Bio Readings: Evolution, Population Genetics Flashcards
(Understanding Evolution) evolution by natural selection describes a mechanism for how species
change over time
(Understanding Evolution) ideas about the evolution of animals were reintroduced by naturalist buffon in the 18th century, who observed that various geographic regions have different … and …, even when the environments are similiar. It was also accepted that there were ..
plant; animal populations; extinct species
(Understanding Evolution) James Hutton, a Scottish naturalist, proposed that geological change occurred … by the accumulation of small changes from processes operating like they are today over long periods of time
gradually
(Understanding Evolution) Hutton’s theory contrasted with the predominant view that the geology of hte planet was a consequence of … occurring during a relatively brief past
catastrophic events
(Understanding Evolution) Geologist Charles Lyell, Darwin’s friend, presented the notion that the Earth was … than expected, which gave more time for … in species,
older; gradual change
(Understanding Evolution) Lamarck published his theory for the mechanism of evolutionary change known as …, by which modifications in an individual are caused by its …, or the … or … of a structure during its lifetime, could be inherited by its offspring and thus bring about change in a species
inheritance of acquired characteristics; environment; use; disuse
(Understanding Evolution) in the 19th century, the actual mechanism for evolution was independently conceived of and described by two naturalists: … and …
charles darwin; alfred russel wallace
(Understanding Evolution) both darwin and wallace had spent time exploring the natural world on expeditions to the
tropics
(Understanding Evolution) On the Galapagos Islands, Darwin observed species of organisms on different islands that were clearly similar, yet had …
distinct differences
(Understanding Evolution) one of the species Darwin observed were the ground finches. He imagined that the derivative species might be modified from one of the
original mainland species
(Understanding Evolution) Natural selection, also known as “…” is the more prolific reproduction of individuals with favorable traits that survive … because of those traits; this leads to …
survival of the fittest; environmental change; evolutionary change
(Understanding Evolution) according to Darwin, natural selection was an inevitable outcome of 3 natural principles:
- most characteristics of organisms are …
- more offspring are … than are able to …, so resources for survival and reproduction are … This leads to … for recourses in each generation (this came from reading an essay by Malthus about population limitation)
- offspring … among each other in regard to their characteristics and those variations are inherited
inherited; produced; survive; limited; competition; vary
(Understanding Evolution) Darwin and Wallace reasoned that offspring with inherited characteristics which allow them to best compete for limited resources will .. and have more … than those individuals with variations that are less able to compete. Because characteristics are inherited, these traits will be better … in the next generation. this will lead to change in populations over generations in a process called …
survive; offspring; represented; descent with modification
(Understanding Evolution) ultimately, natural selection leads to greater … of the population to its local environment; it is the only mechanism known for … evolution
adaptation; adaptive
(Understanding Evolution) The Grants performed an experiment on the Galapagos finches, showing … in the distribution of beak shapes over generations
natural selection
(Understanding Evolution) natural selection can only take place if there is … among individuals in a population. These differences must have some … basis, otherwise the selection will not lead to change in the next generation
variation; genetic
(Understanding Evolution) genetic diversity in a population comes from two main mechanism: … and …
mutation; sexual reproduction
(Understanding Evolution) …, a change in DNA, is the ultimate source of …, or new genetic variation in any population
mutation; new alleles
(Understanding Evolution) the genetic changes causes by mutation can have one of three outcomes on the phenotype:
a mutation affects the phenotype of the organism in a way that gives it …—lower likelihood of survival or fewer offspring
a mutation may produce a phenotype with a … effect on fitness
and many mutations will also have … effect on the fitness of the phenotype; these are called … mutations
reduced fitness; beneficial; no; neutral
(Understanding Evolution) sexual reproduction also leads to genetic diversity: twhen two parents reproduce, unique combinations of alleles assemble to produce the unique genotypes and thus … in each of the offspring
phenotypes
(Understanding Evolution) a heritable trait that helps the survival and reproduction of an organism in its present environment is called an
adaptation
(Understanding Evolution) scientists describe groups of organisms becoming adapted to their environment when a change in the range of genetic variation occurs over time that … or … the “fit” of the population to its environment
increases; maintains
(Understanding Evolution) whether or not a trait is favorable depends on the … at the time. The same traits are not always selected because environmental conditions can change
environmental conditions
(Understanding Evolution) when two species evolve in diverse directions from a common point, it is called
divergent evolution