Genetics 342

Hammond

Tamarin textbook

 

 

Chapter 1—Genetics and the Scientific Method

 

 

A Brief Overview of the Modern History of Genetics

 

1859—Charles Darwin published “The Origin of the Species”

 

1665—Robert Hooke coined the word “cell” from his cork analysis

 

1674-1683—Anton von Leeuwenhoek studies “wee beaties” in water (protozoans, bacteria)

 

1833—Robert Brown discovered cell nuclei (also described Brownian motion)

 

1835-1839—Hugo von Mohl documented mitosis

 

1858—Virchow proposed the cell theory—cells come from other cells

 

1866—Gregor Mendel published his works on inheritance

 

1875—Hertwig described zygote formation from fusion of egg and sperm

 

1879-1885—Flemming described chromosomes, more details of mitosis

 

1890—Hertwig and Boveri described details of meiosis

 

1900—Mendel’s work rediscovered by de Vries, Correns, and Tschermak

 

1913—first genetic map of fruit fly by Sturtevant

 

1927—X ray mutations by Stadler and Muller

 

1944—Avery, McCarty, MacLeod showed that DNA was the genetic material

 

1953—Watson and Crick determined double-helical structure of DNA

 

1968-1973—Smith, Nathans, et al., discovered/described restriction endonucleases

 

1972—Paul Berg made first recombinant molecule

 

1999 and beyond—up to you!

 


 

The Three General Areas of Genetics

 

Classical genetics—deals with chromosomal theory of inheritance

        Genes are located on chromosomes in a linear fashion

        Positions can be determined by looking at offspring

 

Molecular genetics—study of the genetic material

        Structure, replication, and expression of DNA

        Genetic engineering/recombinant DNA technology

 

Evolutionary genetics—study of the mechanisms of evolutionary change

        Changes in gene frequencies in populations

 

Current trend?  Molecular genetics has proven especially beneficial to the understanding of the other two areas (classical and evolutionary)

 

 

 

How Do We Know?

 

Genetics is an empirical science

        We learn by observation/experimentation

 

Scientific method—see figure 1.2

 

Notice the loop?