Under what environmental conditions would a zygote not undergo meiosis

A zygote will not undergo meiosis in an environmental state that is not favorable for the zygote’s survival i.e. the chance of the zygote to survive is not certain. Take for example, chlamydomonas will form a zygote under normal asexual mitotic reproduction in a favorable environmental condition. However, under unfavorable environmental conditions the organism also reproduce sexually to form a zygote but will never proceed to meiotic division because of the unfavorable environmental state.

a community that experiences major changes undergoes progress

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.