[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.38,0:00:03.47,Default,,0000,0000,0000,,- In an attempt to rescue\Na small isolated population
Dialogue: 0,0:00:03.47,0:00:05.32,Default,,0000,0000,0000,,of snakes from decline,
Dialogue: 0,0:00:05.32,0:00:06.59,Default,,0000,0000,0000,,a few male snakes
Dialogue: 0,0:00:06.59,0:00:08.35,Default,,0000,0000,0000,,from several larger populations
Dialogue: 0,0:00:08.35,0:00:10.65,Default,,0000,0000,0000,,of the same species were introduced
Dialogue: 0,0:00:10.65,0:00:13.34,Default,,0000,0000,0000,,into the population in 1992.
Dialogue: 0,0:00:13.34,0:00:15.73,Default,,0000,0000,0000,,The snakes reproduce sexually,
Dialogue: 0,0:00:15.73,0:00:18.70,Default,,0000,0000,0000,,and there are abundant\Nresources in the environment.
Dialogue: 0,0:00:18.70,0:00:20.49,Default,,0000,0000,0000,,The figure below shows the results
Dialogue: 0,0:00:20.49,0:00:22.75,Default,,0000,0000,0000,,of a study of the snake population
Dialogue: 0,0:00:22.75,0:00:25.15,Default,,0000,0000,0000,,both before and after the introduction
Dialogue: 0,0:00:25.15,0:00:26.91,Default,,0000,0000,0000,,of the outside males.
Dialogue: 0,0:00:26.91,0:00:30.39,Default,,0000,0000,0000,,In the study, the numbers\Nof captured snakes
Dialogue: 0,0:00:30.39,0:00:33.26,Default,,0000,0000,0000,,indicates the overall population size.
Dialogue: 0,0:00:33.26,0:00:36.99,Default,,0000,0000,0000,,So, let's look it, let's look\Nat this, at the study here,
Dialogue: 0,0:00:36.99,0:00:38.34,Default,,0000,0000,0000,,the data from the study.
Dialogue: 0,0:00:38.34,0:00:42.14,Default,,0000,0000,0000,,So 1989, they captured a bunch of snakes,
Dialogue: 0,0:00:42.14,0:00:43.66,Default,,0000,0000,0000,,the total snakes captured,
Dialogue: 0,0:00:43.66,0:00:47.02,Default,,0000,0000,0000,,but a small fraction\Nof them were juveniles.
Dialogue: 0,0:00:47.02,0:00:52.02,Default,,0000,0000,0000,,It looks like about five of\Nthe 19 snakes were juvenile
Dialogue: 0,0:00:52.03,0:00:54.85,Default,,0000,0000,0000,,and we see that the total\Npopulation seems to be declining.
Dialogue: 0,0:00:54.85,0:00:57.38,Default,,0000,0000,0000,,The total snakes captured,\Nwhich they say is a...
Dialogue: 0,0:00:58.87,0:01:01.40,Default,,0000,0000,0000,,is an indication of overall population.
Dialogue: 0,0:01:01.40,0:01:04.77,Default,,0000,0000,0000,,That that is declining, and\Nthen they introduced the males
Dialogue: 0,0:01:04.77,0:01:07.99,Default,,0000,0000,0000,,from the outside and then\Nit takes a couple years
Dialogue: 0,0:01:07.99,0:01:12.55,Default,,0000,0000,0000,,but then the population\Nseems to increase again.
Dialogue: 0,0:01:12.55,0:01:14.59,Default,,0000,0000,0000,,So, let's see what the questions are.
Dialogue: 0,0:01:14.59,0:01:17.80,Default,,0000,0000,0000,,Describe one characteristic\Nof the original population
Dialogue: 0,0:01:17.80,0:01:20.50,Default,,0000,0000,0000,,that may have led to\Nthe population's decline
Dialogue: 0,0:01:20.50,0:01:24.32,Default,,0000,0000,0000,,in size between 1989 and 1993.
Dialogue: 0,0:01:24.32,0:01:27.25,Default,,0000,0000,0000,,So, we can only theorize,\Nthey haven't told us a lot,
Dialogue: 0,0:01:27.25,0:01:29.95,Default,,0000,0000,0000,,they have told us it's a small population.
Dialogue: 0,0:01:29.95,0:01:32.16,Default,,0000,0000,0000,,So they say small and it's a small,
Dialogue: 0,0:01:32.16,0:01:35.70,Default,,0000,0000,0000,,isolated, small isolated population.
Dialogue: 0,0:01:35.70,0:01:38.31,Default,,0000,0000,0000,,So when you have a small\Nisolated population,
Dialogue: 0,0:01:38.31,0:01:40.40,Default,,0000,0000,0000,,some things can happen\Nthat are a lot less likely
Dialogue: 0,0:01:40.40,0:01:43.10,Default,,0000,0000,0000,,than if you have a large\Nun-isolated population.
Dialogue: 0,0:01:43.10,0:01:44.98,Default,,0000,0000,0000,,For example, you might have,
Dialogue: 0,0:01:44.98,0:01:47.33,Default,,0000,0000,0000,,actually I'll just answer it right here.
Dialogue: 0,0:01:47.33,0:01:49.26,Default,,0000,0000,0000,,You might have an uneven distribution
Dialogue: 0,0:01:49.26,0:01:51.49,Default,,0000,0000,0000,,of males, females so not enough males.
Dialogue: 0,0:01:52.40,0:01:56.50,Default,,0000,0000,0000,,Not enough males.
Dialogue: 0,0:01:56.50,0:01:57.76,Default,,0000,0000,0000,,That's less likely to happen if you
Dialogue: 0,0:01:57.76,0:01:59.30,Default,,0000,0000,0000,,have a really large population,
Dialogue: 0,0:01:59.30,0:02:01.05,Default,,0000,0000,0000,,but a small isolated population,
Dialogue: 0,0:02:01.05,0:02:03.90,Default,,0000,0000,0000,,well, you know, there's a\Nchance that you could skew
Dialogue: 0,0:02:03.90,0:02:06.72,Default,,0000,0000,0000,,one way or the other and if\Nyou don't have enough males
Dialogue: 0,0:02:06.72,0:02:08.21,Default,,0000,0000,0000,,you're not going to have\Nenough reproduction,
Dialogue: 0,0:02:10.18,0:02:11.73,Default,,0000,0000,0000,,you might have
Dialogue: 0,0:02:11.73,0:02:15.74,Default,,0000,0000,0000,,too few young snakes in their prime
Dialogue: 0,0:02:15.74,0:02:17.34,Default,,0000,0000,0000,,of their reproductive age,
Dialogue: 0,0:02:17.34,0:02:21.33,Default,,0000,0000,0000,,so, too, too few young,
Dialogue: 0,0:02:22.88,0:02:25.94,Default,,0000,0000,0000,,young reproducing snakes,
Dialogue: 0,0:02:25.94,0:02:28.84,Default,,0000,0000,0000,,reproducing snakes,
Dialogue: 0,0:02:28.84,0:02:30.83,Default,,0000,0000,0000,,and there could be a bunch of reasons why
Dialogue: 0,0:02:30.83,0:02:34.30,Default,,0000,0000,0000,,this maybe happened, maybe\Nthere was some type of
Dialogue: 0,0:02:34.30,0:02:36.87,Default,,0000,0000,0000,,calamity that happened, you know, in 1988,
Dialogue: 0,0:02:36.87,0:02:38.78,Default,,0000,0000,0000,,where a lot of the young snakes died
Dialogue: 0,0:02:38.78,0:02:40.94,Default,,0000,0000,0000,,or some type of a predator\Nand so all the snakes
Dialogue: 0,0:02:40.94,0:02:42.66,Default,,0000,0000,0000,,that are left are the ones that are older
Dialogue: 0,0:02:42.66,0:02:45.96,Default,,0000,0000,0000,,and they're not as viable\Nin terms of reproduction,
Dialogue: 0,0:02:45.96,0:02:48.35,Default,,0000,0000,0000,,but that's one possibility there.
Dialogue: 0,0:02:48.35,0:02:51.31,Default,,0000,0000,0000,,You could have some type\Nof, it's a small population,
Dialogue: 0,0:02:51.31,0:02:53.92,Default,,0000,0000,0000,,you could have, because of the lack,
Dialogue: 0,0:02:53.92,0:02:56.98,Default,,0000,0000,0000,,you could have a mutation\Nthat is just disproportionatly
Dialogue: 0,0:02:56.98,0:02:58.66,Default,,0000,0000,0000,,showing up in that population which makes
Dialogue: 0,0:02:58.66,0:03:00.59,Default,,0000,0000,0000,,it less likely to reproduce.
Dialogue: 0,0:03:00.59,0:03:03.77,Default,,0000,0000,0000,,So, mutation,
Dialogue: 0,0:03:05.40,0:03:08.50,Default,,0000,0000,0000,,mutation in population,
Dialogue: 0,0:03:09.56,0:03:11.51,Default,,0000,0000,0000,,that makes it less likely to reproduce.
Dialogue: 0,0:03:11.51,0:03:13.46,Default,,0000,0000,0000,,For the actual test, you\Njust have to describe
Dialogue: 0,0:03:13.46,0:03:15.14,Default,,0000,0000,0000,,one characteristic and these are
Dialogue: 0,0:03:15.14,0:03:17.36,Default,,0000,0000,0000,,all possible characteristics.
Dialogue: 0,0:03:17.36,0:03:19.88,Default,,0000,0000,0000,,Then in part b, they\Nsay, propose one reason
Dialogue: 0,0:03:19.88,0:03:21.92,Default,,0000,0000,0000,,that the introduction of the outside males
Dialogue: 0,0:03:21.92,0:03:24.69,Default,,0000,0000,0000,,rescued the snake population from decline.
Dialogue: 0,0:03:24.69,0:03:27.18,Default,,0000,0000,0000,,So, for part b, I'll do\Nthat right over here.
Dialogue: 0,0:03:27.18,0:03:30.07,Default,,0000,0000,0000,,Part b, well, if you had not enough males,
Dialogue: 0,0:03:30.07,0:03:34.44,Default,,0000,0000,0000,,introducing males, so it could re-balance,
Dialogue: 0,0:03:34.44,0:03:36.24,Default,,0000,0000,0000,,could re-balance
Dialogue: 0,0:03:38.41,0:03:40.47,Default,,0000,0000,0000,,male female ratio,
Dialogue: 0,0:03:40.47,0:03:44.72,Default,,0000,0000,0000,,male female ratio,
Dialogue: 0,0:03:44.72,0:03:47.52,Default,,0000,0000,0000,,it could have introduced\Nsome genetic diversity
Dialogue: 0,0:03:47.52,0:03:49.11,Default,,0000,0000,0000,,so you don't have the mutation,
Dialogue: 0,0:03:49.11,0:03:52.20,Default,,0000,0000,0000,,could introduce,
Dialogue: 0,0:03:53.28,0:03:57.14,Default,,0000,0000,0000,,introduce genetic diversity
Dialogue: 0,0:03:57.14,0:03:59.11,Default,,0000,0000,0000,,Once again this is a\Nsmall, isolated population,
Dialogue: 0,0:03:59.11,0:04:00.91,Default,,0000,0000,0000,,those are triggers in your heads, okay,
Dialogue: 0,0:04:00.91,0:04:03.06,Default,,0000,0000,0000,,there might not be a lot\Nof genetic diversity there.
Dialogue: 0,0:04:03.06,0:04:05.34,Default,,0000,0000,0000,,Introduce genetic diversity.
Dialogue: 0,0:04:08.14,0:04:10.54,Default,,0000,0000,0000,,The introduced male snakes\Nmight have been younger.
Dialogue: 0,0:04:10.54,0:04:11.77,Default,,0000,0000,0000,,So, could...
Dialogue: 0,0:04:12.93,0:04:13.83,Default,,0000,0000,0000,,introduce...
Dialogue: 0,0:04:16.20,0:04:17.04,Default,,0000,0000,0000,,younger,
Dialogue: 0,0:04:19.40,0:04:20.14,Default,,0000,0000,0000,,younger snakes.
Dialogue: 0,0:04:20.14,0:04:23.18,Default,,0000,0000,0000,,They didn't tell us whether\Nthe males from the outside,
Dialogue: 0,0:04:23.18,0:04:25.40,Default,,0000,0000,0000,,what age they were but\Nthese are just theories
Dialogue: 0,0:04:25.40,0:04:26.23,Default,,0000,0000,0000,,based on what they did tell us
Dialogue: 0,0:04:26.23,0:04:28.05,Default,,0000,0000,0000,,that that's one of the possibilities,
Dialogue: 0,0:04:28.05,0:04:29.75,Default,,0000,0000,0000,,and once again, you only\Nhave to describe one,
Dialogue: 0,0:04:29.75,0:04:31.55,Default,,0000,0000,0000,,so you could just say,\Ncould have re-balanced
Dialogue: 0,0:04:31.55,0:04:34.65,Default,,0000,0000,0000,,the male female ratio, and then part c,
Dialogue: 0,0:04:35.57,0:04:39.96,Default,,0000,0000,0000,,part c, describe how the\Ndata support the statement
Dialogue: 0,0:04:39.96,0:04:42.53,Default,,0000,0000,0000,,that there are abundant\Nresources in the environment.
Dialogue: 0,0:04:44.00,0:04:46.02,Default,,0000,0000,0000,,Well, you know, if you just saw this data
Dialogue: 0,0:04:46.02,0:04:47.96,Default,,0000,0000,0000,,you could have said, well\Nmaybe one of the reasons
Dialogue: 0,0:04:47.96,0:04:50.46,Default,,0000,0000,0000,,for even part a is that you\Ndidn't have abundant resources,
Dialogue: 0,0:04:50.46,0:04:53.41,Default,,0000,0000,0000,,but notice when you introduce\Nmales from the outside,
Dialogue: 0,0:04:53.41,0:04:56.24,Default,,0000,0000,0000,,now all of a sudden, the\Npopulation keeps increasing.
Dialogue: 0,0:04:56.24,0:04:58.87,Default,,0000,0000,0000,,So, the fact that the\Npopulation keeps increasing
Dialogue: 0,0:04:58.87,0:05:01.96,Default,,0000,0000,0000,,and actually goes above\Nwhere it was in 1989,
Dialogue: 0,0:05:01.96,0:05:03.08,Default,,0000,0000,0000,,well, that's a pretty good indication
Dialogue: 0,0:05:03.08,0:05:04.80,Default,,0000,0000,0000,,that you have abundant\Nresources, there's nothing
Dialogue: 0,0:05:04.80,0:05:07.14,Default,,0000,0000,0000,,that's putting a ceiling\Non this growth once you
Dialogue: 0,0:05:07.14,0:05:10.85,Default,,0000,0000,0000,,somehow fix the problem by\Nintroducing these outside males.
Dialogue: 0,0:05:10.85,0:05:13.67,Default,,0000,0000,0000,,So, I could say, population,
Dialogue: 0,0:05:14.82,0:05:16.14,Default,,0000,0000,0000,,population
Dialogue: 0,0:05:17.85,0:05:20.96,Default,,0000,0000,0000,,keeps growing
Dialogue: 0,0:05:22.77,0:05:25.99,Default,,0000,0000,0000,,from '93, or especially from '95,
Dialogue: 0,0:05:25.99,0:05:30.22,Default,,0000,0000,0000,,1995 onward, onward,
Dialogue: 0,0:05:30.22,0:05:33.22,Default,,0000,0000,0000,,wouldn't happen if we\Nhad limited resources,
Dialogue: 0,0:05:33.22,0:05:36.96,Default,,0000,0000,0000,,wouldn't have happened
Dialogue: 0,0:05:36.96,0:05:38.48,Default,,0000,0000,0000,,without abundant resources.
Dialogue: 0,0:05:38.48,0:05:39.60,Default,,0000,0000,0000,,Wouldn't have happened,
Dialogue: 0,0:05:42.30,0:05:43.28,Default,,0000,0000,0000,,happened...
Dialogue: 0,0:05:44.14,0:05:47.78,Default,,0000,0000,0000,,without abundant resources.
Dialogue: 0,0:05:49.40,0:05:53.66,Default,,0000,0000,0000,,Abundant resources.
Dialogue: 0,0:05:53.66,0:05:54.61,Default,,0000,0000,0000,,And we're done.