Chapter 1. *Biological Evolution Change in the properties of groups of organisms over the course of generations. *Populations do evolve: they undergo descent with modification
.
*No more dramatic example of evolution by natural selection can be imagined than today’s crisis in antibiotic resistance.
*As the use of antibiotics increases, so does the incidence of bacteria that are resistant to those antibiotics; thus any gains made are almost as quickly lost.
*Essentialism
Variation is accidental imperfection.
*As late as the 18th century, natural history was justified partly as a way to reveal the plan of creation so that we might appreciate God’s wisdom.
Carolus Linnaeus
, who established the framework of modern taxonomy in his
Systema Naturae
.
*Belief in the literal truth of biblical story of creation started to fade away in 18th century, when a philosophical movement called the
Enlightenment
, largely inspired by Newton’s explanations of physical phenomena.
*Lamarck
proposed that each species originated individually by spontaneous generation from nonliving matter, starting at the bottom of the chain of being
.
*The theory of evolution based on this principle is called
Lamarckism
.
*The Origin of Species contains two major theses. First one is
Darwin’s Theory of descent with modification
. It holds that all species, living and extinct, have descended, without interruption, from one or a few original forms of life. Second one is
The origin of species is
Darwin’s theory of the casual agents of evolutionary change
.
Evolution as such is the simple proposition that the characteristics of lineages of organisms change over time.
Common descent is a view of evolution that is radically different from the scheme
Lamarck had proposed. Darwin was first to argue that species had diverged from common ancestors. Gradualism is Darwin’s proposition that the differences between even radically different organisms have evolved incrementally, by small steps through intermediate forms.
Populational change is Darwin’s hypothesis that evolution occurs by changes in the proportions of individuals within a population that have particular inherited characteristics.
Natural selection was Darwin’s brilliant hypothesis, independently conceived by
Wallace, that changes in the proportions of different types of individuals are caused by difference in their ability to survive and reproduce, and that such changes result in the evolution of adaptations, meaning organisms fit to their environment.
*The creationist movement opposes the teaching of evolution in public schools, or at least demands “equal time” for creationist beliefs.
*
NeoLamarckism includes several theories based on the old idea of inheritance of modifications acquired during an organisms’s lifetime.
*
Theories of Orthogenesis (Straightline evolution) held that the variation that arises is directed toward fixed goals, so that a species evolves in a predetermined direction without the aid of natural selection.
*
Mutationist theories were advanced by some geneticists who observed that discretely different new phenotypes can arise by a process of mutation.
*
Evolutionary synthesis adaptive evolution is caused by natural selection acting on particulate genetic variation, is often referred to as neoDarwinism .
Chapter 1 : Evolutionary Biology Charles Darwin : “ all the organic beings which have ever lived on this earth have descended from some one primordial form” . Changes are due to evolutionary history. Theodosius Dobzhansky
Nothing in Biology makes sense , except the light of evolution.
What is evolution? Biological Evolution
change in the properties of groups of organisms over the course of generations. The development or ontogeny of an individual organism is not evolution .
Individual organisms do not evolve groups of
