1. Historical Hypotheses of Inheritance

2. For much of human history people were unaware of the scientific details of how babies were conceived and how heredity worked.

3. Clearly they were conceived, and clearly there was some hereditary connection between parents and children, but the mechanisms were not readily apparent.

4. The Greek philosophers had a variety of ideas.

5. Hippocrates speculated that "seeds" were produced by various body parts and transmitted to offspring at the time of conception.

6. Aristotle thought that male and female semen mixed at conception.

7. Aeschylus proposed the male as the parent, with the female as a "nurse for the young life sown within her".

8. With the invention of the microscope in the 1700s, some scientists speculated they saw a "little man" (homunculus) inside each sperm.

9. These scientists formed a school of thought known as the "spermists".

10. They contended the only contributions of the female to the next generation were the womb in which the homunculus grew, and prenatal influences of the womb.

11. An opposing school of thought, the ovists, believed that the future human was in the egg, and that sperm merely stimulated the growth of the egg.

12. Another idea, pangenesis, was an idea that males and females formed "pangenes" in every organ.

13. These pangenes subsequently moved through their blood to the genitals and then to the children.

14. The terms "blood relative", "full-blooded", and "royal blood" are relics of pangenesis.

15. Francis Galton experimentally tested and disproved pangenesis during the 1870s.

16. Gregor Mendel’s work in the new field of genetics during the 1840s provided insight on the topic of heredity.

17. We are going to begin our exploration of genetic by learning about what this important scientist discovered.