<P> The repercussions of parthenogenesis in sharks, which fails to increase the genetic diversity of the offspring, is a matter of concern for shark experts, taking into consideration conservation management strategies for this species, particularly in areas where there may be a shortage of males due to fishing or environmental pressures . Although parthenogenesis may help females who cannot find mates, it does reduce genetic diversity . </P> <P> In 2011, recurring shark parthenogenesis over several years was demonstrated in a captive zebra shark, a type of carpet shark . DNA genotyping demonstrated that individual zebra sharks can switch from sexual to parthenogenetic reproduction . </P> <P> Parthenogenesis in birds is known mainly from studies of domesticated turkeys and chickens, although it has also been noted in the domestic pigeon . In most cases the egg fails to develop normally or completely to hatching . The first description of parthenogenetic development in a passerine was demonstrated in captive zebra finches, although the dividing cells exhibited irregular nuclei and the eggs did not hatch . </P> <P> Parthenogenesis in turkeys appears to result from a conversion of haploid cells to diploid; most embryos produced in this way die early in development . Rarely, viable birds result from this process, and the rate at which this occurs in turkeys can be increased by selective breeding, however male turkeys produced from parthenogenesis exhibit smaller testes and reduced fertility . </P>

4. why is parthenogenesis and hermaphroditism important to the evolution of some species