Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
0
00:00:00,000 --> 00:00:01,020
PETER REDDIEN: Starting at the beginning,
1
00:00:01,020 --> 00:00:02,880
people have been trying to understand
2
00:00:02,880 --> 00:00:06,520
the principles of genetics for well over a century.
3
00:00:06,520 --> 00:00:10,080
And I think it's important to start at the beginning
4
00:00:10,080 --> 00:00:15,510
because there's some ambiguity to how traits are passed on.
5
00:00:15,510 --> 00:00:19,170
When you just look at the results of crosses,
6
00:00:19,170 --> 00:00:21,823
that require some sophistication to explain.
7
00:00:21,823 --> 00:00:24,240
OK, so there's things like Mendel's Peas, where everything
8
00:00:24,240 --> 00:00:27,150
looks nice and simple, but in real-world crosses,
9
00:00:27,150 --> 00:00:28,600
things look a lot more complex.
10
00:00:28,600 --> 00:00:32,040
Including for most of our traits,
11
00:00:32,040 --> 00:00:33,283
lots of diseases as well.
12
00:00:33,283 --> 00:00:34,950
All right, so I'm going to go into that,
13
00:00:34,950 --> 00:00:37,290
then we're going to start simple.
14
00:00:37,290 --> 00:00:39,690
So here's an example of this, all right,
15
00:00:39,690 --> 00:00:42,870
so if you cross a white Snapdragon
16
00:00:42,870 --> 00:00:45,360
with a red Snapdragon.
17
00:00:45,360 --> 00:00:47,310
The offspring look pink.
18
00:00:47,310 --> 00:00:51,630
All right, and so there's lots of examples of this.
19
00:00:51,630 --> 00:00:54,757
Where you take individuals or look at
20
00:00:54,757 --> 00:00:56,340
crosses that have happened in the wild
21
00:00:56,340 --> 00:00:58,500
with different species, and where
22
00:00:58,500 --> 00:01:01,488
there's some variation in some trait within individuals,
23
00:01:01,488 --> 00:01:03,030
and you look at the offspring, and it
24
00:01:03,030 --> 00:01:06,370
looks like blending or mixing of some kind.
25
00:01:06,370 --> 00:01:08,760
So this led to all kinds of blending ideas,
26
00:01:08,760 --> 00:01:12,490
mixing theories related to how genetics could be explained
27
00:01:12,490 --> 00:01:14,667
and heredity could be explained.
28
00:01:14,667 --> 00:01:16,500
Where you could imagine, there's some amount
29
00:01:16,500 --> 00:01:19,630
of substance, some substance in this white Snapdragon.
30
00:01:19,630 --> 00:01:21,630
Some other amount in this red substance and they
31
00:01:21,630 --> 00:01:24,450
inherit some part from both, and you get
32
00:01:24,450 --> 00:01:28,390
some kind of blended outcome.
33
00:01:28,390 --> 00:01:31,890
Similarly, if you look at human traits, like height,
34
00:01:31,890 --> 00:01:35,160
you'll see that it doesn't exist as we all intuitively know
35
00:01:35,160 --> 00:01:36,600
in discrete states.
36
00:01:36,600 --> 00:01:39,480
It's not that you're either tall or short.
37
00:01:39,480 --> 00:01:41,070
There's a continuum of heights if you
38
00:01:41,070 --> 00:01:43,000
look across a population.
39
00:01:43,000 --> 00:01:45,570
And if you look at the frequency distribution of people
40
00:01:45,570 --> 00:01:48,090
in a population and measure their height,
41
00:01:48,090 --> 00:01:52,560
that distribution will resemble a normal distribution.
42
00:01:52,560 --> 00:01:54,620
So how do we explain something like height?
43
00:01:54,620 --> 00:01:56,750
And you can have individuals that
44
00:01:56,750 --> 00:01:58,820
have offspring where one parent was tall,
45
00:01:58,820 --> 00:02:01,280
the other parent was short, and the offspring
46
00:02:01,280 --> 00:02:03,110
are not either tall or short but can
47
00:02:03,110 --> 00:02:06,080
be some intermediate height.
48
00:02:06,080 --> 00:02:10,520
So because lots of crosses if you look at it in biology
49
00:02:10,520 --> 00:02:14,090
and including in human pedigrees and looks
50
00:02:14,090 --> 00:02:16,850
like this for traits where there's this blending.
51
00:02:16,850 --> 00:02:19,010
Then it's very hard to try to come up
52
00:02:19,010 --> 00:02:23,420
with some clean, simple explanation for heredity.
53
00:02:23,420 --> 00:02:26,600
And we have to deal with this complexity
54
00:02:26,600 --> 00:02:28,633
when it comes to understanding biology
55
00:02:28,633 --> 00:02:30,050
and when it comes to understanding
56
00:02:30,050 --> 00:02:31,880
things like human disease.
57
00:02:31,880 --> 00:02:35,510
And we will, hopefully, give you a deep understanding
58
00:02:35,510 --> 00:02:37,660
of this in this class.
4471
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.
Afrikaans
Albanian
Amharic
Arabic
Armenian
Azerbaijani
Basque
Belarusian
Bengali
Bosnian
Bulgarian
Catalan
Cebuano
Chichewa
Chinese (Simplified)
Chinese (Traditional)
Corsican
Croatian
Czech
Danish
Dutch
English
Esperanto
Estonian
Finnish
Frisian
Galician
Georgian
German
Greek
Gujarati
Haitian Creole
Hawaiian
Hungarian
Icelandic
Indonesian
Irish
Italian
Japanese
Kazakh
Khmer
Korean
Kurdish (Kurmanji)
Kyrgyz
Lao
Latvian
Lithuanian
Luxembourgish
Macedonian
Malagasy
Malay
Maltese
Maori
Mongolian
Myanmar (Burmese)
Nepali
Norwegian
Pashto
Polish
Portuguese
Romanian
Russian
Samoan
Serbian
Sesotho
Shona
Sinhala
Slovak
Slovenian
Somali
Spanish
Swahili
Swedish
Tajik
Thai
Turkish
Ukrainian
Urdu
Uzbek
Vietnamese
