Historical Background of Genetics

Prehistoric Times Between 8000 & 1000 BC 5000 BC Horses, camels, oxen were domesticated 5000 BC Cultivation of plants like maize, wheat and rice Assyrian art depicts artificial pollination of the date palm (Babylonia)

Greek Influence (Global Age of Greek) Give attention to subjects of reproduction and heredity of human beings Evident in the writings of the Hippocratic School of Medicine (500-400 BC) Aristotle (384-322 BC)

Hippocrates (Treatise On The Seed) Argues that male semen is formed in numerous parts of the body. “Humors” act as the bearers of hereditary traits, diseased or healthy.

Aristotle Male semen was formed from blood and that its generative power resides in a Vital Heat. The Vital Heat has the capacity to produce offspring of the same form. I generated offspring by cooking and shaping the menstrual blood produced by the female, which was the physical substance giving rise to an offspring.

Dawn of Modern Biology

William Harvey (1960) Theory of epigenesist (organism is delivered from substances present in the egg) New structures are not present initially but instead are formed de novo in the embryo.

Theory of Performation 17th Century Sex cells contains complete miniature adult called homunculus

other significant findings… John Dalton (1808) atomic theory Matthias Schleiden and Theodor Schwann Cell theory Redi, Spallanzani and Louis Pasteur Disprove the spontaneous generation theory

The Fixity of Species Animal and plant groups remains unchanged in form from the moment of their appearance. Popularized by several including Carolus Linnaeus

Darwin and Evolution The origin of species in 1859 Species arose from modifications Theory of Natural Selection Book on “Variations in Animals and Plants under Domestication” (explanation on how heritable variations arises gradually over time) Gemmules -physical units gathered by blood into the semen, subject to alternation

Discoveries in 19th Century Matters is composed of atoms. Cells are the fundamental units of living organisms. Nuclei somehow serve as the “life force” of the cell. Chromosomes housed within the nuclei somehow play an important role in heredity.

Modern Genetics Early Scientists Charles Darwin Gregor Mendel Genetics Dawn of Modern Biology Charles Darwin Gregor Mendel Genetics

Concepts Related to Genetics