0:03 hello again ABS 470 online students
0:06 Professor Jared rathel here and I wanted
0:08 to start by thanking you for rejoining
0:13 me for lecture 1.2 so today I pose the
0:17 question why even bother studying
0:19 mammals and I'm going to make the
0:24 argument that although they are few in
0:27 number relative to like arthropods in
0:30 the system they can have highly
0:33 influential roles in structuring
0:36 ecological communities
0:41 were dependent upon mammals for food for
0:46 dairy for fiber for biomedical models next
0:48 next
0:50 if we ignore
0:54 the impacts of the mammals around us
0:58 I believe we do so at our own peril
1:00 and then lastly
1:02 we're mammals
1:05 so my biggest Hope For You in taking
1:09 this class is that you have a richer
1:12 understanding of homo sapiens of what we
1:19 so the first big idea that I want you to
1:22 gather from this lecture is that mammals
1:25 although their populations are
1:28 considerably smaller than other life
1:30 forms in the ecosystem like plants or
1:33 invertebrates they're going to form
1:37 these critical links in both terrestrial
1:39 and Aquatic systems like you can see
1:42 here so for example
1:47 African elephants by knocking over some
1:50 trees and then denuding others of leaves
1:53 and branches they're going to maintain
1:56 the grasslands within which they live by
1:59 keeping the trees at Bay and the
2:01 Savannah open
2:04 further elephants are going to eat
2:08 copious amounts of food and then uh drop
2:12 large bombs like you can see on the left
2:16 but that elephant feces is incredibly
2:20 nutrient Rich okay and they're going to
2:22 drop it sometimes kilometers tens of
2:24 kilometers from where they consumed it
2:28 so it's an important part in the cycling
2:31 of nutrients and there's been good
2:33 evidence that suggests when elephants
2:37 are present in African savannas as well
2:39 as in Southeast Asia they're going to
2:43 structure plant communities
2:46 similarly the presence of prairie dogs
2:48 right here in the desert Southwest is
2:51 associated with communities with higher
2:53 plant biodiversity
2:55 and then finally on the bottom right
2:59 here when whales massive whales die and
3:01 the carcasses sink to the sea floor
3:04 they're going to provide this ecological
3:09 succession this feeding Bonanza for rat
3:13 fish and hagfish and deep water sharks
3:15 so we're going to return to community
3:19 ecology specifically keystone species
3:22 like the sea otter here that's munching
3:25 on sea urchins keeping sea urchin
3:28 populations in check and maintaining the
3:30 health of those kelp forests we're going
3:32 to come back to sea otters and keystone
3:36 species in week six
3:40 beavers on the right here are considered
3:45 ecosystem Engineers so by slowing Rivers
3:49 down with their dams they create these
3:52 vital Wetlands they create habitat for
3:56 fish and Aquatic macroinvertebrates amphibians
3:58 amphibians
4:02 the insects uh they become really
4:05 abundant in all of those snags right
4:08 around the wetlands and so again we're
4:10 returning to a community ecology trust
4:12 me it's it's fun
4:16 um at a later date which brings us to
4:20 canis lupus here on the bottom left and
4:24 service olathes the gray wolf and the
4:27 elk of Yellowstone National Park and
4:29 your first discussion prompt
4:33 so gray wolves were part of the natural
4:36 ecosystem in Yellowstone National Park
4:40 but were deliberately exterminated uh
4:43 there as well as throughout much of the
4:47 uh contiguous 48 states in the 1920s you
4:49 guys probably know the story they were
4:52 trapped they were poisoned they would
4:54 pop where they go in and kill the pups
4:55 in the den
4:58 so my question to you is how would you
5:01 expect this extermination this removal
5:06 to affect ecosystem functions
5:10 so I want your initial discussion uh
5:14 response your comments to be concise
5:17 like peer-reviewed journals that's the
5:19 style we're aiming for they need to be
5:21 less than 300 words they need to
5:24 describe your conclusions present the
5:27 evidence or reasoning involved that
5:31 helped you get to that end point and
5:33 lastly I want a sentence or two
5:37 connecting your conclusions to content
5:39 in this course either from these
5:41 lectures or from your textbook readings
5:43 or your activities
5:47 and then you'll be randomly assigned a
5:50 colleague's discussion post and in less
5:53 than 200 words I want you to tell them
5:56 in a response what you liked what
5:59 they've done well uh feedback on what
6:02 they may have missed
6:04 um or maybe didn't elaborate well on
6:07 didn't Express well and then anything
6:10 you may have learned in Reading their post
6:11 post
6:14 so before you complete your initial post
6:16 don't forget to check out the resources
6:19 that are on canvas including an amazing
6:21 video it's been remastered it's called
6:25 how wolves change Rivers as well as the
6:29 famed or inFAMOUS Ripple and bashetta
6:32 it's often cited publication in
6:35 biological conservation so obviously
6:38 many of us are dependent upon mammals
6:43 for meat so think uh cattle
6:48 pigs lamb the Sami have their reindeer
6:51 or on the bottom right rabbits as well
6:57 as for dairy so again cows goats wool so
7:01 I think sheep and alpaca and lastly
7:03 Transportation right those Cowboys are
7:05 riding horses
7:07 if you've gone down into the Grand
7:10 Canyon or maybe have a super high you
7:13 may have caught a ride on a mule or had
7:18 a mule carry your stuff the Bedouin in
7:22 Arabia are riding on their camels the
7:24 Sami had been known to hook their
7:27 reindeer up to sleds so interestingly
7:31 it's hypothesized uh that goats which
7:32 were the first ungulate to be
7:35 domesticated it's thought dogs were the
7:37 first animal to be domesticated and
7:39 we'll talk about them on the next slide
7:42 but the goats were
7:45 the evidence suggests that goats were
7:48 domesticated about 10 000 years ago in
7:52 the zargos mountains and what is today
7:57 present-day Iran uh another interesting
8:00 factoid for you uh today an average
8:03 sized slaughterhouse in the United
8:16 so obviously uh mammals such as dogs and
8:22 cats ferrets my kids both have dwarf
8:25 hamsters they've clearly become our
8:29 companions right so we derive uh
8:32 pleasure from spending time uh with
8:34 these other species
8:36 an interesting study came out a few
8:40 years ago that measured oxytocin levels
8:45 and so uh when a human Companion Pets
8:49 his dog both the human and the dog get a
8:52 little jolt a little Spike of oxytocin
8:56 which is the feel-good pro-social hormone
8:58 hormone
9:01 so quite frankly I mean let's admit it
9:04 some dogs live such a Pampered existence
9:06 that you have to ask who is
9:09 domesticating who
9:13 okay so rodents have served as an
9:17 important biomedical research model for
9:19 over a century now because of their anatomical
9:20 anatomical
9:23 physiological and genetic similarity to
9:26 us to humans as well as their small size
9:30 the ease and cheapness of maintaining
9:32 rodent cultures as well as their short
9:34 life cycle and they produce lots of
9:38 young so early on researchers were able
9:42 to select and breed for certain lines
9:44 that Express traits associated with disease
9:45 disease
9:49 today it's relatively straightforward to
9:51 manipulate the mouse genome using crispr
9:55 to model diseases caused by gene mutation
9:56 mutation
10:00 so the mus musculus the house mouse
10:04 genome was first published in December
10:07 2002. and
10:09 that brings us to your second assignment
10:12 built into this lecture uh your first
10:15 primary literature summary
10:20 so we know that three-toed sloths carry
10:24 an incredible diversity of micro and
10:28 macro organisms in their coarse outer
10:31 hair so this is all algae here growing
10:34 in their hair along with a whole bunch
10:38 of microbes and protists and fungi
10:42 so conserving rain forests in Panama and
10:47 Costa Rica where these mall sloths are
10:50 distributed May in the long run be
10:53 greatly beneficial to us right
10:56 conserving these areas is going to help
10:59 us because they represent
11:02 repositories for these wondrous
11:05 compounds that can we can exploit
11:08 so they're uh in this study it talks
11:11 about 50 strains of fungi that were
11:15 cultured from a sloth back hair of which
11:19 20 had antibiotic properties
11:22 okay so I want you to to uh read this
11:24 primary literature article and remember
11:27 when reviewing primary literature for
11:30 abs 470 I want you to focus really on
11:33 that abstract the introduction as well
11:37 as the discussion sections please don't
11:40 get mired down in the methodologies okay
11:44 particularly in the uh statistics okay
11:47 again I want your summaries to be terse
11:50 and direct just like a peer-reviewed
11:52 journal just like your discussion posts
11:55 and I've got further directions that are
11:57 on canvas so next I want you to
12:01 recognize that mammals can be disease
12:06 reservoirs or even vectors so causing
12:10 disease transmitting diseases to us
12:15 bats are the leading cause of rabies in
12:16 the United States
12:20 researchers in China have posited that
12:24 it may have been a Pangolin a trafficked
12:27 Pangolin in a wet Market
12:29 that initially spread the novel
12:34 coronavirus covid-19 to humans
12:40 prions or Rogue proteins in infected
12:43 animal flesh so consuming prions can
12:46 cause rare but very serious
12:49 neurodegenerative disorders in humans
12:53 and then of course there are the rodents
12:55 so infected fleas living on ground
12:59 squirrels can Vector the plague deer
13:01 mice and cotton rats are going to shed
13:05 the deadly hantavirus in their urine and
13:11 [Music]
13:15 furthermore mammals can be incredibly
13:20 destructive as non-native invasive species
13:21 species
13:26 particularly on Islands so the Mongoose
13:29 which you see here on the left
13:33 um with the uh blood red uh mouth there
13:35 was introduced to the Hawaiian Islands in
13:37 in
13:40 1872. they purposefully brought Mongoose
13:43 over in an attempt to control rats
13:48 invasive rats and preserve or maximize
13:52 sugar cane yields you've probably heard
13:54 this story you may know it didn't work
13:58 out so well so rats are nocturnal
14:01 Mongoose are diurnal so instead of
14:05 eating rats the Mongoose primarily began
14:08 voraciously consuming uh the eggs of
14:10 ground nesting birds as well as the
14:13 birds themselves themselves as well as a
14:16 sea turtle eggs
14:20 on the uh right here
14:25 below right we see a feral cat that is
14:30 preying upon a native marsupial in
14:32 Australia so of course uh felids are
14:36 placental mammals they did not evolve uh
14:39 in Australia the only naturally
14:42 occurring placental is the dingo that
14:45 probably recently uh colonized Australia
14:49 from Indonesia so feral cats really have
14:50 no business being there and they have decimated
14:51 decimated
14:54 wallaby populations rabbits are another
14:59 huge issue in Australia
15:03 so important idea here to study
15:07 mammology today is to study conservation biology
15:08 biology
15:10 so of the
15:15 6500 species of modern mammals that have
15:16 been identified
15:20 approximately one in five are already
15:23 gone or are threatened or in danger in
15:25 serious decline
15:26 so you may have seen these
15:29 heart-wrenching photos on the left from
15:33 National Geographic this is Sudan the
15:38 last male Northern white rhinoceros last
15:40 male it's a sexually reproducing species
15:42 there's two females left I believe but
15:46 it essentially guarantees Extinction so
15:49 rhinos have been hammered by poaching
15:54 the horns are very valuable in Chinese
15:56 markets for the use in traditional medicines
15:58 medicines
16:00 which is particularly infuriating
16:03 because Rhino horn is made from the
16:06 super abundant protein keratin same
16:09 stuff that makes up your fingernails
16:13 on the right is the vaquita or the
16:15 little sea cow or the panda porpoise
16:18 which lives right south of us in the sea
16:19 of Cortez
16:22 this little guy is on the knife's edge
16:25 of Extinction so there's probably 30 or
16:28 less of them left so if you haven't seen
16:30 it already I would highly encourage you
16:35 to check out the movie Sea Of Shadows so
16:38 my colleague and friend Rue Mahoney was
16:41 the field director for this movie
16:44 Leonardo DiCaprio paid for it anyways
16:46 it's an eye-opening film also it's a
16:49 it's a tear-jerker and the final reason
16:53 why we should be studying mammals is
16:55 because we're mammals
16:58 so there are approximately 7.5 billion
17:01 of us on planet Earth that's billion
17:04 with a B demographers estimate that our
17:08 population will hit 9 billion and 2050
17:11 and top out at carrying capacity let's
17:17 hope between 11 and 13 billion and 2100.
17:20 so humans are now the fundamental
17:23 drivers of
17:26 eco-evolutionary processes on planet
17:29 Earth so much so that conservation biologists
17:31 biologists
17:34 geologists and demographers most of them
17:39 now agree that we've left the relatively
17:43 stable Epoch the Holocene within which
17:47 modern agriculture evolved and we've
17:51 entered a new epoch the age of humans
17:54 the anthropocene
17:57 so in short it is a really important
18:03 many thanks for listening to the lecture
18:08 and please reach out to me if you want to
18:08 to
18:12 exchange emails or a video conference
18:14 and discuss any of these Concepts in
18:16 Greater detail okay I'll see you next
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