Nancyvarkey: Created page with "{|border=1 ||'''Time''' ||'''Narration''' |- ||00:01 ||Welcome to this tutorial on '''Natural Selection''', an interactive '''PhET simulation'''. |- ||00:08 ||In this '''tut..."

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Created page with "{|border=1 ||'''Time''' ||'''Narration''' |- ||00:01 ||Welcome to this tutorial on '''Natural Selection''', an interactive '''PhET simulation'''. |- ||00:08 ||In this '''tut..."

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{|border=1
||'''Time'''
||'''Narration'''

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||00:01
||Welcome to this tutorial on '''Natural Selection''', an interactive '''PhET simulation'''.

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||00:08
||In this '''tutorial''', we will demonstrate '''Natural Selection''', an interactive '''PhET simulation'''.

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||00:17
||Here, I am using: '''Ubuntu Linux Operating System''' version 16.04,

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||00:26
||'''Java''' version 1.8.0,

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||00:30
||'''Firefox Web Browser''' version 60.0.2.

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||00:35
||Learners should be familiar with biology and ecology.

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||00:41
||Using this '''simulation''', we will look at a population of rabbits for effects:

Of mutations and selection factors,

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||00:52
||Of environment,

On pedigree.

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||00:55
||Let us begin.

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||00:58
||'''Mutations'''-

Mutations are alterations in the '''nucleotide sequence''' of any genetic element.

They are passed onto offspring.

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||01:11
||Mutations may or may not change the observable traits or '''phenotype''' of an organism.

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||01:18
||Inheritance of mutations can be dominant or recessive.

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||01:25
||Use the given '''link''' to download the '''simulation'''.

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||01:30
||I have already downloaded the '''Natural Selection simulation''' to my '''Downloads folder'''.

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||01:37
||To open the '''jar file''', open the '''terminal'''. At the '''terminal prompt''', type: '''cd Downloads''' and press '''Enter'''.

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||01:48
||Type: '''java space hyphen jar space natural-selection_en.jar'''.

Press '''Enter'''.

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||02:03
||File opens in the '''browser''' in ''''html' format'''.

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||02:08
||This is the '''interface''' for the '''Natural Selection simulation'''.

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||02:13
||Observe the rabbit hopping in the '''simulation''' panel.

Click the '''Pause''' button at the bottom of the '''interface'''.

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||02:22
||Now we will explore the '''interface'''.

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||02:25
||The '''interface''' has '''Simulation''' panel;

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||02:29
||On the left side, '''Add Mutation''',

'''Edit Genes''',

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||02:35
||in the middle- '''Graph''',

'''Time until next generation''' progress bar,

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||02:42
||'''Play/Pause button, Step button''',

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||02:46
||on the right side, '''Selection Factor''',

'''Environment''',

'''Chart'''.

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||02:54
||Clicking on the '''Reset All button''' takes you back to the starting point.

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||02:59
||Let us keep the default settings: '''None''' for '''Selection Factor''',

'''Equator''' for '''Environment''',

'''Population''' for '''Chart'''.

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||03:11
||Observe the '''Population''' versus '''Time''' graph.

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||03:15
||It shows the number of rabbits along the y-axis and '''time''' on the x-axis.

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||03:22
||Click '''Play''' button at the bottom of the '''interface'''.

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||03:26
||In the graph, observe how the black line moves to the right.

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||03:31
||Keep clicking on the '''Step''' button to move the '''simulation''' along faster.

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||03:37
||If there are no rabbits left, you will see a ''''Game Over' pop-up box''' like this.

The text will read “'''All of the bunnies died!”'''

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||03:48
||Click on the '''Play Again''' button to resume the '''simulation'''.

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||03:53
||Click on '''Add a Friend''' to add another rabbit to the '''simulation'''.

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||03:58
||Click on '''Pause''' at the bottom of the interface.

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||04:03
||'''Generations of Progeny'''..

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||04:06
||Observe the '''label'''s on the right and Roman numerals on the left of each row.

Generation '''P''' is shown in row I (one).

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||04:17
||The '''F1''' generation in row II (two) is made up of the progeny or children of generation P.

And so on until row V (five).

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||04:30
||We will allow the population to grow until '''F3'''. This would be three steps after the mating pair.

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||04:41
||Click '''Play''' at the bottom of the interface.

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||04:45
||Note how the '''progress bar''' is full when a new generation begins.

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||04:52
||The '''progress bar''' starts moving to the left as a generation starts growing.

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||04:58
||Click '''Pause''' button.

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||05:01
||Click the second button at the top left corner of the graph to '''zoom out'''.

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||05:08
||You can now see the height of the next step.

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||05:12
||The black line shows the total number of rabbits in the graph.

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||05:17
||Under '''Selection Factor''', click the ''''Food' radio button'''.

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||05:22
||Under '''Add Mutation''', click the '''Long Teeth''' button.

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||05:27
||A text-box “'''Mutation coming'''” appears at the bottom of the '''simulation''' panel.

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||05:33
||Note the yellow triangle with the lightning inside.

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||05:37
||This indicates a '''mutation'''. You can see a picture of long teeth in the text-box.

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||05:45
||Under '''Edit Genes''', the rows next to the '''Teeth''' label have become active.

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||05:52
||The radio-buttons can now be clicked.

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||05:56
||For each row, two options appear under the '''Dominant''' and '''Recessive columns'''.

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||06:03
||To the left of each row, are the pictures of '''long''' and '''short teeth'''.

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||06:09
||Default selections are '''dominant mutation''' for '''long teeth''' and '''recessive''' for '''short teeth'''.

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||06:17
||Observe the '''progress bar''' and the graph after the '''mutation''' has been added.

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||06:22
||Let us allow the population to grow for another three generations after the mutation.

Keep clicking on the '''Step''' button.

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||06:33
||The interval between two narrow steps in the graph corresponds to a generation.

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||06:41
||Click on the second '''Zoom Out''' button in the graph until you see the steps.

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||06:47
||Observe how differently coloured lines appear in the graph after mutation and '''food''' selection.

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||06:56
||Note that the timing of mutations and selection factors will affect population growth.

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||07:03
||The legend below the graph gives the different colours and what they mean.

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||07:09
||We introduced a dominant mutation for '''long teeth'''.

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||07:14
||Let us look at the magenta line for long teeth, the olive line for short teeth.

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||07:23
||Initially, the olive line is above the magenta line.

The number of short-toothed rabbits is higher than that of the long-toothed rabbits.

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||07:36
||Later, the magenta line is above the olive line.

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||07:41
||The number of long-toothed rabbits has increased relative to the short-toothed ones.

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||07:49
||This means that long teeth help rabbits survive by eating the available food.

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||07:57
||'''Fur Mutation''': Set up conditions to study effects of a '''fur mutation''' on survival of rabbits.

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||08:06
||Keep '''brown fur''' as the '''dominant mutation''' and white fur as the recessive mutation.

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||08:13
||Choose '''wolves''' as the '''selection factor'''.

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||08:17
||Allow the population to grow for another 3 generations after the mutation.

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||08:25
||Observe how the wolves move in and out, killing the rabbits.

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|| 08:31
||Brown rabbits begin to appear after the mutation was introduced.

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|| 08:37
||Note that we are still looking at effects of the dominant long teeth mutation besides brown fur.

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||08:46
||Compare numbers of rabbits having white and brown fur in the graph and '''simulation''' panel.

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||08:55
||Initially, there are more white rabbits than brown rabbits.

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||09:02
||Later, the number of brown rabbits has increased relative to white ones.

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||09:10
||At the equator, with wolves killing the rabbits, brown fur is an advantage for survival.

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|| 09:18
||This strategy to blend with the environment is called '''camouflage'''.

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||09:24
||What can you say about the numbers of long and short-toothed rabbits?

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|| 09:31
||Sometimes a mutation changes the '''phenotype''' of all rabbits.

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|| 09:37
||If so, the graph will not compare the mutation versus the wild type (unmutated) phenotypes.

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|| 09:45
||Here, there are more long-toothed rabbits than short-toothed ones.

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||09:53
||'''Tail Mutation'''-

Set up conditions to study effects of a tail mutation on survival of rabbits.

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|| 10:02
||Keep long tail as the dominant mutation and short tail as the recessive mutation.

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|| 10:09
||Choose '''wolves''' as the '''selection factor'''.

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|| 10:13
||Allow the population to grow for another 3 generations after the mutation.

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||10:20
||Keep clicking on the '''Step''' button to move the '''simulation''' along faster.

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||10:28
||Click on the 2nd '''Zoom Out''' button.

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||10:31
||Note the number of rabbits with brown fur, long teeth and short tails.

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|| 10:38
||It is higher than that of rabbits with white fur, short teeth and long tails.

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||10:49
||Brown fur and short tails help escape from wolves.

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|| 10:55
||Long teeth help survival by making it easier to eat vegetation.

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||11:01
||Under '''Chart''', click '''Pedigree'''.

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||11:04
||Note the text, “'''Click a Bunny'''” at the top.

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|| 11:08
||Let us click on the rabbit at the left bottom corner of the '''simulation''' panel.

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|| 11:16
||Observe how the selected rabbit is framed inside a blue rectangle.

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||11:22
||The '''pedigree chart''' appears for the rabbit framed in the blue rectangle.

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||11:28
||Click on the top right '''button''' in the '''Pedigree''' window.

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||11:33
||The '''Pedigree''' window is separated and the '''Population''' chart appears behind it.

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|| 11:41
||We can now '''resize''' the '''Pedigree''' window.

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||11:46
||Note the color of the previous four generations of rabbits above the selected rabbit.

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|| 11:54
||Red crosses on the rabbits indicate that they are dead.

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|| 11:59
||The yellow triangle with the lightning symbol inside indicates a mutation.

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|| 12:06
||It shows that that rabbit underwent a mutation; so its '''genotype''' and '''phenotype''' changed.

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||12:14
||'''Pedigree''' analysis allows study of inheritance of '''gene'''s based on data about phenotypes.

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||12:23
||Click repeatedly on the '''Step''' button.

Rabbits can be seen all over the continents on the planet Earth.

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||12:33
||Observe the caption, “'''Bunnies have taken over the world!'''”

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|| 12:38
||These are the long-term effects of the '''simulation''' under these conditions.

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||12:44
||Do refer to '''Additional material''' provided with this '''tutorial'''.

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||12:50
||Let us summarize.

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||12:52
||In this tutorial, we have demonstrated how to use the '''Natural Selection PhET simulation'''.

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||13:00
||Using this '''simulation''', we looked at a population of rabbits for effects:

Of mutations and selection factors,

Of environment,

On pedigree.

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||13:13
||As an '''assignment'''-
observe the rabbits: for effects of mutations and selection factors in '''Arctic''' environment.

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|| 13:23
||After switching mutations from '''dominant''' to '''recessive''' and vice versa.

For changes in '''pedigree''', under different conditions.

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||13:34
||The video at the following link summarizes the '''Spoken Tutorial project'''.

Please download and watch it.

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||13:43
||The '''Spoken Tutorial Project '''team conducts workshops using '''spoken tutorials''' and gives certificates on passing '''online''' tests.

For more details, please write to us.

|-
||13:55
||Please post your timed queries in this forum.

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||13:59
||This project is partially funded by '''Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching'''.

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||14:08
||'''Spoken Tutorial Project''' is funded by '''NMEICT, MHRD''', Government of India.

More information on this mission is available at this link.

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||14:21
||This is '''Vidhya Iyer''' from '''IIT Bombay''', signing off.

Thank you for joining.
|-
|}

PhET/C3/Natural-Selection/English-timed - Revision history

Nancyvarkey: Created page with "{|border=1 ||'''Time''' ||'''Narration''' |- ||00:01 ||Welcome to this tutorial on '''Natural Selection''', an interactive '''PhET simulation'''. |- ||00:08 ||In this '''tut..."