Chapter 2 - GENETIC BASES OF DEVELOPMENT Evolution and...

Info iconThis preview shows pages 1–16. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: GENETIC BASES OF DEVELOPMENT Evolution and Heredity We inherit genes from our parents Evolution: nature of genes has evolved Genes determine behaviors and physical traits E Traits that are adaptive E Aid in survival and reproduction Evolution Basic concept: Individuals that possess traits that aid in survival are more likely to live to pass on those traits to their offspring Individuals w/out those traits are less likely to reproduce The population gradually changes so that nearly all individuals possess these adaptive traits Natural Selection Outline of evolution/speciation Evolve through single celled organism, through primitive forms, underwater vertebrates, forms with limbs, forms with developed neural systems E Phylogeny: the evolutionary history of a given organism (or species the organism belongs to) What does this have to do with individual development? Ontogeny: the developmental history of an individual Human Embryo: single cell, then simple multi-cellular form, then simple form with gills, then development of skeletal structure, and musculoskeletal system, and nervous system/brain structures A classic philosophical question among developmental theorists... Does Ontogeny recapitulate phylogeny? Does the development of an individual organism follow the same path/stages as the development of the species? Why might it do so? Do genes have anything to do with it? Heredity and Chromosomes Each egg and each sperm contain 23 chromosomes Fertilization: sperm and egg combine Embryo has 46 chromosomes E Defines the childs heredity Including sex and other physical traits Chromosomal abnormalities Down Syndrome E Trisomy 21: An extra copy of chromosome 21 (have 3 instead of 2) E Facial deformities, delayed motor and mental abilities E Increased risk with age of mother Klinefelter syndrome E Males have extra x chromosome (XXY instead of XY) E Undeveloped testes and some feminine features (including breasts) Fragile X syndrome E Damaged X chromosome E Delayed or reduced mental abilities Chromosomal abnormalities Turner syndrome E Females missing one of the X chromosomes E Some physical deformity, infertility and some mental retardation XYY syndrome E Males with an extra Y chromosome E Slight increases in physical growth rate E Slight delays in language development Chromosomes Each chromosome is a DNA molecule Each chromosome consists of 30,000- 50,000 genes Genes regulate development of physical and psychological traits and abilities E How? Effects of genes Individuals not the sole product of their genes Environmental factors influence development as well Genotype: a persons genetic makeup Phenotype: a persons actual features The genotype and phenotype are not identical Development Genes determine genotype Genes + Environment determine phenotype What is inherited?...
View Full Document

This note was uploaded on 05/16/2011 for the course DEP 2004 taught by Professor Staff during the Spring '08 term at University of Central Florida.

Page1 / 61

Chapter 2 - GENETIC BASES OF DEVELOPMENT Evolution and...

This preview shows document pages 1 - 16. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online