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Hybrid vs cross breed

  1. Mar 22, 2016 #1
    What is the difference between a hybrid and a crossbreed?
     
  2. jcsd
  3. Mar 22, 2016 #2

    Evo

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    This is so easily found on google. Did you check anywhere for the answer? We encourage people to look for answers first, then if they are stumped, to come to us with what is stumping them.

    Anyway, I googled it for you.

     
    Last edited: Mar 22, 2016
  4. Mar 22, 2016 #3
    i did but the definitions are not technical enough
     
  5. Mar 22, 2016 #4

    Evo

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    Hybrids are parents of two different species, crossbreeds are parents of the same species. What "technical" information are you wanting?
     
  6. Mar 22, 2016 #5
    that is not as simple as that. hybrid rice comes from same species - Oryza sativa. most commercial chickens are hybrids from the same species - G gallus.
     
  7. Mar 22, 2016 #6

    Evo

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    They are from the same species, but what are you trying to say?
    Now *that* part would be hybridization.

    https://en.wikipedia.org/wiki/Chicken#Origins

    If you have specific questions, ask the *specific* questions, do not ask a vague question.

    I don't have time to look, please post your source. Which hybrid rice comes from that species and would not be considered a crossbreed? Thank you.
     
    Last edited: Mar 22, 2016
  8. Mar 22, 2016 #7

    jim mcnamara

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    Example: Let's say plants. You have two individuals of the same species that are homozygous for quite a few different traits, then their offspring become heterozygous for those traits. You have offspring called hybrids. Hybrids do not breed true. Crossbreeding is the intentional act of creating hybrid offspring. A lot of garden and crop vegetables are hybrids, which plays well for both the seed companies and the farmer/consumer growing plants from the seeds. Generally more heterozygous plants, deliberately created by crossbreeding, display more robust traits - larger fruit or seed size, resistance to insects, and so on.

    Humans have cultural sanctions against inbreeding - brother and sister marrying for example. So you can view this as culturally enforced 'crossbreeding' in humans if you like.

    Inbreeding is the deliberate creation of animals or plants that breed true. Because the individuals are more homozygous the mature individual is far more likely to have become homozygous recessive for a deleterious trait. A sort of accidental happenstance. This can happen not so much "on purpose" but from the Founder Effect, also called a Bottleneck. Contrived example: When there is a small founding population of humans on an island many years later the descendants all arose from just 4 or 5 people. Because nobody immigrated to the island to bring in new genetic material, everybody on the island shares a huge common percent of alleles.

    So, this population is very likely to have lots of homozygous loci. (places on a chromosome). This is also why dog breeds like Dalmations have issues. Native Americans populations faced a massive die off from European diseases. So some Native American some populations have higher incidences of traits believed to be recessive. Cheetahs have low genetic diversity for the same reason. Familial polydactyly (extra fingers) in some New Jersey Pine Barrens very isolated towns arose as a result of human inbreeding, for example. And a limited founding population.

    This kind of human population isolation and populations being founded by a single family is no longer common. I guess Brigadoon is our only hope for something like remote Polynesian Islands in 1900.

    I do not want to cite 10 resources but here are some links:

    http://evolution.berkeley.edu/evolibrary/article/bottlenecks_01
    https://en.wikipedia.org/wiki/Dalmatian_(dog)
    Familial Polydactyly in Thomson and Thompson 'Medical Genetics' or if you cannot afford a $500 dollar textbook:
    https://www.nlm.nih.gov/medlineplus/ency/article/003176.htm
    Seed grower story (Non-Scientific): http://www.burpee.com/gardenadvicecenter/get-to-know/the-legacy-of-w.-atlee-burpee/legacy.html
    http://www.burpee.com/gardenadvicecenter/get-to-know/the-legacy-of-w.-atlee-burpee/legacy.html
     
    Last edited: Mar 22, 2016
  9. Mar 22, 2016 #8

    Ygggdrasil

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    There may not be consistent definitions of the terms across different fields. For example, in agriculture, hybrid seeds refer to seeds produced from crossing two different varieties of the same species.
     
  10. Mar 22, 2016 #9

    jim mcnamara

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    @Ygggdrasil good point. Hybrid can also mean interspecific crosses. I went with a more plant approach because of the example the OP used.
     
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