5 ms·
> Some breeding bulls are used to impregnate tens of thousands of cows. I fail to remember the details but one of them 30-40 years ago had a genetic defect whic
by ejstronge 8y ago
> Some breeding bulls are used to impregnate tens of thousands of cows. I fail to remember the details but one of them 30-40 years ago had a genetic defect which contaminated a lot of the US stock.
The other side to that story is that, while the breeding male's genes led to more spontaneous abortions (i.e., pregnancies that ended unexpectedly with calf loss), his daughters produced a lot more milk. From the same article:
> That’s a crazy number, but here’s an even crazier one: Despite the lethal mutation, using Chief’s sperm instead of an average bull’s still led to $30 billion dollars in increased milk production over the past 35 years. That’s how much a single bull could affect the industry.
- Gibbon1 8y agoThe cautionary note is this wasn't discovered until the recessive gene effected about 10% of the cattle population. Given the unknowns there is the potential that malign genetics wouldn't be discovered until several generation have passed. Human generations are 20-40 years. Possible that propagating rare mutations that appear to have beneficial effect may come at a high cost that is only apparent 50-100 years from now.
- ejstronge 8y agoI share your general concern, but would like to point out that this particular example couldn’t happen in human genetics for a variety of reasons (we are less consanguineous, practice assortative mating, get extensive medical care including fertility treatments). A bigger issue would be one particular implementation of genetic testing taking off in a group of humans who might otherwise be expected to produce offspring together. Perhaps - community of wealthy families all ordering the same IQ boosting agent may find that their grandchildren all share some unusual, genetically recessive ailment.