Species formation without branching of the evolutionary line of descent is called as:
1. anagenesis, or phyletic evolution
2. cladogenesis, or divergent evolution
3. convergent evolution
4. allopatry

According to the modern view of Darwinism, the unit of natural selection is the :
1. population
2. individual
3. species
4. community

In recent years, DNA sequences (nucleotide sequence) of mtDNA and Y chromosomes were considered for the study of human evolution, because