I don't mean it in a bad way sir but you explain way better in the comment section. If you consider including written notes in your videos I am sure your channel will get more recognition in terms of views etc Thank you and much love
Calculations depends on the problem. For example A1=2 cm A2=1 cm. A cross A1A2 xA1A2 will result in 1/4 A1A1 - 4 cm; 1/2 A1A2 - 3 cm; and 1/4 A2A2 - 2 cm.
@@GeneticsLessons why only NSH? BSH can be used to analyze influence of the environment on the phenotype among monozygotic twins. Further this knowledge can be applied in the medicine. Am I right?
does "total phenotypic variance" means variance in phenotype of one trait? or is it variance in phenotype of all traits given (ex if variance in arm length and leg length given)
Thank you so much for your video. This is my layman understanding...dominance and epistasis overshadow the effects of a gene. This overshadowed gene wants to contribute in some way, so it adds a little effect to the phenotype...though small it adds up and contributes to the effect of dominance and epistasis. This additive effect is observable for all genes that contribute to the phenotype of that trait, whether dominant or recessive. Hence, narrow sense is the more practical equation to use. My question is, how do you assess and quantify the additive effect? Would love your feedback...geneticists are pretty non-existent in my country.
Ohh THANK YOU VERY MUCH sir......finally I understand.... Which measures of heritability (broad/narrow)will be appropriate for selection in a mixture of homozygous line and for segregating generations..and How?
Most traits are polygenic, meaning more than one gene contributes to their phenotypes. In this case, an individual inherits multiple copies of each allele, rather than inheriting one copy of each allele, from each parent. So, when a trait is polygenic, the alleles are additive.
Broad-sense heritability (H^2) and narrow-sense heritability (h^2) are both measures of the proportion of phenotypic variation in a trait that is due to genetic variation. However, they are different in terms of how they define and estimate the genetic components of this variation. Broad-sense heritability is defined as the proportion of total phenotypic variance that is due to genetic variance, regardless of whether that variance is due to additive, dominant, epistatic, or other genetic effects. Broad-sense heritability can be estimated using a variety of statistical methods, such as analysis of variance (ANOVA) or parent-offspring regression. Narrow-sense heritability, on the other hand, is defined as the proportion of total phenotypic variance that is due to additive genetic variance only. This means that it only considers the effects of genetic factors that are passed down from parents to offspring in a predictable and linear manner. Narrow-sense heritability can be estimated using methods such as the half-sib correlation or the full-sib regression. In general, broad-sense heritability is always equal to or greater than narrow-sense heritability. This is because broad-sense heritability includes all genetic variation, including non-additive effects, while narrow-sense heritability only includes additive effects. Therefore, it is unlikely that the two heritability measures would be exactly the same. However, there may be rare cases where broad-sense and narrow-sense heritability are very similar, particularly if the non-additive genetic effects are very small or negligible. In practice, the two measures are often used together to provide a more complete understanding of the genetic basis of a trait and to guide breeding and selection strategies.
A group of 4 month old hogs has an average weight of 76kg. The average weight of selected breeders is 84kg. If narrow sense is 40%. What is expected average weight of first generation of progeny after selection?
Heritability. ... The broad-sense heritability is the ratio of total genetic variance to total phenotypic variance. H2 = VG/VP. The narrow-sense heritability is the ratio of additive genetic variance to the total phenotypic variance. In scientific terms, heritability is a statistical concept (represented as h²) that describes how much of the variation in a given trait can be attributed to genetic variation. Broad-sense heritability refers to the portion of total phenotypic variation which is explained through total genetic variance, while narrow-sense heritability on the other hand refers only to the portion which is explained through use of additive genetic variance.
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I don't mean it in a bad way sir but you explain way better in the comment section. If you consider including written notes in your videos I am sure your channel will get more recognition in terms of views etc
Thank you and much love
Nikolai, for the additivity with A being 2cm and a being 1cm, won't they have 1 cm or 1.5 cm children? Why is it 3cm?
Calculations depends on the problem.
For example A1=2 cm A2=1 cm.
A cross A1A2 xA1A2 will result in 1/4 A1A1 - 4 cm;
1/2 A1A2 - 3 cm; and 1/4 A2A2 - 2 cm.
@@GeneticsLessons Okay thank you!
Thanks for the video. I understand what broad sense and narrow sense heritability are now. What is the use of calculating them separately, though?
Only narrow sense heritability has practical application in a breeding,
@@GeneticsLessons why only NSH? BSH can be used to analyze influence of the environment on the phenotype among monozygotic twins. Further this knowledge can be applied in the medicine. Am I right?
does "total phenotypic variance" means variance in phenotype of one trait? or is it variance in phenotype of all traits given (ex if variance in arm length and leg length given)
In one trait : )
Watch my new video " How to develop super memory" th-cam.com/video/9k2sM_jcZUQ/w-d-xo.html
Thank you so much for your video. This is my layman understanding...dominance and epistasis overshadow the effects of a gene. This overshadowed gene wants to contribute in some way, so it adds a little effect to the phenotype...though small it adds up and contributes to the effect of dominance and epistasis. This additive effect is observable for all genes that contribute to the phenotype of that trait, whether dominant or recessive. Hence, narrow sense is the more practical equation to use. My question is, how do you assess and quantify the additive effect? Would love your feedback...geneticists are pretty non-existent in my country.
Just wonder, which country are you from?
Ohh THANK YOU VERY MUCH sir......finally I understand....
Which measures of heritability (broad/narrow)will be appropriate for selection in a mixture of homozygous line and for segregating generations..and How?
Narrow sense heritability.
Sir, can i ask?
What is variant aditif ?
Thanks
Most traits are polygenic, meaning more than one gene contributes to their phenotypes. In this case, an individual inherits multiple copies of each allele, rather than inheriting one copy of each allele, from each parent. So, when a trait is polygenic, the alleles are additive.
can the broad-sense heritability and narrow-sense heritability ever be the same?
Broad-sense heritability (H^2) and narrow-sense heritability (h^2) are both measures of the proportion of phenotypic variation in a trait that is due to genetic variation. However, they are different in terms of how they define and estimate the genetic components of this variation.
Broad-sense heritability is defined as the proportion of total phenotypic variance that is due to genetic variance, regardless of whether that variance is due to additive, dominant, epistatic, or other genetic effects. Broad-sense heritability can be estimated using a variety of statistical methods, such as analysis of variance (ANOVA) or parent-offspring regression.
Narrow-sense heritability, on the other hand, is defined as the proportion of total phenotypic variance that is due to additive genetic variance only. This means that it only considers the effects of genetic factors that are passed down from parents to offspring in a predictable and linear manner. Narrow-sense heritability can be estimated using methods such as the half-sib correlation or the full-sib regression.
In general, broad-sense heritability is always equal to or greater than narrow-sense heritability. This is because broad-sense heritability includes all genetic variation, including non-additive effects, while narrow-sense heritability only includes additive effects. Therefore, it is unlikely that the two heritability measures would be exactly the same.
However, there may be rare cases where broad-sense and narrow-sense heritability are very similar, particularly if the non-additive genetic effects are very small or negligible. In practice, the two measures are often used together to provide a more complete understanding of the genetic basis of a trait and to guide breeding and selection strategies.
Thanks man.👍
Can h help me to solve a question?
A group of 4 month old hogs has an average weight of 76kg. The average weight of selected breeders is 84kg. If narrow sense is 40%. What is expected average weight of first generation of progeny after selection?
Please help.. Tmr having exam. Ur help is very much appreciated
I have many videos on this topic with step-by-step solutions - please check play list "plant and animal breeding".
Here is a solution of your problem: th-cam.com/video/Xup2gE4XnvI/w-d-xo.html
Thanks!
Welcome!
can u please tell me what exactly is broad and narrow spectrum heritablity
Heritability. ... The broad-sense heritability is the ratio of total genetic variance to total phenotypic variance. H2 = VG/VP. The narrow-sense heritability is the ratio of additive genetic variance to the total phenotypic variance.
In scientific terms, heritability is a statistical concept (represented as h²) that describes how much of the variation in a given trait can be attributed to genetic variation.
Broad-sense heritability refers to the portion of total phenotypic variation which is explained through total genetic variance, while narrow-sense heritability on the other hand refers only to the portion which is explained through use of additive genetic variance.
thank u
Welcome
@@GeneticsLessons I had problems understanding this topic in class. Thanks to your video, my douts disappeared
🙏👍