1 00:00:00,120 --> 00:00:01,800 The following content is provided 2 00:00:01,800 --> 00:00:04,030 under a Creative Commons license. 3 00:00:04,030 --> 00:00:06,880 Your support will help MIT OpenCourseWare continue 4 00:00:06,880 --> 00:00:10,740 to offer high quality educational resources for free. 5 00:00:10,740 --> 00:00:13,360 To make a donation or view additional materials 6 00:00:13,360 --> 00:00:17,237 from hundreds of MIT courses, visit MIT OpenCourseWare 7 00:00:17,237 --> 00:00:17,862 at ocw.mit.edu. 8 00:00:22,490 --> 00:00:24,940 PROFESSOR: OK, I want to say a little more 9 00:00:24,940 --> 00:00:30,890 about these phenomena of cryptic female choice. 10 00:00:30,890 --> 00:00:37,260 And I just had mentioned one change on the male side 11 00:00:37,260 --> 00:00:41,390 that seemed to be an evolutionary response 12 00:00:41,390 --> 00:00:43,980 to cryptic female choice and what 13 00:00:43,980 --> 00:00:46,140 can the male do to close that. 14 00:00:46,140 --> 00:00:48,730 And we talked about several behavioral things they do. 15 00:00:52,510 --> 00:00:56,090 We mentioned some research on primates. 16 00:00:56,090 --> 00:00:59,140 And we ended talking about this discovery 17 00:00:59,140 --> 00:01:01,840 of two different kinds of sperm. 18 00:01:01,840 --> 00:01:09,916 And this article gives you a pretty good idea. 19 00:01:09,916 --> 00:01:15,690 A sterile sperm caste protects brother fertile sperm 20 00:01:15,690 --> 00:01:19,240 from female-mediated death in Drosophila, 21 00:01:19,240 --> 00:01:21,720 one species of Drosophila. 22 00:01:21,720 --> 00:01:27,720 So that means that there can be some sperm that are the guards, 23 00:01:27,720 --> 00:01:29,550 and they can't fertilize the egg. 24 00:01:29,550 --> 00:01:34,750 But they can protect that sperm, the fertile ones, 25 00:01:34,750 --> 00:01:37,550 from being destroyed by female toxins 26 00:01:37,550 --> 00:01:41,890 or whatever that she may-- because females have evolved 27 00:01:41,890 --> 00:01:45,500 various ways to make their mate choice 28 00:01:45,500 --> 00:01:48,340 in their reproductive tract. 29 00:01:48,340 --> 00:01:50,730 So that's what this-- and there's 30 00:01:50,730 --> 00:01:55,230 a lot of articles on this phenomenon just recently. 31 00:01:55,230 --> 00:02:06,885 This is all after this discovery about different kinds of sperm. 32 00:02:06,885 --> 00:02:10,400 It happened around 2000, 2001. 33 00:02:10,400 --> 00:02:14,160 And the articles have appeared on fish and insects. 34 00:02:14,160 --> 00:02:16,790 This is just that one article. 35 00:02:16,790 --> 00:02:25,120 But Alcock points out that all of these things, especially 36 00:02:25,120 --> 00:02:27,970 the female reproductive tract, is adaptably 37 00:02:27,970 --> 00:02:30,720 designed to promote sperm choice. 38 00:02:30,720 --> 00:02:33,590 In other words, her choice-- which sperm she 39 00:02:33,590 --> 00:02:36,960 wants to use to fertilize her eggs. 40 00:02:36,960 --> 00:02:39,520 That kind of thing just never occurred to biologists 41 00:02:39,520 --> 00:02:45,480 before what he calls the sociobiological revolution that 42 00:02:45,480 --> 00:02:48,160 started with the publication, really, 43 00:02:48,160 --> 00:02:51,405 with EO Wilson's book who reviewed all that stuff. 44 00:02:51,405 --> 00:02:53,510 Of course, it had started earlier 45 00:02:53,510 --> 00:02:59,010 with the people we've mentioned that talked 46 00:02:59,010 --> 00:03:01,165 about the adaptive individual choice 47 00:03:01,165 --> 00:03:05,440 as being the major factor in evolution, 48 00:03:05,440 --> 00:03:07,930 the adaptationist approach. 49 00:03:07,930 --> 00:03:12,850 But these are some reviews. 50 00:03:12,850 --> 00:03:15,950 I just wanted to mention a few of them 51 00:03:15,950 --> 00:03:18,680 that came out a few years ago. 52 00:03:18,680 --> 00:03:19,840 Look at the second one. 53 00:03:19,840 --> 00:03:25,970 This became a common term in the news media-- Sperm Wars-- The 54 00:03:25,970 --> 00:03:27,660 Science of Sex. 55 00:03:27,660 --> 00:03:32,610 This was a book that had some extensive speculations 56 00:03:32,610 --> 00:03:36,960 about sperm competition in humans. 57 00:03:36,960 --> 00:03:43,740 Not based on firm experimental studies-- 58 00:03:43,740 --> 00:03:46,750 it was based on a few observations 59 00:03:46,750 --> 00:03:48,150 made by medical people. 60 00:03:48,150 --> 00:03:52,850 But it's still not all that certain 61 00:03:52,850 --> 00:03:57,300 how much cryptic choice-- most of it's 62 00:03:57,300 --> 00:03:59,890 quite overt in their behavior. 63 00:04:05,690 --> 00:04:07,040 So all these articles are that. 64 00:04:07,040 --> 00:04:08,220 And you'll find many more. 65 00:04:08,220 --> 00:04:11,330 And just a few years ago when I searched the literature, 66 00:04:11,330 --> 00:04:15,490 I found reports on spiders, a cricket, a beetle, 67 00:04:15,490 --> 00:04:17,680 various flies, and fish. 68 00:04:17,680 --> 00:04:20,899 These are just examples of those articles. 69 00:04:20,899 --> 00:04:23,710 One on the beetle-- there's the red flower beetle. 70 00:04:23,710 --> 00:04:29,450 So this is another topic. 71 00:04:29,450 --> 00:04:32,500 It's another concept of what can happen 72 00:04:32,500 --> 00:04:40,760 with this competition between the two sexes in reproduction. 73 00:04:40,760 --> 00:04:44,060 And it's our most blatant example of it. 74 00:04:44,060 --> 00:04:47,040 It's called genomic imprinting. 75 00:04:47,040 --> 00:04:51,180 It doesn't mean behavioral imprinting at all. 76 00:04:51,180 --> 00:04:52,780 It has a totally different meaning 77 00:04:52,780 --> 00:04:55,025 from the behavioral use of the term imprinting. 78 00:04:57,770 --> 00:05:02,780 It's when one gene can have different effects 79 00:05:02,780 --> 00:05:06,860 on the offspring depending on whether the gene, the allele, 80 00:05:06,860 --> 00:05:14,790 comes from the mother or the father, 81 00:05:14,790 --> 00:05:17,380 because male and female interests are not identical 82 00:05:17,380 --> 00:05:21,740 unless they practice strict monogamy. 83 00:05:21,740 --> 00:05:26,680 And the early tests of that, they didn't confirm that. 84 00:05:26,680 --> 00:05:29,020 But I think that's just because they 85 00:05:29,020 --> 00:05:32,960 used to think monogamy meant just what it says. 86 00:05:32,960 --> 00:05:35,340 But in fact, many monogamous pairs 87 00:05:35,340 --> 00:05:36,735 are not completely monogamous. 88 00:05:39,950 --> 00:05:44,950 So for example-- and I apply this 89 00:05:44,950 --> 00:05:51,390 to humans-- I'm asking here, what about human fetus sizes 90 00:05:51,390 --> 00:05:55,110 where the fetus can be so big that it damages or even kills 91 00:05:55,110 --> 00:05:57,200 the mother? 92 00:05:57,200 --> 00:06:02,280 Why would females evolve so they could ever 93 00:06:02,280 --> 00:06:04,470 produce such a large fetus? 94 00:06:04,470 --> 00:06:05,740 And yet, that has happened. 95 00:06:05,740 --> 00:06:10,080 And some women, without modern obstetrics, 96 00:06:10,080 --> 00:06:14,660 wouldn't survive the birth of all the fetuses 97 00:06:14,660 --> 00:06:19,260 that they might nevertheless carry. 98 00:06:19,260 --> 00:06:24,320 So it's not adaptive for the female to do that. 99 00:06:24,320 --> 00:06:27,710 But it may be for the male in many cases. 100 00:06:27,710 --> 00:06:30,610 When you think about earlier evolutionary times, 101 00:06:30,610 --> 00:06:34,580 if the male had many choices, he might 102 00:06:34,580 --> 00:06:37,670 have had a number of different wives. 103 00:06:37,670 --> 00:06:40,280 What matters to him, just from the standpoint 104 00:06:40,280 --> 00:06:41,500 of genetic fitness? 105 00:06:41,500 --> 00:06:46,970 I don't mean what matters consciously to him. 106 00:06:46,970 --> 00:06:49,340 He might be madly in love with a woman 107 00:06:49,340 --> 00:06:55,240 that he makes pregnant and then has a fetus that kills her. 108 00:06:55,240 --> 00:06:59,040 The point is what matters from an evolutionary standpoint 109 00:06:59,040 --> 00:07:04,170 is just his genetic fitness, how many genes can he pass on. 110 00:07:04,170 --> 00:07:08,190 And what he can do for that, it's 111 00:07:08,190 --> 00:07:12,795 promoted by the large fetus-- a large, healthier fetus. 112 00:07:16,800 --> 00:07:18,570 Of course, the fetus has to survive 113 00:07:18,570 --> 00:07:21,510 the childbirth for that to work. 114 00:07:21,510 --> 00:07:24,650 But look at this. 115 00:07:24,650 --> 00:07:26,630 Sorry I didn't find a better slide. 116 00:07:26,630 --> 00:07:30,540 This describes genomic imprinting. 117 00:07:30,540 --> 00:07:40,660 And this is about one particular receptor and the molecule 118 00:07:40,660 --> 00:07:45,560 itself that binds to that receptor, IGF2. 119 00:07:45,560 --> 00:07:48,750 And it's a growth factor. 120 00:07:51,480 --> 00:07:53,475 So it promotes somatic growth. 121 00:07:56,530 --> 00:07:57,480 This is in mice. 122 00:07:57,480 --> 00:08:03,005 Now, the genes from the mother, the receptor is turned on. 123 00:08:06,290 --> 00:08:09,670 The growth factor is off. 124 00:08:09,670 --> 00:08:10,460 But look. 125 00:08:10,460 --> 00:08:15,090 If it comes from the father, the receptor is off, 126 00:08:15,090 --> 00:08:19,410 and that molecule is on, the one that promotes growth. 127 00:08:19,410 --> 00:08:21,860 So you can investigate those effects 128 00:08:21,860 --> 00:08:24,540 by looking at-- so for example, you 129 00:08:24,540 --> 00:08:29,500 delete the mother's IGF2 receptor gene. 130 00:08:29,500 --> 00:08:34,316 The one that is normally on for her, you just delete it. 131 00:08:34,316 --> 00:08:35,024 And what happens? 132 00:08:38,110 --> 00:08:39,355 Fetuses that are huge. 133 00:08:43,150 --> 00:08:49,266 You delete the father's IGF2 gene, 134 00:08:49,266 --> 00:08:51,100 and you get little, tiny offspring. 135 00:08:54,930 --> 00:08:59,300 If you delete both of them, then you get normal size offspring. 136 00:08:59,300 --> 00:09:01,930 So the particular growth factor, its main function 137 00:09:01,930 --> 00:09:10,890 seems to be involved in this genomically imprinted gene, 138 00:09:10,890 --> 00:09:16,950 where the male and female alleles have 139 00:09:16,950 --> 00:09:18,130 very different effects. 140 00:09:18,130 --> 00:09:19,325 And they're the same gene. 141 00:09:24,920 --> 00:09:27,550 And so they just say here, the imprints on the IGF2 142 00:09:27,550 --> 00:09:35,610 and the IGF2 receptor genes normally cancel each other out. 143 00:09:35,610 --> 00:09:38,520 Changing the imprint of one copy of the gene 144 00:09:38,520 --> 00:09:42,660 has a dramatic effect on the size of the offspring. 145 00:09:42,660 --> 00:09:48,660 So this kind of results supports the genetic conflict hypothesis 146 00:09:48,660 --> 00:09:51,190 in a particularly dramatic way. 147 00:09:51,190 --> 00:09:56,710 And this was just from the early discoveries. 148 00:09:56,710 --> 00:10:03,530 And just a few years ago, I found this website. 149 00:10:03,530 --> 00:10:08,530 The whole website's devoted to genetic imprinting-- 150 00:10:08,530 --> 00:10:11,370 because it was such a puzzle. 151 00:10:11,370 --> 00:10:13,890 It was only this sociobiological interpretation 152 00:10:13,890 --> 00:10:19,380 that made any sense, but it still seems so unusual. 153 00:10:19,380 --> 00:10:22,490 And there was this one study I found where they showed effects 154 00:10:22,490 --> 00:10:27,030 that went beyond the fetal and infancy periods-- 155 00:10:27,030 --> 00:10:29,050 in fact, effects later in life. 156 00:10:32,650 --> 00:10:34,410 And there were arguments-- what good 157 00:10:34,410 --> 00:10:37,460 is genomic imprinting, the function 158 00:10:37,460 --> 00:10:41,230 of parent-specific gene expression-- in Nature 159 00:10:41,230 --> 00:10:43,930 Reviews a few years ago. 160 00:10:43,930 --> 00:10:50,930 And then, if you do look at that website, which I did today, 161 00:10:50,930 --> 00:10:54,160 I found-- and this is just 2013. 162 00:10:54,160 --> 00:10:59,010 Look at all these articles, all on this phenomenon, 163 00:10:59,010 --> 00:11:04,110 its variations, how long it lasts, and so forth. 164 00:11:04,110 --> 00:11:07,490 So that just gives you an idea of the impact of sociobiology 165 00:11:07,490 --> 00:11:08,765 also on human genetics. 166 00:11:11,580 --> 00:11:13,920 But of course, they're studying it mainly in mice. 167 00:11:13,920 --> 00:11:18,260 But the first question I was asking there, 168 00:11:18,260 --> 00:11:21,950 I'm applying it to possible explanation 169 00:11:21,950 --> 00:11:29,600 for very large human heads, human fetuses, born 170 00:11:29,600 --> 00:11:33,320 to women where it can damage. 171 00:11:33,320 --> 00:11:35,450 So let's get back to bird behavior a little bit. 172 00:11:35,450 --> 00:11:37,055 We don't have too much to go. 173 00:11:37,055 --> 00:11:38,930 We'll talk a little bit more about EO Wilson. 174 00:11:38,930 --> 00:11:41,460 And I would like to have a little time 175 00:11:41,460 --> 00:11:46,230 at the end of the class to discuss your project because I 176 00:11:46,230 --> 00:11:49,360 think for next week, we're just going to have the homework. 177 00:11:49,360 --> 00:11:51,960 I know you've got a homework due today, right? 178 00:11:51,960 --> 00:11:57,600 So next week, the readings are quite easy after these chapters 179 00:11:57,600 --> 00:11:59,870 that these classes are based on. 180 00:11:59,870 --> 00:12:01,910 So you can let me talk about those things, 181 00:12:01,910 --> 00:12:04,340 and you can work on your projects. 182 00:12:04,340 --> 00:12:08,860 And I will formulate the thing, put it online. 183 00:12:08,860 --> 00:12:12,030 I'd like you to come up with a couple of topics 184 00:12:12,030 --> 00:12:14,480 and several articles about each one. 185 00:12:14,480 --> 00:12:15,795 Give me your references. 186 00:12:19,820 --> 00:12:21,460 Some people know already what they 187 00:12:21,460 --> 00:12:24,320 want to talk-- they're pretty sure they want their project 188 00:12:24,320 --> 00:12:25,277 to be. 189 00:12:25,277 --> 00:12:26,860 But let's see if we have a little time 190 00:12:26,860 --> 00:12:28,234 for that at the end of the class. 191 00:12:33,750 --> 00:12:36,730 Did we talk a little bit about helpers at the nest before? 192 00:12:36,730 --> 00:12:40,166 I think we did a little bit, and Scott. 193 00:12:40,166 --> 00:12:41,540 But some of the best studies have 194 00:12:41,540 --> 00:12:46,160 been done in this Seychelles warbler. 195 00:12:46,160 --> 00:12:48,650 So what are the advantages for a young bird 196 00:12:48,650 --> 00:12:51,040 if they help their parents rear siblings 197 00:12:51,040 --> 00:12:52,715 by becoming a helper at the nest? 198 00:12:52,715 --> 00:12:54,560 It's a kind of altruism. 199 00:12:54,560 --> 00:12:57,690 It's very common in birds. 200 00:12:57,690 --> 00:13:02,360 And of course, it's very common in humans, where the mother 201 00:13:02,360 --> 00:13:06,140 and father get help from their own offspring 202 00:13:06,140 --> 00:13:07,535 in rearing further offspring. 203 00:13:11,230 --> 00:13:13,780 And Alcock does say a little more about it 204 00:13:13,780 --> 00:13:15,520 that Scott's book did. 205 00:13:15,520 --> 00:13:18,211 This is a picture of this beautiful little bird 206 00:13:18,211 --> 00:13:18,960 in the sea shells. 207 00:13:22,680 --> 00:13:24,770 These are the kinds of advantages 208 00:13:24,770 --> 00:13:26,290 it could have for the young bird. 209 00:13:26,290 --> 00:13:31,900 They gain experience in taking care of young. 210 00:13:31,900 --> 00:13:34,900 They're promoting the survival of close relatives, which 211 00:13:34,900 --> 00:13:40,230 means it does affect their own genetic fitness-- not 212 00:13:40,230 --> 00:13:43,460 directly, but indirectly-- by supporting 213 00:13:43,460 --> 00:13:46,920 the survival of their siblings. 214 00:13:46,920 --> 00:13:54,080 And that is critical if done, say, in poor-- where there's 215 00:13:54,080 --> 00:13:56,670 not that much food in the environment. 216 00:13:56,670 --> 00:13:59,740 Sometimes if they don't have a helper at the nest, 217 00:13:59,740 --> 00:14:02,960 the chances of getting the offspring to even survive 218 00:14:02,960 --> 00:14:06,840 are very low because two birds just can't bring enough. 219 00:14:06,840 --> 00:14:10,500 But it works best on the richer territories. 220 00:14:10,500 --> 00:14:15,460 In such areas, if the territory is so deficient in food, 221 00:14:15,460 --> 00:14:17,730 then having the helper at the nest 222 00:14:17,730 --> 00:14:23,300 doesn't help, because you've got to feed him, too, or her. 223 00:14:23,300 --> 00:14:25,010 So to gain experience, they promote 224 00:14:25,010 --> 00:14:26,610 the survival of close relatives. 225 00:14:26,610 --> 00:14:30,030 And they can also inherit that territory if they stay around. 226 00:14:30,030 --> 00:14:32,750 After all, the parents will get old, stop reproducing. 227 00:14:32,750 --> 00:14:35,210 Then they can take over the territory. 228 00:14:35,210 --> 00:14:37,890 The helpers are usually female. 229 00:14:37,890 --> 00:14:41,440 They're used by the adult pairs that have better territories. 230 00:14:44,190 --> 00:14:48,340 And there were studies in the Seychelles of these warblers 231 00:14:48,340 --> 00:14:55,140 by this sociobiologist, Komdeur, published in 1997. 232 00:14:55,140 --> 00:14:57,280 He made this surprising discovery 233 00:14:57,280 --> 00:15:00,600 that the females can actually regulate 234 00:15:00,600 --> 00:15:01,980 the sex of their offspring. 235 00:15:05,580 --> 00:15:07,505 So why would that ability evolve? 236 00:15:10,580 --> 00:15:16,910 Well, it's explained in terms of her fitness-- 237 00:15:16,910 --> 00:15:19,820 the fitness of the female-- and the behavioral differences 238 00:15:19,820 --> 00:15:21,760 between male and female offspring. 239 00:15:21,760 --> 00:15:26,210 If she biases her offspring towards the female, 240 00:15:26,210 --> 00:15:28,250 it's because she's on a good territory. 241 00:15:28,250 --> 00:15:31,150 She can make good use of the helper at the nest. 242 00:15:31,150 --> 00:15:36,540 And it's the females that are most likely to become helpers. 243 00:15:36,540 --> 00:15:38,960 So this is the actual results. 244 00:15:38,960 --> 00:15:42,720 Before this study, no one ever checked 245 00:15:42,720 --> 00:15:44,790 to choose whether birds could actually 246 00:15:44,790 --> 00:15:47,300 choose which sex to reproduce in their offspring. 247 00:15:47,300 --> 00:15:49,060 And now it's been found to be more common. 248 00:15:49,060 --> 00:15:52,820 But it was first discovered in these warblers. 249 00:15:52,820 --> 00:15:54,850 So on good territories, the helper at the nest 250 00:15:54,850 --> 00:15:56,030 is beneficial. 251 00:15:56,030 --> 00:15:58,520 The helper is usually a daughter. 252 00:15:58,520 --> 00:16:04,290 On poor territories, there's not enough food for the extra bird. 253 00:16:04,290 --> 00:16:06,675 So that led him to make this test. 254 00:16:06,675 --> 00:16:09,420 And he found that on poor territories, 255 00:16:09,420 --> 00:16:13,060 77% males were hatched. 256 00:16:13,060 --> 00:16:16,820 Better for her genetic fitness if she 257 00:16:16,820 --> 00:16:20,905 passes on more genes and more offspring, 258 00:16:20,905 --> 00:16:24,785 if she produces males. 259 00:16:28,660 --> 00:16:31,330 More of them will survive-- because only 260 00:16:31,330 --> 00:16:35,630 a certain percentage of them are going to survive anyway. 261 00:16:35,630 --> 00:16:38,420 And if only one survives, it's more likely to be a male 262 00:16:38,420 --> 00:16:40,050 if she has a lot of males. 263 00:16:40,050 --> 00:16:45,620 And on rich territories-- only 13% males. 264 00:16:45,620 --> 00:16:48,090 So the effects are dramatic in how much she 265 00:16:48,090 --> 00:16:51,540 can skew the sex of her offspring is. 266 00:16:51,540 --> 00:16:54,040 AUDIENCE: How do you know it's choice and not a side effect 267 00:16:54,040 --> 00:16:56,750 of the environment? 268 00:16:56,750 --> 00:16:59,830 PROFESSOR: And that has certainly been studied. 269 00:16:59,830 --> 00:17:02,480 And they've varied that. 270 00:17:02,480 --> 00:17:07,170 And of course, there are effects to the environment, 271 00:17:07,170 --> 00:17:09,420 but they're affecting that female. 272 00:17:09,420 --> 00:17:12,630 You'd like to know, well, if you control things 273 00:17:12,630 --> 00:17:16,800 like temperature, you could say nutrition could affect it. 274 00:17:16,800 --> 00:17:20,190 Yes, and they've had to control for those things. 275 00:17:20,190 --> 00:17:23,260 And Komdeur tried to do that. 276 00:17:23,260 --> 00:17:27,380 And as best as he could tell, it was the female actually 277 00:17:27,380 --> 00:17:29,210 able to change that. 278 00:17:29,210 --> 00:17:32,030 But then it was discovered in other animals. 279 00:17:32,030 --> 00:17:36,710 In the tawny owl, for example, they 280 00:17:36,710 --> 00:17:39,950 had female-based clutches on territories 281 00:17:39,950 --> 00:17:44,590 with more abundant prey, which were the field voles. 282 00:17:44,590 --> 00:17:47,740 In June, although that's the month the chicks fledge, 283 00:17:47,740 --> 00:17:50,530 the eggs were laid in March. 284 00:17:50,530 --> 00:17:53,125 And yet the sex was biased. 285 00:17:59,810 --> 00:18:03,000 It indicates that the parent owls produce more female chicks 286 00:18:03,000 --> 00:18:06,260 on territories with higher numbers of their major prey, 287 00:18:06,260 --> 00:18:08,560 the field vole, at the time the young are fledging. 288 00:18:08,560 --> 00:18:11,960 It's adaptive because the females, but not the males, 289 00:18:11,960 --> 00:18:14,770 appear to enjoy a subsequent reproductive advantage 290 00:18:14,770 --> 00:18:18,730 from being reared under good food conditions. 291 00:18:18,730 --> 00:18:21,040 So that's a direct effect on which 292 00:18:21,040 --> 00:18:22,525 animals will survive the best. 293 00:18:26,100 --> 00:18:28,190 And then I'd point this thing out about the dates. 294 00:18:30,870 --> 00:18:33,920 The decision of the owls to bias the sex 295 00:18:33,920 --> 00:18:36,960 has to be made in March. 296 00:18:36,960 --> 00:18:38,610 So they're actually predicting what 297 00:18:38,610 --> 00:18:40,370 the prey density will be in June. 298 00:18:47,970 --> 00:18:51,420 Some of these phenomenon of sex biasing were known, 299 00:18:51,420 --> 00:18:54,930 but they nobody had figured out quite what they meant. 300 00:18:54,930 --> 00:18:57,335 It was the benefits for genetic fitness 301 00:18:57,335 --> 00:18:59,550 that Komdeur was investigating. 302 00:18:59,550 --> 00:19:02,110 And that's what affected his hypothesis. 303 00:19:02,110 --> 00:19:06,760 I'm sure he was familiar with some of these other sex biasing 304 00:19:06,760 --> 00:19:09,440 studies, but nobody had studied it 305 00:19:09,440 --> 00:19:12,570 in terms of why they might be doing it. 306 00:19:12,570 --> 00:19:16,460 And so after his study and the tawny owl study, then 307 00:19:16,460 --> 00:19:19,180 it was-- this is from the introduction 308 00:19:19,180 --> 00:19:23,880 to that paper on tawny owls. 309 00:19:23,880 --> 00:19:30,710 He's citing the earlier findings, 310 00:19:30,710 --> 00:19:37,550 and he's citing findings on yellow-headed blackbirds 311 00:19:37,550 --> 00:19:42,930 where they-- you see it goes back to 1980. 312 00:19:42,930 --> 00:19:45,650 The kestrels-- 1992. 313 00:19:45,650 --> 00:19:48,620 The fitness gain to the parents of producing different sex 314 00:19:48,620 --> 00:19:53,020 offspring in conditions of different resource availability 315 00:19:53,020 --> 00:19:55,050 has seldom been investigated. 316 00:19:55,050 --> 00:19:58,890 And that's why he wanted to do it in the tawny owls. 317 00:19:58,890 --> 00:20:06,250 And he cites Komdeur-- actually published in both '96 and '97-- 318 00:20:06,250 --> 00:20:07,920 which shows that it appears to increase 319 00:20:07,920 --> 00:20:11,380 the fitness of the parents because females are the helping 320 00:20:11,380 --> 00:20:15,025 sex, more likely to be beneficial 321 00:20:15,025 --> 00:20:16,330 if the food is abundant. 322 00:20:19,970 --> 00:20:22,790 Then there was this study on resource availability 323 00:20:22,790 --> 00:20:25,150 in goshawk offspring. 324 00:20:25,150 --> 00:20:27,630 Remember, we saw a goshawk attacking a rabbit 325 00:20:27,630 --> 00:20:28,805 in one of the videos? 326 00:20:32,680 --> 00:20:41,940 And it was related to spatial and temporal variation 327 00:20:41,940 --> 00:20:45,460 in the availability of the woodland grouse 328 00:20:45,460 --> 00:20:48,880 that they're feeding on. 329 00:20:48,880 --> 00:20:51,240 So the broods are large and male-biased 330 00:20:51,240 --> 00:20:53,310 when the grouse density is high. 331 00:20:53,310 --> 00:20:57,380 They're small and female-biased at times 332 00:20:57,380 --> 00:20:59,655 when the grouse density is low. 333 00:21:04,230 --> 00:21:08,920 And they also found that, in fact, the effects carry over. 334 00:21:08,920 --> 00:21:11,360 If they have a lot more of one sex in one year, 335 00:21:11,360 --> 00:21:15,060 they're much more likely-- the other sex will 336 00:21:15,060 --> 00:21:17,050 be more dominant the next year. 337 00:21:25,610 --> 00:21:27,550 And they are suggesting that it maximizes 338 00:21:27,550 --> 00:21:29,990 go goshawk reproductive success. 339 00:21:29,990 --> 00:21:33,710 Although the details of exactly how they do it and so forth 340 00:21:33,710 --> 00:21:34,430 is not known. 341 00:21:34,430 --> 00:21:41,220 So there, in fact, have been-- I found this in a PhD thesis 342 00:21:41,220 --> 00:21:45,660 in 2007, where a specific mechanism is proposed. 343 00:21:45,660 --> 00:21:48,970 So now we're talking about proximate mechanisms 344 00:21:48,970 --> 00:21:50,230 for this sex biasing. 345 00:21:55,500 --> 00:22:00,700 They found that in starlings-- the variation in plasma 346 00:22:00,700 --> 00:22:03,780 corticosterones related to maternal condition. 347 00:22:07,000 --> 00:22:09,660 And they tend abandon their nests 348 00:22:09,660 --> 00:22:12,670 if they had high levels of corticosterone, which 349 00:22:12,670 --> 00:22:15,970 would indicate they are under a lot higher stress of one 350 00:22:15,970 --> 00:22:16,830 sort or another. 351 00:22:22,230 --> 00:22:27,395 And if they experimentally elevate the yolk corticosterone 352 00:22:27,395 --> 00:22:31,261 in the eggs, it selectively decreases male offspring 353 00:22:31,261 --> 00:22:31,760 quality. 354 00:22:31,760 --> 00:22:37,410 It increases pre and postnatal male mortality. 355 00:22:37,410 --> 00:22:40,570 So for the mother, the result is an allocation 356 00:22:40,570 --> 00:22:45,930 towards evolutionarily less expensive daughters 357 00:22:45,930 --> 00:22:48,445 and a sex-specific lowering of current reproductive 358 00:22:48,445 --> 00:22:48,945 investment. 359 00:22:55,010 --> 00:22:59,570 So ultimately, the way he's interpreting it is it 360 00:22:59,570 --> 00:23:02,540 increases maternal fitness, and it's 361 00:23:02,540 --> 00:23:08,160 the mother that's making this kind of decision. 362 00:23:08,160 --> 00:23:11,745 And he's relating it very specifically this steroid. 363 00:23:15,700 --> 00:23:19,780 This is from just one more topic here 364 00:23:19,780 --> 00:23:26,070 from the discussion questions in Alcock. 365 00:23:26,070 --> 00:23:30,580 He asks, why would a male bird exercise 366 00:23:30,580 --> 00:23:32,630 the adoption [INAUDIBLE]? 367 00:23:32,630 --> 00:23:34,990 You can ask that about humans. 368 00:23:34,990 --> 00:23:38,310 Why do you adopt, like becoming a step-parent? 369 00:23:38,310 --> 00:23:39,150 Not your genes. 370 00:23:42,780 --> 00:23:46,530 And so you have to consider benefits 371 00:23:46,530 --> 00:23:49,820 for the genetic fitness of those males. 372 00:23:49,820 --> 00:23:54,880 For one thing, a bird he rears that's not his own offspring 373 00:23:54,880 --> 00:23:58,970 could become a future helper when he does have offspring. 374 00:23:58,970 --> 00:24:01,830 It could result in-- let's say the mates are 375 00:24:01,830 --> 00:24:05,070 very hard to find. 376 00:24:05,070 --> 00:24:08,265 Well, he's got a potential mate there if he's rearing. 377 00:24:08,265 --> 00:24:12,210 And if it's a female, the bird gets older. 378 00:24:12,210 --> 00:24:13,810 Then he could have a mate. 379 00:24:16,950 --> 00:24:19,680 These are possible benefits for genetic fitness. 380 00:24:19,680 --> 00:24:23,950 Or it may just be the result of proximate mechanisms operating 381 00:24:23,950 --> 00:24:25,830 in an abnormal situation. 382 00:24:25,830 --> 00:24:29,230 So it's not easy to decide in those things 383 00:24:29,230 --> 00:24:34,540 without pretty long-m term studies of the birds that 384 00:24:34,540 --> 00:24:37,270 do this. 385 00:24:37,270 --> 00:24:41,770 I want to go through a little more from EO Wilson. 386 00:24:41,770 --> 00:24:45,300 And I will post the whole file of all these notes. 387 00:24:51,320 --> 00:24:53,900 These are the concepts we went over. 388 00:24:53,900 --> 00:24:55,640 This is where-- his general statements 389 00:24:55,640 --> 00:24:58,030 that we've gone over. 390 00:24:58,030 --> 00:24:59,380 And these are the definitions. 391 00:24:59,380 --> 00:25:01,985 You should know the difference between population and society. 392 00:25:01,985 --> 00:25:08,930 You know what a deme is-- the smallest local set of organisms 393 00:25:08,930 --> 00:25:12,010 within which interbreeding occurs freely. 394 00:25:12,010 --> 00:25:15,260 And that's in use in theory. 395 00:25:15,260 --> 00:25:18,750 Of course, in reality, it's not always 396 00:25:18,750 --> 00:25:20,130 totally random and so forth. 397 00:25:23,820 --> 00:25:27,880 Then we talked about the multiplier effect. 398 00:25:27,880 --> 00:25:33,620 Small effect in proximate mechanisms, 399 00:25:33,620 --> 00:25:38,480 a detail about behavior can become multiplied 400 00:25:38,480 --> 00:25:41,430 in the social interactions of the animals 401 00:25:41,430 --> 00:25:45,400 and result in very different societies. 402 00:25:45,400 --> 00:25:47,930 The evolutionary pacemaker, [? McLean ?] argued, 403 00:25:47,930 --> 00:25:48,540 was behavior. 404 00:25:51,170 --> 00:25:53,920 When behavior changes, if something is very adaptive, 405 00:25:53,920 --> 00:25:57,265 it could lead in evolution to structural changes. 406 00:26:00,300 --> 00:26:02,730 He talks about adaptive demography. 407 00:26:02,730 --> 00:26:05,640 I'll talk about life tables later, 408 00:26:05,640 --> 00:26:07,310 where he brings that up again. 409 00:26:07,310 --> 00:26:10,340 It simply means that for some species, 410 00:26:10,340 --> 00:26:15,660 it's more adaptive that many of the animals are very young. 411 00:26:15,660 --> 00:26:19,305 Other species, it's not so adaptive. 412 00:26:19,305 --> 00:26:21,580 That depends on the way they reproduce. 413 00:26:21,580 --> 00:26:24,340 So we'll talk about that at the end here. 414 00:26:28,036 --> 00:26:29,410 And of course, we've talked a lot 415 00:26:29,410 --> 00:26:33,410 about ultimate versus proximate causation. 416 00:26:33,410 --> 00:26:35,450 And we talked about behavioral scaling 417 00:26:35,450 --> 00:26:36,900 when we talked about, for example, 418 00:26:36,900 --> 00:26:43,200 density-dependent behavior, where animals in groups 419 00:26:43,200 --> 00:26:45,970 behave quite differently from solitary animals. 420 00:26:45,970 --> 00:26:50,620 They alter the way they're foraging and so forth. 421 00:26:50,620 --> 00:26:52,350 Or they behave differently if they're 422 00:26:52,350 --> 00:26:55,450 big than when they're small. 423 00:26:55,450 --> 00:26:58,390 And it has great effects on their mating behavior, 424 00:26:58,390 --> 00:27:00,200 for example. 425 00:27:00,200 --> 00:27:05,110 We talked about phylogenetic inertia and both variation, 426 00:27:05,110 --> 00:27:08,680 genetic variation, and the effects of genetic swamping. 427 00:27:08,680 --> 00:27:11,500 You should know what that term means. 428 00:27:11,500 --> 00:27:15,940 And then we talked about various [INAUDIBLE]. 429 00:27:15,940 --> 00:27:17,190 This has come up in the class. 430 00:27:20,010 --> 00:27:22,590 We talked a little bit about-- not much of inbreeding taboos, 431 00:27:22,590 --> 00:27:25,190 because there's not a whole lot known. 432 00:27:25,190 --> 00:27:29,540 But he did talk about how to compute genetic relatedness 433 00:27:29,540 --> 00:27:32,740 using path analysis. 434 00:27:32,740 --> 00:27:34,360 But this, we haven't talked about. 435 00:27:36,920 --> 00:27:39,720 This is the formula for rate of change 436 00:27:39,720 --> 00:27:43,040 in the size of a whole population, 437 00:27:43,040 --> 00:27:46,310 the dNdT-- the number, the rate of change 438 00:27:46,310 --> 00:27:48,260 in the number with time. 439 00:27:48,260 --> 00:27:53,450 So what is r, and what is K? 440 00:27:53,450 --> 00:27:57,170 K you call the carrying capacity of the environment. 441 00:28:00,400 --> 00:28:05,830 If the population density goes above K, 442 00:28:05,830 --> 00:28:09,770 the as you can see from the formula, 443 00:28:09,770 --> 00:28:13,990 then the population won't keep increasing. 444 00:28:13,990 --> 00:28:16,100 That's why it's called carrying capacity. 445 00:28:16,100 --> 00:28:18,130 The environment only has enough resources 446 00:28:18,130 --> 00:28:21,450 to support a certain population level. 447 00:28:21,450 --> 00:28:28,490 r has to do with the rate at which reproduction happens. 448 00:28:28,490 --> 00:28:33,030 So when you talk about r-selection, 449 00:28:33,030 --> 00:28:34,940 where you're talking about species 450 00:28:34,940 --> 00:28:38,050 with a very rapid growth in numbers 451 00:28:38,050 --> 00:28:42,710 by a very high birth rate, what are examples? 452 00:28:42,710 --> 00:28:43,550 Think of the frog. 453 00:28:43,550 --> 00:28:46,690 He lays hundreds of eggs. 454 00:28:46,690 --> 00:28:50,540 Those flies-- think of fly larvae. 455 00:28:50,540 --> 00:28:53,850 One fly, all these eggs can hatch 456 00:28:53,850 --> 00:28:59,330 in the cracks in your apartment, and all these maggots appear. 457 00:28:59,330 --> 00:29:04,710 Why do all these maggots appear if you leave food out? 458 00:29:04,710 --> 00:29:06,770 There r-reproducers. 459 00:29:06,770 --> 00:29:08,190 They're opportunists. 460 00:29:08,190 --> 00:29:11,059 If they get the opportunity, then huge numbers 461 00:29:11,059 --> 00:29:11,850 will be reproduced. 462 00:29:11,850 --> 00:29:16,830 But of course, there's a huge mortality also in r-producers. 463 00:29:16,830 --> 00:29:17,860 Think of mammals. 464 00:29:17,860 --> 00:29:22,762 Think of mice and rats. 465 00:29:22,762 --> 00:29:24,970 If they're able to, they'll reproduce. 466 00:29:24,970 --> 00:29:27,960 We say, they reproduce like rabbits. 467 00:29:27,960 --> 00:29:30,120 Well, they're r-producers. 468 00:29:30,120 --> 00:29:31,880 They are opportunists. 469 00:29:31,880 --> 00:29:34,320 If there's a lot more food available and not many 470 00:29:34,320 --> 00:29:38,940 predators, you get huge numbers. 471 00:29:38,940 --> 00:29:42,930 If you kill off their predators-- 472 00:29:42,930 --> 00:29:44,390 you kill off the wolves. 473 00:29:44,390 --> 00:29:47,390 You kill off all the animals preying on deer. 474 00:29:47,390 --> 00:29:48,270 What happens? 475 00:29:48,270 --> 00:29:50,390 Like in New Jersey-- you get so many deer 476 00:29:50,390 --> 00:29:52,850 they're causing car accidents. 477 00:29:52,850 --> 00:29:54,770 They're eating up the corn in the fields 478 00:29:54,770 --> 00:29:56,128 and so on and so forth. 479 00:30:00,040 --> 00:30:01,460 So what is K-selection? 480 00:30:01,460 --> 00:30:03,070 Here, we're talking about species 481 00:30:03,070 --> 00:30:05,670 with more stable numbers. 482 00:30:05,670 --> 00:30:08,260 It's often close to the carrying capacity of the environment. 483 00:30:08,260 --> 00:30:12,150 But there's much slower growth or even no growth 484 00:30:12,150 --> 00:30:16,170 of a population because of few births per female, 485 00:30:16,170 --> 00:30:18,210 more prolonged periods of development. 486 00:30:18,210 --> 00:30:22,070 And of course, humans and other large primates are K-producers. 487 00:30:28,710 --> 00:30:30,530 So I'd like you to know these. 488 00:30:30,530 --> 00:30:34,370 They're very basic in population biology, 489 00:30:34,370 --> 00:30:39,420 important for when you talk about conservation, 490 00:30:39,420 --> 00:30:41,715 important when you consider behavior of animals. 491 00:30:45,830 --> 00:30:48,240 A little bit about life tables related 492 00:30:48,240 --> 00:30:51,370 to adaptive demography-- how many animals 493 00:30:51,370 --> 00:30:54,070 are different ages? 494 00:30:54,070 --> 00:31:00,840 And I took this just because of a mistake Wilson made. 495 00:31:00,840 --> 00:31:03,750 He talks about K-selection animals. 496 00:31:08,480 --> 00:31:11,160 This is the curve, sort of an ideal. 497 00:31:11,160 --> 00:31:14,100 You have a little bit of fall off when they're very young. 498 00:31:14,100 --> 00:31:18,750 And then you're not getting much die off 499 00:31:18,750 --> 00:31:20,570 until you reach old age. 500 00:31:20,570 --> 00:31:25,060 And then the decline happens until they're all dead. 501 00:31:25,060 --> 00:31:33,040 So this is K-selection life table. 502 00:31:33,040 --> 00:31:36,670 These are extreme r-selection animals-- 503 00:31:36,670 --> 00:31:40,209 huge numbers of young, but very high mortality 504 00:31:40,209 --> 00:31:41,000 when they're young. 505 00:31:41,000 --> 00:31:45,920 And then only a few of them grow to be very old. 506 00:31:45,920 --> 00:31:51,730 These are the animals with a lot of predators 507 00:31:51,730 --> 00:31:54,290 and perhaps other factors, too. 508 00:31:54,290 --> 00:31:58,640 And then he does something interesting. 509 00:31:58,640 --> 00:32:02,050 Here he's got some animals in between, 510 00:32:02,050 --> 00:32:04,220 like song birds are there. 511 00:32:06,960 --> 00:32:08,970 So they're not all at these two extremes 512 00:32:08,970 --> 00:32:11,440 of r-selection and K-selection. 513 00:32:11,440 --> 00:32:14,840 But then he just deals with humans, 514 00:32:14,840 --> 00:32:21,900 and if you ignore my dashed blue line there, 515 00:32:21,900 --> 00:32:30,480 he plots humans in Japan, which are fairly close to what 516 00:32:30,480 --> 00:32:33,990 he plots for humans up here. 517 00:32:33,990 --> 00:32:37,700 And here's this curve for India. 518 00:32:37,700 --> 00:32:39,800 He's claiming that in some countries, 519 00:32:39,800 --> 00:32:41,690 they're closer to r-selection. 520 00:32:41,690 --> 00:32:43,620 They have a lot of young. 521 00:32:43,620 --> 00:32:44,296 Well, it's true. 522 00:32:44,296 --> 00:32:45,920 They have more young, and a lot of them 523 00:32:45,920 --> 00:32:50,180 don't survive-- but nothing like those mice, 524 00:32:50,180 --> 00:32:52,300 and certainly not like flies. 525 00:32:52,300 --> 00:32:57,550 And then I realized-- this seemed unlikely to me 526 00:32:57,550 --> 00:33:00,400 that it was so different, so I noticed 527 00:33:00,400 --> 00:33:06,570 that his ordinate wasn't put on the log scale. 528 00:33:06,570 --> 00:33:08,670 So here we're dealing with log-log plots. 529 00:33:08,670 --> 00:33:13,010 Here we're not dealing with log-log plots. 530 00:33:13,010 --> 00:33:15,010 This is all linear in his. 531 00:33:15,010 --> 00:33:18,070 So I replotted using a logarithmic coordinate. 532 00:33:18,070 --> 00:33:25,170 And here's how India comes out-- not so different from Japan. 533 00:33:25,170 --> 00:33:30,550 So good science involves good quantitative work 534 00:33:30,550 --> 00:33:31,510 in many cases. 535 00:33:31,510 --> 00:33:36,020 And that just shows how even a great scientist like EO Wilson, 536 00:33:36,020 --> 00:33:41,620 who has been an incredibly good scientist in studying 537 00:33:41,620 --> 00:33:45,100 social insects, especially bees and wasps, 538 00:33:45,100 --> 00:33:49,250 can still make such a mistake when 539 00:33:49,250 --> 00:33:51,590 he's trying to review an enormous field 540 00:33:51,590 --> 00:33:52,340 like sociobiology. 541 00:33:55,650 --> 00:33:59,820 Then he talks about group selection and altruism, 542 00:33:59,820 --> 00:34:02,960 and he introduces these concepts. 543 00:34:02,960 --> 00:34:05,800 He calls it the evolution of altruism, 544 00:34:05,800 --> 00:34:10,070 selfishness, and spite-- three very different types 545 00:34:10,070 --> 00:34:13,159 of social behaviors, all of which occur in humans. 546 00:34:15,670 --> 00:34:19,645 And he interprets it all in terms of inclusive fitness 547 00:34:19,645 --> 00:34:21,880 effects. 548 00:34:21,880 --> 00:34:24,960 Then he goes on and talks about reciprocal altruism, the Good 549 00:34:24,960 --> 00:34:30,980 Samaritan behavior, which was analyzed by Trivers, 550 00:34:30,980 --> 00:34:33,920 and then giving various other examples 551 00:34:33,920 --> 00:34:37,560 of altruistic behavior-- [? thwarting; ?] 552 00:34:37,560 --> 00:34:39,840 cooperative breeding, like we saw 553 00:34:39,840 --> 00:34:45,900 in the cats; food sharing, which is common in many species, 554 00:34:45,900 --> 00:34:49,185 certainly in humans; ritualized combat. 555 00:34:53,460 --> 00:34:58,330 And he's dealing with humans at the end, 556 00:34:58,330 --> 00:35:02,530 and he has this arrogant chapter, 557 00:35:02,530 --> 00:35:04,420 The Field of Righteousness. 558 00:35:04,420 --> 00:35:08,000 But let's look at this cute figure. 559 00:35:08,000 --> 00:35:10,690 There he just shows altruism, all 560 00:35:10,690 --> 00:35:12,785 interpreted in terms of genetic fitness. 561 00:35:20,350 --> 00:35:29,630 You see in black there the genes of one individual . 562 00:35:29,630 --> 00:35:38,010 So here, this individual is helping a sibling-- shares 563 00:35:38,010 --> 00:35:38,965 half his genes. 564 00:35:47,420 --> 00:35:52,240 What are the consequences if this guy helps this guy? 565 00:35:52,240 --> 00:35:55,030 Well by helping, he's giving up resources or something. 566 00:35:55,030 --> 00:36:00,710 And it could result in reduction of his own fitness, 567 00:36:00,710 --> 00:36:04,005 but an increase in the fitness of the one he helped. 568 00:36:06,680 --> 00:36:16,400 So the end result can be still a good level of genetic fitness. 569 00:36:16,400 --> 00:36:17,465 That's altruism. 570 00:36:20,330 --> 00:36:22,320 Now, what about selfishness? 571 00:36:22,320 --> 00:36:27,250 Here, the guy, he's going to protect his resources. 572 00:36:27,250 --> 00:36:29,170 So he fights with his sibling. 573 00:36:29,170 --> 00:36:31,060 He clubs him. 574 00:36:31,060 --> 00:36:32,740 [LAUGHTER] 575 00:36:32,740 --> 00:36:35,950 So the result is you're reducing the average fitness 576 00:36:35,950 --> 00:36:37,930 of his siblings if he behaves that way. 577 00:36:37,930 --> 00:36:40,430 But he's increasing his own because he ends up 578 00:36:40,430 --> 00:36:43,270 with more resources. 579 00:36:43,270 --> 00:36:45,220 So that's selfishness. 580 00:36:45,220 --> 00:36:46,015 What about spite? 581 00:36:50,610 --> 00:36:55,320 Here, one of his siblings with an mate, 582 00:36:55,320 --> 00:37:03,780 perhaps, have resources that he had hoped to get, 583 00:37:03,780 --> 00:37:10,895 so he harms the unrelated individual. 584 00:37:10,895 --> 00:37:15,245 And he's much more likely to harm that one. 585 00:37:15,245 --> 00:37:18,510 That might help the related individual, 586 00:37:18,510 --> 00:37:20,750 but look what it does to him. 587 00:37:20,750 --> 00:37:24,320 It doesn't increase his genetic fitness at all, 588 00:37:24,320 --> 00:37:27,420 except very indirectly. 589 00:37:27,420 --> 00:37:30,490 So he calls that spite. 590 00:37:30,490 --> 00:37:31,795 With spite, you hurt yourself. 591 00:37:35,330 --> 00:37:37,830 But presumably, that's adaptive. 592 00:37:37,830 --> 00:37:42,270 And then it will help your genetic fitness indirectly. 593 00:37:42,270 --> 00:37:45,340 So that's the concepts of altruism, selfishness, 594 00:37:45,340 --> 00:37:51,420 and spite that Wilson reviews in his book, Sociobiology. 595 00:37:51,420 --> 00:37:54,500 I will post a little outline. 596 00:37:54,500 --> 00:37:55,960 I don't know if I posted it yet. 597 00:37:55,960 --> 00:38:01,085 It's probably down below because I posted it in last year, 598 00:38:01,085 --> 00:38:02,500 of the later chapters. 599 00:38:02,500 --> 00:38:04,730 It just gives you a sense of that entire book 600 00:38:04,730 --> 00:38:07,830 and how he reviews individual behavior 601 00:38:07,830 --> 00:38:09,140 in different groups of animals. 602 00:38:09,140 --> 00:38:13,320 And that can be useful for some of you in looking for topics. 603 00:38:13,320 --> 00:38:25,140 So what I'd like to do now is talk a little bit 604 00:38:25,140 --> 00:38:26,040 about your projects. 605 00:38:30,130 --> 00:38:39,940 So I'm going to-- read those instructions that I posted. 606 00:38:39,940 --> 00:38:43,370 They're posted right at the top there on the website. 607 00:38:43,370 --> 00:38:47,500 You'll see the assignment. 608 00:38:47,500 --> 00:38:49,880 Make sure you understand the details of that. 609 00:38:49,880 --> 00:38:51,270 It's actually two pages. 610 00:38:51,270 --> 00:38:56,290 I really spell out what we're after. 611 00:38:56,290 --> 00:38:58,790 And then you don't have a lot of time now. 612 00:38:58,790 --> 00:39:02,120 This is like a big homework. 613 00:39:02,120 --> 00:39:04,110 The smaller one is the preliminary 614 00:39:04,110 --> 00:39:10,330 to you turning in a PowerPoint presentation 615 00:39:10,330 --> 00:39:11,960 just before Thanksgiving. 616 00:39:11,960 --> 00:39:13,220 So there's not a lot of time. 617 00:39:13,220 --> 00:39:15,020 You've got to get busy on it now. 618 00:39:15,020 --> 00:39:17,620 That's why I'm decided not to give any more assignments. 619 00:39:17,620 --> 00:39:18,720 I won't even give a quiz. 620 00:39:18,720 --> 00:39:21,850 I want you just to work on the projects now, 621 00:39:21,850 --> 00:39:26,190 because the reading is very easy now, the rest of Alcock. 622 00:39:26,190 --> 00:39:34,140 Let's say you decided you wanted to study giraffes. 623 00:39:34,140 --> 00:39:40,580 Well, I don't want a paper just reviewing 624 00:39:40,580 --> 00:39:43,340 anything you can find on giraffes. 625 00:39:43,340 --> 00:39:45,170 I want you to come up with a question. 626 00:39:45,170 --> 00:39:49,480 You could ask, for example, I want 627 00:39:49,480 --> 00:39:52,060 to know why giraffes have long necks. 628 00:39:52,060 --> 00:39:55,350 This is actually an example from reports-- one report, 629 00:39:55,350 --> 00:39:58,030 at least-- that I had in the past in this class. 630 00:40:02,670 --> 00:40:06,240 I don't want and ethogram of the giraffe, 631 00:40:06,240 --> 00:40:08,610 but it doesn't mean you can't cite some of that 632 00:40:08,610 --> 00:40:10,310 if it's relevant. 633 00:40:10,310 --> 00:40:11,400 But let's ask this. 634 00:40:11,400 --> 00:40:13,320 Why does a giraffe of a long neck? 635 00:40:13,320 --> 00:40:15,172 Well, remember the why question now. 636 00:40:15,172 --> 00:40:17,820 It has different answers. 637 00:40:17,820 --> 00:40:22,170 Why could be proximate mechanisms. 638 00:40:22,170 --> 00:40:23,730 It could be some ethology. 639 00:40:23,730 --> 00:40:26,979 What does he do with his long neck in his social behavior? 640 00:40:26,979 --> 00:40:29,520 What does he do with it in his feeding behavior and so forth? 641 00:40:29,520 --> 00:40:31,530 Or, why did it evolve? 642 00:40:31,530 --> 00:40:35,540 What makes it adaptive for the giraffe? 643 00:40:35,540 --> 00:40:39,125 How does it help him interact with his environment? 644 00:40:39,125 --> 00:40:42,940 Well of course, he could feed from tree branches. 645 00:40:42,940 --> 00:40:46,470 He's tall enough to do it. 646 00:40:46,470 --> 00:40:48,640 Well, what evidence for that is it? 647 00:40:48,640 --> 00:40:49,750 And how does it hurt him? 648 00:40:49,750 --> 00:40:51,062 What are the costs? 649 00:40:51,062 --> 00:40:54,270 There are a lot of difficulties of having such a long neck. 650 00:40:54,270 --> 00:40:58,760 So you do have to deal with some proximate issues 651 00:40:58,760 --> 00:41:02,490 because you want to deal with costs and benefits 652 00:41:02,490 --> 00:41:03,950 for that species. 653 00:41:03,950 --> 00:41:05,710 That's just an example. 654 00:41:05,710 --> 00:41:07,950 I want you to try to think in terms 655 00:41:07,950 --> 00:41:15,400 of both adaptive purpose when you ask why questions 656 00:41:15,400 --> 00:41:18,845 and with ethological details of the animal. 657 00:41:21,560 --> 00:41:24,300 If you have difficulty coming up with questions, 658 00:41:24,300 --> 00:41:26,820 please talk to us. 659 00:41:26,820 --> 00:41:31,620 You can always send me email, just propose some things. 660 00:41:31,620 --> 00:41:34,230 You can give me an example of the questions. 661 00:41:34,230 --> 00:41:36,580 But I think most of you are following 662 00:41:36,580 --> 00:41:38,340 these things in the class quite well. 663 00:41:38,340 --> 00:41:42,760 You know how we're doing it and the way Alcock covers it, 664 00:41:42,760 --> 00:41:47,980 the way Scott covers it, the way Lorenz talked about behavior. 665 00:41:47,980 --> 00:41:52,165 Try to find actual experiments testing the ideas. 666 00:41:54,680 --> 00:41:57,620 Now, there are journals of animal behavior, 667 00:41:57,620 --> 00:42:01,920 but these papers occur in other kinds of journals, too. 668 00:42:01,920 --> 00:42:05,320 So there's a journal called Animal Behavior. 669 00:42:05,320 --> 00:42:07,320 There's another one that's just called Behavior. 670 00:42:07,320 --> 00:42:09,870 They're two journals that deal only with this. 671 00:42:09,870 --> 00:42:11,845 But then you will find ornithology journals 672 00:42:11,845 --> 00:42:14,050 if you deal with birds. 673 00:42:14,050 --> 00:42:16,402 You'll find menology journals, and they'll [? even ?] 674 00:42:16,402 --> 00:42:17,110 include a little. 675 00:42:17,110 --> 00:42:19,640 You'll have behavioral ecology, which 676 00:42:19,640 --> 00:42:21,740 has a lot of-- if you just search 677 00:42:21,740 --> 00:42:23,670 under behavioral ecology, you can 678 00:42:23,670 --> 00:42:28,380 find where people are publishing specific journals that 679 00:42:28,380 --> 00:42:32,460 deal with the effects of usually behavior and environment 680 00:42:32,460 --> 00:42:33,140 interactions. 681 00:42:33,140 --> 00:42:36,870 But there's a lot relevant to sociobiology in such journals. 682 00:42:36,870 --> 00:42:41,100 If you just look at papers and the journals being cited 683 00:42:41,100 --> 00:42:45,125 by Alcock, for example, you'll get lots of examples of places 684 00:42:45,125 --> 00:42:46,950 to look. 685 00:42:46,950 --> 00:42:49,880 You can go to the library and look directly, 686 00:42:49,880 --> 00:42:53,670 or you can get on the library site, MIT library site, 687 00:42:53,670 --> 00:42:59,950 and pull up journals and scan them. 688 00:42:59,950 --> 00:43:01,210 That's one way to find them. 689 00:43:01,210 --> 00:43:05,000 Or you can just think of things you know about already, things 690 00:43:05,000 --> 00:43:08,260 you've heard in the class, things you've read about, 691 00:43:08,260 --> 00:43:12,610 especially in this class, and do your search. 692 00:43:12,610 --> 00:43:16,520 I don't want a neurophysiology. 693 00:43:16,520 --> 00:43:20,410 I don't want a strictly neuroscience paper. 694 00:43:20,410 --> 00:43:22,870 It's got be on the topics of the class. 695 00:43:22,870 --> 00:43:24,600 Use the principles in the class. 696 00:43:24,600 --> 00:43:27,980 And I spell that out in the instructions. 697 00:43:27,980 --> 00:43:32,120 I want you to be explicit about what 698 00:43:32,120 --> 00:43:34,780 you're talking about demonstrates. 699 00:43:34,780 --> 00:43:36,805 Interpret things in terms of these principles. 700 00:43:41,720 --> 00:43:47,660 So in one week then, we want to see a couple of topics. 701 00:43:47,660 --> 00:43:49,550 I know most of you will spend a lot of time 702 00:43:49,550 --> 00:43:50,560 on more than one topic. 703 00:43:50,560 --> 00:43:52,210 But in the course of your doing this, 704 00:43:52,210 --> 00:43:56,840 you'll probably discover which one you're more likely to do. 705 00:43:56,840 --> 00:44:00,060 Now if you do come up with two topics and you turn it in 706 00:44:00,060 --> 00:44:03,330 and then in the following time you have to prepare it, 707 00:44:03,330 --> 00:44:05,880 you decide to change your topic, please let us 708 00:44:05,880 --> 00:44:10,670 know because we might want to give you some feedback. 709 00:44:10,670 --> 00:44:14,970 And we will get busy and give you the feedback right away. 710 00:44:14,970 --> 00:44:19,350 We'll read all of these because we 711 00:44:19,350 --> 00:44:21,710 want to help you give good reports. 712 00:44:21,710 --> 00:44:26,160 You'll be graded on the PowerPoint presentation, not 713 00:44:26,160 --> 00:44:27,520 the oral presentation. 714 00:44:27,520 --> 00:44:29,940 But we like you to have the experience of giving it. 715 00:44:29,940 --> 00:44:32,330 The class would like to hear other reports. 716 00:44:32,330 --> 00:44:34,750 We'll divide into three classes. 717 00:44:34,750 --> 00:44:37,160 You'll be told which class to go to 718 00:44:37,160 --> 00:44:40,080 and where they're going to meet. 719 00:44:40,080 --> 00:44:42,590 I haven't figured that out yet. 720 00:44:42,590 --> 00:44:49,250 And when you make the PowerPoint, 721 00:44:49,250 --> 00:44:51,890 get familiar with PowerPoint if you've never used it, 722 00:44:51,890 --> 00:44:56,120 because we want pictures as well as words, pretty much the way 723 00:44:56,120 --> 00:44:58,410 I've done in the class. 724 00:44:58,410 --> 00:45:00,005 If you have videos, that's possible. 725 00:45:04,130 --> 00:45:08,490 And you won't get a chance to say everything 726 00:45:08,490 --> 00:45:10,480 in the oral report. 727 00:45:10,480 --> 00:45:12,310 You might want to present some background. 728 00:45:12,310 --> 00:45:16,240 Just use the Notes section slides-- 729 00:45:16,240 --> 00:45:18,045 things that you could bring up in a talk 730 00:45:18,045 --> 00:45:22,220 if the talk were longer, but you won't have time in your report 731 00:45:22,220 --> 00:45:25,435 here because you're limited to 12 minutes. 732 00:45:28,430 --> 00:45:31,170 To allow a little time for questions, 733 00:45:31,170 --> 00:45:33,410 12 would be the maximum. 734 00:45:33,410 --> 00:45:35,700 I tell people to aim 10 to 12 minutes so you 735 00:45:35,700 --> 00:45:38,210 can leave a little time for questions. 736 00:45:38,210 --> 00:45:40,710 You don't have a lot of time. 737 00:45:40,710 --> 00:45:45,480 The problem here is coming up with a short enough report. 738 00:45:45,480 --> 00:45:50,730 So you can put extra information in those Notes section. 739 00:45:50,730 --> 00:45:52,440 But for the slides itself, come up 740 00:45:52,440 --> 00:45:54,770 with a talk that you can actually give, 741 00:45:54,770 --> 00:45:58,860 assuming there's four talks in a session.