Linkage of characteristics.
When Mendel had studied his pea plants (see 1865), he had followed the course of seven characteristics and found them all to be inherited independently. It was natural to suppose, therefore, that every characteristic had its own factors, which all reached the fertilized egg cell independently.
When Sutton pointed out that the chromosomes were Mendel's factors, however (see 1902), there was a problem: there weren't enough different chromosomes to account for all inherited characteristics.
Bateson, who first applied the laws of heredity to animals (see 1902), pointed out that indeed not all characteristics were independently inherited--some were transmitted together--so it might be supposed that a single chromosome contained more than one factor, perhaps many more than one factor. It might be that Mendel, by pure chance, had chosen seven factors that were each on a different chromosome.
The thought that a chromosome was not a factor but a collection of factors was a crucial one in the development of genetics. (It was Bateson, incidentally, who introduced the term genetics.)
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|Publication:||Asimov's Chronology of Science & Discovery, Updated ed.|
|Article Type:||Reference Source|
|Date:||Jan 1, 1994|
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