Evolution Flashcards
Describe the ideas proposed by Jean Lamarck involving inheritance of acquired characteristics.
Lamarck hypothesized that disuse resulted in the degeneration of organs. So, he thought that “need” was dictated by environmental change and that change involved movement toward perfection. This led him to conclude that species could not become extinct, rather they simply evolved into different species.
Describe the major influences on Darwin during his early years including his voyage on the H.M.S. Beagle,
Charles Darwin grew up with a family of physicians and pursued this path also by entering medical school. He later found he could not bare watching people suffer so his father recommended he become a Clergymen. He did not enjoy that either, besides his encounters with scientists in Cambridge and medical school. He then developed a keen interest in beetles, and eventually would make valuable contributions to Bettle taxonomy. Later Darwin is nominated a naturalist by John S. Henlow and became a naturalist on the H.M.S Beagle and made some of the most revolutionary ideas on plants and animals on one of the islands off the coast of Ecuador.
Recognize Darwin’s major works (e.g. On the origin of Species by Means of Natural Selection)
On the Origin of Species by Means of Natural Selection, 1859.
Zoology of the Beagle Voyage, 1843.
Fertilization of Orchids, 1862.
The Variation of Plants and Animals under Domestication, 1873.
The Descent of Man, 1871.
Describe the significance of Alfred Wallace
Helped Darwin develop the theory of Natural Selection.
He realized that just as animals are shaped by where they live, regions can also be defined by the animals that live there.
He had the revolutionary idea of evolution by natural selection entirely independently of Charles Darwin
Define Fossil
Any remains, impressions, or traces of organisms of a former geological age. Gave evidence that species change over time and leave descendants.
Recognize example of vestigial structures
One example of vestigial structure would be wings of flightless birds, wisdom teeth.
Describe how Natural selection acts on phenotypes rather than genotypes
Natural selection works on the phenotype of an organism because this is what interacts with the environment. The Phenotype is the observable traits and physical qualities that help an organism survive in the environment.
Define Genetic drift
Occurs when chance events influence the frequency of genes (evolutionary change). Genetic drift often leads to loss of alleles from a population. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation. It could also cause initially rare alleles to become much more frequent, and even fixed.
Define Allopatric speciation
Speciation that occurs in populations separated by geographical barriers. Allopatric speciation due to geographic separation: The northern spotted owl and the Mexican spotted owl inhabit geographically separate locations with different climates and ecosystems.
Define Punctuated Equilibrium Model
The idea that evolutionary change can occur rapidly over thousands of years and that these periods of rapid change are interrupted by periods of constancy (stasis).
Population genetics
The study of genetic events in gene pools
Gene pool
The sum of all genes in a population.
Explain the formula, p + q = 1, and describe how p and q represent the frequency of two alternative alleles in a population. Explain the significance of the equation p2+2pq+q2=1
Helps calculate the genetic variation of a population at equilibrium. “p” represents the frequency of the dominant allele in gene pool and “q” represents the frequency of recessive allele. The sum of the allele frequencies for all the alleles at the locus must be 1.
It allows one to determine the proportion of individuals that are carriers for a recessive allele.
