Is Sexual Reproduction Important?

          In the selected reading, Dr. Tatiana's Sex Advice to All Creation by Olivia Judson, animals were invited to a talk show about the benefits and costs of sexual and asexual reproduction. The sexually reproducing animals, like the rams, pigeons, mice, and armadillos as depicted in this reading, argue that sexual reproduction is the best way to reproduce and that asexually reproducing organisms will become extinct. The asexually reproducing organism that was interviewed in the story was a rotifer called Philodina. The Philodina argued that its species is an asexually reproducing species and that organisms can survive using asexual reproduction for a long time, unlike what the sexually reproducing organisms argued about.
         Sex is important because it causes more genetic variation which can lead to an organism to adapt better to its environment. "Sex, they insist, is essential. And ancient asexuals -- creatures such as the bdelloid rotifers that have lived without sex for millions of years -- should not exist" (Judson 216). Reproduction does not cause genetic variation by itself, it needs genetic mutation alone to create genetic variation which is rare and unreliable. This is the reason why most asexual species go extinct. "But although asexuality often evolves -- it pops up in groups from jellyfish to dandelions, from lizards to lichens -- it rarely persists for long" (Judson 216). The main benefits of sexual reproduction is the genetic variation created when the sperm and egg fuse together to form a genetically unique zygote which grows into a genetically unique organism. "In eukaryotic sex, you get half your genes from your mother and half from your father.... Thus, at the end of meiosis, each sperm and egg carries one complete but unique mixture of genes -- a complete but shuffled deck" (Judson 219). The costs of sexual reproduction is the dangers of STDs and parasites and that it takes up a lot of energy. The benefits of asexual reproduction is that the genes stay relatively the same, so organisms can become extremely adapted to their environment. The costs are also that genes stay the same. "[Philodina's] proof rests on the fact that cloning for millions of years has dramatic effects on the way genes evolve. 'Being asexual for generations leaves an unmistakable mark, a molecular tattoo on your genes,' she said smugly, ' If you always clone, there's only one source of genetic novelty, only one thing that could cause my genes from to differ from my mother's, grandmother's, or great-great-grandmother's: mutation" (Judson 222).
          Some things that are confusing to me are that how mutations occur, why they occur, and how they impact the organism with them.