Psychobiology
Chris Chandler
Chapter 2-4, 7, 9, 14-17, 22, 23
Online chapter 17
Tessa Faber
,Chapter 2 – Genetics and Evolution
Introduction
The Human Genome Project has mapped human genes.
In The Beginning – Evolution
Charles Darwin, the godfather of evolution, wrote about the origins of species against a
backdrop of pro-creationism.
Evolution: the change in inherited characteristics over successive generations.
Pro-creationism: the view that evolution is untrue and that humans and the world were
created by a superior being (a god).
The idea that species change and evolve over time is now a well-established fact in science.
Theories are structures of ideas that explain and interpret facts. Evidence is paramount in
any theory.
Darwin initiated the evolutionary account of life on earth and published The origin of species
(1859) at a time when Christianity stated that God had created all species from scratch.
Darwin’s Revolutionary Theory – The Theory of Evolution
Darwin proposed that all organism are related and share a common ancestor. His theory of
descent with modification encapsulated how modern organisms are (successful) adaptations
of previous generations. These modifications occur in the process of what he referred to as
natural selection. Certain characteristics of the organism are more beneficial within a
particular environment. Thus, those organisms that possess beneficial characteristics are
more likely to survive and reproduce.
Natural selection: the process by which any characteristic of an individual that allows it to
survive to produce more offspring will continue in the species.
Via reproduction, these characteristics are passed to the next generation. Organisms that
are not ideally equipped to interact with their environment stand a smaller chance of being
able to adapt to that environment, thus limiting their opportunity to survive and reproduce.
The phrase often used for this is ‘survival of the fittest’; this means that those organisms
that ‘fit into’ their environment are more successful at survival.
Reproduction: the production of offspring by a sexual or asexual process.
Survival of the fittest: the continuation of an organism that ahs successfully adapted to the
environment which means they live long enough to produce.
A comparison can be made between natural selection, traditional selective breeding and the
more recent advances in genetic modification.
• With natural selection, there is no specific plan, the environment is the influence and
evolution is a relatively slow process.
, • The selective breeding of animals is a specific, and intentional, act that produces
offspring with particular characteristics that were present in the parental generation
and is comparatively quick.
• Genetic modification is an even quicker form of selection in which genes are added
or deleted for the benefit of the organism or, if not the recipient organism, then at
least mankind.
Selective breeding: the breeding of animals and plants specifically to display a particular
trait.
Evidence: The Case in Support of the Theory of Evolution
Darwin presented a great deal of evidence to support the theory of evolution via natural
selection. The supporting evidence derives from the following general features.
• Biogeography. Organisms are the best fit for their unique environment.
• Fossil records. Sedimentary rock formations allow us to chart the time course of
evolution. Looking at different geological layers reveals changing fossils and these
changes permit the palaeontologist to chart the evolution of species.
• Structural similarity. Across species there are comparative similarities. Arms, paws,
flippers and wings all have similar skeletal structures but serve different function
(although the same construct-movement).
• Embryology. There are similar stages in utero across species. Ernest Haeckel
presented the ontogeny recapitulates phylogeny (ORP) theory as he supported
Darwin’s theories in Germany. The essence of the ORP theory is that during
development, every organism goes through every stage of its evolutionary past.
• Molecular biology. Molecular biology – the discipline that looks at the actual
elements of genes – supports Darwin’s account of evolution and the evidence he
originally presented. Ultimately, we share common strands of genetic material with
other organisms, and some are closer than others.
The Organism and the Environment
Genetics is at the heart of the age-old dilemma in psychology, that of nature versus nurture,
or genes versus experience. The Darwinian account is a very good example of how the
environment changes biology and behavior, albeit over an extended period of time.
Darwinian: the central theory of evolution as proposed by Charles Darwin.
In psychology we are interested in how our experiences and environments influence the
expression of our genes.
Johnston and Edwards (2002) provide an integrative model of the development of
behaviour, and have acknowledged the importance of the environment. They consider the
development of behaviour to be a product of interactions between genetics, the
environment and perception.
Essentially behaviour will be determined not purely by genetic make-up but also by
experiences, interpretations and perceptions of the environment. Not only is the
environment important, it is also subject to individual differences due to the interpretation
and perception of that environment; the environment is not an absolute.
, The Evolution of Humans
From an evolutionary perspective, humankind ahs evolved from its progenitor species. We
have to accept that humans are a recent development in evolutionary history. Our history
spans hundreds of millions of years.
After the Earth was created about 600 million years ago, the first signs of life appeared,
arising from complex water-dwelling organisms. Then 150 million years later organism with
nerves were evident. Surrounding these new nerves were bone structures. These bone
structures with vertebrae would subsequently be known as the spine. Life in the water was
hard and some of these first incarnations of fish ventured onto the land. This was an
evolutionary step in the development of amphibians. Eventually the fins and gills
characteristic of water-borne creatures developed, or should we say evolved, into legs and
lungs.
Amphibians: a cold-blooded vertebrate animal, e.g. frog.
Amphibians were subject to further evolutionary adaptations. Reptiles, such as lizards and
snakes, are an evolutionary branch arising from amphibians. The need to be close to a
source of water for a quick dip was no longer important.
Mammals evolved from reptiles about 180 million years ago. They continued to evolve and
developed the ability to produce an internal environment suitable for the protection and
development of their offspring – pregnancy.
The development in utero of a new living organism permits greater safety and protection
from harsh environments. That is not to say life in utero is free from danger – there are
many challenges to the foetus, for example alcohol is a well-known teratogen and can cause
foetal alcohol syndrome.
Mammal: a warm-blooded vertebrate animal that usually has hair/fur and the females
produce milk.
Foetus: an unborn offspring of a mammal, in particular more than eight weeks after
conception.
In the the category of mammals, humans are exceptional and are arguably the most
advanced form of life comparing from the order of primates.
Of the numerous families of primates, humans are members of the family Hominines. Within
this family are two genera: Australopithecus and Homo. We come from the Homo group –
humans are Homo sapiens.
Homo species emerged about 2 million ears ago and are thought to have come from one
species of Australopithecus.
Homo sapiens: the primate species to which modern humans belong.
It is suggested that Homo sapiens can all be traces back to Africa. About 200,000 years ago
Homo sapiens appeared and about 50,000 years ago modern humans began to migrate out
of Africa. This is the ‘Out of Africa’ hypothesis’.
The planet looked different all those years ago and people moved from the African plains in
search of resources. The environmental pressures have therefore shaped modern humans
Chris Chandler
Chapter 2-4, 7, 9, 14-17, 22, 23
Online chapter 17
Tessa Faber
,Chapter 2 – Genetics and Evolution
Introduction
The Human Genome Project has mapped human genes.
In The Beginning – Evolution
Charles Darwin, the godfather of evolution, wrote about the origins of species against a
backdrop of pro-creationism.
Evolution: the change in inherited characteristics over successive generations.
Pro-creationism: the view that evolution is untrue and that humans and the world were
created by a superior being (a god).
The idea that species change and evolve over time is now a well-established fact in science.
Theories are structures of ideas that explain and interpret facts. Evidence is paramount in
any theory.
Darwin initiated the evolutionary account of life on earth and published The origin of species
(1859) at a time when Christianity stated that God had created all species from scratch.
Darwin’s Revolutionary Theory – The Theory of Evolution
Darwin proposed that all organism are related and share a common ancestor. His theory of
descent with modification encapsulated how modern organisms are (successful) adaptations
of previous generations. These modifications occur in the process of what he referred to as
natural selection. Certain characteristics of the organism are more beneficial within a
particular environment. Thus, those organisms that possess beneficial characteristics are
more likely to survive and reproduce.
Natural selection: the process by which any characteristic of an individual that allows it to
survive to produce more offspring will continue in the species.
Via reproduction, these characteristics are passed to the next generation. Organisms that
are not ideally equipped to interact with their environment stand a smaller chance of being
able to adapt to that environment, thus limiting their opportunity to survive and reproduce.
The phrase often used for this is ‘survival of the fittest’; this means that those organisms
that ‘fit into’ their environment are more successful at survival.
Reproduction: the production of offspring by a sexual or asexual process.
Survival of the fittest: the continuation of an organism that ahs successfully adapted to the
environment which means they live long enough to produce.
A comparison can be made between natural selection, traditional selective breeding and the
more recent advances in genetic modification.
• With natural selection, there is no specific plan, the environment is the influence and
evolution is a relatively slow process.
, • The selective breeding of animals is a specific, and intentional, act that produces
offspring with particular characteristics that were present in the parental generation
and is comparatively quick.
• Genetic modification is an even quicker form of selection in which genes are added
or deleted for the benefit of the organism or, if not the recipient organism, then at
least mankind.
Selective breeding: the breeding of animals and plants specifically to display a particular
trait.
Evidence: The Case in Support of the Theory of Evolution
Darwin presented a great deal of evidence to support the theory of evolution via natural
selection. The supporting evidence derives from the following general features.
• Biogeography. Organisms are the best fit for their unique environment.
• Fossil records. Sedimentary rock formations allow us to chart the time course of
evolution. Looking at different geological layers reveals changing fossils and these
changes permit the palaeontologist to chart the evolution of species.
• Structural similarity. Across species there are comparative similarities. Arms, paws,
flippers and wings all have similar skeletal structures but serve different function
(although the same construct-movement).
• Embryology. There are similar stages in utero across species. Ernest Haeckel
presented the ontogeny recapitulates phylogeny (ORP) theory as he supported
Darwin’s theories in Germany. The essence of the ORP theory is that during
development, every organism goes through every stage of its evolutionary past.
• Molecular biology. Molecular biology – the discipline that looks at the actual
elements of genes – supports Darwin’s account of evolution and the evidence he
originally presented. Ultimately, we share common strands of genetic material with
other organisms, and some are closer than others.
The Organism and the Environment
Genetics is at the heart of the age-old dilemma in psychology, that of nature versus nurture,
or genes versus experience. The Darwinian account is a very good example of how the
environment changes biology and behavior, albeit over an extended period of time.
Darwinian: the central theory of evolution as proposed by Charles Darwin.
In psychology we are interested in how our experiences and environments influence the
expression of our genes.
Johnston and Edwards (2002) provide an integrative model of the development of
behaviour, and have acknowledged the importance of the environment. They consider the
development of behaviour to be a product of interactions between genetics, the
environment and perception.
Essentially behaviour will be determined not purely by genetic make-up but also by
experiences, interpretations and perceptions of the environment. Not only is the
environment important, it is also subject to individual differences due to the interpretation
and perception of that environment; the environment is not an absolute.
, The Evolution of Humans
From an evolutionary perspective, humankind ahs evolved from its progenitor species. We
have to accept that humans are a recent development in evolutionary history. Our history
spans hundreds of millions of years.
After the Earth was created about 600 million years ago, the first signs of life appeared,
arising from complex water-dwelling organisms. Then 150 million years later organism with
nerves were evident. Surrounding these new nerves were bone structures. These bone
structures with vertebrae would subsequently be known as the spine. Life in the water was
hard and some of these first incarnations of fish ventured onto the land. This was an
evolutionary step in the development of amphibians. Eventually the fins and gills
characteristic of water-borne creatures developed, or should we say evolved, into legs and
lungs.
Amphibians: a cold-blooded vertebrate animal, e.g. frog.
Amphibians were subject to further evolutionary adaptations. Reptiles, such as lizards and
snakes, are an evolutionary branch arising from amphibians. The need to be close to a
source of water for a quick dip was no longer important.
Mammals evolved from reptiles about 180 million years ago. They continued to evolve and
developed the ability to produce an internal environment suitable for the protection and
development of their offspring – pregnancy.
The development in utero of a new living organism permits greater safety and protection
from harsh environments. That is not to say life in utero is free from danger – there are
many challenges to the foetus, for example alcohol is a well-known teratogen and can cause
foetal alcohol syndrome.
Mammal: a warm-blooded vertebrate animal that usually has hair/fur and the females
produce milk.
Foetus: an unborn offspring of a mammal, in particular more than eight weeks after
conception.
In the the category of mammals, humans are exceptional and are arguably the most
advanced form of life comparing from the order of primates.
Of the numerous families of primates, humans are members of the family Hominines. Within
this family are two genera: Australopithecus and Homo. We come from the Homo group –
humans are Homo sapiens.
Homo species emerged about 2 million ears ago and are thought to have come from one
species of Australopithecus.
Homo sapiens: the primate species to which modern humans belong.
It is suggested that Homo sapiens can all be traces back to Africa. About 200,000 years ago
Homo sapiens appeared and about 50,000 years ago modern humans began to migrate out
of Africa. This is the ‘Out of Africa’ hypothesis’.
The planet looked different all those years ago and people moved from the African plains in
search of resources. The environmental pressures have therefore shaped modern humans
