Exam 1 PPTs - 5 Flashcards
Empirical research on sampling error as a mechanism of evolution: the founder effect:
- populations are often … when they have just been founded by a group of individuals that have moved to a new location
- the allele frequencies in the new population are likely, simply by …, to be different from what they were in the … population
- this is called the founder effect
small;
chance;
source;
Polynesian field crickets:
- Native to … and …
- Also found on islands across the …, including …
northern Australia;
New Guinea;
Pacific; Hawaii
Polynesian field crickets:
- If Polynesian crickets dispersed across the Pacific by hopping from island to island aboard boats, then each island’s population would likely have been founded by …
a small number of individuals
Polynesian field crickets:
- Tinghitella and colleagues determined the genotypes of 394 crickets from 19 populations at …
- microsatellites are regions of … with many … alleles
seven microsatellite loci;
noncoding DNA;
easily identifiable
Founder effects are often seen in … human populations
genetically isolated
Founder effects are often seen in genetically isolated human populations:
- The … people of the Eastern Caroline Islands, located bout 2,700 miles southwest of Hawaii, are descended from 20 survivors of a …
- … devastated Pingelap Atoll in about 1775
Pingelapese;
typhoon;
famine
Founder effects are often seen in genetically isolated human populations:
- Among the survivors was a heterozygous carrier of a … allele of the CNGB3 gene
- this gene encodes one component of a protein crucial to the function of … cells
recessive loss-of-function;
cone
Founder effects are often seen in genetically isolated human populations:
- carriers of this gene have …, a condition characterized by complete …, extreme … to light, and …
achromatopsia;
color blindness;
sensitivity;
poor visual acuity
Founder effects are often seen in genetically isolated human populations:
- achromatopsia is …, affecting less than … person in 20,000
- Among today’s 3000 Pingelapese, however, about 1 in … are achromats
rare;
1;
20
Founder effects are often seen in genetically isolated human populations:
- sampling error by the typhoon, a founder effect, left the allele at a frequency of at least …%
- its current frequency is more than …%
2.5;
20
An experiment on random fixation and loss of heterozygosity:
- Peter Buri studied these phenomena empirically, in lab populations of the … Drosophila melanogaster
- Buri established … populations of flies, each with eight females and eight males
- All the founders were … for an eye color gene called brown
- They all had the genotype …
fruit fly;
107;
heterozygotes;
bw75/bw
An experiment on random fixation and loss of heterozygosity:
- Buri maintained these populations for … generations
- kept the population size at … by picking eight females and eight males …
19;
16;
at random
An experiment on random fixation and loss of heterozygosity:
- During Buri’s experiment there was dramatic … in nearly all 107 of the fruit fly populations, but … had nothing to do with it
evolution;
natural selection
Random fixation and loss of heterozygosity in natural populations:
- Alan Templeton and colleagues (1990) tested predictions about the random fixation of alleles by documenting the reuslts of a natural experiment in …
- Although now largely covered in oak-hickory forest, the Ozarks were part of a … during an extended period of hot, dry climate that lasted from 8,000 to 4,000 ya
Missouri’s Ozark Mountains;
desert
Random fixation and loss of heterozygosity in natural populations:
- On exposed rocky outcrops, were small remnants of … habitat called … Living in these areas were relict populations of …
desert;
glades;
collared lizards
Random fixation and loss of heterozygosity in natural populations:
- Templeton and colleagues (2001) believed that the nearly complete loss of genetic diversity in the glade populations had doomed the Ozark collared lizards to … via … and change in … and …
extinction;
pathogen;
biological; physical environment
Random fixation and loss of heterozygosity in natural populations:
- Templeton and colleagues surveyed 130 Ozark glades. Consistent with their expectations, two-thirds of them were already …
devoid of collared lizards
Random fixation and loss of heterozygosity in natural populations:
- Andrew Young and colleagues reviewed evidence of these processes among populations of various sizes
- The researchers compiled data from the literature on … and a …
- From these data they plotted two measures of … against …
three flowering herbs; tree;
overall genetic diversity;
census breeding population size
Effective population size:
- The effective population size is the size of an ideal theoretical population that would … at the same rate as an …
- the effective population size is virtually … than the actual population size
lose heterozygosity;
actual population of interest;
always smaller
Random drift:
- bc the fluctuations in allele frequency from one generation to the next are caused by …, every population follows a …
- genetic drift has a more rapid and dramatic effect on allele frequencies in … populations than in … populations
- given sufficient time, genetic drift can produce substantial changes in allele frequencies even in populations that are fairly …
random sampling error;
unique evolutionary path;
small; large;
large
