Darwin's theory of evolution

What kind of specimen (choose one) Darwin collected during his five-year voyage aboard the Beagle? How this piece of evidence contributed to Darwin's understnding of the mechanism of evolution?

Genetic / Evolution

Early in the last century, English physician Archibald Garrod noticed that about half the albinos he saw in the course of his practice were the children of first cousins who had married each other. In almost all of the cases of albinism that he saw, whether or not the parents were related to each other, both of the parents were normall pigmented. a) What is the most likely mode of inheritance of albinism in humans? b) Suppose you married your cousin. Would your children be albino? Explain. c) Suppose you want to calculate the frequency of the albinism allele in the English population, based on Garrod's data. Would you be able to apply the second part of the Hardy-Weinberg Law? Why or ... click for more

Genetics/ Evolution

You have found a sex-limited gene that codes for male color in a Lake Victoria cichlid fish species. The dominant (R) allele codes for a red color and the recessive (r) allele codes for a greenish color. a) As you examine different populations of this species, you find that the R allele predominates in some populations and r allele predominated in others. Give two possible reasons for these difference. b) Are the two reasons you have given mutually exclusive? That is, does one rule out the other? c) What kind of selection would cause the female fish in the red-male and greenish-male populations to have behave differently? d) Design an experiment to test whether there really a... click for more

Genetic / Evolution

The blood disease beta-thalassemia results from homozygosity for a defective allele in the gene coding for the beta hemoglobin subunit. Homozygotes for the beta-thalassemia allel die in childhood, while heterozygotes appear normal. This disease is common in the region around the Mediterranean sea, including the island of Sardinia, where malaria was prevalent until recently. You visit this island in order to examine the frequency of the allele in people who have lived there for thousands of years. a) You find that the frequency of children born with the disease in the population is 0.01. What is the frequency of heterozygotes for the allele? What assumption must you make to arrive at your... click for more

Polymorphisms

You are investigating the Bmp4 gene, which is involved in beak development, in the Darwin's finch Geospiza fortis. You find a DNA polymorphism, a single-base difference between two alleles at this locus. a) Does this polymorphism necessarily have an effect on the phenotypes of the birds of this species? Justify your answer. b) DNA samples have been saved from the G. fortis that lived on the island of Daphne Major. The samples were taken from birds that lived before and after the severe drought that Peter and Rosemary Grant investigated. How could you see these samples to investigate the relationship between the Bmp4 polymorphism that you have discovered and the phenotypic differences... click for more