What would be the consequences if there is no meiosis in organisms that reproduce sexually?

Answer 1

Meiosis is required for the production of gametes, haploid cells for sexual reproduction (eggs and sperm). Without meiosis, there would be no sexual reproduction.

Most macroscopic life is diploid, meaning we have two copies of each type of chromosome (one from each parent). Sexual reproduction means that each parents contributes genetic material to make a new combination of genes in the offspring. If there was not a way to halve each parent's contribution, then each new generation would have more and more chromosomes, which would result in the offspring either dying or becoming a different species.

Answer 2

This is a good thought-provoking experiment. If meiosis were to become non-existent, genetic variation would stop as well, as this is the only way organisms have genetic variation. In asexual reproduction, organisms make a clone of themselves.

For many species, the genetic variation is what allows the species to manage with changes in the environment. With the earth's conditions presently changing, this lack of genetic variation would lead to the extinction of many, if not all, species.

For humans, this would mean no more birth, since there is no more gametes. Instead, humans would have to find a way to clone themselves and introduce genetic variation through artificial means. If this is not done, the human population may cease to exist in time.