0:04 [Music] hello
0:05 hello
0:07 it's ranger olivia here and in the last
0:09 video we talked about traits
0:11 and today we are going to talk about
0:13 what happens to an animal's traits
0:15 when their environment changes as we
0:16 said before
0:17 animals get their traits from their
0:20 parents but they're also shaped by the
0:21 environment around them
0:23 so what do you think happens when the
0:29 let's take a simple example first say
0:30 that you went
0:32 camping and it was really sunny when you
0:33 left but then it rained
0:35 since it was sunny when you left you
0:37 didn't pack a rain jacket
0:39 and you got soaked the next time you go camping
0:40 camping
0:42 even if it's sunny outside when you
0:44 leave you will hopefully learn something
0:44 from the first
0:48 experience and pack a rain jacket let's
0:49 say that it rains almost
0:52 every time you go camping now how would
0:54 you adapt to the situation
0:55 would you check the weather before you
0:58 leave get better rain gear or pack more
1:00 gear to keep your things dry
1:02 you might even move camping sites in
1:05 hopes for a drier experience
1:06 now let's say that when you grow up you
1:09 have kids and you teach them to always
1:12 be prepared for rain on camping trips
1:14 then they have kids and they tell them
1:15 to always be prepared for rain on
1:16 camping trips
1:19 and so on and so forth now you have
1:21 multiple generations of prepared
1:24 campers well this is a very simple
1:28 and light example this happens in real
1:30 life with animals physical and
1:31 behavioral traits
1:33 over generations so it takes quite a bit
1:34 of time
1:36 these changes and traits help species
1:38 better survive
1:40 in new environments but sometimes if
1:41 they don't
1:44 adapt quickly enough or well enough it
1:46 can be a matter of life or death
1:48 let's look at a real-life example to
1:50 better understand this
1:53 in the 1800s researchers in england were
1:54 collecting moths
1:56 called peppered moss there were two
1:58 different types of these moths one type
1:59 was light gray
2:01 peppered with black spots and the other
2:03 type was much darker in color
2:05 peppered with white spots they noted
2:07 that most of the moss they collected in
2:09 the study were light-colored type
2:11 then many years later they collected a
2:13 new batch and noted that this time
2:15 most of the moss they collected were the
2:16 darker colored type
2:18 they decided to dig a little deeper and
2:20 found the dark colored moths
2:22 were actually a gene mutation in the dna
2:24 of the light-colored moss
2:27 once a mutation was present dark-colored moths
2:28 moths
2:31 would produce dark-colored offspring it
2:32 could have stopped there
2:33 but it didn't quite explain why
2:35 researchers were now finding more dark
2:36 colored moss
2:40 so they dug even deeper it turns out
2:42 it had to do with their changing environment
2:43 environment
2:45 during the 1800s europe and america were
2:48 experiencing the industrial revolution
2:50 which basically meant we could build
2:53 things faster by building factories
2:55 while this sounds nice factories caused
2:56 a lot of air pollution
2:59 and was responsible for releasing large
3:01 amounts of smoke and smog into the environment
3:02 environment
3:04 it was so much smog that it left a layer
3:06 of black suit
3:09 on once lighter colored trees moths rest
3:11 on trees during the day
3:13 and do most of their flying at night you
3:16 may now see where the story is going
3:19 as the trees became darker with suit the
3:21 light-colored moths became easier to see
3:25 which made them easier prey for birds
3:26 the dark-colored moths that now blended
3:28 in with the trees better
3:31 survive longer this gave them a better
3:32 chance of producing
3:34 offspring with their same dark colored jeans
3:35 jeans
3:38 over time the dark-colored moth became
3:39 the more common
3:42 of the two color forms what's even more
3:44 amazing is that after the clean air act
3:46 had passed in 1950
3:48 the air cleared up and the trees became
3:50 lighter again guess what happened
3:52 now the light-colored peppered moss has
3:54 been the more common in the population
4:00 because it is better camouflaged
4:02 this story shows you that animals best
4:04 suited for a particular environmental change
4:04 change
4:07 will have a better chance for survival
4:08 and thus a better chance of passing on
4:11 their traits to the next generation
4:14 but what it also might show you is that
4:16 variations of traits within different populations
4:17 populations
4:20 make a population stronger because the
4:22 environment changes frequently
4:24 and different traits might be better in
4:25 different circumstances
4:27 what would have happened if the peppered
4:29 moths did not have a genetic
4:32 mutation that made their wings dark
4:35 if a population has the same traits and
4:36 no genetic differences
4:38 then when something changes in their
4:40 environment they may not be able to
4:41 overcome it as well
4:44 or maybe not even at all let's turn to a
4:48 more recent example for this explanation
4:50 if you don't know about the emerald ash
4:52 borer already you should
4:54 it is an invasive species of beetle that
4:56 is found in eastern russia northern
4:58 china japan and korea and before june 2002
4:59 2002
5:02 it had never been found in america it
5:04 feeds specifically on ash trees
5:06 it burrows in the cambium layer of the
5:08 bark to lay its eggs
5:10 when the eggs hatch their larvae eat
5:12 this cambium layer or the living layer
5:13 of the bark
5:14 essentially starving the tree of
5:16 everything it needs to survive and
5:17 eventually killing it
5:19 it's not such a big problem in places
5:21 that this bug has always lived
5:22 because this bug has always been there
5:24 for thousands of years other animals
5:26 have lived alongside it and developed a
5:27 taste for it
5:28 in other words they have natural
5:31 predators in asia but since they are new here
5:31 here
5:33 the animals here that know nothing about
5:35 this bug haven't really grown a taste
5:36 for it
5:38 so it doesn't have any natural predators
5:40 and it goes unchecked
5:42 this is a real problem for the ash trees
5:45 that are declining at an alarming rate
5:47 scientists are working feverishly trying
5:48 to find a solution
5:50 but so far the solutions they have found
5:52 to treat the trees are not cost
5:54 effective enough to be practiced on
5:56 millions of trees throughout the us
5:57 one of the biggest hopes is that
5:59 somewhere out there there are some ash
6:01 trees that have a genetic mutation
6:03 that allows them to be safe from the
6:04 emerald ash borer
6:06 hopefully they will produce more seed
6:07 and eventually trees
6:10 that will also be safe we really don't
6:11 know about the future of these trees in
6:12 our forest
6:14 but in the meantime we can stop the
6:16 spread of this species and many other
6:17 invasive species
6:19 by not traveling with firewood and
6:21 always thoroughly cleaning camping gear
6:24 before going into another forest [Music]
6:26 [Music]
6:28 so to recap traits come from your parents
6:29 parents
6:31 but they are also shaped by the
6:33 environment around you
6:35 animals that have the best suited traits
6:37 for an environmental change
6:39 are better able to survive and thus pass
6:42 their traits on to the next generation
6:44 and populations that have many genetic variations
6:45 variations
6:48 are stronger because they are better
6:49 able to adapt to the environmental changes
6:51 changes
6:53 i hope you enjoyed this video and
6:54 learned something new
