Darwin rocks
Started a new book this week, entitled 'The Mating Mind'. It's all about how sexual selection has shaped the human mind throughout its evolutionary history. Explains all the elaborate displays (art, music etc) that humans engage in that seem to have little bearing on our overall fitness (reproductive success). Other notable theorists and evolutionary/cognitive psychologists have passed off these traits as merely icing on the cake, or side effects from our enlarge brains and cognitive powers.
For those of you who's evolutionary theory is a bit rough, sexual selection (SS) is not the same as natural selection (NS), although both contribute to an organisms fitness. NS is concerned more with solving ecological problems that pose a survival threat, ie. staying warm in cold environments, having the right beak size to crack certain seeds, echo location to detect flying insects etc. SS drives the formation of traits that increase the chance of a successful mating encounter. Even an animal superbly suited to the current environment is a genetic dead end if it fails to generate offspring. So any trait (behavioural or morphological) that increases the likelihood of successful mating would under go intense selection. Darwin originally proposed SS to explain the bizarre ornaments found throughout the animal kingdom that seem to defy logic, and may actually compromise an organism (peacocks tails - not the best for predator avoidance).
The peacocks tail (and deer antlers, male bird song) is actually an honest indicator of male fitness. Only those well suited to their environment are able to divert energy to such costly displays and still survive. Peahens that have a preference for these traits will in turn have better quality offspring. These offspring by necessity now contain the genes for both the trait (if male) and the preference (if female). It then becomes a positive feedback loop that continues until some equilibrium is met, ie. the trait becomes so extreme that the costs outweigh the benefits. There is some debate over how the 'preference' first appears in an gene pool, but whatever the route (ie mutation) the end result is the same... run away selection. It's always random and dependent on local conditions. Computer simulations rarely follow the same course, suggesting SS is a potent mechanism for speciation.
In humans the scene is a tad more complex. Having extremely altricial young, both male and female invest heavily offspring. This sets the stage for both sexes to be selective when choosing a mate, although there are sex differences in the characteristics desired by each. I'm sure some of you are familiar with the notion of men ranking youth and attractiveness as more important than females, who in turn, favour resource potential. This is what you would expect from evolutionary principles. However, ranked higher and evenly by both sexes are 'kindness' and 'intelligence'. According to a study I read today, the preference for these characteristics suggest that a species specific force is at work in addition to straight inter-sex dynamics. Again, a result of the nature of our young and relatively 'monogamous' mating strategies (rare in mammals).
Being only 70 pages into the book, I can't say how exactly displays like art, dancing, music, humour etc increase an individuals fitness, but I can speculate.
Humans collect information about reality through our sense organs. Based on this information an internal model of the world is generated, subsequently directing behaviour. Any organism with a better 'model' (containing more accurate spatial and temporal patterns and/or more patterns in general) will have an advantage over those with inferior models. Thus, selection should drive us to process relevant environmental (including social) information with increased efficiency and accuracy. We should then have indicator mechanisms to advertise this ability, and conversely, the capability to detect signals from others.
Now... indulge me for a second. I would say that in general, people that do things well are more attractive than people doing the same thing less well. Could be anything, and certainly not all tasks are equal in the attractiveness they attract. But why is this? Same task, difference in performance, different level of attraction. What causes this difference? Ready?
The individuals differ in their models of physical reality. One is more realistic, at least in the context of the task at hand, and is generating the desired result more effectively than the other. If better models are selected for, then surely it's not a great leap to see how skills are attractive and could serve as an indicator of overall fitness. After all, brain tissue is metabolically expensive to create, not to mention the time constraints involved when learning new skills. If you can do that thing you do well, and still function adequately in other domains... chances are you're a catch.
Cool stuff eh? And no need to invoke a higher dimensional being to explain it.
For those of you who's evolutionary theory is a bit rough, sexual selection (SS) is not the same as natural selection (NS), although both contribute to an organisms fitness. NS is concerned more with solving ecological problems that pose a survival threat, ie. staying warm in cold environments, having the right beak size to crack certain seeds, echo location to detect flying insects etc. SS drives the formation of traits that increase the chance of a successful mating encounter. Even an animal superbly suited to the current environment is a genetic dead end if it fails to generate offspring. So any trait (behavioural or morphological) that increases the likelihood of successful mating would under go intense selection. Darwin originally proposed SS to explain the bizarre ornaments found throughout the animal kingdom that seem to defy logic, and may actually compromise an organism (peacocks tails - not the best for predator avoidance).
The peacocks tail (and deer antlers, male bird song) is actually an honest indicator of male fitness. Only those well suited to their environment are able to divert energy to such costly displays and still survive. Peahens that have a preference for these traits will in turn have better quality offspring. These offspring by necessity now contain the genes for both the trait (if male) and the preference (if female). It then becomes a positive feedback loop that continues until some equilibrium is met, ie. the trait becomes so extreme that the costs outweigh the benefits. There is some debate over how the 'preference' first appears in an gene pool, but whatever the route (ie mutation) the end result is the same... run away selection. It's always random and dependent on local conditions. Computer simulations rarely follow the same course, suggesting SS is a potent mechanism for speciation.
In humans the scene is a tad more complex. Having extremely altricial young, both male and female invest heavily offspring. This sets the stage for both sexes to be selective when choosing a mate, although there are sex differences in the characteristics desired by each. I'm sure some of you are familiar with the notion of men ranking youth and attractiveness as more important than females, who in turn, favour resource potential. This is what you would expect from evolutionary principles. However, ranked higher and evenly by both sexes are 'kindness' and 'intelligence'. According to a study I read today, the preference for these characteristics suggest that a species specific force is at work in addition to straight inter-sex dynamics. Again, a result of the nature of our young and relatively 'monogamous' mating strategies (rare in mammals).
Being only 70 pages into the book, I can't say how exactly displays like art, dancing, music, humour etc increase an individuals fitness, but I can speculate.
Humans collect information about reality through our sense organs. Based on this information an internal model of the world is generated, subsequently directing behaviour. Any organism with a better 'model' (containing more accurate spatial and temporal patterns and/or more patterns in general) will have an advantage over those with inferior models. Thus, selection should drive us to process relevant environmental (including social) information with increased efficiency and accuracy. We should then have indicator mechanisms to advertise this ability, and conversely, the capability to detect signals from others.
Now... indulge me for a second. I would say that in general, people that do things well are more attractive than people doing the same thing less well. Could be anything, and certainly not all tasks are equal in the attractiveness they attract. But why is this? Same task, difference in performance, different level of attraction. What causes this difference? Ready?
The individuals differ in their models of physical reality. One is more realistic, at least in the context of the task at hand, and is generating the desired result more effectively than the other. If better models are selected for, then surely it's not a great leap to see how skills are attractive and could serve as an indicator of overall fitness. After all, brain tissue is metabolically expensive to create, not to mention the time constraints involved when learning new skills. If you can do that thing you do well, and still function adequately in other domains... chances are you're a catch.
Cool stuff eh? And no need to invoke a higher dimensional being to explain it.
posted by Ian at 12:02 AM
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