Genetics and Evolutionary Foundations Chap3

Darwin’s Theory

"Charles Darwin proposed the theory of evolution to explain both differences and similarities between species. Evolutionary theory also applies to behavior."

What are genes?

"Genes are segments of DNA that provide codes for proteins; they influence behavior through biological processes."

What are structural proteins?

"Proteins that form the structure of cells and tissues."

What are enzymes?

"Proteins that control the rate of chemical reactions in the body."

What is DNA?

"Deoxyribonucleic acid; the molecule that carries genetic information."

What are coding genes?

"Genes that serve as templates for RNA

What are regulatory genes?

"Genes that regulate the activity of coding DNA; once thought to be 'junk DNA.'"

How do genes interact with the environment?

"Genes work only through interaction with the environment — every aspect of surroundings except the genes themselves influences genetic expression."

What is genotype?

"The set of genes an individual inherits."

What is phenotype?

"The observable properties of the body and behavioral traits influenced by genes and environment."

How are genes passed through reproduction?

"DNA exists in chromosomes; humans have 23 pairs — 22 autosomal and one pair of sex chromosomes (XX or XY)."

What are chromosomes?

"Structures within cells that contain DNA and carry genetic information."

What is mitosis?

"Cell division producing identical cells (for growth and repair)."

What is meiosis?

"Cell division that produces reproductive cells (sperm and eggs) with half the number of chromosomes

Why is genetic diversity important?

"It increases the chance of survival by creating varied combinations of genes across generations."

What are identical twins?

"Twins from one fertilized egg that splits; share 100% of their genes."

What are fraternal twins?

"Twins from two separate fertilized eggs; share about 50% of their genes."

What is homozygous?

"Having two identical genes (alleles) at a locus on a chromosome pair."

What is heterozygous?

"Having two different genes (alleles) at a locus on a chromosome pair."

What are alleles?

"Different forms of a gene that can occupy the same locus on a pair of chromosomes."

What is a dominant gene?

"A gene that expresses its observable effects in either homozygous or heterozygous conditions."

What is a recessive gene?

"A gene that expresses its observable effects only in the homozygous condition."

What is Mendelian inheritance?

"The pattern discovered by Gregor Mendel

What are examples of single-gene inheritance?

"Fearfulness in dogs and genetic disorders such as phenylketonuria (PKU)."

What is selective breeding?

"Modifying specific behaviors or traits by mating individuals with or without certain characteristics."

What is epigenetics?

"Study of gene-regulating activity that doesn’t involve DNA code changes but can persist across generations."

What is DNA methylation?

"An epigenetic mechanism where methyl groups attach to DNA

What is natural selection?

"Process where traits increasing survival and reproduction are passed on more often than others."

What is artificial selection?

"Human-controlled selective breeding to produce desired traits."

What are Darwin’s core concepts of natural selection?

"Overproduction of offspring

What provides the material for natural selection?

"Genetic diversity — reshuffling of genes during reproduction and mutations."

What causes evolution to occur?

"Environmental changes that select for traits advantageous in new conditions."

Why does evolution have no foresight?

"It does not aim toward a goal; changes occur based on current environmental pressures

What is the naturalistic fallacy?

"The false belief that what is natural is inherently good or right."

What is functionalism in psychology?

"Approach explaining behavior by what it accomplishes for the individual; how traits help survival and reproduction."

What is a distal explanation?

"An evolutionary-level explanation of why a behavior exists (its survival or reproductive function)."

What is a proximate explanation?

"An immediate explanation describing how a behavior occurs (its mechanisms)."

What are limitations of functionalist thinking?

"Some traits are vestigial

What are species-typical behaviors?

"Behaviors characteristic of all members of a species

What is biological preparedness?

"The innate ability to learn certain behaviors easily because they were adaptive in evolution."

What is an example of a species-typical reflex in humans?

"Infants are born with a stepping reflex."

What are the key questions for studying behavior?

"1) What environmental conditions are needed? 2) What internal mechanisms are involved? 3) What are the behavior’s consequences? 4) Why did natural selection favor it?"

What are homologies?

"Similarities due to common ancestry; used to study evolutionary development of behaviors."

What are analogies?

"Similarities due to convergent evolution — independent evolution of similar traits."

Why are homologies important in psychology?

"They help trace the evolutionary history of behaviors such as facial expressions or emotional displays."

What drives evolution?

"Mating — the passing of genes to the next generation."

What are the four mating systems?

"Polygyny, monogamy, polyandry and promiscuity

What is parental investment?

"Time

What does Trivers’ theory (1972) state?

"The sex that invests more in offspring will be more selective in mate choice; the other sex will compete for access."

What is polygyny?

"Mating system with one male and multiple females; associated with high female and low male parental investment."

What is polyandry?

"Mating system with one female and multiple males; associated with high male and low female parental investment."

What is monogamy?

"Mating system where one male pairs with one female; both invest equally in offspring."

What is promiscuity?

"Mating system involving multiple mating partners with group-level care or cooperation."

What are human mating patterns?

"Mostly monogamous but partly polygamous; romantic love and jealousy influence mating."

What are sex differences in aggression?

"Males are generally more violent; aggression often linked to mating competition and reproductive success."

What is cooperation?

"Helping others while also helping oneself (e.g.

What is altruism?

"Helping others at a cost to oneself; explained by kin selection or reciprocity theories."

What is kin selection theory?

"Apparent altruism makes evolutionary sense if it helps genetic relatives survive and reproduce."

What is reciprocity theory?

"Helping others with expectation of future help — cooperation over time."