Evolution Flashcards
What was Cucier attempting to explain through his idea of Catastrophism?
Why fossils looked so different over time
Before Darwin’s time, what was the prevailing idea for the age of the earth?
Earth was only a few thousand years old and was made in one week by God.
What were the two parts of Lamarck’s explanation for a mechanism of evolution?
- Body parts evolved in correlation with how much they were used.
- Modification that an organism acquires is passed onto offspring
What are the 3 parts of Natural Selection?
- Organisms are locked into historical constraints
- Organisms adapt to the environment
- Not all evolution is adaptive
What contributions did Thomas Malthus make to Darwin’s theory?
Malthus inspired Darwins theory of natural selection. Helped Darwin realize the importance of overpopulation and variability in different populations.
Describe a homologous structure
Represents variations on a structural theme that was present in a common ancestor
Describe a vestigial structure
Remnants of features that served a function in an organisms ancestors
Describe an analogous structure
Species that have body parts which have similar functions to another species, but no common ancestor
What are the five conditions of the Hardy-Weinberg Equilibrium?
No mutation, random mating, no gene flow, large population size, and no natural selection
What is a cline?
Gradual change in a trait along a geographical area
What does an organisms level of “fitness” mean?
Contribution of a genotype to the next generation in comparison to alternate genotypes at the same locus
Describe directional selection
Shifts the overall makeup of the population by favoring variants of one extreme
Describe stabilizing selection
Favors intermediate variants and selects against the extremes. The trend is toward reduced phenotype variation and the maintenance of the status quo
Describe disruptive selection
Favors variants of opposite extremes over intermediate invidividals
Describe sexual selection
Natural selection arising through preference of one sex
Describe how molecular biology has contributed evidence in support of evolution
Molecular biology describes that heredity is reflected in an organisms genes and protein products
Describe how the fossil record has contributed evidence in support of evolution
The fossil record is incomplete, but it shows that life on earth was once different than life found on earth today
Describe how biogeography has contributed evidence in support of evolution
Biographical is the geographical distribution of organisms, it provides clues about how species, both alive and extinct, are related to each other.
Describe how embryology has contributed evidence in support of evolution
Embryology is when closely related organisms go through similar stages in their embryonic development, it supports evolution as some homologues structures can only be seen in embryo development
Describe how homologues structures has contributed evidence in support of evolution
Homologues structures show that structures are similar because of a common ancestry
Describe how vestigial structures contributed evidence in support of evolution
Vestigial structures show common ancestry as some parts within the body serve no purpose due to it being evolved from a common ancestor.
Describe the five causes of microevolution
- Genetic drift
- Gene flow
- Mutations
- Nonrqndom mating
- Natural Selection
Describe what genetic drift is
Genetic drift are changes in the gene pool of a small population due to chance. It is more important in small populations
Describe gene flow
Gene flow is the migration of fertile individuals or the transfer if gamete between populations
What are mutations, and what is the rate in which mutations occur?
Mutations are a change at a single locus. If this new allele increases in frequency it is due to genetic drift or natural selection. The rate of mutations is 10 to the 5th power gamates.
Describe nonrandom mating and the two types of nonrandom mating.
Nonrandom mating is when the number of homozygous loci increases within a population. One type of nonrandom mating is inbreeding, which is when individuals mate with their neighbors or self-fertilize. The second type of nonrandom mating is assortative mating, which is when individuals mate with partners like themselves in certain phenotypes.
What is natural selection?
Natural selection is when variation among individuals exist, and some leave more offspring than others.
