CH. 8 Flashcards Preview

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Flashcards in CH. 8 Deck (20):
1

Value (in animal breeding)

Any measure applied to an individual as opposed to a pop. Exs. are phenotypic value, genotypic value, breeding value, and environmental effect,

2

Population Measure

Any measure applied to a population as opposed to an individual

3

Population Parameter

A true (as opposed to estimated) population measure. Exs. are true population means, variances, and standard deviation; true correlations between traits; and true heritabilities

4

Sample Statistic

An estimate of a population parameter

5

Normal Distribution

The statistical distribution that appears graphically as a symmetric, bell-shaped curve

6

Mean

an arithmetic average

7

Variation (in most animal breeding applications)

differences among individuals within a population

8

Variance

A mathematical measure of variation

9

Standard Deviation

a mathematical measure of variation that can be thought of as an avg. deviation from the mean. The square root of the variance

10

Variable

Any quantity that can take on different numerical values. All elements (except mean) of the genetic model for quantitative traits- P, BV, E, etc. are considered variables

11

Covariation

How two traits or values vary together in a pop

12

Covariance (cov(X,Y))

the basic measure of covariation

13

Correlation Coefficient

A measure of the strength (consistency, reliability) of the relationship between two variables.

14

Phenotypic Correlation

A measure of the strength (consistency, reliability) of the relationship between performance in one trait and performance in another trait

15

Genetic Correlation

A measure of the strength (consistency, reliability) of the relationship between breeding values for one trait and breeding values for another trait

16

Environmental Correlation

A measure of the strength (consistency, reliability) of the relationship between environmental effects on one trait and environmental effects on another trait

17

Regression Coefficient

The expected or avg. change in one variable (Y) per unit change in another (X)

18

True Values

An unknown, underlying attribute that affects animal performance. Exs. include breeding value, progeny difference, gene combination value, producing ability, environmental effect, etc.

19

Predicted Value

A prediction of a true value. The most common predicted values are estimated breeding value, expected progeny difference, and most probable producing ability

20

Prediction Equation

A mathematical equation used to calculate a predicted value based (usually) on phenotypic data.