Pop: 246181
Y: 166. 3272m and 3272f born. Pop: 249116
Y: 167. 4766m and 4766f born. Pop: 255204
Y: 168. 1710m and 1710f born. Pop: 255074
Y: 169. 2417m and 2417f born. Pop: 256290
Y: 170. 2948m and 2948f born. Pop: 258612
Y: 171. 3954m and 3954f born. Pop: 262866
Y: 172. 2159m and 2159f born. Pop: 263481
Y: 173. 3430m and 3430f born. Pop: 266861
Y: 174. 1981m and 1981f born. Pop: 267155
Y: 175. 2650m and 2650f born. Pop: 268513
Y: 176. 3658m and 3658f born. Pop: 271891
Y: 177. 5205m and 5205f born. Pop: 278496
Y: 178. 1900m and 1900f born. Pop: 278446
Y: 179. 2783m and 2783f born. Pop: 280252
Y: 180. 2907m and 2907f born. Pop: 282257
Y: 181. 3885m and 3885f born. Pop: 286016
Y: 182. 2745m and 2745f born. Pop: 287447
Y: 183. 4266m and 4266f born. Pop: 292152
Y: 184. 2058m and 2058f born. Pop: 292271
Y: 185. 2785m and 2785f born. Pop: 293619
Y: 186. 3933m and 3933f born. Pop: 297289
Y: 187. 5492m and 5492f born. Pop: 304145
Y: 188. 2072m and 2072f born. Pop: 304075
Y: 189. 3138m and 3138f born. Pop: 306233
Y: 190. 2855m and 2855f born. Pop: 307707
Y: 191. 3804m and 3804f born. Pop: 310799
Y: 192. 3404m and 3404f born. Pop: 313075
Y: 193. 5150m and 5150f born. Pop: 319083
Y: 194. 2245m and 2245f born. Pop: 319144
Y: 195. 3091m and 3091f born. Pop: 320760
Y: 196. 4080m and 4080f born. Pop: 324370
Y: 197. 5624m and 5624f born. Pop: 331087
Y: 198. 2435m and 2435f born. Pop: 331364
Y: 199. 3769m and 3769f born. Pop: 334521
Y: 200. 2872m and 2872f born. Pop: 335699
Y: 201. 3833m and 3833f born. Pop: 338495
Y: 202. 4051m and 4051f born. Pop: 341704
Y: 203. 5973m and 5973f born. Pop: 348982
Y: 204. 2394m and 2394f born. Pop: 348960
Y: 205. 3370m and 3370f born. Pop: 350811
Y: 206. 4153m and 4153f born. Pop: 354227
And breakdown of those alive at year 207:
0 yr olds: 4153 males and 4153 females.
1 yr olds: 3370 males and 3370 females.
2 yr olds: 2394 males and 2394 females.
3 yr olds: 5973 males and 5973 females.
4 yr olds: 4051 males and 4051 females.
5 yr olds: 3794 males and 3603 females.
6 yr olds: 2843 males and 2699 females.
7 yr olds: 3731 males and 3542 females.
8 yr olds: 2410 males and 2288 females.
9 yr olds: 5567 males and 5286 females.
10 yr olds: 4039 males and 3835 females.
11 yr olds: 3060 males and 2905 females.
12 yr olds: 2222 males and 2110 females.
13 yr olds: 5098 males and 4841 females.
14 yr olds: 3369 males and 3199 females.
15 yr olds: 3765 males and 3575 females.
16 yr olds: 2826 males and 2683 females.
17 yr olds: 3106 males and 2949 females.
18 yr olds: 2026 males and 1923 females.
19 yr olds: 5306 males and 5038 females.
20 yr olds: 3753 males and 3564 females.
21 yr olds: 2625 males and 2491 females.
22 yr olds: 1915 males and 1818 females.
23 yr olds: 3925 males and 3727 females.
24 yr olds: 2493 males and 2368 females.
25 yr olds: 3488 males and 3311 females.
26 yr olds: 2576 males and 2447 females.
27 yr olds: 2437 males and 2313 females.
28 yr olds: 1642 males and 1559 females.
29 yr olds: 4451 males and 4228 females.
30 yr olds: 3090 males and 2933 females.
31 yr olds: 2209 males and 2097 females.
32 yr olds: 1629 males and 1547 females.
33 yr olds: 2792 males and 2651 females.
34 yr olds: 1732 males and 1645 females.
35 yr olds: 3140 males and 2983 females.
36 yr olds: 2311 males and 2195 females.
37 yr olds: 1870 males and 1775 females.
38 yr olds: 1303 males and 1237 females.
39 yr olds: 3609 males and 3425 females.
40 yr olds: 2444 males and 2319 females.
41 yr olds: 1808 males and 1715 females.
42 yr olds: 1346 males and 1277 females.
43 yr olds: 1967 males and 1869 females.
44 yr olds: 1215 males and 1152 females.
45 yr olds: 2895 males and 2747 females.
46 yr olds: 2112 males and 2005 females.
47 yr olds: 1541 males and 1461 females.
48 yr olds: 1092 males and 1037 females.
49 yr olds: 2740 males and 2603 females.
50 yr olds: 1789 males and 1698 females.
51 yr olds: 1633 males and 1552 females.
52 yr olds: 1220 males and 1158 females.
53 yr olds: 1459 males and 1384 females.
54 yr olds: 928 males and 881 females.
55 yr olds: 2559 males and 2429 females.
56 yr olds: 1847 males and 1755 females.
57 yr olds: 1125 males and 1066 females.
58 yr olds: 818 males and 776 females.
59 yr olds: 1985 males and 1885 females.
60 yr olds: 1241 males and 1177 females.
61 yr olds: 1416 males and 1345 females.
62 yr olds: 1056 males and 1000 females.
63 yr olds: 1147 males and 1090 females.
64 yr olds: 766 males and 725 females.
65 yr olds: 2297 males and 2178 females.
66 yr olds: 1626 males and 1543 females.
67 yr olds: 997 males and 945 females.
68 yr olds: 725 males and 687 females.
69 yr olds: 1306 males and 1240 females.
70 yr olds: 693 males and 657 females.
71 yr olds: 1111 males and 1055 females.
72 yr olds: 745 males and 709 females.
73 yr olds: 592 males and 559 females.
74 yr olds: 365 males and 346 females.
75 yr olds: 990 males and 939 females.
76 yr olds: 612 males and 583 females.
77 yr olds: 278 males and 263 females.
78 yr olds: 189 males and 177 females.
79 yr olds: 304 males and 289 females.
80 yr olds: 157 males and 149 females.
81 yr olds: 351 males and 332 females.
82 yr olds: 232 males and 221 females.
83 yr olds: 156 males and 148 females.
84 yr olds: 95 males and 90 females.
85 yr olds: 270 males and 256 females.
86 yr olds: 156 males and 149 females.
87 yr olds: 105 males and 99 females.
88 yr olds: 67 males and 63 females.
89 yr olds: 76 males and 72 females.
90 yr olds: 39 males and 36 females.
91 yr olds: 115 males and 108 females.
92 yr olds: 73 males and 70 females.
93 yr olds: 36 males and 34 females.
94 yr olds: 20 males and 19 females.
95 yr olds: 56 males and 54 females.
96 yr olds: 27 males and 27 females.
97 yr olds: 13 males and 12 females.
98 yr olds: 6 males and 5 females.
99 yr olds: 16 males and 13 females.