PRESENT-DAYTHEORIES OF

EVOLUTIONLesson #21

NEO-DARWINISM

Explanations for variation

•Mendel’s laws explain transmission.

•Sexual reproduction allows for gene

recombination.

•Gene recombination in meiosis

•Mutation: cause for rapid changes in genes.Changes the view of the evolutionary unit

• It is the population what natural selection acts

on.

The synthetic

theory of

evolution

•Darwin’s ideas and gene

frequencies.

The theory of

the selfish

gene

•The unit of evolution is the

gene

•Competition is within the

genes

•Aim to increase frequencies

Endosymbiotic

theory

•Eukaryotic cells originate

from the fusion of two kinds

of bacteria.

•Phagocytosis of cell which

became cellular organelles:

mitocondria and chloroplasts

•Symbiotic relationship