Here is a simple Genomic pedigree
chart. 2 separate chromosome segments
are shown for each ancestor. (During
meiosis , they divide-recombination). The earliest generation, are all one
color for illustrative purposes. Dairy
cattle have 30 chromosomes, including the
X and Y. On average each
chromosome carries millions of base pairs, and thousands of genes.
1)For the first segment,
the sire has inherited ½ from each piece.
In the second segment, the majority was inherited from one piece (both
of these are an example of a crossover).
The individual has received portions of the first segment that are
traced back to the grandparent generation.
2) The dam has inherited most of
one segment from one portion of her sire’s piece, and a mixture (double
crossover) from her dam’s piece. The
individual has segments that can be traced to all grandparents.
In this example…. Say the light green segment from the
paternal grand dam was one that was high milk production; the offspring, inheriting a large segment
from her, could mean that through this recombination, this animal would have a
higher PTA for milk that a full sib.