Cupid's chemicals
When it comes to love it seems we are at the mercy of our biochemistry. One of the best known researchers in this area is Helen Fisher of Rutgers University in New Jersey. She has proposed that we fall in love in three stages. Each involving a different set of chemicals.
Three Stages of Falling in Love
Stage 1: LustLust is driven by the sex hormones testosterone and oestrogen. Testosterone is not confined only to men. It has also been shown to play a major role in the sex drive of women. These hormones as Helen Fisher says "get you out looking for anything". Stage 2: Attraction This is the truly love-struck phase. When people fall in love they can think of nothing else. They might even lose their appetite and need less sleep, preferring to spend hours at a time daydreaming about their new lover. In the attraction stage, a group of neuro-transmitters called 'monoamines' play an important role:
Stage 3: Attachment This is what takes over after the attraction stage, if a relationship is going to last. People couldn't possibly stay in the attraction stage forever, otherwise they'd never get any work done! Attachment is a longer lasting commitment and is the bond that keeps couples together when they go on to have children. Important in this stage are two hormones released by the nervous system, which are thought to play a role in social attachments:
The frisky Prairie Vole
It was thought that the two hormones, vasopressin and oxytocin, released after mating, could forge this bond. In an experiment, male prairie voles were given a drug that suppresses the effect of vasopressin. The bond with their partner deteriorated immediately as they lost their devotion and failed to protect their partner from new suitors.
Looking in their genes
When it comes to choosing a partner, are we at the mercy of our subconscious? Researchers studying the science of attraction draw on evolutionary theory to explain the way humans pick partners.It is to our advantage to mate with somebody with the best possible genes. These will then be passed on to our children, ensuring that we have healthy kids, who will pass our own genes on for generations to come. When we look at a potential mate, we are assessing whether we would like our children to have their genes. There are two ways of doing this that are currently being studied, (to find out more click on the links): pheromones and appearance. Collected by
ISWAR & et al
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This month, Smithsonian published a fascinating article about the history of chickens and how they basically took over the world. Obviously, chickens couldn't have established their empire without reproduction, so I thought I'd take a behind-the-scenes look at how chickens became so prominent. As it turns out, chicken procreation is a lot weirder than I thought. Here are just a few of the finer points. 1) Asymmetrical gonads Here's how gonads are usually arranged: males have two testes, and females have two ovaries. Both genders usually have one gonad on the right side of their body and one on the left. It's pretty simple. In contrast, hens only have one functional ovary. In fact, most birds have this lopsided anatomy probably because it's more practical for flight. Birds need to be light and compact in order to fly, so they only develop one of their gonads. For most male birds, the right testes is also smaller than the left. This tren...