Between 8000 & 1000 BC
 Horses, camels, oxen were
5000 BC
 Cultivation of plants like
maize, wheat
and rice
 Assyrian art depicts artificial
pollination of the date palm
Give attention to subjects of
reproduction and heredity of human
 Evident in the writings of the
Hippocratic School of Medicine
(500-400 BC)
 Aristotle (384-322 BC)
 Argues that male semen is formed
in numerous parts of the body.
 “Humors” act as the bearers of
hereditary traits, diseased or
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.
 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.
 17th Century
 Sex cells contains
complete miniature
adult called
John Dalton (1808)
 atomic theory
Matthias Schleiden and Theodor Schwann
 Cell theory
Redi, Spallanzani and Louis Pasteur
 Disprove the spontaneous generation theory
Animal and plant groups remains
unchanged in form from the moment of
their appearance.
 Popularized by several including Carolus
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
Matters is composed of atoms.
Cells are the fundamental units of living
 Nuclei somehow serve as the “life force”
of the cell.
 Chromosomes housed within the nuclei
somehow play an important role in
Early Scientists
Dawn of Modern Biology
Charles Darwin
Gregor Mendel