It is true that it is possible for a population to not evolve for a while.
There is something called the Hardy-Weinberg theorem, which characterizes the distributions of genotype frequencies in populations that are not evolving.
There are 5 Hardy-Weinberg assumptions:
- no mutation
- random mating
- no gene flow
- infinite population size
- and no selection (natural nor forced).
You can see that some of these are kinda extreme and really hard to get, but with approximations, we can work.
For example, instead of an "infinite population size" we have enough with a really large population, such that genetic drift is negligible.
Concluding, yes, it is possible (but really difficult) for a population to not evolve for a while (at least, in nature), as long as the 5 assumptions above are met.
If you want to learn more, you can read:
brainly.com/question/19431143
Answer:
Answered below.
Explanation:
A karyotype is defined as the size, shape, and number of chromosomes present in an organism.
An analysis is usually done on a karyotype to see if individuals have abnormal numbers or sizes of chromosomes. Such abnormalities may arise from;
Deletion: which implies that a chromosomal part is missing.
Duplication: where parts of a chromosome are repeated.
Translocation: which occurs when a chromosomal part breaks off and gets attached to another chromosome.
Nondisjunction: in which chromosomes do not separate from the parent cells.
Common chromosomal disorders arising from these abnormalities include;
Down's syndrome
Edwards syndrome
Turner's syndrome
Klinefelter syndrome
Prada-willi syndrome
Cri-du-chat syndrome
Patau's syndrome
Answer:
The correct answer is b. must be present in a population before natural selection can act upon the population
Explanation:
Genetic variation can be caused by mutation, recombination between chromosomes during meiosis and by fusion of two genetically different gametes during sexual reproduction.
This genetic variation is necessary for the evolution of any population. Natural selection acts on every individual and it decreases the frequency of those alleles that are not suited for the environment and increase the frequency of those alleles which helps the individual to survive in the changing environment.
Therefore genetic variation must be present in the population before natural selection act on the.
The person credited with first recognizing (in the 1860s) that living cells cannot arise spontaneously, but arise only from previously existing cells, is Rudolf Virchow.
He is German <span>physician and pathologist, who invented </span>the modern concept of pathological processes. <span>He used the cell theory to explain the effects of </span>disease in the organs and tissues of the body.
