Darwin and Adaptive Variation
Darwin started from the observation that animals regularly produce far more offspring than the food supply can support, and plants produce many more than enough seeds to maintain the plant population. This puts every species in competition with others for survival. Only the survivors grow to maturity and reproduce themselves.
Almost always a species reproduces according to its own kind. Darwin proposed that the characteristics of a species vary slowly over many generations when exceptional offspring propagate new capabilities.
From time to time a random mutation produces an individual with some characteristic unusual for its species. A mutant dog may have only three legs, for example. Mutations are changes in the genetic structure that affect the development of the embryo. Usually such changes are fatal. Only a few mutant embryos develop to maturity. Even then, most mutations are disadvantageous. A three-legged dog cannot pursue prey as rapidly as a normal dog. Such a dog is unlikely to survive unless someone keeps it as a pet and feeds it.
Very infrequently a mutation changes a characteristic in a way that is advantageous for the individual’s survival. A beneficial mutation may provide better camouflage or stronger armor or faster escape from predators. The rare, favorably mutant individual is more likely than normal individuals to survive to maturity.
If the mutation is heritable the mutant will pass on its advantage to its offspring. In theory, these offspring in turn produce more and more favored mutants. The mutants compete for survival with dwindling numbers of normal individuals. After many generations, most of the individuals in the population have the mutation. In this way the mutants become the normal members of the species. Then a new cycle of improvement can begin.
The greatest survival potential thus selects naturally certain random changes in form or characteristics. This is what Darwin meant by the phrase “survival of the fittest.” Darwin said that biology goes through a natural process of evolution. (Evolution means development, but biologists reserve the word “development” for the growth of an individual organism from embryonic to adult form.) He published his speculations in The Origin of Species in 1859. Darwin pointed out that every species needs its food, and many species are the food of other species. Predators evolve at the same time as their prey. Every time a species evolves a variation that favors its survival, it disfavors some other species, and that species has to evolve, too, or decline in numbers. Darwin proposed that such cycles of improvement repeat themselves endlessly.
Today’s Darwinists say that the dominant variation of the species is the one that is “naturally designed” for survival. This, they say, is why some species are so well adapted that they appear to be creatively designed. They say that there is no designer apart from nature, but the struggle for survival constitutes a natural, “automatic” design mechanism.
Any design mechanism must make identifiable changes in the form or morphology of organisms for survival advantage, changes that clearly adapt the species to the environment. Statements like “the fit are more likely to survive” are vacuous if the only way we know an organism is fit is that it survives.
Finches and Form Adaptation
Darwin began to get his ideas from observing the finches of the Galapagos Islands. Some finches had hard, short, strong beaks, well adapted to crushing seeds. Other finches had longer but weaker beaks that they inserted between cactus spines to eat the pulp. There were 14 species, all with small variations in morphology that made each suitable to differing conditions on different islands.
The capability of making small adjustments in form or structure in response to environmental change is structural adaptability. The changes are called adaptive morphology. This capability is a seldom-achieved goal of the most creative human designers. Let’s see what is right about Darwin’s concept. We will limit ourselves to provable science, excluding the many unsupported extrapolations of Darwin’s ideas.
An important industrial goal is to design systems with artificial intelligence. Design engineers would like to imitate the Darwinian mechanism. Once systems are sufficiently intelligent, designers hope that the systems themselves will make small variations in behavior or even structure to improve performance. Let’s consider, for example, where aerospace engineers are going with “robust design.”
Adaptive Behavior and Structure
An aerospace system is robust if it can complete its mission and report back to Earth even when there are unanticipated difficulties. Aerospace engineers often try to design into their systems a capacity for adaptive behavior, the ability to change activity modes depending on needs and environment. For example, when walking on dry land, we save energy by swinging our legs but scarcely lifting our feet. When we need speed we switch to running mode, lifting our feet much higher. If we walk in water over our ankles we quickly discover it is easier to lift our feet out of the water before swinging our legs forward. Our new behavior, constrained by need, minimizes our energy expenditure in a new environment. We use our intelligence to adapt our behavior to new circumstances and requirements. Intelligent instruments should be able to imitate us.
Far beyond the goal of designing adaptive behavior into systems is the goal of designing systems that can change their form to meet new requirements. When our path lies across deep water, we adapt our behavior and swim, but we don’t grow longer toes with webbing between them. We walk on snow much as we walk in shallow water, lifting our feet before swinging our legs. But if we come to deep snow, we can’t just make our feet broader to keep from sinking in. Instead we strap snowshoes or skis on our feet. That is, we change our shoes, not our feet, to adapt to new conditions.
Do we ever change our own form? Yes, in a sense. Soldiers in basic training must slim down to fighting trim through exercise and diet. This helps them crawl through small tunnels and climb over high barriers. Within limits we can adapt our form to new conditions and purposes.
Some aerospace robots can adapt their behavior but very few can adapt their structure. We have to watch cartoons to see ordinary cars or airplanes turn into intelligent fighting robots.
Almost always a species reproduces according to its own kind. Darwin proposed that the characteristics of a species vary slowly over many generations when exceptional offspring propagate new capabilities.
From time to time a random mutation produces an individual with some characteristic unusual for its species. A mutant dog may have only three legs, for example. Mutations are changes in the genetic structure that affect the development of the embryo. Usually such changes are fatal. Only a few mutant embryos develop to maturity. Even then, most mutations are disadvantageous. A three-legged dog cannot pursue prey as rapidly as a normal dog. Such a dog is unlikely to survive unless someone keeps it as a pet and feeds it.
Very infrequently a mutation changes a characteristic in a way that is advantageous for the individual’s survival. A beneficial mutation may provide better camouflage or stronger armor or faster escape from predators. The rare, favorably mutant individual is more likely than normal individuals to survive to maturity.
If the mutation is heritable the mutant will pass on its advantage to its offspring. In theory, these offspring in turn produce more and more favored mutants. The mutants compete for survival with dwindling numbers of normal individuals. After many generations, most of the individuals in the population have the mutation. In this way the mutants become the normal members of the species. Then a new cycle of improvement can begin.
The greatest survival potential thus selects naturally certain random changes in form or characteristics. This is what Darwin meant by the phrase “survival of the fittest.” Darwin said that biology goes through a natural process of evolution. (Evolution means development, but biologists reserve the word “development” for the growth of an individual organism from embryonic to adult form.) He published his speculations in The Origin of Species in 1859. Darwin pointed out that every species needs its food, and many species are the food of other species. Predators evolve at the same time as their prey. Every time a species evolves a variation that favors its survival, it disfavors some other species, and that species has to evolve, too, or decline in numbers. Darwin proposed that such cycles of improvement repeat themselves endlessly.
Today’s Darwinists say that the dominant variation of the species is the one that is “naturally designed” for survival. This, they say, is why some species are so well adapted that they appear to be creatively designed. They say that there is no designer apart from nature, but the struggle for survival constitutes a natural, “automatic” design mechanism.
Any design mechanism must make identifiable changes in the form or morphology of organisms for survival advantage, changes that clearly adapt the species to the environment. Statements like “the fit are more likely to survive” are vacuous if the only way we know an organism is fit is that it survives.
Finches and Form Adaptation
Darwin began to get his ideas from observing the finches of the Galapagos Islands. Some finches had hard, short, strong beaks, well adapted to crushing seeds. Other finches had longer but weaker beaks that they inserted between cactus spines to eat the pulp. There were 14 species, all with small variations in morphology that made each suitable to differing conditions on different islands.
The capability of making small adjustments in form or structure in response to environmental change is structural adaptability. The changes are called adaptive morphology. This capability is a seldom-achieved goal of the most creative human designers. Let’s see what is right about Darwin’s concept. We will limit ourselves to provable science, excluding the many unsupported extrapolations of Darwin’s ideas.
An important industrial goal is to design systems with artificial intelligence. Design engineers would like to imitate the Darwinian mechanism. Once systems are sufficiently intelligent, designers hope that the systems themselves will make small variations in behavior or even structure to improve performance. Let’s consider, for example, where aerospace engineers are going with “robust design.”
Adaptive Behavior and Structure
An aerospace system is robust if it can complete its mission and report back to Earth even when there are unanticipated difficulties. Aerospace engineers often try to design into their systems a capacity for adaptive behavior, the ability to change activity modes depending on needs and environment. For example, when walking on dry land, we save energy by swinging our legs but scarcely lifting our feet. When we need speed we switch to running mode, lifting our feet much higher. If we walk in water over our ankles we quickly discover it is easier to lift our feet out of the water before swinging our legs forward. Our new behavior, constrained by need, minimizes our energy expenditure in a new environment. We use our intelligence to adapt our behavior to new circumstances and requirements. Intelligent instruments should be able to imitate us.
Far beyond the goal of designing adaptive behavior into systems is the goal of designing systems that can change their form to meet new requirements. When our path lies across deep water, we adapt our behavior and swim, but we don’t grow longer toes with webbing between them. We walk on snow much as we walk in shallow water, lifting our feet before swinging our legs. But if we come to deep snow, we can’t just make our feet broader to keep from sinking in. Instead we strap snowshoes or skis on our feet. That is, we change our shoes, not our feet, to adapt to new conditions.
Do we ever change our own form? Yes, in a sense. Soldiers in basic training must slim down to fighting trim through exercise and diet. This helps them crawl through small tunnels and climb over high barriers. Within limits we can adapt our form to new conditions and purposes.
Some aerospace robots can adapt their behavior but very few can adapt their structure. We have to watch cartoons to see ordinary cars or airplanes turn into intelligent fighting robots.