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.
The answer is B)Atmosphere
Answer:
1. Parasitism
2. Mutualism
3. Competition
4. Commensalism
Explanation:
The given are all different ecological relationships. These relationships how the members of the ecosystem interact with each other.
Parasitism is a relationship where one organism is harmed and the other one benefits. However, parasitism is specifically referring to a relationship where one lives inside the other organism, causing it harm by directly feeding off them or depriving it from getting nutrients.
Mutualism is a relationship were both organisms benefit from the relationship. In the example, the aphids provide protection for the ants while the ants provide food to the aphids (honey dew). Another example of a mutualistic relationship would be the tickbird and the rhino. The rhino benefits because the tickbird eats the ticks of the rhino, and in return, the tickbird is fed.
Competition is a relationship between organisms that compete for resources. In the case of your question the two grasses are competing against each other for the nutrients and water. Animals also share this type of relationship, especially when those that prey on the same animals for food.
Commensalism is a relationship between organisms where one benefits and the other does not benefit, but is NOT harmed. A good example would be the remora and sharks. Remoras are fish that swim with sharks. They swim beneath the sharks fins. The sharks provides them protection from other predators and remoras benefit because they get to eat scraps of the sharks food as well.
They are both are types of explanations.
