Historical Geology Chapter Vocabulary
Chapter 7-Evolution
based upon Historical Geology-by Wicander and Monroe
Charles Darwin-1831-HMS Beagle
Galapagos finches-beaks
theory of evolution
Jean-Baptiste de Lemarck-1809
inheritance of acquired characteristics (1st attempt to provide mechanism)
but genes cannot be altered by physical actions
Charles Darwin-1882-On the Origin of Species
Natural Selection
1. All species have inheritable variations.
2. Some variations are more favorable than others.
3. More offspring will be produced than will make it to adulthood.
4. Favorable variations are more likely to survive.
Gregor Mendel (monk)- 1860s
worked with garden peas
determined inheritance was based on pairs of genes
dominant, recessive, partial dominance
deoxyribonicnucleic acid (DNA) molecules (chromosomes)
regions of DNA molecules are genes
humans have 46 chromosomes
cell division of meiosis splits cells into having only half of chromosome pairs
combination of sperm and egg creates full pairs of chromosomes
genetic variations
mutations (chromosomal or point mutations)
mutations: useful, lethal, neutral
mutagens: chemicals, cosmic rays, x rays, radioactivity, ultraviolet light
genetic drift works in small populations