What happens in meiosis during anaphase i?

During anaphase I of meiosis, the sister chromosomes of the homologous pairs, that were lined up in bivalent pairs in the metaphase plate in metaphase I, have now moved to opposite poles of the parent cell and the cell is lengthened. The spindle fibers are still attached to the centromeres of the chromosomes as the cell moved to next stage of Telophase I. During Telophase I, the nucleus membrane begins to form around the chromosomes on the opposite poles and the parent cell begins to pinch off at the region between the two formed nuclei.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".