The cladogram below was created to show the evolutionary relationships between different vertebrates.

which of the following inferences can be made, based on this information?

a. amphibians and birds share a more recent common evolutionary ancestor than sharks and birds.
b. birds and sharks do not share a common evolutionary ancestor.
c. having a bony skeleton did not provide an evolutionary advantage to sharks or ray-finned fish.
d. rabbits and primates diverged more recently than crocodiles and birds.

a. Amphibians and birds share a more recent common evolutionary ancestor than sharks and birds.

Explanation:

A cladogram is a diagrammatic representation of the phylogenetic relationship of recently evolved species with their common ancestors. The relationship is defined on the basis of genetic, molecular, morphological make up of the organisms. The node in the cladogram defines a divergence or difference between the two taxon.

Birds and amphibians share a more recent common ancestor than shark and birds because they can be seen lying closer at the terminal ends of the cladogram.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.