1 00:00:00,557 --> 00:00:03,065 (comical synthesized music) 2 00:00:03,065 --> 00:00:06,483 NARRATOR: They're extremely awkward on land... 3 00:00:09,102 --> 00:00:11,367 And not exactly graceful in the water. 4 00:00:13,142 --> 00:00:16,851 But there's something endearing about these egg-laying mammals. 5 00:00:17,415 --> 00:00:20,621 Platypuses can only be found in the rivers, streams, and lakes 6 00:00:20,621 --> 00:00:23,682 along the East Coast of Australia. 7 00:00:25,092 --> 00:00:28,729 But they range as far North as Northern Queensland, all the way down 8 00:00:28,729 --> 00:00:31,186 to the Southern island of Tasmania. 9 00:00:32,090 --> 00:00:34,601 That's quite a range for these little creatures. 10 00:00:34,601 --> 00:00:36,937 But there are gaps between populations. 11 00:00:36,937 --> 00:00:39,799 Large tracts of land between the rivers and lakes 12 00:00:39,799 --> 00:00:44,284 make it difficult for the platypuses to migrate from one area to another. 13 00:00:45,512 --> 00:00:47,183 Researchers believe it's possible 14 00:00:47,183 --> 00:00:50,851 that isolated pockets of animals could have evolved differently, 15 00:00:50,851 --> 00:00:53,708 could even be separate subspecies. 16 00:00:54,555 --> 00:00:59,118 The interesting things about platypus are that, as you come up the coast from Tasmania, 17 00:00:59,118 --> 00:01:01,528 they get smaller. 18 00:01:01,528 --> 00:01:05,999 As well as that, their body size is actually less in some of the Northern ones, 19 00:01:05,999 --> 00:01:08,360 so the maximum weight for one in this area 20 00:01:08,360 --> 00:01:12,957 is somewhere in the region of a kilogram, about two and a half pounds. 21 00:01:12,957 --> 00:01:17,444 Whereas they're around about three times that weight in Tasmania. 22 00:01:17,444 --> 00:01:20,614 NARRATOR: Stephen Kolomyjec from James Cook University 23 00:01:20,614 --> 00:01:25,960 is using genetic material to determine gene flow from one population to another. 24 00:01:25,960 --> 00:01:27,818 He examines the size and health 25 00:01:27,818 --> 00:01:30,419 of populations as well. 26 00:01:30,419 --> 00:01:36,230 What fascinates him the most are the differences between the Northern and Southern platypuses. 27 00:01:36,230 --> 00:01:39,666 The platypuses up here in North Queensland are about a third of the size of the ones down South, 28 00:01:39,666 --> 00:01:42,493 which is a pretty big size difference. 29 00:01:42,493 --> 00:01:45,604 It may be because of climate, but it may be because of actual differences 30 00:01:45,604 --> 00:01:47,708 in the species itself. 31 00:01:47,708 --> 00:01:51,131 BLAIR: Populations here are isolated from the populations in the South, 32 00:01:51,131 --> 00:01:54,753 so we're interested in looking at the effects of the gaps in the range, 33 00:01:54,753 --> 00:01:59,119 and especially this far North, and one of the tools that we're using to do that 34 00:01:59,119 --> 00:02:01,982 is population genetics. 35 00:02:05,666 --> 00:02:09,029 NARRATOR: Stephen and his colleague David Blair are working in some of the oldest 36 00:02:09,029 --> 00:02:11,796 rainforest in the world. 37 00:02:11,796 --> 00:02:13,100 KOLOMYJEC: This is Dirran Creek. 38 00:02:13,100 --> 00:02:17,337 It's a tributary of the North Johnstone River Catchment. 39 00:02:17,337 --> 00:02:21,475 It's one of the many Upland freshwater streams in North Queensland, 40 00:02:21,475 --> 00:02:24,311 and it's abundant in platypuses. 41 00:02:24,311 --> 00:02:28,468 NARRATOR: Collecting genetic samples from a platypus can be rather challenging. 42 00:02:28,468 --> 00:02:31,618 Special nets are carefully placed in the streams. 43 00:02:31,618 --> 00:02:35,434 They're not weighted down, so platypuses can swim up to the surface 44 00:02:35,434 --> 00:02:39,382 once they become entangled, to prevent drowning. 45 00:02:39,382 --> 00:02:43,297 With the nets in place, the team awaits until nightfall, when platypuses 46 00:02:43,297 --> 00:02:45,605 are more active. 47 00:02:45,605 --> 00:02:48,532 Then it's time to collect their subjects. 48 00:02:49,570 --> 00:02:56,543 Here's something most people might not be aware of: A platypus should always be held by its tail. 49 00:02:56,543 --> 00:02:58,933 Especially if it's a male. 50 00:02:58,933 --> 00:03:03,716 They're one of the few venomous mammals, with a spur on the hind foot 51 00:03:03,716 --> 00:03:06,317 capable of injecting some rather potent 52 00:03:06,317 --> 00:03:08,592 and painful venom. 53 00:03:08,592 --> 00:03:14,119 So gripping the fatty tail is best for the platypus and the handler. 54 00:03:14,119 --> 00:03:17,230 Now it's time to collect the necessary data. 55 00:03:17,230 --> 00:03:18,999 The platypus is weighed... 56 00:03:18,999 --> 00:03:19,600 KOLOMYJEC: 200. 57 00:03:19,600 --> 00:03:21,503 NARRATOR: And measured, both the body... 58 00:03:21,503 --> 00:03:22,246 KOLOMYJEC: 43. 59 00:03:22,246 --> 00:03:23,871 NARRATOR: And the sizable bill. 60 00:03:23,871 --> 00:03:25,032 KOLOMYJEC: 53. 61 00:03:25,032 --> 00:03:28,794 NARRATOR: The scientists extract samples of DNA. 62 00:03:28,794 --> 00:03:31,905 BLAIR: The principal samples that we're collecting for that is a small piece of skin 63 00:03:31,905 --> 00:03:35,415 from the toe web on the edge of the foot. 64 00:03:35,415 --> 00:03:39,486 That gives us enough DNA, when we take that back to the laboratory, 65 00:03:39,486 --> 00:03:42,819 to be able to do quite a lot of genetic analysis. 66 00:03:42,819 --> 00:03:47,928 In addition to that, we're collecting a little bit of toe skin to go to a laboratory in Adelaide, 67 00:03:47,928 --> 00:03:52,866 where researchers are making cell cultures, for further genetic work. 68 00:03:52,866 --> 00:03:54,601 They're interested in chromosome studies. 69 00:03:54,601 --> 00:04:00,140 They're interested in studies on the rather strange sex chromosomes that platypus have. 70 00:04:00,140 --> 00:04:05,379 Well, most mammals have an XY sex-determining system. 71 00:04:05,379 --> 00:04:09,568 Well, the platypus has gone rather a long way further than that. 72 00:04:09,568 --> 00:04:13,754 The platypus has five X chromosomes and five Y chromosomes. 73 00:04:13,754 --> 00:04:16,190 You can ask the question "Why?" 74 00:04:16,190 --> 00:04:18,392 I can't give you an answer. 75 00:04:18,392 --> 00:04:20,460 NARRATOR: Once the platypus is microchipped... 76 00:04:20,460 --> 00:04:21,094 KOLOMYJEC: There we go. 77 00:04:21,094 --> 00:04:24,198 NARRATOR: It's released back into the water. 78 00:04:24,198 --> 00:04:26,233 KOLOMYJEC: Just let him go gently. 79 00:04:26,233 --> 00:04:29,119 We hope to learn how much difference there is between Northern populations 80 00:04:29,119 --> 00:04:30,838 from Southern populations. 81 00:04:30,838 --> 00:04:33,740 Up here in the North, there are a few gaps where they just do not occur. 82 00:04:33,740 --> 00:04:36,510 And there are no historical records of them ever occurring in those areas. 83 00:04:36,510 --> 00:04:41,448 And so we're looking at what kind of effect these gaps have had on their genetic health. 84 00:04:41,448 --> 00:04:44,816 The actual species -- they might be very different, they might not be different. 85 00:04:44,816 --> 00:04:50,395 It depends on when the last platypus was able to cross these gaps. 86 00:04:51,491 --> 00:04:54,461 NARRATOR: If the smaller Northern platypuses are found to be genetically different 87 00:04:54,461 --> 00:05:00,200 from the Southern platypuses, they may be recognized as a newly identified subspecies, 88 00:05:00,200 --> 00:05:07,444 making them an even more unique version of one of the most unique animals on the planet. 89 00:05:11,380 --> 00:05:14,314 ANNOUNCER: Sponsored by National Geographic Mission Programs, 90 00:05:14,314 --> 00:05:17,050 taking science and exploration 91 00:05:17,050 --> 99:59:59,999 into the new millennium.