<span> Both of them are nucleic acids. And that is about the only similarity they share. ;)
One of the major differences between the two is that DNA is double-stranded and RNA is single stranded. Also, DNA contains the nucleotide T whereas RNA contains U.
RNA copies the genetic information found within DNA and uses it to assemble protein, as well as ribosomes. Hence, RNA is a crucial part in protein synthesis, being directly involved in it, whereas DNA is indirectly involved in this process.
There are three types of RNA: mRNA (messenger RNA), rRNA (ribosomal RNA) and tRNA (transfer RNA). As far as DNA is concerned, there is only one type of DNA. ;) Another difference.
Also, in some viruses the RNA replaces the DNA but the DNA will never replace the RNA. Yet another difference. </span>
Answer:
Genetic drift
Explanation:
Genetic drifts is a change in the frequencies of alleles due to chance or at random. Therefore there is no environmental or survival influences.
There are two types. The founders effect caused when a small group migrates from a larger group and forms a new population causing a change in the genetic pool.
Bottleneck effect is caused by the sudden reduction of population due to environmental or human activities.
The observed genetic changes in the question were due to genetic drift.
Being born prematurely and
congenital defects.
Tropical rain forest
Tropical dry forest
Tropical dry forest / savannah
Desert
Temperate grassland
Temperate woodland
Temperate deciduous forest
Northwest coniferous forest
Boreal forest
Tundra