Chapter 1 - Scientific Movements Leading to Evolutionary Psychology (Under Construction)
How did Darwin envision his theory of natural selection as applicable to behaviour and what evidence supports this view?
1) All behaviour requires underlying physical structures. Ex: bipedal locomotion which requires physical structures of two legs and a muscles to support them in the movement. 2) Species can be bred for certain behavioural characteristics using the principle of selection. Ex: Dogs can be bred for passivity or aggression. These point to the conclusion that behaviour isn't exempt from evolution.
What are the four kinds of questions that ethologists ask about behaviour?
1) Developmental influences on behaviour. 2) Immediate influences on behaviour. 3) Phylogenetic origins of behaviour. 4) Adaptive function of behaviour.
What were the two important conclusions that came from the fundamental assumptions of behaviourism that were violated?
1) Rats, monkeys and humans seem predisposed to learn some things easily and others not at all. 2) The external environment is not the sole determinant of behaviour, something happens cognitively that must be taken into account.
What were the objections to Darwin's theory?
1) That is theory of evolution lacked a coherent theory of inheritance. Darwin preferred a "blending" theory which suggested that offspring were mixtures of their parents. His blending theory was incorrect, and critics were correct that his theory lacked a solid theory of heredity. 2) Biologists couldn't imagine how the early stages of evolution of an adaptation could be useful to an organism. Darwin's theory requires that each and every step in the gradual evolution of adaptation be advantageous in the currency of reproduction. Aka partial wings or eyes must yield an adaptive advantage before they evolve and fully develop. While partial forms can offer adaptive advantages, this objections based on ignorance and a difficulty to conceptualize. 3) Religious creationists view species as immutable (unchanging) and created by a deity over the gradual process of evolution by selection. His theory implied that the emergency of humans and other species was blind, resulting from the slow, unplanned, cumulative process of selection. Contrasting with the view that creationists held of humans as part of God's plan/design. This controversy continues today.
What are the five guiding principles of evolutionary psychology?
1) The brain is a physical system designed to generate behavior that is appropriate to one's environmental circumstances. -Environmental inputs enter the brain resulting in useful behavioural outputs. 2) Neural circuitry is the product of evolution by natural selection, and evolved as a means of solving problems that our ancestors faced over the course of human evolutionary history. -"Problems" = challenges to survival and/or reproduction. -Two characteristics of problems that mattered: recurring over long periods of time & implications for reproduction of genes. -There are problems and sub-problems. Ex: A BIG problem is how to reproduce. A major sub-problem is how to survive long enough to reach reproductive age. A more specific sub-problem is to avoid predication. Followed by a 3rd sub-problem of how to detect presence of predators and produce avoidant behavioural responses. Ex: Another major sub-problem is how to engage in successful reproductive behaviour. Followed by a sub-problem of attracting a good mate. And a 3rd specific sub-problem is to identify potentially "good" mates and make self attractive to those potential mates or producing offspring and helping them survive. 3) Consciousness is just the tip of iceberg. 4) Evolved psychology is defined by functional specialization and modularity. -Buss: evolved psychological mechanisms tend to be problem-specific; humans possess many evolved psychological mechanisms. 5) Our modern skulls house a Stone Age mind.
What three forces coalesced into what become the cognitive revolution?
1) The violations of the fundamental laws of learning. 2) The study of language. 3) The rise of computers and the information processing metaphor.
What are the four key questions evolutionary psychology focuses on?
1) Why is the mind designed the way it is - what causal processes created, fashioned, or shaped the human mind into its current form? 2) How is the human mind designed - what are its mechanisms or component parts and how are they organized? 3) What are the functions of the component parts and their organized structure - what is the mid designed to do? 4) How do input from the current environment interact with the design of the human mind to produce observable behaviour?
Jean-Baptiste Lamarck
1744-1829 Was one of the first scientists to use the word biology, which recognized the study of life as a distinct science. He believed in tow major causes of species change: 1) A natural tendency for each species to progress toward a higher form. 2) Th inheritance of acquired characteristics. He proposed that animals must struggle to survive and it is this struggle which causes their nerves to secrete a fluid that enlarges the organs involved in the struggle. He had a theory about giraffe necks; long necks to assist with food consumption (recent evidence suggests the necks also play a role in mate competition through battle) and the changes that came about were passed down to succeeding generations. "The inheritance of acquired characteristics".
Baron Georges Léopold Chrétien Frederick Dagobert Cuvier
1769-1832 Proposed another theory of change in life forms called "catastrophism" to which species are extinguished periodically by sudden catastrophes, such as meteorites, and then replaced by different species.
Fixed Action Pattern
A sequence of unlearned acts directly linked to a simple stimulus.. They are the stereotypic behavioural sequences an animal follows after being triggered by a well-defined stimulus. Once a fixed pattern is triggered, the animal performs it to completion. Ex: showing a male duck a plastic model of a female duck will trigger a rigid sequence of courting behaviour. Fixed action pattern as a concept was useful in allowing ethologists to partition the ongoing stream of behaviour into discrete units for analysis.
Out of Africa Theory
A theory of the radical transformation to a singular human form, proposes that modern humans evolved quite recently in one location - Africa - then migrated into Europe and Asia, replacing all previous populations, including the Neanderthals. The different existing groups had evolved into essentially different species, so interbreeding was unlikely or rare. It posits a single location of modern human origins that occurred only recently during the past 100,000 years.
Multiregional Continuity Theory (MRC)
A theory of the radical transformation to a singular human form, states that after the first migration from Africa 1.8 million years ago, the different groups of humans in different parts of the world slowly evolved in parallel with each other, all gradually becoming modern humans. The emergence of modern humans didn't occur in a single area, but rather in different regions of the world wherever humans lived (multi regional). The evolution of different groups into a anatomically modern human form resulted as a consequence of gene flow between the different groups, which interbred enough to prevent divergence into separate species.
Group Selection Theory
Adaptations evolved for the benefit of the group through differential survival and reproduction of group; evolution takes place on a group level, not just individual, cooperative groups will outperform other groups. According to the theory, only species that possessed characteristics beneficial to their group survived. Those that acted selfishly perished because of the over-exploitation of the critical food resources on which the species relied. It acts collectively on all members of a given group. May also be defined as selection in which traits evolve according to the fitness (survival and reproductive success) of groups or, mathematically, as selection in which overall group fitness is higher or lower than the mean of the individual members' fitness values. Typically the group under selection is a small cohesive social unit, and members' interactions are of an altruistic nature.
What are the four key issues that the ethology movement was interested in? Aka: The 4 Why's Of Behaviour
Advanced by Nikolaas Tinbergen in 1951, the 4 why's are: 1) The immediate influences on behaviour (ex: movement of the mother). 2) the developmental influences on behaviour (ex: events during the animal's lifetime that cause changes). 3) The function of behaviour or "adaptive purpose" it fulfills (ex: keeping the baby animal close to the mother which helps it survive). 4) The evolutionary or phylogenetic origins of behaviour (ex: what sequence of evolutionary events led to the origins of an imprinting mechanism in the animal.)
Who do all modern humans appear to share a common ancestry with?
Africans who lived perhaps 120,000 to 220,000 years ago.
Charles Darwin (1809-1882)
After Cambridge, he traveled via ship for 5 years collecting samples of birds and other animals from the Galapagos Islands. He discovered that finches, which he'd presumed were all the same species, actually varied so much that they constituted different species. Each island in the Galapagos had a distinct species of finch. He determined that these finches had a common ancestor but became different because of ecological conditions on each island. The geographic variation was pivot to his conclusion that species are not immutable but change over time. He struggled with differing theories of change and needed to explain the existence of adaptation; change and why organisms appeared so well designed for their environment. After unearthing a key point in Malthus's "Essay on the principle of population", Darwin introduced the idea that organisms exist in numbers far greater that can survive and reproduce: struggle for existence and that favourable variations tend to be preserved and unfavourable ones die out. When this process is repeated generation after generation, the end result is the formation of a new adaption. His answer to the puzzle was "natural selection" which contained 3 essential ingredients: variation, inheritance and differential reproductive success.
What disciplines does evolutionary psychology pull together?
All disciplines of the mind; including brain imaging; learning and memory, attention, emotion, passion; attraction, jealousy, sex; self esteem, status and self-sacrifice; parenting, persuasion and perception; kinship, warfare, and aggression; cooperation, altruism, and helping; ethics, morality, religion and medicine; and commitment, culture, and consciousness.
Ontogeny
All the developmental events that occur during the existence of a living organism. Ontogeny begins with the changes in the egg at the time of fertilization and includes developmental events to the time of birth or hatching and afterward—growth, remolding of body shape, and development of secondary sexual characteristics.
Neanderthals
Approximately 200,000 years ago. They had weak chins and receding foreheads. Thick skulls which encased a large brain of 1,450 cubic centimetres. Built for tough living and cold climates. They were short limbed and stocky. They had solid bodies with a thick skeletal structure, which was needed for muscles far more powerful than those of modern humans. They had advanced tools, and formidable hunting skills. Their teeth had marks of heavy wear and tear, which suggest they frequently chewed through tough foods or to soften leather for clothing. They buried their dead. Lived through ice and cold, and thrived all over Europe and Middle East. 30,000 years ago they suddenly went extinct despite withstanding and flourishing through the ie aces and sudden changes for 170,000 years. Their disappearance coincided with the sudden arrival of anatomically modern Homo Sapiens.
When did the brains in the Homo line begin to expand more rapidly?
Around 1.2 million years ago were it more than doubled in size to the modern human level of approximately 1,350 cubic centimetres. The period of most rapid brain expansion occurred between 500,000 and 100,000 years ago.
William James and the Psychology of Instincts
At the core of James's theory was a system of "instincts". Publishing "Principles of Psychology" in 1890, his instincts were not always blind or inevitably expressed. The could be modified by experience or overridden by other instincts. Many contradict each other and so cannot always be expressed. His list of instincts was controversial. Beginning at birth with physical instincts such as crying, biting, staring, sucking, etc and then moving to walking, talking, etc. As each child grows, they instincts of imitation, vocalization, emulation, pugnacity, fear of definite objects, shyness, sociability, play, curiosity, acquisitiveness occur. As adults, there are instincts for hunting, modesty, love, and parenting and more. All instincts evolved through natural selection and adaptations to solve specific adaptive problems. He believed that humans had many more instincts than other animals, and the length of the list was its downfall. Skeptics believe the list wasn't so large, fewer in number and more generalized; aka a behavioural theory of learning.
Darwin's Theory of Sexual Selection
Based on his observations of strange structures on animals which had nothing to do with survival or how some species sexes differed significantly in their size and structure when they both confronted similar survival problems. His answer was a second evolutionary theory: sexual selection. Contrasting to natural selection, this theory focused on adaptations that arose as a consequence of successful mating. He proposed two primary means by which sexual selection could operate: 1) Intrasexual competition - competition between members of one sex where the outcomes of which contributed to mating access to the other sex. Ex: two stags locking horns in combat. Victor gains sexual access to the female. Whatever qualities led to the success during the same sex battle such as size, strength, athletic ability, etc., are passed on to the next generation. Qualities linked to losing also get passed on. Evolution can occur simply as a consequence of intrasexual competition. 2) Intersexual selection - preferential mate choice. If members of one sex have some consensus about the qualities that are desired in members of the opposite sex, then individuals of the opposite sex who possess those qualities will be preferentially chosen as mates. Those who lack fail to get mates. Evolutionary change occurs because the qualities that are desired increase in frequency with the passing of each generation. He called this "female choice" because he observed that throughout the animal world, females of many species were discriminating or choosy about who they mated with.
Why is evolution by natural selection NOT forward-looking and intentional?
Because natural selection merely acts on variants that happen to exist. Evolution can't look in to the future and foresee distant needs.
What did being warm-blooded give mammals the advantage of?
Being able to run metabolic processes at a constant temperature.
How is natural selection gradual?
Changes take generations, dozens, hundred, thousands, and millions of years sometimes for the process of selection to gradually shape the organic mechanisms. Some are slow, others rapid, and sometimes long periods of no change followed by quick sudden change known as punctuated equilibrium. But even rapid changes occur in tiny increments in each generation and take many generations to occur.
Modern Synthesis
Discarded a number of misconceptions in biology, including Lamarck's theory of inheritance of acquired characteristics and blending theory. Confirmed the importance of Darwin's theory of natural selection, but with firmer footing of particulate gene inheritance. A movement during the 1930s and 1940s.
Sociobiology
Edward Wilson's book: Sociobiology: The New Synthesis. Provided a synthesis of cellular biology, integrative neurophysiology, ethology, comparative psychology, population biology, and behavioural ecology. It examined species and proclaimed that the same fundamental explanatory principles could be applied to all. It synthesized under one umbrella a diversity of scientific endeavours and gave the emerging field a name. Created a controversy because of its grand claims to explain human nature. Had little empirical evidence on humans to support the view. Many misunderstandings about evolutionary theory and its application to humans.
How is human behaviour being genetically determined misunderstood?
Evolutionary theory doesn't imply genetic determinism but represents an interactionist framework. Human behaviour can't occur without evolved adaptations and the environmental input that triggers the development and activation for these adaptations. The reason adaptations evolve is that they afford organisms tools to grapple with the problems posed by the environment. Notions of genetic determinism - behaviours caused by genes without input or influence from the environment are false.
Derek Freeman
Found that Samoan islanders whom Mead depicted in utopian terms were intensely competitive and had murder/rape rates higher than the USA. And, the men were intensely sexually jealous, contrasting with Mead's free love theory. He was widely criticized but research has confirmed his findings and the existence of human universals such as jealousy, love, rage and fear.
How does Freud's theory of instincts correspond to Darwin's two major theories of evolution?
Freud's life-preserving instincts correspond to Darwin's natural selection, sometimes referred to as "survival selection", and Freud's sexual instincts corresponds closely to Darwin's theory of natural selection.
Problems with Radical Behaviourism
Harry Harlow's monkeys showed the opposite result with the babies leaning toward the cloth mother over the wire mother. They didn't seek out food reinforcement as their primary response. John Garcia gave rats some food, and then a dose of radiation which made them sick. The rats learned never to eat a certain type of food. The rats seemed to be "preprogrammed" to learn some things easily such as food linked with nausea but it was difficult to learn other things such as training rats to avoid buzzers or light flashes. Martin Seligman proposed it was easy to condition people to develop certain types of fears such as for snakes or rats. But, it was very difficult to condition people to develop less natural fears such as for cars or electrical outlets.
Trivers's Seminal Theories
He published three seminal papers all in the early 70s. 1) Theory of reciprocal altruism among non-kin: the conditions under which mutually beneficial exchange relationships or transactions could evolve. 2) Parental investment theory: provided a powerful statement of the conditions under which sexual selection would occur for each sex. 3) Theory of parent-offspring conflict: the notion that parents and their progeny will get into predictable sorts of conflicts because they share only 50% of their genes. Ex: parents weaning their children before they are ready to stop in order to free up resources to invest in other children. What might be optimal for the child may not be optimal for the parent.
What did Darwin seek to explain?
He wanted to not only explain why change takes place over time, but the way it proceeds; to determine how new species emerge, as well as why they vanish; to explain component parts and why they exist in those particular forms; their qualitative features, their function, and how they help organisms to accomplish specific tasks.
What was at the core of Freud's initial theory of psychoanalysis?
His proposal of the instinctual system which included two fundamental classes of instincts. 1) Life Preservative Instincts: includes the need for food, air, water and shelter, and the fear of snakes, heights, and dangerous humans. These instincts served the function of survival. 2) Sexual Instincts: mature sexuality culminated in the final stage of adult development (genital stage) which led directly to reproduction which was the essential feature of mature sexuality. He eventually changed his theory and combined the life and sexual instincts in to one group called "life instincts" and a second called "death instincts". He sought to establish psychology as an autonomous discipline and his thinking moved away from its initial Darwinian anchoring.
What three district groups of hominids roamed the world 300,000 years ago?
Homo Neanderthalensis in Europe, Homo Erectus in Asia, and Homo Sapiens in Africa.
How is evolution as an unchangeable process a misunderstanding?
Humans can and do create physical environments that are relatively free of friction, or create environments are contain significant amounts of friction. This is desired change - a change that prevents or causes the activation of underlying mechanisms. Ex: Humans can alter their behaviour such as a social behaviour change such as a sexual over-perception bias; when a women smiles at a man and he assumes she's sexually interested. Its this over-perception bias which is likely a part of an evolved psychological adaptation in men that motivates them to seek out causal sexual opportunities. Knowledge of this mechanism allows for the possibility of change. Knowledge can be used to change behaviours in areas in which change is desired. While changing behaviour isn't easy, it gives power.
George C. Williams
In 1966 published Adaptation and Natural Selection. A book that contributed to three key shifts in evolutionary theory. His book brought the scientific community one step closer to the Darwinian revolution by creating the downfall of group selection as a preferred and dominant explanation through illuminating inclusive fitness theory, and putting the concept of adaptation on a more rigorous and scientific footing. He was influential in showing that understanding adaptations requires being "gene-centered." Pioneered the idea of gene selection being part of Darwinism--the idea is that animals don't select each other; genes do. And when an animal dies, its gene still lives on and gets passed to future generations He also provided the criterion for determining when we should invoke the concept of adaptation: reliability, efficiency and economy.
Evolved Psychological Mechanisms
In evolutionary psychology, psychological mechanisms that are the result of evolution by selection; that is, they exist and have endured because they have been adaptive to survival and reproductive success. Psychological adaptations are problem-solving neurocognitive mechanisms that survived the process of natural selection because of their value in solving adaptive problems. The main feature of an evolved psychological mechanism is its functionality, how it contributes to the survival or reproductive success of the individual in whose brain the mechanism resides. More inclusively, an evolved psychological mechanism's function can be viewed in terms of its contribution to the survival or reproductive success of individuals who share genes with the individual in whose brain the mechanism resides.
What did Darwin's theory of natural selection offer explanations for?
It explained the origin of new species, accounted for the modification of organic structures over time, and accounted for the apparent purposive quality of the component parts of those structures - how they seemed to be designed to serve particular functions which contributed to survival or reproduction. However he failed to recognize the full importance of geographic isolation as a precursor to natural selection in the formation of new species.
What is evolution?
It refers to change over time.
What did the anatomical evidence suggest regarding OOA or MRC theories of radical transformation into a singular human form?
It suggested that Neanderthals and Homo sapiens differed dramatically. The Neanderthals had a large cranial vault; proposed brow ridges; a massive facial skeleton; large, heavily worn incisors; a protruding mid-face; short stature and thick boned stocky body build. The early Homo sapiens looked like modern humans: a cranial value with a vertical rather than sloping forehead; a reduced facial skeleton without a protruding mid-face; lower jaw and pronounced chin; and more slightly built bones. These large differences suggest that Neanderthals and early modern humans were isolated from each other rather than mating with each other and possibly evolved into two separate species - supporting OOA theory.
What did biologists before Darwin notice?
Lamark was the first to use the word biology and noticed the struggle of survival, inheritance of acquired characteristics, higher formation progression, while Cuvier had the theory of catastrophism. They also noticed the bewildering variety of species, some with structural similarities. Ex: humans, chimps and orangutans; they all have 5 digits on each hand and foot. Or bird wings being similar to seals flippers. This suggested that one was modified from the other and that life was not static. They looked at embryological development; how development was similar in some species and strikingly different in others. Ex: loop-like arterial pattern near bronchial slits in embryos of mammals, birds and frogs which suggests that these species might have come from the same ancestors millions of years earlier. All this evidence, prior to 1859, suggested life is not fixed. Another key observation by evolutionists before Darwin was that many species possess characteristics that seem to have a purpose. A turtle's shell, porcupine's quills, or the beaks of birds. But there was no causal process to explain this phenomena - it was Darwin who answered this question.
Are natural selection and sexual selection the only causes of evolutionary change?
No. Some changes can occur because of a process called a genetic drift which is random changes in the genetic makeup of a population. Random changes come through several processes, including mutations (random hereditary changes in DNA), founder effects and genetic bottlenecks. Founder effects occur when a small portion of a population establishes a new colony and the founders of the new colony are not genetically representative of the original population. Random change can occur through genetic bottlenecks which can happen when a population shrinks, such as by an earthquake or catastrophe. The survivors carry only a subset of the genes from the original population. While natural selection is the primary cause of evolutionary change, and the only known cause of adaptations, its not the ONLY cause of evolutionary change.
Founder Effects
Occur when a small portion of a population establishes a new colony and the founders of the new colony are not genetically representative of the original population. Ex: 200 colonizers who migrate to a new island happen by "chance" to include an unusually large number of redheads. As the population on the island grows, (2,000pple) it will contain a larger proportion of redheads than the original population from which the colonizers came. Thus the founder effects produced evolutionary change in this case which is an increase in gene coding for red hair.
When did the first mammals originate?
Over 200 million years ago.
Punctuated Equilibrium
Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change.
Inclusive Fitness Theory
Proposed by Willian D. Hamilton in the early 1960s, it was a radical revision of evolutionary theory. Initially rejected and misunderstood, it was finally published in 1964 and sparked a revolution that transformed the entire field of biology. He reasoned that "classical fitness" which is the measure of an individuals direct reproductive success in passing on genes through production of offspring was TOO NARROW to describe the process of evolution by selection. He said it should be broadened to "inclusive fitness" and theorized that natural selection favours characteristics that cause an organism's genes to be passed on, regardless of whether the organism produces offspring directly. Parental care was reinterpreted as caring for kin who carry copies of the parent's genes. But an organism can also increase the reproduction of its genes by helping family members to survive and reproduce. Relatives have some probability of carrying copies of the organism's genes. Inclusive fitness isn't a property of an individual or organism but a property of its actions/effects. It can be viewed as the sum of an individual's own reproductive success (classical) PLUS the effects of it's actions on reproductive success of genetic relatives (inclusive). The effects of relatives must be weighted by he appropriate degree fo genetic relatedness to the target organism. Ex: identical twins have genetic relatedness of 1.0 vs. full siblings at 0.50. An implication of inclusive fitness theory is that acts of altruism will be directed more toward closely related individuals over distant relatives.
Margaret Mead
Purported to have discovered cultures in which "sex roles" were totally reversed and sexual jealousy was absent. Island paradises inhabited by peaceful people who celebrated shared sexuality and free love with no competition, rape, fight or murder. However many researchers found these reports to be false.
Genetic Drift
Random changes in the genetic makeup of a population. A change in allele frequency in a population, due to the forces of chance. Oftentimes, mutations in cells can have no effect. These changes in genetics can increase or decrease in a population, simply due to chance. Although variations of genes (also known as alleles) can be selected for because they help or hinder an organism with reproducing. When the allele is not responsible for the change in its frequency in a population, genetic drift is acting on the allele. Genetic drift is much more likely in smaller populations of organisms. Genetic drift can easily be confused with natural selection. The difference is whether or not the allele is actively participating in the change in allele frequencies. If the allele affects an organism in a way that causes more reproduction of the DNA, the allele will increase in frequency. If it causes harm, it will decrease. This is caused by the allele's direct effects on the organism and the environment. This is natural selection. When the allele is increased or decreased simply because it was present in the organisms that survived, this is genetic drift.
What was William's criterion for determining the invocation of adaptation?
Reliability, efficiency and economy. 1) Reliability: does the mechanism regularly develop in most or all members of the species, across all normal environments and perform dependably in the contexts in which it is designed to function "reliably".. 2) Efficiency: does the mechanism solve a particular adaptive problem well. 3) Economy: does the mechanism solve the adaptive problem without extorting huge costs from the organism. Adaptation isn't invoked to merely explain the usefulness of a biological mechanism, but to explain the improbable usefulness (too precisely functional to have arisen by chance alone). Hypotheses about adaptations are probability statements about why a reliable, efficient and economic set of design features that could not have arisen by chance alone.
Cognitive Revolution
Returned psychology to the respectability of looking inside the heads of people over just the external contingencies of reinforcement. Psychologists began to be more explicit about causal processes. An information processing model; information is taken as input; the procedures the mechanism employs to transform it; the representations and procedures that process the information; and the information, physiological activity, and manifest behaviour the mechanism produces output.
When and where did the earliest traces of controlled fire occur?
Roughly 1.6 million years ago in Africa. Clear evidence of fire in Europe didn't occur until 1 million years later.
When did Homo Erectus emerge?
Roughly 1.8 million years ago. They migrated out of Africa into Asia through gradual population expansion into lands with abundant resources. Its unclear if they knew how to use fire.
When did the first crude tools appear?
Roughly 2.5 million years ago. Oldowan stone tools which were fashioned by stone flaking to create a sharp edge. Used to separate bone on carcasses and extract marrow. While crude from today's standards, back then they required a level of skill and technological mastery. They were so successful that they remained essentially unchanged for more than 1 million years. They were linked with the first group in the genus Homo/Homo habilis, or "handy man". Roughly 1.8 million years ago, bipedal toolmaking primates evolved into a successful branch known as Homo erectus. 1.5 million years ago the Acheulean hand axe. Took more skill to design and symmetry not shown in earlier tools. The axe varied in size an shape and little is known about their precise uses. The common quality is the flaking on two opposing surfaces, resulting in a sharp edge around the periphery of the implement.
How long did ti take to get from the origins of the first life on earth to modern humans in the 21st century?
Roughly 3.7 billion years.
What is one of the most critical developments of the primate line that led to modern humans?
Roughly 4.4 million years ago; bipedal locomotion - the ability to walk, stride, run on two feet over four. Evolved on the African savanna. Afforded the ability to cover long distances in an efficient manner, greater visual angle for detection of predators and prey, decreased surface area of body exposed to harmful sun rays, and freed up hands. Opened up for not only movement but the evolution of toolmaking, game hunting and evolution of the brain.
When did primates evolve?
Roughly 85 million years ago.
Gregor Mendel (1822-1884)
Show that inheritance was "particulate" and not blended. Qualities of parents aren't blended but rather passed on intact to their offspring in distinct genes. Genes aren't acquired by experience. He demonstrated this through cross breeder different strains of pea plants; dominant and recessive traits.
Gene's Eye Thinking
Stemming from the inclusive fitness movement, Its point is that the gene is the fundamental unit of inheritance and that unit is passed on intact in the process of reproduction. Genes producing effects that increase their own replicative success will replace other genes, producing evolution over time. Adaptations are selected and evolve because they promote inclusive fitness. Dawkin's The Selfish Gene: The gene's-eye view, or selfish gene theory, can be defined as the idea that the gene is the ultimate beneficiary of selection. Whereas organisms and their phenotypes are unique occurrences, each a product of the genome and its environment at a particular time, genes are the only units passed on intact and thus survive across generations. The gene is therefore the fundamental unit of selection.
What are well-developed in primates?
Stereoscopic vision which gives them an advantage in jumping from branch to branch.
What was the controversy which came from Darwin's theory?
That humans descended from apes.
What did Freud propose about human motivation?
That sexuality was a motivating force and "the" driving force of human behaviour regardless of age. All of a human's psychological mechanisms are merely ways of channelling our sexuality.
Bipedal Locomotion
The ability to walk, stride, and run on two feet.
What was the one assumption from the behaviourist paradigm that cognitive psychologists carried over?
The assumption of domain-generality. Domain-general learning processes were replaced by domain-general cognitive mechanisms. They missed the idea that there might be privileged classes of information that the cognitive mechanisms were specifically designed to process. A problem with this assumption about information processing is combinatorial explosion. With a domain-general program that lack specialized processing rules, the number of alternative options open to it in any given situation is infinite. Rapid proliferation of response options caused by combining two or more sequential possibilities. A combinatorial explosion renders a computer or person incapable of solving even the simplest tasks without special programming.
How is adaptation as a notion of mechanisms with evolved functions misunderstood?
The current collection of adaptive mechanisms that make up humans isn't optimally designed. Many factors that cause the existing design of adaptation can be far from optimal. A contraint on optimal design is evolutional time lags. A change in the environment brings new selection pressures, but evolutionary change occurs slowly, requiring generations of recurrent selection pressure, and humans aren't necessarily designed for the previously environments of which they are a product. Ex: taste preferences for fat/sugar, adaptation in a past environment during scarcity, now leads to heart disease, diabetes, etc. The time lag from hunter-gatherer to today's environment means that some of our existing evolved mechanisms may not be optimally designed for current times. The 2nd constraint on optimal design is the cost of adaptations. Ex: Driving - forcing people to drive slow to save lives, but the cost of that would be very high. OR an evolved mechanism for everyone to fear snakes. While it would reduce snake bites/death, it would stop people from gathering food, hunting, etc.
Genetic Determinism
The doctrine that argues that behaviour is controlled exclusively by genes with little or no role for environmental influence.
Genotypes
The entire collection of genes within an individual. They are broken up with each generation.
Phylogeny
The history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms. Fundamental to phylogeny is the proposition that plants or animals of different species descended from common ancestors. The evidence for such relationships is nearly always incomplete, for the vast majority of species that have ever lived are extinct, and relatively few of their remains have been preserved in the fossil record. Most phylogenies therefore are hypotheses and are based on indirect evidence. Different phylogenies often emerge using the same evidence. There is universal agreement that the tree of life is the result of organic descent from earlier ancestors and that true phylogenies are discoverable, at least in principle.
How do proponents of MRC theory challenge OOA theory?
The interpretation of the genetic evidence, stating that there are enough anomalies such as in Australian fossil sites, to raise legitimate concerns. Recent genetic evidence might cause the balance to shift more to MRC theory. The genetic evidence appears to refute an exclusive version of the African origins of humans because there is some evidence of interbreeding between the most recent African arrivals and the more ancient populations occupying Europe and Asia. Recent studies estimate that modern humans contain perhaps 2% of the Neanderthal DNA.
What did the genetic evidence suggest regarding OOA or MRC theories of radical transformation into a singular human form?
The oldest Neanderthal from which DNA has been extracted from Croatia (42,000 years ago) and reveals that Neanderthal DNA is distinct form that of modern humans, implying that the two lineages diverged perhaps 400,000 years ago or longer. This suggests that substantial interbreeding between the two groups was unlikely, although recent evidence points to a little interbreeding. Second, if the DNA of modern humans contained Neanderthal DNA, we'd expect it to be most similar to living Europeans who reside in the Neanderthals former territory. But that DNA is no closer to that of living Europeans that it is to the DNA of people in other parts of the world. Third, modern human populations show an exceptionally low amount of genetic variation, suggesting that we all came from a relatively small population of more genetically homogeneous founding ancestors. Forth, there is more genetic variation among modern African populations than among populations elsewhere in the world. Consistent with the view the modern Homo sapiens first evolved in Africa which it had longer time to accumulate genetic diversity, and then a subset migrated and colonized the new langs. All this evidence supports OOA theory.
Imprinting
The process by which certain animals form attachments during a critical period very early in life. Ex: ducklings imprinting on the first moving object they observe and form an association during ta critical period of development; usually the duck's mother. They will follow the object anywhere, and is a form of learning - an association is formed between the duckling and mother that wasn't there before the exposure to her motion. This type of learning is preprogrammed and part of evolved structures of the duck's biology. First noticed by biologist Douglas Spalding, later rediscovered by Oskar Heinroth, but it was Konrad Lorenz who studied it extensively. He showed that imprinting occurred during a critical period early in life. He was one of the founders of ethology.
What are the speculations about the causes of rapid brain size increase in Homo Erectus?
The rise of toolmaking, tool use, complex communication, cooperative large game hunting, climate and social competition. Its possible that all these factors played some role in the expansion of the human brain.
What do all human fossils from 30,000 years ago to today share?
The same anatomical form: a distinct skull shape, a large brain (1,350 cubic centimetres), a chin, and a lightly built skeleton.
Ethology
The scientific study of how animals behave, particularly in natural environments. It was the first major discipline to form around the study of behaviour from an evolutionary perspective and one of its first phenomena to be documented was imprinting. It is defined as the study of the proximate mechanisms and adaptive value of animal behaviour. They study forced psychologists to reconsider the role of biology in the study of human behaviour. It set the stage for an important scientific revolution, brought about by a fundamental reformulation of Darwin's theory.
Gene
The smallest discrete unit that is inherited by offspring intact.
What is Evolutionary Psychology?
The study of cognition, affect and behaviour in the here and now with specific selection pressures on ancestral populations. Includes cognitive, affective and behavioural neuroscience, anatomy and physiology, developmental biology, evolutionary biology and population genetics.
What did the archeological evidence suggest regarding OOA or MRC theories of radical transformation into a singular human form?
The tools and other artifacts left behind shows that 100,000 years ago, Neanderthals and Homo sapiens were quite similar. Both had stone tools but lacked tools of bone, ivory or antler; and hunting was limited to less dangerous species. Population densities were low, fireplaces were rudimentary, and neither showed a penchant for art or decoration. 40,000 to 50,000 years ago, a massive transformation occurred, described sometimes as the "creative explosion". The tools became diverse in their fashion and materials. Burials were more elaborate and goods entombed with the deceased. They began to hunt dangerous large animals. The population densities mushroomed. Further arts and decorations. Its been suggested that a new brain adaptation led to this explosion. BUT the Neanderthals did not partake in this explosion. It was almost exclusively limited to Homo sapiens. Archeological evidence supports OOA theory.
Noam Chomsky
Theorist who believed that humans have an inborn or "native" propensity to develop language. A language organ with an underlying structure which is invariant across languages.
What three sources of evidence did scientists test to see whether Out Of Africa Theory or Multiregional Continuity Theory was the correct assumption regarding the radical transformation to a single human form?
They looked at anatomical, archeological and genetic evidence.
What is the goal of evolutionary psychology?
To understand the human mind/brain mechanisms.
What are the three essential ingredients of Darwin's natural selection?
Variation, inheritance and differential reproductive selection. 1) Variance: organisms vary in all sorts of ways such as wing length, trunk strength, bone mass, cell structure, fishing ability, defences and social cunning. Variation is essential for process of evolution to operate as it provides "raw materials" for evolution. 2) Inheritance: only some of the variations are inherited; passed down reliably from parent to offspring, then on to the generations. Other variations such as a deformity caused by an environmental accident aren't inherited. Only the variations that are inherited play a role in the evolutionary process. 3) Differential reproductive selection: organisms with some heritable variants leave more offspring because these attributes help with the tasks of survival or reproduction. An organism can survive for many years, and still not pass on its inherited qualities to future generations. To pass on these qualities, it must reproduce. Thus differential reproductive success brought about by the possession of heritable variants that increase or decrease an individual's chances of surviving and reproducing is the bottom line of evolution by natural selection. Success or failure is defined by reproductive success relative to others. The characteristics of organisms that reproduce more than others, get passed down to future generations at a greater frequency. Survival is critical for reproduction and takes a critical role.
Mammals
Warm blooded, with evolved mechanisms that regulate internal body temperature to maintain a constant warm level despite environmental perturbations. Designed by feeding young through secretions via mammary glands. Mammal comes from "mamma" the Latin word for breast. Human breasts are an adaptation whose origins can be traced more than 200 million years. Feeding this way is distinctive. A second distinction and major development in evolution of placental mammals appx 114 million years ago. As contrasted with egg-laying nonplacentals.
What astonishing fact came from Darwin's theory?
Was that it united all species into one grand tree of descent. Each species was viewed as being connected with all others through a common ancestry. Ex: Humans and chimps sharing 98% of their DNA. Furthermore, many human genes turn out to have counterpart genes in a transparent worm called Caenorhabditis Elegans. They have a highly similar chemical structure, which suggested that humans and this worm evolved from a distant common ancestor. His theory made it possible to locate humans on the tree of life, showing their place in nature, and their links with all other living creatures.
Rise of Behaviourism
William James; human behaviour mainly driven by instincts. Watson believed emphasized classical conditioning. Skinner pioneered radical behaviourism and operant conditioning. Behaviourists assumed that the innate properties of humans were few in number, what was innate was a general ability to learn by reinforcing consequences. Any reinforcer could follow any behaviour and learning would occur equally in all cases. Any behaviour could be shaped by manipulating the contingencies of reinforcement. Behaviourists believed that humans have no distinct nature.