Answer:
- Interruption in the genetic flow between separated groups
- The emergence of new mutations in each of the groups, and their accumulation in time. Slow and gradual differentiation between populations.
- Genetic divergence by natural selection and reproductive isolation
- Prezigotic isolation mechanisms
Explanation:
Allopatric speciation consists of the geographic separation of a continuous genetic background that can give 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 flux, as the two new groups that are separated can not get together and mate anymore. These barriers might be geographical or ecological.
The process of allopatric speciation involves different steps that affect organisms:
- 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 will be favored by selection if occurs a secondary contact between the new species in formation.
Answer:
Humans see optical illusions when the visual system (the eyes and the brain) attempts to interpret an image that evokes a perception that deviates from reality. Your brain displays an image that makes the most “sense,” but it is not always what is actually in front of our eyes.
Paleontology deals with fossils and helps in learning the changes of living organisms in sequence.
Biogeography deals with the distribution of species across the mother earth.
Embryology deals with the study of the similarities and difference that exists in the embryos of different species or organisms.
Anatomy deals with the study of the similarities and difference that exists among different species or organisms.
<u>Explanation: </u>
As an organism dies, the remaining of these organisms will be buried in soil. These are fossils. Paleontology supports evolution with the information that are related to the fossils, footprints etc. With these we can study the evolution of organisms and also the changes they undergo. There are some technologies like radiometric dating that can be used for the determination of these rocks and fossils ages.
Charles Darwin suggested that the evolution of species were form their ancestor. Biogeography supports evolution by explaining about the distribution of different species over the earth. Embryology and Anatomy supports evolution by describing about the similarity and difference in the species of living organisms. Embryology deals with the embryos and anatomy deals with the structure.
Answer:
The Atmosphere
Explanation:
1816 was a year without summer because the billions of tons of ash that was spewed blocked radiation preventing it from reaching the surface of the earth.
A volcano is a break in the crust of planetary bodies like Earth that allows gasses, volcanic ash, and hot lava to escape. Volcanos are one of the major factors that cause climate changes on Earth mostly because of their cooling effect.
The ash, gasses and lava usually escape to the atmospheric layer of the earth with their cooling effect. And they cool the earth by blocking incoming solar radiation. This can go on for months or years depending on the components and severity of the eruption and can lead to "a year without summer" as witnessed in 1816.
Answer:
Prophase
Explanation:
During prophase, the nuclear envelope and nucleolus are dissolved and the chromosomes condense. The centrioles and spindle fibers begin to form at opposite poles of the cell.
