Functional<\/strong>: describes why a structure\/behaviour evolved as it did. A gene that is prevalent in a large population provides some advantage; gene can spread through process called genetic drift<\/li>\n<\/ol>\n<\/li>\n<\/ul>\nGEiETICS AiD BEHAVIOUR\u00a0 Mendellian Genetics <\/u><\/strong><\/p>\n\n- Before 19th<\/sup> C, scientists thought inheritance occurred by a blending of the sperm and egg<\/li>\n
- Gregor Mendel:<\/strong> inheritance occurs through genes<\/strong> (units of heredity, maintain structural identity from one generation to another)<\/li>\n
- Genes come in pairs because aligned along chromosomes <\/strong>(strands of genes). Gene is part of chromosome, composed of Some genes overlap between chromosomes, other outcome depends on 2+ genes.<\/li>\n
- DNA serves as template for RiA<\/strong>, single stranded molecule, that codes for protein<\/li>\n
- DNA contains 4 bases \u2013 A, G, C, T; order of bases determines order of bases along an RNA molecule, which determines amino acids that compose a protein.<\/li>\n
- Proteins consist of 20 amino acids.<\/li>\n
- Some proteins part of body structures, others enzymes<\/strong> (biological catalyzes that regulates chemical rxns in body)<\/li>\n
- Homozygous<\/strong>: identical pair of genes on 2 chromosomes<\/li>\n
- Heterozygous<\/strong>: unmatched pair of genes<\/li>\n
- Dominant<\/strong>: strong effect in a homozygous or heterozygous<\/li>\n<\/ul>\n
\uf0b7 Recessive: effects only in homozygous conditions <\/em>Sex-Linked and Sex-Limited Genes \uf0b7 Sex-linked genes<\/h3>\n\n- Present in both sexes, genes on sex chromosomes (X and Y), all other chromosomes are autosomal chromosomes<\/strong><\/li>\n
- Females (two X chromosomes); Males (X and Y chromosome)<\/li>\n<\/ul>\n
\uf0b7 Sex-limited genes<\/h3>\n\n- Present in both sexes, generally on autosomal chromosomes, but active mainly in one sex (sex hormones activate in one sex or other) Genetic Changes<\/strong><\/li>\n
- Genes change in several ways<\/li>\n
- Mutation<\/strong>: heritable change in a DNA molecule. Evolution selected best makeup of every gene, new mutation is rarely advantageous<\/li>\n
- Duplication\/deletion<\/strong>: part of a chromosome that should appear once, appears twice or not at all o When this happens to just a tiny portion of a chromosome, it\u2019s called microduplication or microdeletion<\/li>\n<\/ul>\n
\uf0a7 Can be a possible explanation of schizophrenia<\/p>\n
\n- Epigenetics<\/strong>: changes in gene expression without modification of DNA sequence; certain genes active in certain types of cells, or only at a particular time of life<\/li>\n
- Various experiences can also turn a gene on or off<\/li>\n
- Changes in gene expression are also central to learning and memory and to brain changes resulting from drug addiction<\/li>\n
- Epigenetics is new, growing field that will play increasingly important role in our understanding of behavior<\/li>\n
- An experience can modify gene expression; proteins called histones bind DNA into a shape that\u2019s like a string around a ball; the loose ends allow chemical groups to attach. To activate a gene, the DNA must partially unwind from the histones.<\/li>\n
- Result of experience \uf0e0 new proteins into cells\/alter chemical environment<\/li>\n
- Removal of acetyl group causes histone to tighten grip on DNA \uf0e0 turns gene off<\/li>\n
- Adding methyl group to promotes \uf0e0 turns genes off; removing them \uf0e0 turns gene on<\/li>\n<\/ul>\n
\u00a0Heredity and Environment<\/h2>\n\n- To determine contributions of heredity and environment, rely on:<\/li>\n
- Monozygotic<\/strong>: from one egg (identical twins) \uf0e0 same gene<\/li>\n
- Dizygotic<\/strong>: from two eggs (twins) \uf0e0 not same gene<\/li>\n
- Adopted children<\/strong>: if children resemble their biological parents, there is high heritability. If children are similar to adopted parents, any similarity is due to environmental influences.<\/li>\n
- Virtual twins<\/strong>: children of the same age, adopted at the same time into a single family; grow up in same environment from infancy, but without any genetic similarity<\/li>\n<\/ul>\n
\uf0b7 Genes linked to a behaviour<\/h3>\n\n- Evidence for heritability for almost every behaviour; estimate of heritability for a trait is specific to the population<\/li>\n<\/ul>\n
Environmental Modification: <\/strong>a trait with high heritability can be modified by environmental interventions; the effect of a gene depends on the person\u2019s environment<\/p>\n\n- How genes affect behaviour:<\/strong> hard to explain how gene increases probability for given behaviour; some directly control brain chemicals, others have indirect affect.<\/li>\n<\/ul>\n
\u00a0The Evolution of Behaviour<\/h2>\n\n- Evolution<\/strong>: change over generations in the frequencies of various genes in a population<\/li>\n
- Any change in gene frequencies<\/li>\n
- Do species evolve? Offspring resemble parents; recombination\u2019s, microduplications, and mutations introduce new heritable variations that help or harm chance of survival; certain individuals reproduce more successfully then others, so the new generations will more closely resemble them.<\/li>\n
- Artificial selection<\/strong>: choose individuals with desired trait, make them parents to the next generation.<\/li>\n
- Charles Darwin \uf0e0 nature also selects<\/li>\n<\/ul>\n
Common misunderstandings about evolution<\/h3>\n\n- Failing to use some body structure doesn\u2019t change the genes<\/li>\n
- Lamarckian Evolution<\/strong>: inheritance of acquired characteristics; evidence not found for theory<\/li>\n
- Evolution depends on reproduction, not just survival<\/li>\n
- Evolution doesn\u2019t mean improvement; fitness<\/strong> means number of genes that survive to the next generation \u2013 this can be positive and one point, but negative in the future<\/li>\n
- Genes of current generation evolved because they were fit for previous generations<\/li>\n
- Evolution doesn\u2019t benefit the individual, it benefits the genes<\/li>\n<\/ul>\n
Evolutionary Psychology<\/h3>\n\n- How behaviours evolved<\/li>\n
- Presumed genes of ancestors and why natural selection might favour genes that promote certain behaviours<\/li>\n
- Assume any behaviour arose through natural selection and provided some advantage.<\/li>\n
- BUT some characteristics of species have less relationship to natural selection<\/li>\n
- Altruistic behaviour<\/strong>: action that benefits someone else; help other individuals spread genes<\/li>\n
- Common among humans, less in animal world; may cost little, but still has cost & altruistic behaviour may benefit species, but not gene in the individual.<\/li>\n
- Group selection<\/strong>: altruistic groups survive better \uf0e0 but this is unstable<\/li>\n
- Kin selection<\/strong>: select for a gene that benefits the individual\u2019s relatives \uf0b7 Helpful behaviour is more common towards relatives<\/li>\n
- Reciprocal altruism<\/strong>: individuals help those that will return the favour<\/li>\n<\/ul>\n
THE USE OF AiIMALS Ii RESEARCH <\/u><\/strong><\/p>\n\n- Debate about the use of animals in research<\/li>\n
- Research on animals is responsible for a lot of knowledge on brain and behaviour but we want to minimize animal distress Reasons for Animal Research <\/u><\/strong>\uf0b7 Study non-humans:\n
\n- Underlying mechanisms of behaviour similar across species, easier to study o Brains and behavior of nonhuman vertebrates resemble those of humans in chemistry and anatomy<\/li>\n
- Interested in animals for own sakeo Wider variety of species, relating behaviors of each animal<\/li>\n
- What is learnt about animals sheds light on human evolution o Comparing species<\/li>\n
- Legal or ethical restrictions prevent certain types of research on humanso If research unacceptable with humans, is it also unacceptable with other species? The Ethical Debate <\/u><\/strong><\/li>\n<\/ol>\n<\/li>\n
- In some cases, researchers just observe animals. in others, animals are subject to brain damage, injections that aren\u2019t for their own benefit<\/li>\n
- In many areas, there wouldn\u2019t be as much advancement without animal research<\/li>\n<\/ul>\n