The iris focuses light rays before they enter the posterior portion of the eye
The nervous system, i could be wrong.
Answer & Explanation:
a) a) Mutualistic relationship differs from parasitism because the first one benefits both of the involved organisms. Otherwise, parasitism benefits only one of the organisms and it can harm the host. Therefore, the parasite would have to be smaller than the host and it would be somehow extracting energy from the host.
b) The direction of evolutionary changes would follow some kind of pattern, like coevolution. Therefore, analyzing the phylogenies individually and then contrasting them, would help to understand how the host, as well as the parasite, have been evolving.
c) The phylogeny would also help to understand what changed first, or if they changed together as a result of coevolution.
How old it is compared to another specimen in relation.
Speciation is the adaptive divergence and gradual that leads to two different species.
Reproductive isolation results in speciation when the processes of evolutionary mechanisms, physiological and behaviours are collected.
Mechanism of reproductive isolation helps in preventing members of different species from producing offsprings. A zoologist is a classified way of reproductive isolation whereby it(zoologist) is classified to the mechanism of reproductive isolation into two categories
(i) Pre-zygotic. This one acts before fertilization or before mating when it comes to animals.
(ii) Post-zygotic. It acts after fertilization.
The mechanisms appear I species which are genetically controlled and whose geographic distribution overlaps or are separated.