• Particles from all parts of the body are collected and transmitted to offspring
• The father’s contribution to the child is carried in the semen.
• Women must have a similar fluid that remains internal.
• At conception the two fluids mix and each trait from a parent battles its equivalent from the other parent and the winner in each case is the inherited one.
Male = form and motion (aka the blueprint for the new organism)
Female = matter and body (provides the home
Aristotle (384-322 BC)
• Divided reproduction into three categories which are
•Every gamete carries a potential “child”
•Those offspring must also carry their own offspring in their preformed gametes.
– Every single generation must have been preformed at the time of creation.
– There may be a limit to the number of generations possible for any species
Antony Van Leeuwenhoek (1632-1723)
• First Microscope • Observed and described
spermatozoa in semen • Observed and described the fertilization process.
Gregor Mendel (1822-1884)
• Augustinian monk • Father of modern genetics • He is credited with formulating
the concept of particulate inheritance.
• Packets of information are passed relatively unchanged from one generation to the next.
• The blending effect seen in progeny is due to pairs of factors - one from each parent.
• His work was ignored.
Hugo de Vries, Carl Correns, Erich von Tschermak
Simultaneously and independently recreated Mendel’s work with different plant species.
Discovered Mendel’s papers while preparing their own manuscripts.
Sex (X) linked white eye trait
Thomas Hunt Morgan
Established a direct link between an inherited trait and a chromosome
– Sex (X) linked white eye trait in Drosophila
– Gene Theory – Genetic Linkage – Ushered in Drosophila as a model system for
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