I think homologous structures is a great example and idea that supports the theory of evolution. Homologous structures shows us how our futures evolved by natural selection.
I think the correct answer from the choices listed above is option B. You can find methanogens in the human intestines. These organisms can work with or without oxygen. Too much of oxygen for them is toxic. They are obligate anaerobes.
The research about Linnaeus helped us discover the similarities between different species.The fossils help us understand like taxonomy
Water evaporates from the ocean and land surfaces, is held temporarily as vapour in the atmosphere, and falls back to Earth's surface as precipitation. ... Water that infiltrates Earth's surface becomes groundwater, slowly seeping downward into extensive layers of porous soil and rock called aquifers.
Because the organism is distributed across the world, and isn't seen anymore, scientists can conclude tat they must have evolved. They can compare one species to the fossils they may have found, and determine that they were related. Then by looking at the species on another part of the world compare the same fossils to other animals and determine that they are similar, sharing a common ancestor.
