Human Genetics and Evolution Pt. 1 (CH.4) (copy)

Nature

Influenced by biological factors/genetics

Nurture

Influenced by experiences: environmental/social factors

Plato

Believed who we are is pre-determined from when we were born

Aristotle

Believed we mostly learned through experiences/nuture

Behaviour Genetics

Studies how genes and heredity affect/cause human beahviour

Hereditary

traits passed from parents to their children

Genes

The biochemical units of hereditary found on DNA

Where are genes found

human body - cells - chromosomes - DNA - gene sequences

Genes and proteins

Inside DNA you have genes which manage the development of proteins which makes up cells and serves cells

Chromosomal Inheritance

23 pairs of chromosomes (46 total), each pair has one allele from the mother and one from the father. Sex chromosomes determine bio sex (xx or xy)

Alleles

different versions of a gene (ex. one for hair, eye colour)

Genome

the full collection of a creature/organisms genes. Human genes are nearly the same but have small genetic differences which result in big differences. (ex. Humans and chimpanzees has 1-4% gene difference)

Code to structure

DNA genes are translated into copies (RNA)

Identical twins

shares the same fertilized egg, and has nearly identical DNA

fraternal twins

has two separate eggs, are genetically close rto siblings and share 50% DNA

separated identical twins

Twins grow up in different households/environments/different experiences while having the same genetic predispositions

Indentical vs Fraternal

Similar life experiences/ growing up together but genetically different.

Influence of genes on Heritability

the degree in which traits are different due to genes. Traits heritability are different depending on group, and only has accurate estimates are only valid if measuring same group.

Heritability in Twins despite separation (adoption)

Similar personality, skills/intelligence, interests, preferences and fears. Bio: brain activity/waves, heartrate

Biological vs adoption

Children are more similar to biological parents, except for beliefs (religion, politics, morals, manners, habits, life outcomes) which are mainly determined by adoptive parents

Critiques of Twin Studies

Adoptive families can be similar in how they raise children, as the adoption process is strict and only select families that can provide good education, are financially well off, and have decent values. And so, similarities between separated twins might not be due to genetics but by chance

Genes and environment

Genes impact how the brain works and those how we are in social in environments which also helps shape us

Missing Hereditary problem

While there is strong heritability for traits between adopted twins, the specific genes for these traits aren't identified, the results are based primarly on association studies

Epigenetics

how environmental factors impact genes without changing DNA coding

Self-regulation (epigentics)

genes turn on and off in response to environment (shedding seasons), over generations: obesity

Experience and Brain Development

Quality of environments affect the brain structure

Evolutionary Psychology

Studies how nautral selection affects evolutionalized behaviours

3 requirements for natural selection

leads animals to adapt their genes to meet environmental conditions

Varation

People within a population vary with their traits, and new gene combonations are due to mutation

Genetic Legacy

Our prehistoric lifestyle is incompatible/different to our current way of living life (ie. instead of hunting for food we go to the grocery store)

DIfferences in Mating behaviours

While both sexes face similar survial challenges, due to women's difference in reproduction they need more resources for a baby 9 months, males on the other hand can reproduce without any biological responsibilities

Differences in Sexual Selection

Across all cultures, men are more sexual than woman (thinking of sex, seeking sex) While women this is less as it would be a disadvantage and reproducing is intensive, and dangerous

Prefernces in sexual selection

Men prefer fuller figure because it signals peek fertility, while women are more converned with status, loyalty, resources. Women's choice is directed toward best chance of survival while men's is toward best change of fertility

Evolutionary Psychology explains

it is hard to provide evidence so offers a solution

social transmission of knowledge

communication is complex in humans while simple in animals