The study of artificial selection by Darwin helped him to establish his theory of evolution via natural selection. One of the animals Darwin examined in detail was the domestic rock pigeon. In the 1850s breeding of pigeons was an ancient past time, thus, Darwin decided to keep and breed the pigeons by himself.
While studying pigeons, Darwin established scrupulous determinations of their skeletons and wondered at the breeds' distinct colors, behaviors, and proportions. He also observed the patterns of inheritance of various features, and he demonstrated that birds of very distinct breeds can, however, generate fertile offspring. Thus, supporting the theory that they all originated from a single species.
Answer:
by separating the most important ideas from the detailed text
Answer:
The genes are linked, and the arrangement is coupled (one homolog has both dominant alleles; the other homolog has both recessive alleles).
RY
/
ry
Explanation:
R_= colored aleurone
rr= colorless aeurone
Y_= green plant
yy= yellow plant
They do a testcross between a plant of unknown genotype and phenotype and a plant that is homozygous recessive for both traits (yr/yr) the following F1 is obtained:
- 88 Colored, green (RY/ry)
- 92 colorless, yellow (ry/ry)
- 8 colorless, green (rY/ry)
- 12 colored, yellow (Ry/ry)
If the genes assorted independently, all of the possible offspring phenotypes would appear in the same frequency. However, they obtained 2 phenotypes much more abundant that the other two. Since recombination is a rare event during crossing over, when two genes are linked the recombinant gametes are produced less frequently than the parentals.
We can propose that the phenotypes Colored, green (RY) and colorless yellow (ry) are the parental gametes, and the unknown plant has the arrangement RY/ry, with both genes linked.
Answer:
The blue pigment production is linked to quorum sensing.
Molecular clocks use rates of mutation to measure evolutionary time.Mutations add up at a fairly constant rate in the DNA of species that evolved from a common ancestor. The more mutations that happened in each lineage, the greater is the differences between these lineages.
