ANP 220 Fundamentals of evolutionary theory I

example of class topics

evolution of bipedality

• possible benefits of bipedality (=effects of natural selection

culture and spread of the disease

• possible benefits of genetic disease or chance (effects of natural selection or genetic drift/ founder effects/lack of gene flow

human diversity

• adaptation to environments/culture (-effects of natural selection, gene flow, etc.)

biological evolution

definitions and patterns - descent with modification (change through time)

• small-scale population level - microevolution - genetic inheritance

• large- scale - species level - macroevolution

→ explains biodiversity

genetic inheritance

phenotypes genotypes, DNA, genes, and alleles

energetic variation and mechanisms of genetic change

mutation, gene flow, genetic shuffling and sex, genetic drift, and natural selection

history of life central idea

• species share common ancestors

• depicted through a family tree, phylogeny

• based on similarities also used for classification

phylogeny

= evolutional relationships among organisms (phylogeny w/o time = cladogram)

process of evolution

descent with inherited modifications

• change through time; genetic inheritance

relies on genetic variation - is driven by 4 mechanisms (mutation gene flow, genetic drift; natural selection, sexual reproduction

gene

part of a chromosome that encodes a gene product

• proteins responsible for the structure, functions and regulation of the body tissues and orans

• receptor hormones, oxygen transport, antibodies

• same or different on homologous chromosomes

body cells

two chromosomes of a particular kind

gametes

one chromosome of a particular kind

sex cells that join e and sperm to combine hereditary information

mechanisms of evolutionary change

non-adaptive - mutation - gene flow - genetic drift

adaptive - natural selection - sexual selection

sources of genetic variation

mutation in gametes, gene flow, genetic shuffling, and sexual reproduction

mutation

(random) changes in genetic information - can be harmful, neutral, or beneficial

evolutionary effects of mutations

• DNA changes in gametes

• pass on to next generation

more soucres of genetic variation

mutation in gametes - new genetic info passed on to offspring

gene flow -new genetic info into a population - passed onto offspring

genetic shuffling and sexual reproduction - new combination of genetic info passed on to offspring - combo of parent's genetic info

gene flow

movement of organisms to a new place

introduction of new genetic material

• increases genetic variation in a population

genetic shuffling and sexual reproduction

• new combination of genetic info passed on to offspring

• combination of parents’ genetic

genetic drift - change in allele frequency due to chance

always present

effects - reduces variation - may lead to speciation - stronger in small populations

importamce of genetic drift

controversial - neutral theory of evolution

• most variation because of nutation and genetic drift

may have a strong effect

• some variation accumulated because of genetic drift - RANDOM process

grandfathers of evolutionary theory

Charles Darwin and Alfred Russel Wallace

how to explain biodiversity

evolution by means of natural selection

preconditions for natural selection

inheritance - genetic variation - environmental pressure (filter which selects advantage traits

→ results (natural selection)

• individuals with advantageous traits survive better and have more offspring

• advantageous traits will be more common in the next generation (mire individuals have the trait)

learning objective or ‘what you should know’