Answer:
Species separated by a physical barrier for a long time, suffer allopatric speciation, so they can not interbreed anymore.
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background giving place to two or more new geographically isolated populations. These separations might be due to migration, extinction of geographically intermediate populations, or geological events. In this speciation, some barriers impede genetic interchange, or genetic flow, as the two new populations that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
Vicariance is the geographical separation of an original population into two or more new groups. Discontinuities in the physical environment like rivers, mountains, water, etc., are physical barriers that impede genetic flow between the separated groups.
The process of allopatric speciation involves different steps:
- The emergence of the barrier.
- Interruption in the genetic interchange
- The occurrence of new mutations and their accumulation in time in each population. Slow and gradual differentiation.
- Genetic divergence by natural selection and reproductive isolation makes it impossible for the two groups to mate even if the barrier disappears.
- Prezigotic isolation mechanisms favored by selection once occurs a secondary contact between the new species in formation.
We can do brain scans and things that help us diagnose sickness
Answer:
A bottom-up system concentrates attention on how resources (space and nutrients) influence higher trophic forms , whereas a top-down system focuses on interactions at top level consumers (predators) and their prey influence on lower trophic forms.
Explanation:
hope it helps you !
Answer/Explanation:
Natural selection - over time - selects for traits that improve fitness. A butterfly with wing coloration that looks like a hungry owl would certainly be a deterrent to their natural predators, such as smaller birds. This is because the owl is the predator of the smaller birds, and their instinct is to avoid the owl.
If a mutation arose that resulting in coloration that looked like an owl, (or at least slightly menacing) this would be beneficial to the butterfly, as it would be more camouflaged from predators. This means it would be more likely to reach reproductive age and pass the mutation onto its offspring, who would also have a competitive advantage.
Over time, this would lead to a population of butterflies with coloration that looks more and more owl-like .
Answer:
cellular function.
Explanation:
I can't really explain. That easily. I don't remember much of this subject.
