Question

below is an image showing homologous structures in several mammals. human dog bird whale which of the following conclusions can be drawn regarding this information? these mammals likely share front limb function based on homologous structures. these mammals likely share a common ancestor based on homologous structures. these mammals likely share an omnivorous diet based on homologous structures. these mammals likely share a habitat based on homologous structures. 9 multiple choice 6.25 points there are four mechanisms that can cause changes in the frequencies of genes in populations: mutation, migration, genetic drift, and natural selection. all four are mechanisms of evolutionary change. what is genetic drift? in a population, it is the changes in allelic frequencies of a gene that are due to chance. there is variation in any population; differential reproduction occurs and over time a more advantageous trait exists in the population. a random error/change in the dna sequence. these may be inherited or occur in cells during the lifetime of the organism. also known as gene flow. it is any movement of individuals and/or the genetic material they carry, from one population to another.

Explanation:

• First question: Homologous structures are anatomical features in different organisms that have a similar underlying structure (derived from a common ancestor) but may have different functions. For example, the front - limb bones in humans, dogs, birds, and whales have a similar bone arrangement (humerus, radius/ulna, carpals, metacarpals, phalanges).
• The function of the front - limb is different (e.g., human grasping, dog walking, bird flying, whale swimming), so the first option is incorrect.
• Homologous structures are evidence for a common ancestor. The presence of similar bone structures in these mammals suggests they evolved from a common ancestor, so the second option is correct.
• There is no indication from the homologous bone structure about diet (e.g., whales are not omnivores), so the third option is incorrect.
• Their habitats are different (e.g., humans on land, whales in water), so the fourth option is incorrect.
• Second question:
• Genetic drift is defined as changes in allelic frequencies of a gene in a population that are due to chance.
• The second option describes natural selection (differential reproduction based on advantageous traits).
• The third option describes mutation (random error in DNA).
• The fourth option describes gene flow (movement of individuals/genetic material between populations).

Answer:

First question: These mammals likely share a common ancestor based on homologous structures.
Second question: In a population, it is the changes in allelic frequencies of a gene that are due to chance.