And others define evolution as any process of change, in any domain. For the sake of clarity, in this article, evolution and evolutionary psychology will refer to biological and genetic changes and not evolved cultural changes. This delimitation in the definition is not intended to diminish the importance of culture and learning, rather, it is intended to draw a clearer distinction between two important variables. Throughout ancient history, most people believed human beings had been created directly by God or by some other supernatural phenomenon.
Cultures around the globe often have such stories of creation. Due, in part, to cultural changes in Europe during the Enlightenment, some thinkers began looking for empirical evidence of our genesis. He also hypothesized that competition was the driving force behind evolution. Later, in , Charles Darwin proposed a plausible mechanism for this evolutionary change in his book On the Origin of Species. Thus began the study of evolution by natural selection. Around the same time, Gregor Mendel, an Augustinian monk, discovered the genetic inheritance of traits through his experimentation on pea plants.
parental investment theory essay
Later, advances in science led to discoveries in genetics e. Both process and mechanism were incorporated into biological evolutionary theory. Evolutionary theory has since become the most powerful explanatory system in the life sciences. The theory of natural selection is based on three basic premises: variation, inheritance and adaptation. The premise of variation refers to the idea and observation that all individuals of a particular species show variation in their behavioral and physiological traits.
Those individuals who are better able to garner resources are more likely to produce offspring, and the resulting offspring are likely to inherit those beneficial traits. Through this ongoing process, organisms become adapted to their environment. This process is called biological evolution.
As a metaphor for biological evolution, imagine you have a cake recipe. People like your cakes, so they come to your house and hand copy the recipe. Occasionally there are copy errors or mutations in the recipe.
Most of these mutations result in substandard cakes — for example, a cake made with sawdust instead of flour. Each time a repulsive cake is produced, that mutated recipe is thrown away, while the exact copies are propagated through the neighborhood and into other neighborhoods. At any one time, there are a small percentage of mutated recipes in the community that have yet to be selected out of the pool of recipes.
One day, someone accidentally changes the recipe for the better — it has the addition of chocolate chips. Everyone starts asking for this new mutated recipe. Over time, the original recipe diminishes in number and eventually becomes extinct altogether since it cannot compete with the new recipe. And the cycle continues.
Each preferred mutation is selected for, creating better and better cakes. Now imagine there was a sudden change in the environment: chocolate chips became scarce. Remember that at any one time, there are mutated recipes being created due to copy errors. One of these mutated recipes is perfectly suited for this chocolate chip famine: a cake with yogurt chips instead, which are abundant. Even though yogurt chips are not as tasty as chocolate chips, this yogurt chip trait is propagated through the neighborhood since it is adaptive to the current environment.
In the natural world, as in the metaphor above, genetic copying errors usually lead to either no effect or a reduction in survivability, resulting in these traits being potentially selected out of the gene pool. But on very rare occasions, a mutation might produce an organism that is better fitted to the environment and therefore better able to reproduce.
As with the yogurt chip cookie recipe, an organism that is better fitted to the environment will slowly edge out the competition. It should be noted that there is a difference between a genetic mutation any change in a DNA sequence away from normal and a polymorphism a DNA sequence variation that is common in the population.
Scientists have arbitrarily defined the cut-off point between a mutation and a polymorphism as 1 per cent — if the frequency of a trait is lower than 1 per cent, it is considered a mutation. For example, among all humans, hair color varies from blond to black polymorphism , but occasionally someone is born with no hair mutation.
- Found what you're looking for??
- What are the benefits of parental care? The importance of parental effects on developmental rate.
- stand by me film essay.
- essay writing websites india.
According to evolutionary biology, all living organisms on earth, including humans, are descended from a single common ancestor 4 billion years ago. About 3. Then some of the sea-dwelling animals evolved to live on the land — first insects, then amphibians, reptiles, dinosaurs, birds and mammals. Around 55 million years ago, the first primates evolved. They were small agile tree-dwellers akin to modern lemurs. From this species of primate evolved all modern primates: monkeys, apes and humans.
The first modern humans homo sapiens appear in the fossil record around , years ago in Africa. Since Darwin, many have studied and written within the broad field of evolutionary psychology — that is, the evolutionary-oriented study of human behavior and cognition. A number of distinct camps have emerged including evolutionary psychology, behavioral ecology, ethology, sociobiology, behavioral genetics, evolutionary developmental psychology, biocultural evolution, evolutionary anthropology, Darwinian anthropology, evolutionary neuroscience, and others.
There is considerable overlap, and also disagreement, between these schools of thought. However, divisions and controversies remain between and within each camp. This article is concerned with one of those camps: evolutionary psychology. Also, some consider evolutionary psychology to be rebranding of sociobiology and other previous camps Hampton, Over the millennia, there has been much debate regarding human instincts Hampton, Perhaps in reaction to this heated debate, Darwin altogether avoided the topic of instincts.
He outlined instincts such as fear, love and curiosity as driving forces of human behavior. And later in the early s, William McDougall famously proposed that the human mind has certain innate or inherited tendencies which motivate all thought and action and that these instincts are probably common to all humans Hampton, He defined an instinct as an inherited and innate psycho-physical disposition which determines what someone pays attention to, what someone will feel upon perceiving it, and what someone will do upon that feeling.
This instinct theory has been supported by the observation that other organisms come into the world with innate knowledge and abilities. For example, a recently hatched turtle instinctually crawls to the sea and swims, a puppy instinctually knows how to suckle without being taught, and a foal can walk within minutes after birth. Why would all other animals have instincts while humans would have none? Perhaps it is discomforting to think of our behavior as being dictated by fate and out of our direct control.
Perhaps we like to think of ourselves as beyond nature. Consider the following question: Why do apes suckle their babies? Is it due to instinct? Now consider a second question: Why do human mothers breast feed their infants? Does the mother breast feed because she loves her child and has learned that the infant needs nourishment?
Or is it instinctual? Or is the ape merely motivated by instinct? Is love a tool to motivate instinctual behaviors? These are difficult questions to answer. Perhaps both apes and humans have a mixture of both instinct and reason. Perhaps reason is a product of instinct. Do we have free will? How much does learning and culture play a role in our behavior?
parental investment theory essay – Kajakpolo
Or are we merely slaves to biological impulse? This confusion has not deterred many within several disciplines from attempting to understand our innate human instincts. The notion of instincts was taken up by naturalists and zoologists in Europe in the s who studied animal behavior with an interest in humans as a particularly interesting member of the animal kingdom Hampton, These scientists were interested in innate, inherited, instinctual behavior rather than learned behavior. Ethology has contributed much to our understanding of evolutionary psychology including the concepts of imprinting and critical periods.
Wilson and Richard Dawkins in the s. This discipline analyzes the social behavior of species from a biological and genetic point of view Hampton, Sociobiology has been concerned with various topics such as altruism and parental investment. The core idea of sociobiology is that behavior, in parallel with biology, has evolved under natural and sexual selection. For example, starting in the s, E.
- senior executive resume writing service.
- Study Guide for Exam 1; EP Fall | Glenn Geher.
- essay on toleration john locke.
- the secret garden book essay.
- Bateman's principle.
- Navigation menu.
Human Behavioral Ecology. In the s, human behavioral ecology, a branch of anthropology, emerged as the study of human behavior in its natural and spontaneous contexts Hampton, It assumes that human behavior is adaptive and organized around a wider unconscious strategy to optimize survival and reproduction. In this way, it studies the evolution of adaptive advantages of individual, group, and cultural traits.
The Emergence of Evolutionary Psychology. According to Hampton , evolutionary psychology built upon understandings within instinct theory — the emphasis on psychological dispositions. It also adopted the ethological study of how organisms operate in the here and now and why they have come to exhibit the behaviors that they do. Like sociobiology, evolutionary psychologists views behavioral adaptations as linked to genetic adaptations. And like human behavioral ecology, evolutionary psychology is interested in using depictions of our natural history to test hypotheses.
Massive Modularity. They believe that much, if not all, of our behavior can be explained by internal psychological mechanisms. Different sets of adaptive problems require different computational solutions.
This model argues that these cognitive modules have each evolved through natural selection in response to stimuli that result in advantageous behavior. Each mechanism pays attention to particular environmental cues and reacts according to its evolved function. For example, we evolved a psychological mechanism to reward us with pleasurable neuronal processes when we orgasm.
This is designed to motivate us to have sex and reproduce. As a recent elaboration on this concept, Bernard, Mills, Swenson, and Walsh as cited in Bernard, developed a theory that proposed a model of human behavior using 15 independent neuropsychological adaptations — or motive constructs — that propel behavior.