The constant c is often thought of as the number of species per unit area. It is affected by many factors.

TLS Online TPP Program

#Id: 3510

#Unit 2. Cellular Organization

Mutations occur at the same rate in both exons and introns, but exon mutations are eliminated more effectively by selection.

TLS Online TPP Program

#Id: 3511

#Unit 2. Cellular Organization

Introns may more freely accumulate point substitutions and other changes due to no selection pressure.  Introns evolve or accumulate mutations/changes much more rapidly than exons

TLS Online TPP Program

#Id: 3512

#Unit 2. Cellular Organization

Exons are usually short, typically encoding fewer than 100 amino acids

Exon sequences are conserved by the negative selection of individuals in which the sequences have changed.

TLS Online TPP Program

#Id: 3513

#Unit 2. Cellular Organization

In the fruit fly, gene sizes have a bimodal distribution—many are short but some are quite long

TLS Online TPP Program

#Id: 3514

#Unit 2. Cellular Organization

Overlapping gene are the same sequence of DNA encodes two nonhomologous proteins because it uses more than one reading frame.

TLS Online TPP Program

#Id: 3515

#Unit 2. Cellular Organization

A mutation that confers a more advantageous phenotype to an organism, relative to Individuals in the same population without the mutation, is positive selection of that organism.