Im pretty sure its hypothesis
The answer to your question is D
Answer: Proteins are made using DNA as a template. The DNA is turned into RNA, and the RNA is then turned into DNA.
A change in these nucleotides could end up making some part of the protein different. A single nucleotide change could be silent (no change in the protein) or could change a single amino acid (amino acids are the building blocks of proteins). If that was an important amino acid, the protein might not function at all! A silent change can occur because the same set of nucleotides sometimes makes the same final amino acid (for example, reading "gcc" "gca" "gcg" or "gct" nucleotides all mean "alanine" amino acid).
The deletion of a single nucleotide, or the addition of one, can change the entire sequence of amino acids that come after it! Nucleotides are read in sets of three, so this throws off how the DNA is read. If would be like turning "The brown fox jumps over the dog" into "The gbrow nfo xjump sove rth edo g". Completely different! All of the words are thrown off.
I know it is long but I hope it helped
:D
Species evolve independently possibly due to geographical isolations or behavioural isolations.
Geographical isolation includes the isolation of 2 groups of the same species. Since these 2 groups live in different locations, (e.g. a volcanic eruption resulting in a barrier between one side of an ocean and another side of the ocean), they will have different selection pressures in their different environments as well (e.g. one side of the ocean may have more sunlight and thus more underwater plantations than the other side of the ocean). Natural selection will eliminate those with disadvantageous characteristics (e.g. Fishes that only eat plants and nothing else on the side of the ocean with little plantations) with unfavourable alleles, and select for those with advantageous characteristics (e.g. Fishes are able to eat plants and other organic substances as well on the side of the ocean with little plantations) with favourable alleles.
Since the 2 groups have different selection pressures, natural selection will occur in different ways, selecting for and against different types of fishes with different types of alleles. Also, because of the barrier, they are not able to mate with each other, and there are no mixing of genes from one side of the ocean and the other side. They are genetically isolated. As genetic drift occurs over time, their gene pools become different from each other. Thus, they evolve independently.
Hope this helps! :)
Yes! A recent example could be babies that do not survive child birth for a certain reason, are obviously unable to pass on whatever caused them to die in the first place.
Also, once humans started to domesticate cows and drink their milk (I'm not sure why humans drink a cow's milk) their bodies evolved to continue making the enzyme to digest milk even after they were weaned off their mothers milk. Many people of Asian descend do not have this enzyme, since their culture did/does not raise as much dairy product.
