WEBVTT 00:00:00.000 --> 00:00:02.520 align:middle line:84% The following content is provided under a Creative 00:00:02.520 --> 00:00:04.030 align:middle line:90% Commons license. 00:00:04.030 --> 00:00:06.370 align:middle line:84% Your support will help MIT OpenCourseWare 00:00:06.370 --> 00:00:10.740 align:middle line:84% continue to offer high quality educational resources for free. 00:00:10.740 --> 00:00:13.360 align:middle line:84% To make a donation or view additional materials 00:00:13.360 --> 00:00:17.237 align:middle line:84% from hundreds of MIT courses, visit MIT OpenCourseWare 00:00:17.237 --> 00:00:17.862 align:middle line:90% at ocw.mit.edu. 00:00:17.862 --> 00:00:22.490 align:middle line:90% 00:00:22.490 --> 00:00:24.940 align:middle line:84% PROFESSOR: OK, I want to say a little more 00:00:24.940 --> 00:00:30.890 align:middle line:84% about these phenomena of cryptic female choice. 00:00:30.890 --> 00:00:37.260 align:middle line:84% And I just had mentioned one change on the male side 00:00:37.260 --> 00:00:41.390 align:middle line:84% that seemed to be an evolutionary response 00:00:41.390 --> 00:00:43.980 align:middle line:84% to cryptic female choice and what 00:00:43.980 --> 00:00:46.140 align:middle line:90% can the male do to close that. 00:00:46.140 --> 00:00:48.730 align:middle line:84% And we talked about several behavioral things they do. 00:00:48.730 --> 00:00:52.510 align:middle line:90% 00:00:52.510 --> 00:00:56.090 align:middle line:84% We mentioned some research on primates. 00:00:56.090 --> 00:00:59.640 align:middle line:84% And we ended talking about this discovery of two 00:00:59.640 --> 00:01:01.840 align:middle line:90% different kinds of sperm. 00:01:01.840 --> 00:01:09.916 align:middle line:84% And this article gives you a pretty good idea. 00:01:09.916 --> 00:01:15.690 align:middle line:84% A sterile sperm caste protects brother fertile sperm 00:01:15.690 --> 00:01:19.240 align:middle line:84% from female-mediated death in Drosophila, 00:01:19.240 --> 00:01:21.720 align:middle line:90% one species of Drosophila. 00:01:21.720 --> 00:01:27.720 align:middle line:84% So that means that there can be some sperm that are the guards, 00:01:27.720 --> 00:01:29.550 align:middle line:84% and they can't fertilize the egg. 00:01:29.550 --> 00:01:34.750 align:middle line:84% But they can protect that sperm, the fertile ones, 00:01:34.750 --> 00:01:37.550 align:middle line:84% from being destroyed by female toxins 00:01:37.550 --> 00:01:40.180 align:middle line:90% or whatever that she may-- 00:01:40.180 --> 00:01:42.770 align:middle line:84% because females have evolved various ways 00:01:42.770 --> 00:01:48.340 align:middle line:84% to make their mate choice in their reproductive tract. 00:01:48.340 --> 00:01:50.370 align:middle line:90% So that's what this-- 00:01:50.370 --> 00:01:55.230 align:middle line:84% and there's a lot of articles on this phenomenon just recently. 00:01:55.230 --> 00:02:06.885 align:middle line:84% This is all after this discovery about different kinds of sperm. 00:02:06.885 --> 00:02:10.400 align:middle line:90% It happened around 2000, 2001. 00:02:10.400 --> 00:02:14.160 align:middle line:84% And the articles have appeared on fish and insects. 00:02:14.160 --> 00:02:16.790 align:middle line:90% This is just that one article. 00:02:16.790 --> 00:02:25.120 align:middle line:84% But Alcock points out that all of these things, especially 00:02:25.120 --> 00:02:28.660 align:middle line:84% the female reproductive tract, is adaptably designed 00:02:28.660 --> 00:02:30.720 align:middle line:90% to promote sperm choice. 00:02:30.720 --> 00:02:32.800 align:middle line:90% In other words, her choice-- 00:02:32.800 --> 00:02:36.960 align:middle line:84% which sperm she wants to use to fertilize her eggs. 00:02:36.960 --> 00:02:39.520 align:middle line:84% That kind of thing just never occurred to biologists 00:02:39.520 --> 00:02:45.480 align:middle line:84% before what he calls the sociobiological revolution that 00:02:45.480 --> 00:02:48.160 align:middle line:84% started with the publication, really, 00:02:48.160 --> 00:02:51.405 align:middle line:84% with EO Wilson's book who reviewed all that stuff. 00:02:51.405 --> 00:02:53.510 align:middle line:84% Of course, it had started earlier 00:02:53.510 --> 00:02:59.010 align:middle line:84% with the people we've mentioned that talked 00:02:59.010 --> 00:03:01.165 align:middle line:84% about the adaptive individual choice 00:03:01.165 --> 00:03:05.440 align:middle line:84% as being the major factor in evolution, 00:03:05.440 --> 00:03:07.930 align:middle line:90% the adaptationist approach. 00:03:07.930 --> 00:03:12.850 align:middle line:90% But these are some reviews. 00:03:12.850 --> 00:03:15.950 align:middle line:84% I just wanted to mention a few of them 00:03:15.950 --> 00:03:18.680 align:middle line:90% that came out a few years ago. 00:03:18.680 --> 00:03:19.840 align:middle line:90% Look at the second one. 00:03:19.840 --> 00:03:24.070 align:middle line:84% This became a common term in the news media-- 00:03:24.070 --> 00:03:27.660 align:middle line:90% Sperm Wars-- The Science of Sex. 00:03:27.660 --> 00:03:32.610 align:middle line:84% This was a book that had some extensive speculations 00:03:32.610 --> 00:03:36.960 align:middle line:84% about sperm competition in humans. 00:03:36.960 --> 00:03:43.740 align:middle line:84% Not based on firm experimental studies-- 00:03:43.740 --> 00:03:46.750 align:middle line:84% it was based on a few observations 00:03:46.750 --> 00:03:48.150 align:middle line:90% made by medical people. 00:03:48.150 --> 00:03:52.850 align:middle line:84% But it's still not all that certain 00:03:52.850 --> 00:03:56.350 align:middle line:90% how much cryptic choice-- 00:03:56.350 --> 00:03:59.890 align:middle line:84% most of it's quite overt in their behavior. 00:03:59.890 --> 00:04:05.690 align:middle line:90% 00:04:05.690 --> 00:04:07.040 align:middle line:90% So all these articles are that. 00:04:07.040 --> 00:04:08.220 align:middle line:90% And you'll find many more. 00:04:08.220 --> 00:04:11.330 align:middle line:84% And just a few years ago when I searched the literature, 00:04:11.330 --> 00:04:15.490 align:middle line:84% I found reports on spiders, a cricket, a beetle, 00:04:15.490 --> 00:04:17.680 align:middle line:90% various flies, and fish. 00:04:17.680 --> 00:04:20.899 align:middle line:84% These are just examples of those articles. 00:04:20.899 --> 00:04:23.710 align:middle line:84% One on the beetle-- there's the red flower beetle. 00:04:23.710 --> 00:04:29.450 align:middle line:90% So this is another topic. 00:04:29.450 --> 00:04:32.500 align:middle line:84% It's another concept of what can happen 00:04:32.500 --> 00:04:40.760 align:middle line:84% with this competition between the two sexes in reproduction. 00:04:40.760 --> 00:04:44.060 align:middle line:84% And it's our most blatant example of it. 00:04:44.060 --> 00:04:47.040 align:middle line:90% It's called genomic imprinting. 00:04:47.040 --> 00:04:51.180 align:middle line:84% It doesn't mean behavioral imprinting at all. 00:04:51.180 --> 00:04:54.067 align:middle line:84% It has a totally different meaning from the behavioral use 00:04:54.067 --> 00:04:55.025 align:middle line:90% of the term imprinting. 00:04:55.025 --> 00:04:57.770 align:middle line:90% 00:04:57.770 --> 00:05:02.780 align:middle line:84% It's when one gene can have different effects 00:05:02.780 --> 00:05:06.860 align:middle line:84% on the offspring depending on whether the gene, the allele, 00:05:06.860 --> 00:05:14.790 align:middle line:84% comes from the mother or the father, 00:05:14.790 --> 00:05:17.380 align:middle line:84% because male and female interests are not identical 00:05:17.380 --> 00:05:21.740 align:middle line:84% unless they practice strict monogamy. 00:05:21.740 --> 00:05:26.680 align:middle line:84% And the early tests of that, they didn't confirm that. 00:05:26.680 --> 00:05:31.570 align:middle line:84% But I think that's just because they used to think monogamy 00:05:31.570 --> 00:05:32.960 align:middle line:90% meant just what it says. 00:05:32.960 --> 00:05:35.340 align:middle line:84% But in fact, many monogamous pairs 00:05:35.340 --> 00:05:36.735 align:middle line:90% are not completely monogamous. 00:05:36.735 --> 00:05:39.950 align:middle line:90% 00:05:39.950 --> 00:05:45.760 align:middle line:84% So for example-- and I apply this to humans-- 00:05:45.760 --> 00:05:51.530 align:middle line:84% I'm asking here, what about human fetus sizes where 00:05:51.530 --> 00:05:55.110 align:middle line:84% the fetus can be so big that it damages or even kills 00:05:55.110 --> 00:05:57.200 align:middle line:90% the mother? 00:05:57.200 --> 00:06:02.280 align:middle line:84% Why would females evolve so they could ever 00:06:02.280 --> 00:06:04.470 align:middle line:90% produce such a large fetus? 00:06:04.470 --> 00:06:05.740 align:middle line:90% And yet, that has happened. 00:06:05.740 --> 00:06:10.080 align:middle line:84% And some women, without modern obstetrics, 00:06:10.080 --> 00:06:14.660 align:middle line:84% wouldn't survive the birth of all the fetuses 00:06:14.660 --> 00:06:19.260 align:middle line:84% that they might nevertheless carry. 00:06:19.260 --> 00:06:24.320 align:middle line:84% So it's not adaptive for the female to do that. 00:06:24.320 --> 00:06:27.710 align:middle line:84% But it may be for the male in many cases. 00:06:27.710 --> 00:06:30.610 align:middle line:84% When you think about earlier evolutionary times, 00:06:30.610 --> 00:06:34.740 align:middle line:84% if the male had many choices, he might have had 00:06:34.740 --> 00:06:37.670 align:middle line:90% a number of different wives. 00:06:37.670 --> 00:06:40.280 align:middle line:84% What matters to him, just from the standpoint 00:06:40.280 --> 00:06:41.500 align:middle line:90% of genetic fitness? 00:06:41.500 --> 00:06:46.970 align:middle line:84% I don't mean what matters consciously to him. 00:06:46.970 --> 00:06:49.340 align:middle line:84% He might be madly in love with a woman 00:06:49.340 --> 00:06:55.240 align:middle line:84% that he makes pregnant and then has a fetus that kills her. 00:06:55.240 --> 00:06:59.040 align:middle line:84% The point is what matters from an evolutionary standpoint 00:06:59.040 --> 00:07:04.170 align:middle line:84% is just his genetic fitness, how many genes can he pass on. 00:07:04.170 --> 00:07:08.190 align:middle line:84% And what he can do for that, it's 00:07:08.190 --> 00:07:11.400 align:middle line:90% promoted by the large fetus-- 00:07:11.400 --> 00:07:12.795 align:middle line:90% a large, healthier fetus. 00:07:12.795 --> 00:07:16.800 align:middle line:90% 00:07:16.800 --> 00:07:19.850 align:middle line:84% Of course, the fetus has to survive the childbirth 00:07:19.850 --> 00:07:21.510 align:middle line:90% for that to work. 00:07:21.510 --> 00:07:24.650 align:middle line:90% But look at this. 00:07:24.650 --> 00:07:26.630 align:middle line:84% Sorry I didn't find a better slide. 00:07:26.630 --> 00:07:30.540 align:middle line:84% This describes genomic imprinting. 00:07:30.540 --> 00:07:34.910 align:middle line:84% And this is about one particular receptor 00:07:34.910 --> 00:07:45.560 align:middle line:84% and the molecule itself that binds to that receptor, IGF2. 00:07:45.560 --> 00:07:48.750 align:middle line:90% And it's a growth factor. 00:07:48.750 --> 00:07:51.480 align:middle line:90% 00:07:51.480 --> 00:07:53.475 align:middle line:90% So it promotes somatic growth. 00:07:53.475 --> 00:07:56.530 align:middle line:90% 00:07:56.530 --> 00:07:57.480 align:middle line:90% This is in mice. 00:07:57.480 --> 00:08:03.005 align:middle line:84% Now, the genes from the mother, the receptor is turned on. 00:08:03.005 --> 00:08:06.290 align:middle line:90% 00:08:06.290 --> 00:08:09.670 align:middle line:90% The growth factor is off. 00:08:09.670 --> 00:08:10.460 align:middle line:90% But look. 00:08:10.460 --> 00:08:15.090 align:middle line:84% If it comes from the father, the receptor is off, 00:08:15.090 --> 00:08:19.410 align:middle line:84% and that molecule is on, the one that promotes growth. 00:08:19.410 --> 00:08:23.540 align:middle line:84% So you can investigate those effects by looking at-- 00:08:23.540 --> 00:08:29.500 align:middle line:84% so for example, you delete the mother's IGF2 receptor gene. 00:08:29.500 --> 00:08:34.316 align:middle line:84% The one that is normally on for her, you just delete it. 00:08:34.316 --> 00:08:35.024 align:middle line:90% And what happens? 00:08:35.024 --> 00:08:38.110 align:middle line:90% 00:08:38.110 --> 00:08:39.355 align:middle line:90% Fetuses that are huge. 00:08:39.355 --> 00:08:43.150 align:middle line:90% 00:08:43.150 --> 00:08:49.266 align:middle line:84% You delete the father's IGF2 gene, 00:08:49.266 --> 00:08:51.100 align:middle line:84% and you get little, tiny offspring. 00:08:51.100 --> 00:08:54.930 align:middle line:90% 00:08:54.930 --> 00:08:59.300 align:middle line:84% If you delete both of them, then you get normal size offspring. 00:08:59.300 --> 00:09:01.930 align:middle line:84% So the particular growth factor, its main function 00:09:01.930 --> 00:09:10.890 align:middle line:84% seems to be involved in this genomically imprinted gene, 00:09:10.890 --> 00:09:16.950 align:middle line:84% where the male and female alleles have 00:09:16.950 --> 00:09:18.130 align:middle line:90% very different effects. 00:09:18.130 --> 00:09:19.325 align:middle line:90% And they're the same gene. 00:09:19.325 --> 00:09:24.920 align:middle line:90% 00:09:24.920 --> 00:09:27.550 align:middle line:84% And so they just say here, the imprints on the IGF2 00:09:27.550 --> 00:09:35.610 align:middle line:84% and the IGF2 receptor genes normally cancel each other out. 00:09:35.610 --> 00:09:38.520 align:middle line:84% Changing the imprint of one copy of the gene 00:09:38.520 --> 00:09:42.660 align:middle line:84% has a dramatic effect on the size of the offspring. 00:09:42.660 --> 00:09:48.660 align:middle line:84% So this kind of results supports the genetic conflict hypothesis 00:09:48.660 --> 00:09:51.190 align:middle line:90% in a particularly dramatic way. 00:09:51.190 --> 00:09:56.710 align:middle line:84% And this was just from the early discoveries. 00:09:56.710 --> 00:10:03.530 align:middle line:84% And just a few years ago, I found this website. 00:10:03.530 --> 00:10:08.530 align:middle line:84% The whole website's devoted to genetic imprinting-- 00:10:08.530 --> 00:10:11.370 align:middle line:90% because it was such a puzzle. 00:10:11.370 --> 00:10:13.890 align:middle line:84% It was only this sociobiological interpretation 00:10:13.890 --> 00:10:19.380 align:middle line:84% that made any sense, but it still seems so unusual. 00:10:19.380 --> 00:10:21.442 align:middle line:84% And there was this one study I found 00:10:21.442 --> 00:10:22.900 align:middle line:84% where they showed effects that went 00:10:22.900 --> 00:10:27.030 align:middle line:84% beyond the fetal and infancy periods-- 00:10:27.030 --> 00:10:29.050 align:middle line:90% in fact, effects later in life. 00:10:29.050 --> 00:10:32.650 align:middle line:90% 00:10:32.650 --> 00:10:33.950 align:middle line:90% And there were arguments-- 00:10:33.950 --> 00:10:38.530 align:middle line:84% what good is genomic imprinting, the function of parent-specific 00:10:38.530 --> 00:10:40.700 align:middle line:90% gene expression-- 00:10:40.700 --> 00:10:43.930 align:middle line:84% in Nature Reviews a few years ago. 00:10:43.930 --> 00:10:50.930 align:middle line:84% And then, if you do look at that website, which I did today, 00:10:50.930 --> 00:10:54.160 align:middle line:90% I found-- and this is just 2013. 00:10:54.160 --> 00:10:59.010 align:middle line:84% Look at all these articles, all on this phenomenon, 00:10:59.010 --> 00:11:04.110 align:middle line:84% its variations, how long it lasts, and so forth. 00:11:04.110 --> 00:11:07.490 align:middle line:84% So that just gives you an idea of the impact of sociobiology 00:11:07.490 --> 00:11:08.765 align:middle line:90% also on human genetics. 00:11:08.765 --> 00:11:11.580 align:middle line:90% 00:11:11.580 --> 00:11:13.920 align:middle line:84% But of course, they're studying it mainly in mice. 00:11:13.920 --> 00:11:18.260 align:middle line:84% But the first question I was asking there, 00:11:18.260 --> 00:11:21.950 align:middle line:84% I'm applying it to possible explanation 00:11:21.950 --> 00:11:29.600 align:middle line:84% for very large human heads, human fetuses, born 00:11:29.600 --> 00:11:33.320 align:middle line:90% to women where it can damage. 00:11:33.320 --> 00:11:35.450 align:middle line:84% So let's get back to bird behavior a little bit. 00:11:35.450 --> 00:11:37.055 align:middle line:90% We don't have too much to go. 00:11:37.055 --> 00:11:38.930 align:middle line:84% We'll talk a little bit more about EO Wilson. 00:11:38.930 --> 00:11:41.460 align:middle line:84% And I would like to have a little time 00:11:41.460 --> 00:11:46.230 align:middle line:84% at the end of the class to discuss your project because I 00:11:46.230 --> 00:11:49.360 align:middle line:84% think for next week, we're just going to have the homework. 00:11:49.360 --> 00:11:51.960 align:middle line:84% I know you've got a homework due today, right? 00:11:51.960 --> 00:11:57.600 align:middle line:84% So next week, the readings are quite easy after these chapters 00:11:57.600 --> 00:11:59.870 align:middle line:90% that these classes are based on. 00:11:59.870 --> 00:12:01.910 align:middle line:84% So you can let me talk about those things, 00:12:01.910 --> 00:12:04.340 align:middle line:84% and you can work on your projects. 00:12:04.340 --> 00:12:08.860 align:middle line:84% And I will formulate the thing, put it online. 00:12:08.860 --> 00:12:12.030 align:middle line:84% I'd like you to come up with a couple of topics 00:12:12.030 --> 00:12:14.480 align:middle line:84% and several articles about each one. 00:12:14.480 --> 00:12:15.795 align:middle line:90% Give me your references. 00:12:15.795 --> 00:12:19.820 align:middle line:90% 00:12:19.820 --> 00:12:22.380 align:middle line:84% Some people know already what they want to talk-- 00:12:22.380 --> 00:12:25.138 align:middle line:84% they're pretty sure they want their project to be. 00:12:25.138 --> 00:12:27.096 align:middle line:84% But let's see if we have a little time for that 00:12:27.096 --> 00:12:28.096 align:middle line:90% at the end of the class. 00:12:28.096 --> 00:12:33.750 align:middle line:90% 00:12:33.750 --> 00:12:36.730 align:middle line:84% Did we talk a little bit about helpers at the nest before? 00:12:36.730 --> 00:12:40.178 align:middle line:84% I think we did a little bit, and Scott. 00:12:40.178 --> 00:12:41.970 align:middle line:84% But some of the best studies have been done 00:12:41.970 --> 00:12:46.160 align:middle line:90% in this Seychelles warbler. 00:12:46.160 --> 00:12:48.650 align:middle line:84% So what are the advantages for a young bird 00:12:48.650 --> 00:12:51.710 align:middle line:84% if they help their parents rear siblings by becoming 00:12:51.710 --> 00:12:52.715 align:middle line:90% a helper at the nest? 00:12:52.715 --> 00:12:54.560 align:middle line:90% It's a kind of altruism. 00:12:54.560 --> 00:12:57.690 align:middle line:90% It's very common in birds. 00:12:57.690 --> 00:13:02.360 align:middle line:84% And of course, it's very common in humans, where the mother 00:13:02.360 --> 00:13:06.140 align:middle line:84% and father get help from their own offspring 00:13:06.140 --> 00:13:07.535 align:middle line:90% in rearing further offspring. 00:13:07.535 --> 00:13:11.230 align:middle line:90% 00:13:11.230 --> 00:13:13.780 align:middle line:84% And Alcock does say a little more about it 00:13:13.780 --> 00:13:15.520 align:middle line:90% that Scott's book did. 00:13:15.520 --> 00:13:18.210 align:middle line:84% This is a picture of this beautiful little bird 00:13:18.210 --> 00:13:18.960 align:middle line:90% in the sea shells. 00:13:18.960 --> 00:13:22.680 align:middle line:90% 00:13:22.680 --> 00:13:24.890 align:middle line:84% These are the kinds of advantages it 00:13:24.890 --> 00:13:26.290 align:middle line:90% could have for the young bird. 00:13:26.290 --> 00:13:31.900 align:middle line:84% They gain experience in taking care of young. 00:13:31.900 --> 00:13:34.900 align:middle line:84% They're promoting the survival of close relatives, which 00:13:34.900 --> 00:13:39.960 align:middle line:84% means it does affect their own genetic fitness-- 00:13:39.960 --> 00:13:41.630 align:middle line:90% not directly, but indirectly-- 00:13:41.630 --> 00:13:46.920 align:middle line:84% by supporting the survival of their siblings. 00:13:46.920 --> 00:13:53.750 align:middle line:84% And that is critical if done, say, in poor-- 00:13:53.750 --> 00:13:56.670 align:middle line:84% where there's not that much food in the environment. 00:13:56.670 --> 00:13:59.740 align:middle line:84% Sometimes if they don't have a helper at the nest, 00:13:59.740 --> 00:14:02.960 align:middle line:84% the chances of getting the offspring to even survive 00:14:02.960 --> 00:14:06.840 align:middle line:84% are very low because two birds just can't bring enough. 00:14:06.840 --> 00:14:10.500 align:middle line:84% But it works best on the richer territories. 00:14:10.500 --> 00:14:15.460 align:middle line:84% In such areas, if the territory is so deficient in food, 00:14:15.460 --> 00:14:17.730 align:middle line:84% then having the helper at the nest 00:14:17.730 --> 00:14:23.300 align:middle line:84% doesn't help, because you've got to feed him, too, or her. 00:14:23.300 --> 00:14:25.410 align:middle line:84% So to gain experience, they promote the survival 00:14:25.410 --> 00:14:26.610 align:middle line:90% of close relatives. 00:14:26.610 --> 00:14:30.030 align:middle line:84% And they can also inherit that territory if they stay around. 00:14:30.030 --> 00:14:32.750 align:middle line:84% After all, the parents will get old, stop reproducing. 00:14:32.750 --> 00:14:35.210 align:middle line:84% Then they can take over the territory. 00:14:35.210 --> 00:14:37.890 align:middle line:90% The helpers are usually female. 00:14:37.890 --> 00:14:41.440 align:middle line:84% They're used by the adult pairs that have better territories. 00:14:41.440 --> 00:14:44.190 align:middle line:90% 00:14:44.190 --> 00:14:48.340 align:middle line:84% And there were studies in the Seychelles of these warblers 00:14:48.340 --> 00:14:55.140 align:middle line:84% by this sociobiologist, Komdeur, published in 1997. 00:14:55.140 --> 00:14:57.280 align:middle line:84% He made this surprising discovery 00:14:57.280 --> 00:15:00.600 align:middle line:84% that the females can actually regulate 00:15:00.600 --> 00:15:01.980 align:middle line:90% the sex of their offspring. 00:15:01.980 --> 00:15:05.580 align:middle line:90% 00:15:05.580 --> 00:15:07.505 align:middle line:84% So why would that ability evolve? 00:15:07.505 --> 00:15:10.580 align:middle line:90% 00:15:10.580 --> 00:15:16.910 align:middle line:84% Well, it's explained in terms of her fitness-- 00:15:16.910 --> 00:15:19.820 align:middle line:84% the fitness of the female-- and the behavioral differences 00:15:19.820 --> 00:15:21.760 align:middle line:84% between male and female offspring. 00:15:21.760 --> 00:15:26.210 align:middle line:84% If she biases her offspring towards the female, 00:15:26.210 --> 00:15:28.250 align:middle line:84% it's because she's on a good territory. 00:15:28.250 --> 00:15:31.150 align:middle line:84% She can make good use of the helper at the nest. 00:15:31.150 --> 00:15:36.540 align:middle line:84% And it's the females that are most likely to become helpers. 00:15:36.540 --> 00:15:38.960 align:middle line:90% So this is the actual results. 00:15:38.960 --> 00:15:42.720 align:middle line:84% Before this study, no one ever checked 00:15:42.720 --> 00:15:44.790 align:middle line:84% to choose whether birds could actually 00:15:44.790 --> 00:15:47.300 align:middle line:84% choose which sex to reproduce in their offspring. 00:15:47.300 --> 00:15:49.060 align:middle line:84% And now it's been found to be more common. 00:15:49.060 --> 00:15:52.820 align:middle line:84% But it was first discovered in these warblers. 00:15:52.820 --> 00:15:54.850 align:middle line:84% So on good territories, the helper at the nest 00:15:54.850 --> 00:15:56.030 align:middle line:90% is beneficial. 00:15:56.030 --> 00:15:58.520 align:middle line:84% The helper is usually a daughter. 00:15:58.520 --> 00:16:04.290 align:middle line:84% On poor territories, there's not enough food for the extra bird. 00:16:04.290 --> 00:16:06.675 align:middle line:84% So that led him to make this test. 00:16:06.675 --> 00:16:09.420 align:middle line:84% And he found that on poor territories, 00:16:09.420 --> 00:16:13.060 align:middle line:90% 77% males were hatched. 00:16:13.060 --> 00:16:16.820 align:middle line:84% Better for her genetic fitness if she 00:16:16.820 --> 00:16:20.905 align:middle line:84% passes on more genes and more offspring, 00:16:20.905 --> 00:16:24.785 align:middle line:90% if she produces males. 00:16:24.785 --> 00:16:28.660 align:middle line:90% 00:16:28.660 --> 00:16:30.550 align:middle line:90% More of them will survive-- 00:16:30.550 --> 00:16:32.360 align:middle line:84% because only a certain percentage of them 00:16:32.360 --> 00:16:35.630 align:middle line:90% are going to survive anyway. 00:16:35.630 --> 00:16:38.420 align:middle line:84% And if only one survives, it's more likely to be a male 00:16:38.420 --> 00:16:40.050 align:middle line:90% if she has a lot of males. 00:16:40.050 --> 00:16:41.260 align:middle line:90% And on rich territories-- 00:16:41.260 --> 00:16:45.620 align:middle line:90% only 13% males. 00:16:45.620 --> 00:16:48.630 align:middle line:84% So the effects are dramatic in how much she can skew 00:16:48.630 --> 00:16:51.540 align:middle line:90% the sex of her offspring is. 00:16:51.540 --> 00:16:54.040 align:middle line:84% AUDIENCE: How do you know it's choice and not a side effect 00:16:54.040 --> 00:16:56.750 align:middle line:90% of the environment? 00:16:56.750 --> 00:16:59.830 align:middle line:84% PROFESSOR: And that has certainly been studied. 00:16:59.830 --> 00:17:02.480 align:middle line:90% And they've varied that. 00:17:02.480 --> 00:17:07.170 align:middle line:84% And of course, there are effects to the environment, 00:17:07.170 --> 00:17:09.420 align:middle line:84% but they're affecting that female. 00:17:09.420 --> 00:17:12.300 align:middle line:84% You'd like to know, well, if you control 00:17:12.300 --> 00:17:14.800 align:middle line:84% things like temperature, you could 00:17:14.800 --> 00:17:16.800 align:middle line:90% say nutrition could affect it. 00:17:16.800 --> 00:17:20.190 align:middle line:84% Yes, and they've had to control for those things. 00:17:20.190 --> 00:17:23.260 align:middle line:90% And Komdeur tried to do that. 00:17:23.260 --> 00:17:27.380 align:middle line:84% And as best as he could tell, it was the female actually 00:17:27.380 --> 00:17:29.210 align:middle line:90% able to change that. 00:17:29.210 --> 00:17:32.030 align:middle line:84% But then it was discovered in other animals. 00:17:32.030 --> 00:17:36.710 align:middle line:84% In the tawny owl, for example, they 00:17:36.710 --> 00:17:39.950 align:middle line:84% had female-based clutches on territories 00:17:39.950 --> 00:17:44.590 align:middle line:84% with more abundant prey, which were the field voles. 00:17:44.590 --> 00:17:47.740 align:middle line:84% In June, although that's the month the chicks fledge, 00:17:47.740 --> 00:17:50.530 align:middle line:90% the eggs were laid in March. 00:17:50.530 --> 00:17:53.125 align:middle line:90% And yet the sex was biased. 00:17:53.125 --> 00:17:59.810 align:middle line:90% 00:17:59.810 --> 00:18:03.000 align:middle line:84% It indicates that the parent owls produce more female chicks 00:18:03.000 --> 00:18:06.260 align:middle line:84% on territories with higher numbers of their major prey, 00:18:06.260 --> 00:18:08.560 align:middle line:84% the field vole, at the time the young are fledging. 00:18:08.560 --> 00:18:11.960 align:middle line:84% It's adaptive because the females, but not the males, 00:18:11.960 --> 00:18:14.770 align:middle line:84% appear to enjoy a subsequent reproductive advantage 00:18:14.770 --> 00:18:18.730 align:middle line:84% from being reared under good food conditions. 00:18:18.730 --> 00:18:21.040 align:middle line:84% So that's a direct effect on which 00:18:21.040 --> 00:18:22.525 align:middle line:90% animals will survive the best. 00:18:22.525 --> 00:18:26.100 align:middle line:90% 00:18:26.100 --> 00:18:28.190 align:middle line:84% And then I'd point this thing out about the dates. 00:18:28.190 --> 00:18:30.870 align:middle line:90% 00:18:30.870 --> 00:18:33.920 align:middle line:84% The decision of the owls to bias the sex 00:18:33.920 --> 00:18:36.960 align:middle line:90% has to be made in March. 00:18:36.960 --> 00:18:38.950 align:middle line:84% So they're actually predicting what the prey 00:18:38.950 --> 00:18:40.370 align:middle line:90% density will be in June. 00:18:40.370 --> 00:18:47.970 align:middle line:90% 00:18:47.970 --> 00:18:51.420 align:middle line:84% Some of these phenomenon of sex biasing were known, 00:18:51.420 --> 00:18:54.930 align:middle line:84% but they nobody had figured out quite what they meant. 00:18:54.930 --> 00:18:57.335 align:middle line:84% It was the benefits for genetic fitness 00:18:57.335 --> 00:18:59.550 align:middle line:90% that Komdeur was investigating. 00:18:59.550 --> 00:19:02.110 align:middle line:84% And that's what affected his hypothesis. 00:19:02.110 --> 00:19:06.760 align:middle line:84% I'm sure he was familiar with some of these other sex biasing 00:19:06.760 --> 00:19:09.440 align:middle line:84% studies, but nobody had studied it 00:19:09.440 --> 00:19:12.570 align:middle line:84% in terms of why they might be doing it. 00:19:12.570 --> 00:19:17.680 align:middle line:84% And so after his study and the tawny owl study, then it was-- 00:19:17.680 --> 00:19:23.880 align:middle line:84% this is from the introduction to that paper on tawny owls. 00:19:23.880 --> 00:19:30.710 align:middle line:84% He's citing the earlier findings, 00:19:30.710 --> 00:19:37.750 align:middle line:84% and he's citing findings on yellow-headed blackbirds where 00:19:37.750 --> 00:19:38.430 align:middle line:90% they-- 00:19:38.430 --> 00:19:42.930 align:middle line:90% you see it goes back to 1980. 00:19:42.930 --> 00:19:45.650 align:middle line:90% The kestrels-- 1992. 00:19:45.650 --> 00:19:48.620 align:middle line:84% The fitness gain to the parents of producing different sex 00:19:48.620 --> 00:19:53.020 align:middle line:84% offspring in conditions of different resource availability 00:19:53.020 --> 00:19:55.050 align:middle line:90% has seldom been investigated. 00:19:55.050 --> 00:19:58.890 align:middle line:84% And that's why he wanted to do it in the tawny owls. 00:19:58.890 --> 00:20:01.450 align:middle line:90% And he cites Komdeur-- 00:20:01.450 --> 00:20:03.510 align:middle line:84% actually published in both '96 and '97-- 00:20:03.510 --> 00:20:06.250 align:middle line:90% 00:20:06.250 --> 00:20:07.920 align:middle line:84% which shows that it appears to increase 00:20:07.920 --> 00:20:11.380 align:middle line:84% the fitness of the parents because females are the helping 00:20:11.380 --> 00:20:15.025 align:middle line:84% sex, more likely to be beneficial 00:20:15.025 --> 00:20:16.330 align:middle line:90% if the food is abundant. 00:20:16.330 --> 00:20:19.970 align:middle line:90% 00:20:19.970 --> 00:20:22.790 align:middle line:84% Then there was this study on resource availability 00:20:22.790 --> 00:20:25.150 align:middle line:90% in goshawk offspring. 00:20:25.150 --> 00:20:27.630 align:middle line:84% Remember, we saw a goshawk attacking a rabbit 00:20:27.630 --> 00:20:28.805 align:middle line:90% in one of the videos? 00:20:28.805 --> 00:20:32.680 align:middle line:90% 00:20:32.680 --> 00:20:41.940 align:middle line:84% And it was related to spatial and temporal variation 00:20:41.940 --> 00:20:45.460 align:middle line:84% in the availability of the woodland grouse 00:20:45.460 --> 00:20:48.880 align:middle line:90% that they're feeding on. 00:20:48.880 --> 00:20:51.240 align:middle line:84% So the broods are large and male-biased 00:20:51.240 --> 00:20:53.310 align:middle line:90% when the grouse density is high. 00:20:53.310 --> 00:20:57.380 align:middle line:84% They're small and female-biased at times 00:20:57.380 --> 00:20:59.655 align:middle line:90% when the grouse density is low. 00:20:59.655 --> 00:21:04.230 align:middle line:90% 00:21:04.230 --> 00:21:08.920 align:middle line:84% And they also found that, in fact, the effects carry over. 00:21:08.920 --> 00:21:11.360 align:middle line:84% If they have a lot more of one sex in one year, 00:21:11.360 --> 00:21:14.120 align:middle line:90% they're much more likely-- 00:21:14.120 --> 00:21:17.050 align:middle line:84% the other sex will be more dominant the next year. 00:21:17.050 --> 00:21:25.610 align:middle line:90% 00:21:25.610 --> 00:21:27.980 align:middle line:84% And they are suggesting that it maximizes go 00:21:27.980 --> 00:21:29.990 align:middle line:90% goshawk reproductive success. 00:21:29.990 --> 00:21:33.710 align:middle line:84% Although the details of exactly how they do it and so forth 00:21:33.710 --> 00:21:34.430 align:middle line:90% is not known. 00:21:34.430 --> 00:21:37.720 align:middle line:90% So there, in fact, have been-- 00:21:37.720 --> 00:21:43.420 align:middle line:84% I found this in a PhD thesis in 2007, 00:21:43.420 --> 00:21:45.660 align:middle line:84% where a specific mechanism is proposed. 00:21:45.660 --> 00:21:48.970 align:middle line:84% So now we're talking about proximate mechanisms 00:21:48.970 --> 00:21:50.230 align:middle line:90% for this sex biasing. 00:21:50.230 --> 00:21:55.500 align:middle line:90% 00:21:55.500 --> 00:21:59.130 align:middle line:90% They found that in starlings-- 00:21:59.130 --> 00:22:02.000 align:middle line:84% the variation in plasma corticosterones 00:22:02.000 --> 00:22:03.780 align:middle line:90% related to maternal condition. 00:22:03.780 --> 00:22:07.000 align:middle line:90% 00:22:07.000 --> 00:22:09.660 align:middle line:84% And they tend abandon their nests 00:22:09.660 --> 00:22:12.670 align:middle line:84% if they had high levels of corticosterone, which 00:22:12.670 --> 00:22:15.970 align:middle line:84% would indicate they are under a lot higher stress of one 00:22:15.970 --> 00:22:16.830 align:middle line:90% sort or another. 00:22:16.830 --> 00:22:22.230 align:middle line:90% 00:22:22.230 --> 00:22:27.395 align:middle line:84% And if they experimentally elevate the yolk corticosterone 00:22:27.395 --> 00:22:31.260 align:middle line:84% in the eggs, it selectively decreases male offspring 00:22:31.260 --> 00:22:31.760 align:middle line:90% quality. 00:22:31.760 --> 00:22:37.410 align:middle line:84% It increases pre and postnatal male mortality. 00:22:37.410 --> 00:22:40.570 align:middle line:84% So for the mother, the result is an allocation 00:22:40.570 --> 00:22:45.930 align:middle line:84% towards evolutionarily less expensive daughters 00:22:45.930 --> 00:22:48.445 align:middle line:84% and a sex-specific lowering of current reproductive 00:22:48.445 --> 00:22:48.945 align:middle line:90% investment. 00:22:48.945 --> 00:22:55.010 align:middle line:90% 00:22:55.010 --> 00:22:59.570 align:middle line:84% So ultimately, the way he's interpreting it is it 00:22:59.570 --> 00:23:02.540 align:middle line:84% increases maternal fitness, and it's 00:23:02.540 --> 00:23:08.160 align:middle line:84% the mother that's making this kind of decision. 00:23:08.160 --> 00:23:11.745 align:middle line:84% And he's relating it very specifically this steroid. 00:23:11.745 --> 00:23:15.700 align:middle line:90% 00:23:15.700 --> 00:23:19.780 align:middle line:84% This is from just one more topic here 00:23:19.780 --> 00:23:26.070 align:middle line:84% from the discussion questions in Alcock. 00:23:26.070 --> 00:23:30.580 align:middle line:84% He asks, why would a male bird exercise 00:23:30.580 --> 00:23:32.630 align:middle line:90% the adoption [INAUDIBLE]? 00:23:32.630 --> 00:23:34.990 align:middle line:90% You can ask that about humans. 00:23:34.990 --> 00:23:38.310 align:middle line:84% Why do you adopt, like becoming a step-parent? 00:23:38.310 --> 00:23:39.150 align:middle line:90% Not your genes. 00:23:39.150 --> 00:23:42.780 align:middle line:90% 00:23:42.780 --> 00:23:46.530 align:middle line:84% And so you have to consider benefits 00:23:46.530 --> 00:23:49.820 align:middle line:84% for the genetic fitness of those males. 00:23:49.820 --> 00:23:54.880 align:middle line:84% For one thing, a bird he rears that's not his own offspring 00:23:54.880 --> 00:23:58.970 align:middle line:84% could become a future helper when he does have offspring. 00:23:58.970 --> 00:24:00.510 align:middle line:90% It could result in-- 00:24:00.510 --> 00:24:05.070 align:middle line:84% let's say the mates are very hard to find. 00:24:05.070 --> 00:24:08.265 align:middle line:84% Well, he's got a potential mate there if he's rearing. 00:24:08.265 --> 00:24:12.210 align:middle line:84% And if it's a female, the bird gets older. 00:24:12.210 --> 00:24:13.810 align:middle line:90% Then he could have a mate. 00:24:13.810 --> 00:24:16.950 align:middle line:90% 00:24:16.950 --> 00:24:19.680 align:middle line:84% These are possible benefits for genetic fitness. 00:24:19.680 --> 00:24:23.950 align:middle line:84% Or it may just be the result of proximate mechanisms operating 00:24:23.950 --> 00:24:25.830 align:middle line:90% in an abnormal situation. 00:24:25.830 --> 00:24:29.230 align:middle line:84% So it's not easy to decide in those things 00:24:29.230 --> 00:24:34.540 align:middle line:84% without pretty long-m term studies of the birds that 00:24:34.540 --> 00:24:37.270 align:middle line:90% do this. 00:24:37.270 --> 00:24:41.770 align:middle line:84% I want to go through a little more from EO Wilson. 00:24:41.770 --> 00:24:45.300 align:middle line:84% And I will post the whole file of all these notes. 00:24:45.300 --> 00:24:51.320 align:middle line:90% 00:24:51.320 --> 00:24:53.900 align:middle line:84% These are the concepts we went over. 00:24:53.900 --> 00:24:55.640 align:middle line:84% This is where-- his general statements 00:24:55.640 --> 00:24:58.030 align:middle line:90% that we've gone over. 00:24:58.030 --> 00:24:59.380 align:middle line:90% And these are the definitions. 00:24:59.380 --> 00:25:01.985 align:middle line:84% You should know the difference between population and society. 00:25:01.985 --> 00:25:03.630 align:middle line:90% You know what a deme is-- 00:25:03.630 --> 00:25:06.870 align:middle line:90% 00:25:06.870 --> 00:25:09.670 align:middle line:84% the smallest local set of organisms within which 00:25:09.670 --> 00:25:12.010 align:middle line:90% interbreeding occurs freely. 00:25:12.010 --> 00:25:15.260 align:middle line:90% And that's in use in theory. 00:25:15.260 --> 00:25:18.750 align:middle line:84% Of course, in reality, it's not always 00:25:18.750 --> 00:25:20.130 align:middle line:90% totally random and so forth. 00:25:20.130 --> 00:25:23.820 align:middle line:90% 00:25:23.820 --> 00:25:27.880 align:middle line:84% Then we talked about the multiplier effect. 00:25:27.880 --> 00:25:33.620 align:middle line:84% Small effect in proximate mechanisms, 00:25:33.620 --> 00:25:38.480 align:middle line:84% a detail about behavior can become multiplied 00:25:38.480 --> 00:25:41.430 align:middle line:84% in the social interactions of the animals 00:25:41.430 --> 00:25:45.400 align:middle line:84% and result in very different societies. 00:25:45.400 --> 00:25:47.930 align:middle line:84% The evolutionary pacemaker, [? McLean ?] argued, 00:25:47.930 --> 00:25:48.540 align:middle line:90% was behavior. 00:25:48.540 --> 00:25:51.170 align:middle line:90% 00:25:51.170 --> 00:25:53.920 align:middle line:84% When behavior changes, if something is very adaptive, 00:25:53.920 --> 00:25:57.265 align:middle line:84% it could lead in evolution to structural changes. 00:25:57.265 --> 00:26:00.300 align:middle line:90% 00:26:00.300 --> 00:26:02.730 align:middle line:84% He talks about adaptive demography. 00:26:02.730 --> 00:26:05.640 align:middle line:84% I'll talk about life tables later, 00:26:05.640 --> 00:26:07.310 align:middle line:90% where he brings that up again. 00:26:07.310 --> 00:26:10.340 align:middle line:84% It simply means that for some species, 00:26:10.340 --> 00:26:15.660 align:middle line:84% it's more adaptive that many of the animals are very young. 00:26:15.660 --> 00:26:19.305 align:middle line:84% Other species, it's not so adaptive. 00:26:19.305 --> 00:26:21.580 align:middle line:84% That depends on the way they reproduce. 00:26:21.580 --> 00:26:24.340 align:middle line:84% So we'll talk about that at the end here. 00:26:24.340 --> 00:26:28.035 align:middle line:90% 00:26:28.035 --> 00:26:29.410 align:middle line:84% And of course, we've talked a lot 00:26:29.410 --> 00:26:33.410 align:middle line:84% about ultimate versus proximate causation. 00:26:33.410 --> 00:26:35.450 align:middle line:84% And we talked about behavioral scaling 00:26:35.450 --> 00:26:36.900 align:middle line:84% when we talked about, for example, 00:26:36.900 --> 00:26:43.200 align:middle line:84% density-dependent behavior, where animals in groups 00:26:43.200 --> 00:26:45.970 align:middle line:84% behave quite differently from solitary animals. 00:26:45.970 --> 00:26:50.620 align:middle line:84% They alter the way they're foraging and so forth. 00:26:50.620 --> 00:26:52.350 align:middle line:84% Or they behave differently if they're 00:26:52.350 --> 00:26:55.450 align:middle line:90% big than when they're small. 00:26:55.450 --> 00:26:58.390 align:middle line:84% And it has great effects on their mating behavior, 00:26:58.390 --> 00:27:00.200 align:middle line:90% for example. 00:27:00.200 --> 00:27:05.110 align:middle line:84% We talked about phylogenetic inertia and both variation, 00:27:05.110 --> 00:27:08.680 align:middle line:84% genetic variation, and the effects of genetic swamping. 00:27:08.680 --> 00:27:11.500 align:middle line:84% You should know what that term means. 00:27:11.500 --> 00:27:15.940 align:middle line:84% And then we talked about various [INAUDIBLE].. 00:27:15.940 --> 00:27:17.190 align:middle line:90% This has come up in the class. 00:27:17.190 --> 00:27:20.010 align:middle line:90% 00:27:20.010 --> 00:27:22.590 align:middle line:84% We talked a little bit about-- not much of inbreeding taboos, 00:27:22.590 --> 00:27:25.190 align:middle line:84% because there's not a whole lot known. 00:27:25.190 --> 00:27:29.540 align:middle line:84% But he did talk about how to compute genetic relatedness 00:27:29.540 --> 00:27:32.740 align:middle line:90% using path analysis. 00:27:32.740 --> 00:27:34.360 align:middle line:84% But this, we haven't talked about. 00:27:34.360 --> 00:27:36.920 align:middle line:90% 00:27:36.920 --> 00:27:39.720 align:middle line:84% This is the formula for rate of change 00:27:39.720 --> 00:27:43.930 align:middle line:84% in the size of a whole population, the dNdT-- 00:27:43.930 --> 00:27:48.260 align:middle line:84% the number, the rate of change in the number with time. 00:27:48.260 --> 00:27:53.450 align:middle line:90% So what is r, and what is K? 00:27:53.450 --> 00:27:57.170 align:middle line:84% K you call the carrying capacity of the environment. 00:27:57.170 --> 00:28:00.400 align:middle line:90% 00:28:00.400 --> 00:28:05.830 align:middle line:84% If the population density goes above K, 00:28:05.830 --> 00:28:09.770 align:middle line:84% the as you can see from the formula, 00:28:09.770 --> 00:28:13.990 align:middle line:84% then the population won't keep increasing. 00:28:13.990 --> 00:28:16.100 align:middle line:84% That's why it's called carrying capacity. 00:28:16.100 --> 00:28:18.130 align:middle line:84% The environment only has enough resources 00:28:18.130 --> 00:28:21.450 align:middle line:84% to support a certain population level. 00:28:21.450 --> 00:28:28.490 align:middle line:84% r has to do with the rate at which reproduction happens. 00:28:28.490 --> 00:28:33.030 align:middle line:84% So when you talk about r-selection, 00:28:33.030 --> 00:28:34.940 align:middle line:84% where you're talking about species 00:28:34.940 --> 00:28:38.050 align:middle line:84% with a very rapid growth in numbers 00:28:38.050 --> 00:28:42.710 align:middle line:84% by a very high birth rate, what are examples? 00:28:42.710 --> 00:28:43.550 align:middle line:90% Think of the frog. 00:28:43.550 --> 00:28:46.690 align:middle line:90% He lays hundreds of eggs. 00:28:46.690 --> 00:28:50.540 align:middle line:84% Those flies-- think of fly larvae. 00:28:50.540 --> 00:28:53.850 align:middle line:84% One fly, all these eggs can hatch 00:28:53.850 --> 00:28:59.330 align:middle line:84% in the cracks in your apartment, and all these maggots appear. 00:28:59.330 --> 00:29:04.710 align:middle line:84% Why do all these maggots appear if you leave food out? 00:29:04.710 --> 00:29:06.770 align:middle line:90% There r-reproducers. 00:29:06.770 --> 00:29:08.190 align:middle line:90% They're opportunists. 00:29:08.190 --> 00:29:11.058 align:middle line:84% If they get the opportunity, then huge numbers 00:29:11.058 --> 00:29:11.850 align:middle line:90% will be reproduced. 00:29:11.850 --> 00:29:16.830 align:middle line:84% But of course, there's a huge mortality also in r-producers. 00:29:16.830 --> 00:29:17.860 align:middle line:90% Think of mammals. 00:29:17.860 --> 00:29:22.762 align:middle line:90% Think of mice and rats. 00:29:22.762 --> 00:29:24.970 align:middle line:84% If they're able to, they'll reproduce. 00:29:24.970 --> 00:29:27.960 align:middle line:84% We say, they reproduce like rabbits. 00:29:27.960 --> 00:29:30.120 align:middle line:90% Well, they're r-producers. 00:29:30.120 --> 00:29:31.880 align:middle line:90% They are opportunists. 00:29:31.880 --> 00:29:34.320 align:middle line:84% If there's a lot more food available and not many 00:29:34.320 --> 00:29:38.940 align:middle line:90% predators, you get huge numbers. 00:29:38.940 --> 00:29:40.370 align:middle line:84% If you kill off their predators-- 00:29:40.370 --> 00:29:42.930 align:middle line:90% 00:29:42.930 --> 00:29:44.390 align:middle line:90% you kill off the wolves. 00:29:44.390 --> 00:29:47.390 align:middle line:84% You kill off all the animals preying on deer. 00:29:47.390 --> 00:29:48.270 align:middle line:90% What happens? 00:29:48.270 --> 00:29:49.420 align:middle line:90% Like in New Jersey-- 00:29:49.420 --> 00:29:52.850 align:middle line:84% you get so many deer they're causing car accidents. 00:29:52.850 --> 00:29:54.770 align:middle line:84% They're eating up the corn in the fields 00:29:54.770 --> 00:29:56.128 align:middle line:90% and so on and so forth. 00:29:56.128 --> 00:30:00.040 align:middle line:90% 00:30:00.040 --> 00:30:01.460 align:middle line:90% So what is K-selection? 00:30:01.460 --> 00:30:03.070 align:middle line:84% Here, we're talking about species 00:30:03.070 --> 00:30:05.670 align:middle line:90% with more stable numbers. 00:30:05.670 --> 00:30:08.260 align:middle line:84% It's often close to the carrying capacity of the environment. 00:30:08.260 --> 00:30:12.150 align:middle line:84% But there's much slower growth or even no growth 00:30:12.150 --> 00:30:16.170 align:middle line:84% of a population because of few births per female, 00:30:16.170 --> 00:30:18.210 align:middle line:84% more prolonged periods of development. 00:30:18.210 --> 00:30:22.070 align:middle line:84% And of course, humans and other large primates are K-producers. 00:30:22.070 --> 00:30:28.710 align:middle line:90% 00:30:28.710 --> 00:30:30.530 align:middle line:90% So I'd like you to know these. 00:30:30.530 --> 00:30:34.370 align:middle line:84% They're very basic in population biology, 00:30:34.370 --> 00:30:39.420 align:middle line:84% important for when you talk about conservation, 00:30:39.420 --> 00:30:41.715 align:middle line:84% important when you consider behavior of animals. 00:30:41.715 --> 00:30:45.830 align:middle line:90% 00:30:45.830 --> 00:30:48.240 align:middle line:84% A little bit about life tables related 00:30:48.240 --> 00:30:50.070 align:middle line:90% to adaptive demography-- 00:30:50.070 --> 00:30:54.070 align:middle line:84% how many animals are different ages? 00:30:54.070 --> 00:31:00.840 align:middle line:84% And I took this just because of a mistake Wilson made. 00:31:00.840 --> 00:31:03.750 align:middle line:84% He talks about K-selection animals. 00:31:03.750 --> 00:31:08.480 align:middle line:90% 00:31:08.480 --> 00:31:11.160 align:middle line:84% This is the curve, sort of an ideal. 00:31:11.160 --> 00:31:14.100 align:middle line:84% You have a little bit of fall off when they're very young. 00:31:14.100 --> 00:31:18.750 align:middle line:84% And then you're not getting much die off 00:31:18.750 --> 00:31:20.570 align:middle line:90% until you reach old age. 00:31:20.570 --> 00:31:25.060 align:middle line:84% And then the decline happens until they're all dead. 00:31:25.060 --> 00:31:33.040 align:middle line:84% So this is K-selection life table. 00:31:33.040 --> 00:31:36.670 align:middle line:84% These are extreme r-selection animals-- 00:31:36.670 --> 00:31:39.450 align:middle line:84% huge numbers of young, but very high 00:31:39.450 --> 00:31:41.000 align:middle line:90% mortality when they're young. 00:31:41.000 --> 00:31:45.920 align:middle line:84% And then only a few of them grow to be very old. 00:31:45.920 --> 00:31:51.730 align:middle line:84% These are the animals with a lot of predators 00:31:51.730 --> 00:31:54.290 align:middle line:90% and perhaps other factors, too. 00:31:54.290 --> 00:31:58.640 align:middle line:84% And then he does something interesting. 00:31:58.640 --> 00:32:02.050 align:middle line:84% Here he's got some animals in between, 00:32:02.050 --> 00:32:04.220 align:middle line:90% like song birds are there. 00:32:04.220 --> 00:32:06.960 align:middle line:90% 00:32:06.960 --> 00:32:08.970 align:middle line:84% So they're not all at these two extremes 00:32:08.970 --> 00:32:11.440 align:middle line:90% of r-selection and K-selection. 00:32:11.440 --> 00:32:14.840 align:middle line:84% But then he just deals with humans, 00:32:14.840 --> 00:32:21.900 align:middle line:84% and if you ignore my dashed blue line there, 00:32:21.900 --> 00:32:30.480 align:middle line:84% he plots humans in Japan, which are fairly close to what 00:32:30.480 --> 00:32:33.990 align:middle line:90% he plots for humans up here. 00:32:33.990 --> 00:32:37.700 align:middle line:90% And here's this curve for India. 00:32:37.700 --> 00:32:39.800 align:middle line:84% He's claiming that in some countries, 00:32:39.800 --> 00:32:41.690 align:middle line:90% they're closer to r-selection. 00:32:41.690 --> 00:32:43.620 align:middle line:90% They have a lot of young. 00:32:43.620 --> 00:32:44.380 align:middle line:90% Well, it's true. 00:32:44.380 --> 00:32:47.240 align:middle line:84% They have more young, and a lot of them don't survive-- 00:32:47.240 --> 00:32:52.300 align:middle line:84% but nothing like those mice, and certainly not like flies. 00:32:52.300 --> 00:32:55.380 align:middle line:90% And then I realized-- 00:32:55.380 --> 00:32:59.190 align:middle line:84% this seemed unlikely to me that it was so different, 00:32:59.190 --> 00:33:06.570 align:middle line:84% so I noticed that his ordinate wasn't put on the log scale. 00:33:06.570 --> 00:33:08.670 align:middle line:84% So here we're dealing with log-log plots. 00:33:08.670 --> 00:33:13.010 align:middle line:84% Here we're not dealing with log-log plots. 00:33:13.010 --> 00:33:15.010 align:middle line:90% This is all linear in his. 00:33:15.010 --> 00:33:18.070 align:middle line:84% So I replotted using a logarithmic coordinate. 00:33:18.070 --> 00:33:22.090 align:middle line:90% And here's how India comes out-- 00:33:22.090 --> 00:33:25.170 align:middle line:90% not so different from Japan. 00:33:25.170 --> 00:33:30.550 align:middle line:84% So good science involves good quantitative work 00:33:30.550 --> 00:33:31.510 align:middle line:90% in many cases. 00:33:31.510 --> 00:33:36.020 align:middle line:84% And that just shows how even a great scientist like EO Wilson, 00:33:36.020 --> 00:33:41.620 align:middle line:84% who has been an incredibly good scientist in studying 00:33:41.620 --> 00:33:45.100 align:middle line:84% social insects, especially bees and wasps, 00:33:45.100 --> 00:33:49.250 align:middle line:84% can still make such a mistake when 00:33:49.250 --> 00:33:51.590 align:middle line:84% he's trying to review an enormous field 00:33:51.590 --> 00:33:52.340 align:middle line:90% like sociobiology. 00:33:52.340 --> 00:33:55.650 align:middle line:90% 00:33:55.650 --> 00:33:59.820 align:middle line:84% Then he talks about group selection and altruism, 00:33:59.820 --> 00:34:02.960 align:middle line:84% and he introduces these concepts. 00:34:02.960 --> 00:34:06.970 align:middle line:84% He calls it the evolution of altruism, selfishness, 00:34:06.970 --> 00:34:08.530 align:middle line:90% and spite-- 00:34:08.530 --> 00:34:11.929 align:middle line:84% three very different types of social behaviors, all of which 00:34:11.929 --> 00:34:13.159 align:middle line:90% occur in humans. 00:34:13.159 --> 00:34:15.670 align:middle line:90% 00:34:15.670 --> 00:34:19.645 align:middle line:84% And he interprets it all in terms of inclusive fitness 00:34:19.645 --> 00:34:21.880 align:middle line:90% effects. 00:34:21.880 --> 00:34:24.960 align:middle line:84% Then he goes on and talks about reciprocal altruism, the Good 00:34:24.960 --> 00:34:30.980 align:middle line:84% Samaritan behavior, which was analyzed by Trivers, 00:34:30.980 --> 00:34:33.920 align:middle line:84% and then giving various other examples 00:34:33.920 --> 00:34:36.750 align:middle line:90% of altruistic behavior-- 00:34:36.750 --> 00:34:39.150 align:middle line:84% [? thwarting; ?] cooperative breeding, 00:34:39.150 --> 00:34:44.010 align:middle line:84% like we saw in the cats; food sharing, which 00:34:44.010 --> 00:34:48.020 align:middle line:84% is common in many species, certainly in humans; 00:34:48.020 --> 00:34:49.185 align:middle line:90% ritualized combat. 00:34:49.185 --> 00:34:53.460 align:middle line:90% 00:34:53.460 --> 00:34:58.330 align:middle line:84% And he's dealing with humans at the end, 00:34:58.330 --> 00:35:02.530 align:middle line:84% and he has this arrogant chapter, 00:35:02.530 --> 00:35:04.420 align:middle line:90% The Field of Righteousness. 00:35:04.420 --> 00:35:08.000 align:middle line:84% But let's look at this cute figure. 00:35:08.000 --> 00:35:10.690 align:middle line:84% There he just shows altruism, all 00:35:10.690 --> 00:35:12.785 align:middle line:84% interpreted in terms of genetic fitness. 00:35:12.785 --> 00:35:20.350 align:middle line:90% 00:35:20.350 --> 00:35:29.630 align:middle line:84% You see in black there the genes of one individual . 00:35:29.630 --> 00:35:37.600 align:middle line:84% So here, this individual is helping a sibling-- 00:35:37.600 --> 00:35:38.965 align:middle line:90% shares half his genes. 00:35:38.965 --> 00:35:47.420 align:middle line:90% 00:35:47.420 --> 00:35:52.240 align:middle line:84% What are the consequences if this guy helps this guy? 00:35:52.240 --> 00:35:55.030 align:middle line:84% Well by helping, he's giving up resources or something. 00:35:55.030 --> 00:36:00.710 align:middle line:84% And it could result in reduction of his own fitness, 00:36:00.710 --> 00:36:04.005 align:middle line:84% but an increase in the fitness of the one he helped. 00:36:04.005 --> 00:36:06.680 align:middle line:90% 00:36:06.680 --> 00:36:16.400 align:middle line:84% So the end result can be still a good level of genetic fitness. 00:36:16.400 --> 00:36:17.465 align:middle line:90% That's altruism. 00:36:17.465 --> 00:36:20.330 align:middle line:90% 00:36:20.330 --> 00:36:22.320 align:middle line:90% Now, what about selfishness? 00:36:22.320 --> 00:36:27.250 align:middle line:84% Here, the guy, he's going to protect his resources. 00:36:27.250 --> 00:36:29.170 align:middle line:90% So he fights with his sibling. 00:36:29.170 --> 00:36:31.060 align:middle line:90% He clubs him. 00:36:31.060 --> 00:36:32.740 align:middle line:90% [LAUGHTER] 00:36:32.740 --> 00:36:35.950 align:middle line:84% So the result is you're reducing the average fitness 00:36:35.950 --> 00:36:37.930 align:middle line:84% of his siblings if he behaves that way. 00:36:37.930 --> 00:36:40.430 align:middle line:84% But he's increasing his own because he ends up 00:36:40.430 --> 00:36:43.270 align:middle line:90% with more resources. 00:36:43.270 --> 00:36:45.220 align:middle line:90% So that's selfishness. 00:36:45.220 --> 00:36:46.015 align:middle line:90% What about spite? 00:36:46.015 --> 00:36:50.610 align:middle line:90% 00:36:50.610 --> 00:36:55.320 align:middle line:84% Here, one of his siblings with an mate, 00:36:55.320 --> 00:37:03.780 align:middle line:84% perhaps, have resources that he had hoped to get, 00:37:03.780 --> 00:37:10.895 align:middle line:84% so he harms the unrelated individual. 00:37:10.895 --> 00:37:15.245 align:middle line:84% And he's much more likely to harm that one. 00:37:15.245 --> 00:37:18.510 align:middle line:84% That might help the related individual, 00:37:18.510 --> 00:37:20.750 align:middle line:90% but look what it does to him. 00:37:20.750 --> 00:37:24.320 align:middle line:84% It doesn't increase his genetic fitness at all, 00:37:24.320 --> 00:37:27.420 align:middle line:90% except very indirectly. 00:37:27.420 --> 00:37:30.490 align:middle line:90% So he calls that spite. 00:37:30.490 --> 00:37:31.795 align:middle line:90% With spite, you hurt yourself. 00:37:31.795 --> 00:37:35.330 align:middle line:90% 00:37:35.330 --> 00:37:37.830 align:middle line:90% But presumably, that's adaptive. 00:37:37.830 --> 00:37:42.270 align:middle line:84% And then it will help your genetic fitness indirectly. 00:37:42.270 --> 00:37:45.340 align:middle line:84% So that's the concepts of altruism, selfishness, 00:37:45.340 --> 00:37:51.420 align:middle line:84% and spite that Wilson reviews in his book, Sociobiology. 00:37:51.420 --> 00:37:54.500 align:middle line:90% I will post a little outline. 00:37:54.500 --> 00:37:55.960 align:middle line:90% I don't know if I posted it yet. 00:37:55.960 --> 00:38:01.085 align:middle line:84% It's probably down below because I posted it in last year, 00:38:01.085 --> 00:38:02.500 align:middle line:90% of the later chapters. 00:38:02.500 --> 00:38:04.730 align:middle line:84% It just gives you a sense of that entire book 00:38:04.730 --> 00:38:07.830 align:middle line:84% and how he reviews individual behavior 00:38:07.830 --> 00:38:09.140 align:middle line:90% in different groups of animals. 00:38:09.140 --> 00:38:13.320 align:middle line:84% And that can be useful for some of you in looking for topics. 00:38:13.320 --> 00:38:25.140 align:middle line:84% So what I'd like to do now is talk a little bit 00:38:25.140 --> 00:38:26.040 align:middle line:90% about your projects. 00:38:26.040 --> 00:38:30.130 align:middle line:90% 00:38:30.130 --> 00:38:30.980 align:middle line:90% So I'm going to-- 00:38:30.980 --> 00:38:37.120 align:middle line:90% 00:38:37.120 --> 00:38:39.940 align:middle line:84% read those instructions that I posted. 00:38:39.940 --> 00:38:43.370 align:middle line:84% They're posted right at the top there on the website. 00:38:43.370 --> 00:38:47.500 align:middle line:90% You'll see the assignment. 00:38:47.500 --> 00:38:49.880 align:middle line:84% Make sure you understand the details of that. 00:38:49.880 --> 00:38:51.270 align:middle line:90% It's actually two pages. 00:38:51.270 --> 00:38:56.290 align:middle line:84% I really spell out what we're after. 00:38:56.290 --> 00:38:58.790 align:middle line:84% And then you don't have a lot of time now. 00:38:58.790 --> 00:39:02.120 align:middle line:90% This is like a big homework. 00:39:02.120 --> 00:39:04.110 align:middle line:84% The smaller one is the preliminary 00:39:04.110 --> 00:39:10.330 align:middle line:84% to you turning in a PowerPoint presentation 00:39:10.330 --> 00:39:11.960 align:middle line:90% just before Thanksgiving. 00:39:11.960 --> 00:39:13.220 align:middle line:90% So there's not a lot of time. 00:39:13.220 --> 00:39:15.020 align:middle line:84% You've got to get busy on it now. 00:39:15.020 --> 00:39:17.620 align:middle line:84% That's why I'm decided not to give any more assignments. 00:39:17.620 --> 00:39:18.720 align:middle line:90% I won't even give a quiz. 00:39:18.720 --> 00:39:21.850 align:middle line:84% I want you just to work on the projects now, 00:39:21.850 --> 00:39:26.190 align:middle line:84% because the reading is very easy now, the rest of Alcock. 00:39:26.190 --> 00:39:34.140 align:middle line:84% Let's say you decided you wanted to study giraffes. 00:39:34.140 --> 00:39:41.000 align:middle line:84% Well, I don't want a paper just reviewing anything 00:39:41.000 --> 00:39:43.340 align:middle line:90% you can find on giraffes. 00:39:43.340 --> 00:39:45.170 align:middle line:84% I want you to come up with a question. 00:39:45.170 --> 00:39:49.480 align:middle line:84% You could ask, for example, I want 00:39:49.480 --> 00:39:52.060 align:middle line:84% to know why giraffes have long necks. 00:39:52.060 --> 00:39:54.550 align:middle line:84% This is actually an example from reports-- 00:39:54.550 --> 00:39:58.030 align:middle line:84% one report, at least-- that I had in the past in this class. 00:39:58.030 --> 00:40:02.670 align:middle line:90% 00:40:02.670 --> 00:40:06.240 align:middle line:84% I don't want and ethogram of the giraffe, 00:40:06.240 --> 00:40:08.610 align:middle line:84% but it doesn't mean you can't cite some of that 00:40:08.610 --> 00:40:10.310 align:middle line:90% if it's relevant. 00:40:10.310 --> 00:40:11.400 align:middle line:90% But let's ask this. 00:40:11.400 --> 00:40:13.320 align:middle line:84% Why does a giraffe of a long neck? 00:40:13.320 --> 00:40:15.172 align:middle line:84% Well, remember the why question now. 00:40:15.172 --> 00:40:17.820 align:middle line:90% It has different answers. 00:40:17.820 --> 00:40:22.170 align:middle line:84% Why could be proximate mechanisms. 00:40:22.170 --> 00:40:23.730 align:middle line:90% It could be some ethology. 00:40:23.730 --> 00:40:26.978 align:middle line:84% What does he do with his long neck in his social behavior? 00:40:26.978 --> 00:40:29.520 align:middle line:84% What does he do with it in his feeding behavior and so forth? 00:40:29.520 --> 00:40:31.530 align:middle line:90% Or, why did it evolve? 00:40:31.530 --> 00:40:35.540 align:middle line:84% What makes it adaptive for the giraffe? 00:40:35.540 --> 00:40:39.125 align:middle line:84% How does it help him interact with his environment? 00:40:39.125 --> 00:40:42.940 align:middle line:84% Well of course, he could feed from tree branches. 00:40:42.940 --> 00:40:46.470 align:middle line:90% He's tall enough to do it. 00:40:46.470 --> 00:40:48.640 align:middle line:84% Well, what evidence for that is it? 00:40:48.640 --> 00:40:49.750 align:middle line:90% And how does it hurt him? 00:40:49.750 --> 00:40:51.062 align:middle line:90% What are the costs? 00:40:51.062 --> 00:40:54.270 align:middle line:84% There are a lot of difficulties of having such a long neck. 00:40:54.270 --> 00:40:58.760 align:middle line:84% So you do have to deal with some proximate issues 00:40:58.760 --> 00:41:02.490 align:middle line:84% because you want to deal with costs and benefits 00:41:02.490 --> 00:41:03.950 align:middle line:90% for that species. 00:41:03.950 --> 00:41:05.710 align:middle line:90% That's just an example. 00:41:05.710 --> 00:41:07.950 align:middle line:84% I want you to try to think in terms 00:41:07.950 --> 00:41:15.400 align:middle line:84% of both adaptive purpose when you ask why questions 00:41:15.400 --> 00:41:18.845 align:middle line:84% and with ethological details of the animal. 00:41:18.845 --> 00:41:21.560 align:middle line:90% 00:41:21.560 --> 00:41:24.300 align:middle line:84% If you have difficulty coming up with questions, 00:41:24.300 --> 00:41:26.820 align:middle line:90% please talk to us. 00:41:26.820 --> 00:41:31.620 align:middle line:84% You can always send me email, just propose some things. 00:41:31.620 --> 00:41:34.230 align:middle line:84% You can give me an example of the questions. 00:41:34.230 --> 00:41:37.200 align:middle line:84% But I think most of you are following these things 00:41:37.200 --> 00:41:38.340 align:middle line:90% in the class quite well. 00:41:38.340 --> 00:41:42.760 align:middle line:84% You know how we're doing it and the way Alcock covers it, 00:41:42.760 --> 00:41:47.980 align:middle line:84% the way Scott covers it, the way Lorenz talked about behavior. 00:41:47.980 --> 00:41:52.165 align:middle line:84% Try to find actual experiments testing the ideas. 00:41:52.165 --> 00:41:54.680 align:middle line:90% 00:41:54.680 --> 00:41:57.620 align:middle line:84% Now, there are journals of animal behavior, 00:41:57.620 --> 00:42:01.920 align:middle line:84% but these papers occur in other kinds of journals, too. 00:42:01.920 --> 00:42:05.320 align:middle line:84% So there's a journal called Animal Behavior. 00:42:05.320 --> 00:42:07.320 align:middle line:84% There's another one that's just called Behavior. 00:42:07.320 --> 00:42:09.870 align:middle line:84% They're two journals that deal only with this. 00:42:09.870 --> 00:42:11.845 align:middle line:84% But then you will find ornithology journals 00:42:11.845 --> 00:42:14.050 align:middle line:90% if you deal with birds. 00:42:14.050 --> 00:42:16.402 align:middle line:84% You'll find menology journals, and they'll [? even ?] 00:42:16.402 --> 00:42:17.110 align:middle line:90% include a little. 00:42:17.110 --> 00:42:19.640 align:middle line:84% You'll have behavioral ecology, which 00:42:19.640 --> 00:42:21.740 align:middle line:84% has a lot of-- if you just search 00:42:21.740 --> 00:42:23.670 align:middle line:84% under behavioral ecology, you can 00:42:23.670 --> 00:42:28.380 align:middle line:84% find where people are publishing specific journals that 00:42:28.380 --> 00:42:32.460 align:middle line:84% deal with the effects of usually behavior and environment 00:42:32.460 --> 00:42:33.140 align:middle line:90% interactions. 00:42:33.140 --> 00:42:36.870 align:middle line:84% But there's a lot relevant to sociobiology in such journals. 00:42:36.870 --> 00:42:41.100 align:middle line:84% If you just look at papers and the journals being cited 00:42:41.100 --> 00:42:45.125 align:middle line:84% by Alcock, for example, you'll get lots of examples of places 00:42:45.125 --> 00:42:46.950 align:middle line:90% to look. 00:42:46.950 --> 00:42:49.880 align:middle line:84% You can go to the library and look directly, 00:42:49.880 --> 00:42:53.670 align:middle line:84% or you can get on the library site, MIT library site, 00:42:53.670 --> 00:42:59.950 align:middle line:84% and pull up journals and scan them. 00:42:59.950 --> 00:43:01.210 align:middle line:90% That's one way to find them. 00:43:01.210 --> 00:43:05.000 align:middle line:84% Or you can just think of things you know about already, things 00:43:05.000 --> 00:43:08.260 align:middle line:84% you've heard in the class, things you've read about, 00:43:08.260 --> 00:43:12.610 align:middle line:84% especially in this class, and do your search. 00:43:12.610 --> 00:43:16.520 align:middle line:90% I don't want a neurophysiology. 00:43:16.520 --> 00:43:20.410 align:middle line:84% I don't want a strictly neuroscience paper. 00:43:20.410 --> 00:43:22.870 align:middle line:84% It's got be on the topics of the class. 00:43:22.870 --> 00:43:24.600 align:middle line:90% Use the principles in the class. 00:43:24.600 --> 00:43:27.980 align:middle line:84% And I spell that out in the instructions. 00:43:27.980 --> 00:43:32.280 align:middle line:84% I want you to be explicit about what you're 00:43:32.280 --> 00:43:34.780 align:middle line:90% talking about demonstrates. 00:43:34.780 --> 00:43:36.805 align:middle line:84% Interpret things in terms of these principles. 00:43:36.805 --> 00:43:41.720 align:middle line:90% 00:43:41.720 --> 00:43:47.660 align:middle line:84% So in one week then, we want to see a couple of topics. 00:43:47.660 --> 00:43:49.550 align:middle line:84% I know most of you will spend a lot of time 00:43:49.550 --> 00:43:50.560 align:middle line:90% on more than one topic. 00:43:50.560 --> 00:43:52.210 align:middle line:84% But in the course of your doing this, 00:43:52.210 --> 00:43:56.840 align:middle line:84% you'll probably discover which one you're more likely to do. 00:43:56.840 --> 00:44:00.060 align:middle line:84% Now if you do come up with two topics and you turn it in 00:44:00.060 --> 00:44:03.330 align:middle line:84% and then in the following time you have to prepare it, 00:44:03.330 --> 00:44:05.880 align:middle line:84% you decide to change your topic, please let us 00:44:05.880 --> 00:44:10.670 align:middle line:84% know because we might want to give you some feedback. 00:44:10.670 --> 00:44:14.970 align:middle line:84% And we will get busy and give you the feedback right away. 00:44:14.970 --> 00:44:19.520 align:middle line:84% We'll read all of these because we want 00:44:19.520 --> 00:44:21.710 align:middle line:90% to help you give good reports. 00:44:21.710 --> 00:44:26.160 align:middle line:84% You'll be graded on the PowerPoint presentation, not 00:44:26.160 --> 00:44:27.520 align:middle line:90% the oral presentation. 00:44:27.520 --> 00:44:29.940 align:middle line:84% But we like you to have the experience of giving it. 00:44:29.940 --> 00:44:32.330 align:middle line:84% The class would like to hear other reports. 00:44:32.330 --> 00:44:34.750 align:middle line:90% We'll divide into three classes. 00:44:34.750 --> 00:44:37.160 align:middle line:84% You'll be told which class to go to 00:44:37.160 --> 00:44:40.080 align:middle line:90% and where they're going to meet. 00:44:40.080 --> 00:44:42.590 align:middle line:90% I haven't figured that out yet. 00:44:42.590 --> 00:44:49.250 align:middle line:84% And when you make the PowerPoint, 00:44:49.250 --> 00:44:51.890 align:middle line:84% get familiar with PowerPoint if you've never used it, 00:44:51.890 --> 00:44:56.120 align:middle line:84% because we want pictures as well as words, pretty much the way 00:44:56.120 --> 00:44:58.410 align:middle line:90% I've done in the class. 00:44:58.410 --> 00:45:00.005 align:middle line:84% If you have videos, that's possible. 00:45:00.005 --> 00:45:04.130 align:middle line:90% 00:45:04.130 --> 00:45:08.490 align:middle line:84% And you won't get a chance to say everything 00:45:08.490 --> 00:45:10.480 align:middle line:90% in the oral report. 00:45:10.480 --> 00:45:12.310 align:middle line:84% You might want to present some background. 00:45:12.310 --> 00:45:16.240 align:middle line:84% Just use the Notes section slides-- 00:45:16.240 --> 00:45:18.750 align:middle line:84% things that you could bring up in a talk if the talk 00:45:18.750 --> 00:45:22.220 align:middle line:84% were longer, but you won't have time in your report 00:45:22.220 --> 00:45:25.435 align:middle line:84% here because you're limited to 12 minutes. 00:45:25.435 --> 00:45:28.430 align:middle line:90% 00:45:28.430 --> 00:45:31.170 align:middle line:84% To allow a little time for questions, 00:45:31.170 --> 00:45:33.410 align:middle line:90% 12 would be the maximum. 00:45:33.410 --> 00:45:36.070 align:middle line:84% I tell people to aim 10 to 12 minutes so you can leave 00:45:36.070 --> 00:45:38.210 align:middle line:90% a little time for questions. 00:45:38.210 --> 00:45:40.710 align:middle line:90% You don't have a lot of time. 00:45:40.710 --> 00:45:45.480 align:middle line:84% The problem here is coming up with a short enough report. 00:45:45.480 --> 00:45:50.730 align:middle line:84% So you can put extra information in those Notes section. 00:45:50.730 --> 00:45:52.440 align:middle line:84% But for the slides itself, come up 00:45:52.440 --> 00:45:54.770 align:middle line:84% with a talk that you can actually give, 00:45:54.770 --> 00:45:58.860 align:middle line:84% assuming there's four talks in a session. 00:45:58.860 --> 00:45:59.832 align:middle line:90%