human genetic variation

What factors are important when selecting human research participants?

Biological Factors:

• Age, developmental stage

• Health, ability, addiction

• Sex/gender, sexual orientation

• Race, ethnicity

Non-biological Factors:

• Occupation, work status

• Socio-economic status

• Education, family

• Political views, religion

What is the reproductive binary and its exceptions?

• XX and XY chromosomes define sex at birth

• Sex chromosome anomalies exist (XXY, XXX, Turner syndrome)

• Intersex individuals may have anomalies in sexual organ development

• Environmental factors shape gender identity

• Gender/sex reflects interdependence of biological and social processes

What are the key points about IQ and gender differences?

• Environment, parent education, school type explain most variance

• IQ tests have high reliability but limited validity

• Scores can increase with training

• Gender similarity hypothesis: despite biological differences, psychological traits are very similar between men and women

• Alternative theories exist (dynamic assessment, multiple intelligence)

What is the history of genetic research and its misuse?

• 19th century: Evolution theory, Mendel's experiments

• 20th century: Quantitative genetics, molecular genetics

• Eugenics movement misused genetic concepts

• Scientific racism has deep societal impact

• Opposition to eugenics increased after 1925

• Supremacy ideas persist today

What is genetic variation and how is it measured?

Measurement Methods:

• Biometry: measures observable traits

• Genomics: searches DNA for markers

• Uses markers like short sequences, repeated sequences, SNPs

• Requires computational analysis

Causes of Variation:

• Spontaneous DNA changes

• Environmental conditions

• Genetic recombination

• Multiple variants in populations

• Genetic admixture between populations

What did the Human Genome Project reveal about race?

• Race is a social construct, not biological category

• Higher genetic variation within populations than between them

• Term 'race' in genetics is:

  • Unnecessary (population/cluster more accurate)

  • Dangerous (can lead to racism)

• Different countries categorize populations differently

How do genome-wide association studies (GWAS) work?

Benefits:

• Uses SNPs as markers

• Examines whole genome

• Reveals polygenic traits

• Useful for health applications

Limitations:

• Requires many sequenced genomes

• High false positive rate

• Difficult to interpret non-coding DNA

• Ethical challenges in representation and data use

What is the evidence for human migration patterns?

Major Migration Waves:

• 300,000 years ago: across Africa

• 150-80,000 years ago: Middle East & Eurasia

• 60-40,000 years ago: reached Australia

• 20,000 years ago: reached Americas

Evidence from:

• Mitochondrial DNA

• Mixed diet patterns

• Cultural innovations

• Genetic admixture