-change is in the proportions of genes in the population's gene pool (total of all the genes in all the individuals of the population)
-change takes place across generations
What is Evolutionary Theory? (3)
-stipulates the theory of common descent--all life on Earth is descended from one ancestral popluation
-stipulates that microevolution (small changes in the frequency of genes in a population) over millions of years accounts for the differences in life forms (microevolution accounts for macroevolution = evolution of new species and new groups of organisms)-stipulates that mutation, genetic drift, migration, and natural selection cause evolution
What is Lamarckian Evolution and who proposed it?
Jean Baptiste Lamarck 1744-1829
1-intrinsic drive toward perfection
2-acquisition of characteristics through use and disuse
3-inheritance of acquired characteristics
What is Common Descent & who proposed it?
The theory that all living organisms on Earth descended from a single common ancestor that appeared in the distant past.
What are the alternative hypotheses for the Theory of Common Descent?
-Static-indicating that organisms are recently derived and unchanging.
-Transformation-allows for modification of life forms but no separation. (all living organisms were created, perhaps even millions of years ago, and that changes have occurred in these species but brand-new species have not arisen)
-Separate types- allows for speciation but from several ancestral types (dif types of organisms for ex. plants& animals with backbones arose separately and since their origin have diversified into numerous species)
-Common Descent- repeated speciation from a single ancestral type