Darwin’s Problems He lacked the knowledge of hereditary or How the passing of genes worked
Process of speciation natural selection, change in environment can change the frequency of alleles in a population this is how a new species is created SPECIATION
Populations Those individuals have genes and therefore are a collection of genetic material they are a collection of a species in a community GENE POOL
Gene Pool has genetic variation Mutation: When the DNA changes, usually due to a random mistake while replicating Recombination of gametes: When the genes in gametes mix and match these pieces (CROSSING OVER)
Genetic Recombination Its at random only during Meiosis Sexual reproduction allows for more genetic variation
Mutation Doesn’t always at first alter phenotypes the DNA code becomes different
Frequency of genes/traits always equals 100% Represented by a bar graph single gene trait -->
Polygenetic Trait Most traits Always a Represented by a bell curve
Evolution and genetic change Natural selection on genetic traits can lead to changes in allele frequency and thus to evolution
Natural Selection and Traits Natural selection can affect the distributions of phenotypes Fitness can put a individual on either end of the curve, When fitness varies natural selection acts
Natural Selection in nature 1. More organisms are born than can survive. 2. Organisms vary in their characteristics, even within a species. 3. Variation is inherited 4. Differences in reproduction and survival are due to variation among organisms.
Genetic Drift Random change in allele frequency. Individuals leave more descendants with their alleles by chance, over time it may survive and cause allele to become more common
Think Iceland Founder effect: is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population Norse, irish, english peoples living on a small island mating with no immigration. So now they're mostly all white blond, and a group of Giants