Question

Even though bdelloid rotifers lost the ability to reproduce sexually millions of years ago, the lineage continues to evolve because?

1) The lineage can't evolve, because genetically identical individuals are an evolutionary dead end.
2) They go dormant to escape the harmful effects of mutation.
3) Parthenogenesis allows recombination and the generation of novel genotypes.
4) The females incorporate foreign DNA into their genomes that increased genetic variation within the lineage.
5) All of the above.

Answer 1

Bdelloid rotifers continue to evolve because the females incorporate foreign DNA into their genomes, increasing genetic variation within the lineage. They also have the ability for their eggs to go dormant, helping them survive harsh conditions. Option 4 is correct.

Step-by-step explanation:

The question of why bdelloid rotifers, which have lost the ability to reproduce sexually millions of years ago, continue to evolve inspires curiosity about their survival strategies. Out of the options provided, the correct answer is: 4) The females incorporate foreign DNA into their genomes that increased genetic variation within the lineage. Bdelloid rotifers engage in parthenogenesis, which normally does not allow for genetic recombination in the same way sexual reproduction does. However, they have developed a unique mechanism to increase genetic variation by incorporating foreign DNA from other species into their genomes.

Additionally, some rotifer eggs can go dormant to escape harmful conditions, which could include the effects of harmful mutations, and they can re-emerge when conditions are favorable. This strategy adds to their ability to survive as a lineage. Through these methods, bdelloid rotifers continue to evolve despite their asexual mode of reproduction.