Australian Marsupials have been geographically isolated from Placental mammals for ~50 million years. In that time, many species in both groups have independently evolved the same adaptations via convergent evolution. The analogous adaptations observed in Placental mammals and Marsupials are best explained by…

CHOOSE THE BEST ANSWERS In a population of cows, a single gene controls hair type. The curly hair allele (H) shows incomplete dominance with the straight hair allele (h). The hair of heterozygous individuals (Hh) is wavy. Another gene controls coat color. The red (R) and white (r) alleles are co-dominant. The coloring of heterozygous individuals (Rr) is called roan . After breeding a wavy, roan bull with several wavy, roan females, you observed the following phenotypic ratio in the offspring: 8 curly, red : 16 wavy, roan :  7 straight, white Part 1: Based on this observed ratio,  are the two genes linked?  Part 2:  If they are linked, how are the two genes’ alleles linked?   

Identical (monozygotic) twins were adopted by different families at birth and were raised in different parts of the country. However, both twins grow up to have perfect pitch. This would suggest what about the shared musical talent of these twins?

Originally from South America, potatoes became a common food source in Europe during the late 1700s and early 1800s. During the 1840s, however, the European potato crop collapsed due to the rapid spread of potato blight (a fungal pathogen). The loss of this important food source resulted in mass migration and starvation. Most infamously, the potato blight contributed to the Great Famine in Ireland (though other socio-political factors were also to blame). Before the blight, potatoes were typically propagated clonally, by cutting up the tuber (the part you eat) into pieces and using these pieces to grow new, identical plants. Given what you know about the evolution of sex, why did the clonal propagation of the potato make the crop especially susceptible to a devastating pathogen outbreak?

A study on blood sharing among vampire bats has shown that a hungry bat is more likely to receive a blood meal from another unrelated individual if the hungry bat has fed that same individual in the recent past. This observation supports the hypothesis that sharing of blood meals could have evolved by way of…

Which of the following mechanisms would result in lower genetic diversity within a population?

Which of the following was not involved in the evolution of multicellular organisms from single-celled protists?

Prior to European colonization, tens of thousands of whooping cranes lived in North America. By 1938, due to overexploitation and habitat loss, whooping cranes were virtually extinct, with a total population of only 15 individuals. Since then, careful conservation efforts have increased the North American whooping crane population to over 800 today. From a genetic standpoint, as a result of this catastrophe, whooping cranes experienced a “population bottleneck”, which is a severe form of . The current population of whooping cranes should be expected to have , relative to the pre-colonial population.

Following selection, 80% of individuals with the “AA” genotype survive, all “Aa” individuals survive and 40% of “aa” individuals survive. Their respective relative fitnesses are…

Müller’s ratchet is a cost of asexual reproduction and can explain the evolution of sexual reproduction because…