Slavery abolished in Mexico.
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1820 |
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Christian Friedrich Nasse formulated Nasse's law:
hemophilia occurs only in males and is passed on
by unaffected females.
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1820 |
Debate over slavery in the US heats up;
"The Missouri Compromise" admits Maine into the Union
as a free state, with Missouri to enter the next year
as a slave state.
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1821 |
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1822 |
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T. A. Knight, J. Goss, and A. Seton all independently perform crosses
with the pea and observe dominance in the immediate progeny, and segregation of
various hereditary characters in the next generation. However, they do not
study later generations or determine the numerical ratios in which
the characters are transmitted.
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1822-24 |
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Thomas Andrew Knight confirmed reports of
dominance, recessivity, and segregation in
peas, but did not detect regularities.
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1823 |
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1824 |
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1825 |
John Quincy Adams becomes the sixth president of the United States.
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1826 |
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Karl Ernst von Baer first demonstrated the
mammalian ovum; he regarded the sperm cells as
"Entozoa," i.e., parasites, and named them spermatozoa.
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1827 |
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Publication of Karl Ernst von Baer's
The Embryology of Animals which
strongly opposed preformationism.
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1828 |
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1829 |
Andrew Jackson becomes the seventh president of the United States.
Slavery abolished in Mexico.
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1830 |
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