1. One societal issue that scientists will be able to address using the sequence of the human genome is reduction in the number of disable children born.
Using the sequences of human genome, scientists will be able to detect when a woman is carrying a defective or disable baby, this will allow decision to be made whether to abort the fetus or to keep the pregnancy. This will reduce the number of disable children born and reduce the amount of government resources that are been spent on this sector of the society.
2. By using human genome to assess the risk of giving birth to defective babies, the ethical considerations that will arise include the following:
i. Is it good to abort babies? Is that not murder?
ii. Who will make the decision to abort? The parents or the doctor? what of if the parent want to keep the pregnancy despite the risk?
These ethical questions will need to be addressed depending on the situations that surround the event.
3. Principally, the government ought to be the one to regulate how the human genome sequence is used by scientists. There ought to be a standard which give clear directives on what can be done and what can not be done.
But depending on the situation of the research involved, if human subjects are going to be used, then their consents must be obtained before the research is carried out. For instance, in the issue of pregnancy risk assessment described above, the woman's consent must be obtained before the pregnancy is aborted.
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Scientists combine several well-tested techniques to find out the ages of fossils. The most important are Relative Dating, in which fossils and layers of rock are placed in order from older to younger, and Radiometric Dating, which allows the actual ages of certain types of rock to be calculated.
Relative Dating. Fossils are found in sedimentary rocks that formed when eroded sediments piled up in low-lying places such as river flood plains, lake bottoms or ocean floors. Sedimentary rock typically is layered, with the layers derived from different periods of sediment accumulation. Almost any place where the forces of erosion - or road crews - have carved through sedimentary rock is a good place to look for rock layers stacked up in the exposed rock face. When you look at a layer cake, you know that the layer at the bottom was the first one the baker put on the plate, and the upper ones were added later. In the same way, geologists figure out the relative ages of fossils and sedimentary rock layers; rock layers, and the fossils they contain, toward the bottom of a stack of sediments are older than those found higher in the stack.
Radiometric Dating. Until the middle of the last century, "older" or "younger" was the best scientists could do when assigning ages to fossils. There was no way to calculate an "absolute" age (in years) for any fossil or rock layer. But after scientists learned that the nuclear decay of radioactive elements takes place at a predictable rate, they realized that the traces of radioactive elements present in certain types of rock, such as hardened lava and tuff (formed from compacted volcanic ash), could be analyzed chemically to determine the ages, in years, of those rocks.
Putting Relative and Radiometric Dating Together. Once it was possible to measure the ages of volcanic layers in a stack of sedimentary rock, the entire sequence could be pinned to the absolute time scale. In the Wyoming landscape shown below left, for example, the gray ash layer was found to be 73 million years old. This means that fossils in rock layers below the tuff are older than 73 million years, and those above the tuff are younger. Fossils found embedded within the ash, including the fossil leaves shown below right, are the same age as the ash: 73 million years old. So, there for the relationship between the age of a fossil and the layer of rock in which it was found dates back to about the same time era.
- Got this out of an article, hope it helps! (:
Many owls eat small rodents and similar critters. So let's say the rabbit population might grow if owls weren't there to keep the numbers down.
<span>Foxes probably eat the same sort of small rodents. So if owls weren't there, foxes would have more food to themselves, so their population might go up. </span>
<span>And if foxes had more small rodents to eat, they would eat relatively less of any one species. So if they had plenty of rabbits to eat, they might eat less squirrels, so the squirrel population would go up.</span>
Answer:
A sea sponge 760 million years old
Explanation:
It's unclear exactly how long sea sponges have been around, but they are at least old enough to be the longest-existing creatures on Earth, outside the realm of microorganisms (like bactery). The oldest evidence of a sea sponge found was a fossil discovered just last year in a 760-million-year-old rock. This beat the previous record for oldest sponge fossil, a 635-milloon-year-old sponge discovered in 2009. There may be still older fossils yet to find. But finding an older species is unlikely,as these simple organisms appear to be the progenitors of much more complicated life, including the first multicellular animals.
Photosynthesis? Chloropasy and chloraphyll.
