Exam 2 Part 6 Flashcards
Gene frequencies stay the same in a population from generation to generation UNLESS disturbing forces are introduced; population is NOT evolving
Hardy-Weinburg equilibrium
Random change in the genetic code introducing new alleles in to the gene pool after reproduction; can be neutral or harmful; slow to accumulate major changes into genotype frequencies
Mutation
All variants begin as ____ in specific individuals
Mutations
What is the ultimate source of new genetic variation?
Mutations
_____ exists in all individuals of a population
Variation
Variation is _____
Heritable
Variation leads to differences in individual _______
Fitness
What are the exceptions of X-link dominant/recessive?
Albinism, achondroplasia, sickle cell anemia, Rh factor in blood
Body does not produce melanin, having no protection against UV rays; autosomal homozygous recessive,
Albinism
Not on the sex chromosome; 22 non-sex chromosome pairs
Autosome
On the sex chromosome; 1 pair of sex chromosomes
Allosome
Example of selection against recessive homozygote
Albinism
Example of selection against dominant homozygote
Achondroplasia
Example of selection against heterozygote (2)
Sickle cells, Rh factor in blood
What 4 conditions are found on autosomes/autosomal?
Albinism, achondroplasia, sickle cell, Rh factor
Natural selection acts upon ____ variation; does not create variation/genes
Existing
True or false: Traits that are adaptive can be adaptive in another, or if the environment changes
False; cannot be adaptive in another
What factors are needed for a trait to evolve by natural selection (4)?
Be heritable, increase the fitness of the individual, increase in frequency in a population over generations
Reproductive success, how many offspring (genes) that an organism produces
Fitness
Random changes in gene frequencies from generation to generation caused by chance; effects are greatest in small population, genes/traits are NOT being selected for
Genetic drift
