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Name: Jay
Status: Other
Grade:  Other
Location: N/A
Country: United States
Date: April 2005

How come a tiger and a lion can breed? How come a ligercannot breed?

Tigers and lions can create hybrid offspring but usually hybrids cannot breed because their chromosome numbers are uneven. For example, horses and donkeys can breed to produce the hybrid called a mule. Horses have 62 chromosomes and donkeys have 64 (or the other way around-I forget!). Their mule offspring have 63 chromosomes, an uneven number. So if two mules tried to have babies, the chromosomes wouldn't line up together at meiosis when creating eggs or sperm. So hybrids are usually sterile.


If lions and tigers do not carry the same genes on the same chromosomes (which is only possible if they contain the same number of chromosomes and I don't whether they do or not but you can find out by doing a search on Google), then when the liger sex cells undergo meiosis, the probability that the right complement of chromosomes would end up in the sperm or egg would be approximately 2 in a million (2 to the 20th power times 2) assuming they have 20 pairs of chromosomes. In other words the sperm or egg must contain 20 tiger chromsomes or 20 lion chromosomes and it is a 50-50 probability as to whether a sperm of egg cell receives the tiger chromosome or the lion chromosome during meiosis.

Ron Baker, Ph.D.

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