Thursday, 26 February 2015
There's sexual reproduction, and there's asexual reproduction. Which one is more beneficial, and why?
Why has evolution seemed to have moved from asexual reproduction to sexual reproduction? Although sex is a lot of fun, if you think about it from a pure efficiency standpoint, sex is a lot of work. This question has baffled evolutionary biologists for years. There have been theories that say sexual reproduction assures genetic variety while also eliminating diseases, so in a way it's nature's way of getting rid of problematic DNA sequences.
Why has evolution seemed to have moved from asexual reproduction to sexual reproduction? Although sex is a lot of fun, if you think about it from a pure efficiency standpoint, sex is a lot of work. This question has baffled evolutionary biologists for years. There have been theories that say sexual reproduction assures genetic variety while also eliminating diseases, so in a way it's nature's way of getting rid of problematic DNA sequences.
In the 1990s, Leigh Van Valen created the Red Queen hypothesis, which proposed that organisms must constantly evolve not only to evolve to their environment, but also to prevent from going extinct in the face of ever-evolving opposing organisms. It explains why species are constantly becoming extinct, and suggests that sexual reproduction (as opposed to asexual reproduction) provides an advantage to the individual organism.
A recent study published in Nature Genetics provides a scientific way of looking at this: by sharing genetic material with a mate, an individual becomes stronger and is ultimately better able to fight disease. Researchers compared hundreds genomes from different human populations from around the world and found parts of DNA are rewritten more often than others, causing hot and cold spots of genetic mutation.
When sexual organisms, like humans, reproduce, they release genetic material that can allow the building blocks of genes and chromosomes to combine and mutate beneficially. Some mutations help us, while others increase our risk of diseases. The rarely overwritten "cold spots," it turns out, are where bad mutations tend to survive, but thanks to sex and these mutations, our genetic material "worsens, and then gets better," but ultimately, this "bad" DNA gets overwritten.
Could you imagine how radically different society would be if we reproduced asexually? Aside from being a lot of fun, can you think of any other advantages to sexual reproduction? Share you theories in the comments section below!
