Several fish species became extinct millions of years ago. The graphs provided below show the distribution of fossils of these f
ishes as they occur in several undisturbed layers of sedimentary rock observable in a cliff face. Respond to ALL 4 PARTS below: Explain why the distribution of the fossils in figure 1 support the hypothesis that the extinction of these species was a result of a sudden environmental change. Describe an environmental change that could have produced this kind of fossil distribution. Explain why the distribution of the fossils in figure 2 supports the hypothesis that the extinction of these species was a result of a gradual environmental change. Describe an environmental change that could produce this kind of fossil distribution.
1. Explain why the distribution of fossils in Figure 1 supports the hypothesis that the extinction of these species was the result of a sudden environmental change. This hypothesis can be supported because all the fossils accumulate almost at the same age of the rock layer. That is, all the fossils died almost at the same time.
2. Describe an environmental change that could have produced this type of fossil distribution. Good examples of sudden environmental changes are volcanoes. When a rash occurs, the whole environment suddenly changes for different reasons such as ash or lava, and all living things can die immediately or in a few years by the change in the ecosystem.
3. Explain why the distribution of fossils in Figure 2 supports the hypothesis that the extinction of these species was the result of a gradual environmental change. This is because the fossils accumulate at different ages of the rock layer, that means, the species dying over time. The gradual descent of the fossils is observed.
4. Describe an environmental change that could produce this type of fossil distribution. For example, if a climate change occurs - the temperature increases or decreases - it can cause the trees or plants to die and all the animals in the ecosystem also die when they have no food. But this process is sequential, so the change can take years, centuries or even millions of years.
Astrocytes also called star cells due to their shape are the
most abundant glial cells in the brain. Extensions from these cells encase
capillaries and offer extra control over which materials enter or leave the
intercellular fluid of the CNS thus acting like a permeability membrane.
Polar bear is the organism that has the adaptations which enable it to survive in the tundra. the polar bear has white skin and fur on all its body which helps it to camouflage in the ice and to prevent the loss of heat from its body. The polar bear catch its favourite food in the water which is the fish that provide high nutrition to the polar bear. It is a good swimmer and have large paws with small bumps that helps it to provide support while walking on the ice. The scientific name of polar bear is Ursus maritimus whose features are described in the question.
