THE EVOLVING

MIND

By:-Anjali Srivastava

Mind The brain and its activities,including thought, emotion, and behavior.

Nature The contributions of heredity to our physical structure and behaviors.

Nurture The contributions of environmental factors and experience to our physical structure and behaviors.

Psychology The scientific study of behavior and mental processes.

HAVE YOU NOTICED TWINS???

When we see a identical twins we usually amaze over the similarities..

But if we see scientifically they share the same DNA …then why they are are not completely same.. Why one gets obses one doesnot..one gets cancer one not..??

Let us puzzle our minds and try to solve and find the reasons of difference.

We have the same set of DNA in all the cells,yet some becomes heart cells, some liver cells, likewise different kinds of cells are formed.

The reason behind this is that genes can be turned on or off.

The genes which are not turned off produce the protein needed to built a particular type of cell.

Genes can also be turned off by environmental factors like whether we smoke or drink ,our stress level,what we eat etc.

In mice, gene Agouti produces yellow fur and obesity when turned on and brown fur and normal weight when turned off.

If pregnant mother mice eat food containing bisphenol-A. The BPA seems to have turned on the agouti gene.

Thus, we can conclude that in case of identical twins the difference between them as they grow old is due to differences in their habits which changes the way their genes are turned on and off.

Genes are not just the puppets or blueprints.

Nor just the carriers of heredity. They are active during life span,they

respond to the environment. There are both cause and consequence of

our actions.

GENES, BULLYING, AND EMOTIONAL PROBLEMS

Researchers have known for a long time that victims of bullies often, but not always, develop serious emotional problems later in childhood or adolescence.

Having a particular genetic profile involving serotonin, one of the chemical messengers

BUILDING BLOCKS OF BEHAVIOUR

As we know that each cell in our body except blood cells and sperm or egg cell have two comlpete copies of human genome,that contain instructions for building a human body.

Your personnel set of instructions is called as genotype which interacts with environment to produce observable characteristic called phenotype.

RELATEDNESS

A single human can produce 2^23 (8,388,608) different combinations of his or her chromosome.

Inspite of this much potential variation , we remain very similar to our genetic relatives.

Relatedness is defined as the probability that two persons share copies of the same allele from a common ancestor.

EPIGENETICS When factors other than genotype itself

produces changes in phenotype , its called as epigenetic change.

The environment can determine if and when a particular gene is active.

In one dramatic example it was observed that the rats which were licked(similar to hug)by their moms were calmer than the other rats which were infrequently huged.

By licking their pups,these mothers have influence the expression of gene that determine responses to stress hormone.

BEHAVIOURAL GENETICS The field of behavioural genetics attempts

to identify and understand the links between genetics and behaviour.

Behavioral geneticists are less interested in genes we share with other species than in those that make us different from them.

Recent research points to difference between humans and chimpanzee in a single gene ,the Fox p2 that appears to have had a significant effect on distinctly human behaviours including spoken language.

Behavioral geneticists often speak in terms of the heritability of a particular trait, or the statistical likelihood that variations observed across individuals in a population are due to genetics.

Heritability is usually presented as a ratio of the amount of variation observed in a population due to genetics relative to the total amount of variation due to both genetic and environmental influences.

For example, genes are responsible for us having hearts, but there is no individual variation in the population in terms of the presence of a heart—we all have one. Consequently, the heritability of having a heart is 0.0.

All variation in the population in terms of having or not having a fatal neurological condition known as Huntington’s disease is entirely due to genetics. If you inherit a Huntington’s gene from one parent, you will develop the condition, so the heritability of Huntington’s is 1.0.

Heritability always refers to populations, not to individuals.

Heritability cannot be assessed without taking the environment into account some researchers question the use of adoption studies for assessing the relative influences of genetics and environment on child development.

These studies compare adopted children to their biological and adoptive parents in an effort to assess the relative impact of heritability.

It is important to remember that genes encode for proteins, not behaviors. Genes build proteins that are used to construct brains, and brains may or may not initiate the behavior of drinking alcohol.

EVOLUTION The human genome is the product of millions

of years of evolution, defined by modern biologists as “descent with modification from a common ancestor.”

Charles Darwin proposed that species evolve or change from one form to the next in an orderly manner.

Gregor Mendel (1822–1884), who discovered ways to outline and predict the inheritance of particular traits, like the color of flowers, in his research on pea plants (Mendel, 1866).

In addition to the process of natural selection described by Darwin, evolution can result from mutation, migration, and genetic drift.

Type B blood is virtually absent in contemporary populations of Native Americans, most likely due to chance (Halverson & Bolnick, 2008).

The handful of ancestors crossing the Bering Strait 10,000 years ago appears to have included no individuals with the Type B allele.

Adaptation can refer to either the process or the result of change due to natural selection.

THE CONTEMPORY HUMAN BRAIN

Although we can understand the advantages of big, intelligent brains to survival, we do not know why advances such as agriculture, literacy, and urbanization have not been accompanied by additional increases in brain size.

Genes involved with brain development appear to have changed as recently as 6,000 years ago.

IQ test scores have increased dramatically worldwide over the last 100 years.

It is likely that environmental factors, including nutrition and education, might account for the improvement.

DOES EVOLUTION INFLUENCE BEHAVIOUR Behaviour can be adaptive but behaviour as a

phenotype is considerably more complex. Behaviour is not an anatomical structure like

a wing or an eye. In his Descent of Man, Darwin writes: The difference in mind between man and the

higher animals, great as it is, certainly is one of degree and not of kind. We have seen that the senses and intuitions, the various emotions and faculties, such as love, memory, attention, curiosity, imitation, reason, etc., of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition in lower animals.

ORIGINS OF SOCIAL BEHAVIOUR

A number of factors are believed to influence the social behavior of any particular species, including mating systems, the availability of resources such as food, water, and shelter, the exposure to predators, and competition.

In typical environments, individual animals are likely to come into contact with others, leading to a variety of possible interactions and outcomes.

In altruism, one individual sacrifices himself or herself to benefit another individual.

A honeybee sting, which is suicidal behavior on the part of the bee in an effort to protect its hive .

Charles Darwin himself was puzzled by the apparent sacrifice of some individuals that led to the survival of the group.

If altruism results in the destruction of the individual with altruistic genes, why doesn’t this behavior disappear?

In cases of reciprocal altruism, it is customary to help another individual when you can reasonably expect the other individual to return the favor at some future date.

SEXUAL SELECTION Sexual selection was Darwin’s term for

the development of traits that help an individual compete for mates.

Genghis Khan may have been the most prolific human male in history. His distinctive Y chromosome has been identified in 16 million living men, or 0.5% of the world’s current total.

Women have the ability to make very accurate predictions of a man’s interest in children, simply by looking at a photograph of his face.

TRAITS POSSIBLY INFLUENCED BY SEXUAL

SELECTION Sexual selection might occur in two ways. In

intrasexual selection (intra means “within”), members of one gender compete with each other for access to the other gender.

In intersexual selection (inter means “between”), characteristics of one gender that attract the other might become sexually selected.

Evolutionary psychologists have argued that a number of human traits might have been subjected to sexual selection, including humor and vocabulary.

According to the researchers, environmental influences, such as peer attitudes and exposure to “Dad’s humor,” may have dominated the development of each woman’s sense of humor.

Significant evidence points to a very important role for humor in human mate selection.

Men were interested in women who appreciated, rather than produced, humor, while women were interested in men who made them laugh.

Women appear to signal their interest in a man by laughing frequently ,whereas the frequency of men’s laughter appears to be unrelated to their judgment of a woman’s attractiveness

Producing a good joke requires sophisticated cognitive skills, creativity,and the ability to see situations from more than one point of view, qualities that signal the good intellectual and social functioning preferred by females.

According to evolutionary psychologists, humor might be used by humans to attract mates, because humor indicates intelligence.

INTERPERSONAL RELATIONSHIPS

FROM AN EVOLUTIONARY PERSPECTIVE

The human mind has been shaped by its history.

The evolutionary approach, suggests that another type of compatibility is important for relationships—a compatibility of genes that contribute to the immune system.

A cluster of genes known as the major histocompatibility complex (MHC) appears to be subject to sexual selection.

A child with a heterozygous set of MHC genes is better prepared to battle infections than is a child with MHC genes that are similar to one another.

As a result, our children are more likely to survive if we select a mate that has a different set of MHC genes than we do.

Short of asking potential mates to undergo DNA testing,how are we supposed to accomplish this?

Different configurations of the MHC genes produce distinctive body odors that are easily detected and distinguished from one another.

When men and women were asked to rate the pleasantness of the odors of T-shirts.

They preferred smells associated with MHC genotypes that were different from their own.

Gender did not play a role—smell preference was not influenced by whether the T-shirt wearer had been of the same or the opposite gender as the perceiver.

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