I’m trying to learn more about evolution, and I was wondering where sex came from. If this could be explained in layman’s terms that would be greatly appreciated. Thanks for the input!
Posted: May 3rd 2009
Reed Braden www
The History Channel in the US had a miniseries a while ago called Evolution and there was an episode on sex. I learned a lot from it and the general consensus of what I’ve read from scientists and skeptics who reviewed the series is that it’s both scientifically accurate and publicly accessible.
It’s up on YouTube here: Part 1, Part 2, Part 3, Part 4.
Enjoy… at least until YouTube takes it down.
Posted: May 4th 2009
logicel
Olivia Judson’s Dr Tatiana’s Sex Advice to All Creation is highly recommended to further your understanding regarding the role sex plays in evolution.
Excerpted from the above linked Wikipedia article:
Written in the style of a sex-advice column to animals, the book details the variety of sexual practices in the natural world and provides the reader with an overview of the evolutionary biology of sex.
Posted: May 4th 2009
Eric_PK
Simply stated, sex is very useful for generating useful genetic diversity.
Mutations sometimes produce an advantageous trait, but most often they produce a bad trait – one that ends up not working very well.
Sex, on the other hand, allows you to generate a brand new combination of genes by mixing those between organisms, without most of the downsides that you get with mutation.
Posted: May 3rd 2009
SmartLX www
Good question. In fact, there are several hypotheses about the specific origin of sexual reproduction.
On a really basic level, some simple organisms which reproduced by cell division or self-cloning developed a habit of exchanging some genetic material amongst themselves, at first by simply opening up and letting it seep in or out. The benefits of this simple exchange were so great (the Wikipedia article on the subject is mostly a list of these benefits) that those organisms that could do it soon prospered.
Over time, the mechanism for the exchange solidified. Body parts developed whose sole purpose (at the time) was to facilitate the exchange. Single species divided into two genders, each of which carried half of the equipment. Once intelligence began to develop, instincts came with it which made the act enjoyable and desirable.
Sex itself has diversified since its inception. Some living things are both male and female (especially in the plant kingdom), and some can change gender depending on population (some fish and reptiles). Some species do an external exchange; the female lays the eggs, and then the male fertilises them. Each technique seems to work, so it has a place in the tree of life.
Hope that gets you started. Keep on reading.
Posted: May 3rd 2009