Answer;
all individual variation is due only to environmental factors
A population of organisms will not evolve if all individual variation is due only to environmental factors.
Explanation;
-Evolution of organisms is influenced by several factors which include; natural selection, random genetic drift, mutation, and gene flow.
-Mutation is a random heritable change in a gene or chromosome, resulting from additions, deletions, or substitutions of nitrogen bases in the DNA sequence. Gene flow works to decrease the variation between the two populations.
-Genetic drift is the random change in allele frequency from one generation to the next.. Natural selection is the process by which some organisms have a greater chance of surviving and reproducing than others due to features that are better adapted to the environment.
Catastrophism is associated with major changes that occurs once at a time in a species while gradualism is associated with tiny changes that occurs over a period of time that finally contributes a bigger evolutionary change.
<u>Explanation:</u>
The events that are sudden, short-lived, violent occurring worldwide thereby changing the shape of the Earth is Catastrophic. This process is opposite to contrast to gradualism which is also called as uniformitarianism. This process is associated with slow and also incremental changes. Erosion is the best example for this process.
The formation of major mountain chains and great floods are some of the examples of Catastrophism. Both are associated with the changes that occurs in a species by the time taken for the changes determines whether it is Catastrophism or gradualism.
Explanation:
Halotolerant is the ability of the organism to grow at the higher concentration of salt than the required concentration for its growth.
As we know Mannitol salt is used as selective medium for isolation of pathogenic bacteria. The medium has mannitol salt, phenol red indicator, 7.5% sodium chloride. This high salt concentration inhibits the growth of most bacteria.
Exponential growth.........,,......
