On the off chance that a change happens, if beneficial in the scarcest, normal choice picks it to wind up noticeably the more typical quality, and consequently development happens. For instance the dark demise wiped out one in three Europeans, now researchers are finding that some of the individuals who survived had transformations on their resistant framework cells; they needed regular receptors, or generally had few. (DNA resembles history, obviously, they aren't meeting with dark torment patients, the DNA in Caucasian Europeans goes about as an authentic guide of past bottlenecks.) Because Europeans with this transformation were to the least extent liable to bite the dust of the dark passing they were the well on the way to survive, which is the reason the calamity of the bubonic torment brought about somewhere in the range of 20% of Caucasian European relatives to do not have these receptors on their invulnerable framework cells which thusly diminishes the danger of resistance illnesses, for example, assistants.
Answer:
It is possible to compare the expression of homologous genes in the brain of <em>D. melanoganster</em> and humans, because the expression levels of conserved genes may be associated with the evolution of cognitive features such as complex learning and memory.
Explanation:
Model organisms can be used to understand the patterns and processes that affect human evolution. <em>Drosophila melanogaster </em>is a model organism that has been used to study expression patterns of conserved genes in the course of evolution. This model organism has also been used to develop genetic mutant lines in order to examine the role of genes evolutionarily conserved in animals, including those involved in neurocognitive development.
In genetic research, an experiment as the above described is framed in a research field named 'Behavioral Genetics', which is a discipline that studies how evolutionarily conserved gene networks may be associated with neurocognitive tasks during brain evolution.
Answer:
Quadrat method is used for estimating the number of individuals in an area. In this method, a large square area on the ground or water surface is marked, call it an enclave. The number of animals present in this enclave is counted. Then by assuming that the animals are less migratory and are uniformly distributed, their number for a large area is estimated by the use of unitary method of calculation. Example a 4 square feet area has 2 snails, then a 1000 square feet area will have (1000 x 2)/4, i.e, 500 snails in it. Fishes can be counted using this method only if they are confined in a small water body like a lake or a pond. Rivers are flowing so the fishes may move along its length which can give us an underestimate or an overestimate of their numbers. Sea has its depth and huge area, and fishes can be moving randomly in it. Hence this method will not work for river and sea fishes.
Explanation:
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