The Challenger Deep is in the southern end of the Mariana Trench. It is estimated to be 305meters deep.
Complete question:
In the 1890s, Northern elephant seals were hunted almost to extinction. An unknown population of less than one hundred animals managed to survive on the tiny island of Guadalupe off of Mexico. The current population of over 100,000 is thought to be derived from that tiny remnant population. Compared to the Southern elephant seals (which did not experience such a bottleneck), the Northern elephant seals likely have -------- (Lower - Higher) genetic diversity and -------- (Lower - Higher) levels of genetic diseases.
Answer:
In the 1890s, Northern elephant seals were hunted almost to extinction. An unknown population of less than one hundred animals managed to survive on the tiny island of Guadalupe off of Mexico. The current population of over 100,000 is thought to be derived from that tiny remnant population. Compared to the Southern elephant seals (which did not experience such a bottleneck), the Northern elephant seals likely have Lower genetic diversity and Higher levels of genetic diseases.
Explanation:
Genetic drift is the random change that occurs in the allelic frequency of a population through generations. The magnitude of this change is inversely related to the size of the original population. These changes produced by genetic drift accumulate in time. Eventually, some alleles get lost, while some others might set. Genetic drift affects a population and reduces its size dramatically due to a disaster or pressure-bottleneck effect- or because of a population split -founder effect-.
In the exposed example, extensive hunting acted as a pressure that reduced the number of Northern elephant seals to fewer than 100. This population experienced one or many generations of small size since these animals were affected by hunting. As the survivors did not have the whole genetic pool of the original population, the population size might have recovered to a current population size of 1000,000 individuals, but <u>the genetic pool might have not</u>. When the small population increases in size, it will have a genetically different composition from the original one. In these situations, there is a<u> reduced genetic variability</u>, with a possibility of developing a peculiar allelic component. If the survivors in the population carried or developed a mutation, probably this mutation passed from generation to generation. It will involve more individuals each time and<u> increase the probability of developing a genetic disease</u>.
The correct answer is 176 g
Answer:
Group behavior, also known as collective behavior, <u>can increase the chances for a species to survive and reproduce because they can rely on each other to accomplish behaviors that are crucial for their survival, such as hunting, migrating, and breeding.</u>
Explanation:
According to ethologists, social species highly depend on the members of their own group for survival. One perfect example is the case of <u>schooling fish</u>. These small species of fish gather in a whole large group and navigate long distances while looking for food. Researchers from Princeton University <u>discovered that their orientation capabilities increased when more individuals joined the group, making them more responsive to the environment.</u>
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Moreover, there have been numerous sources of evidence that demonstrate that <u>orcas (killer whales)</u><u>,</u> which are extremely social creatures<u>, create large pods of around 20 to 30 individuals and 'plan' strategies to hunt. Also, older females swim along younger individuals to teach them hunting skills that are crucial for their survival.</u>
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In addition, <u>herbivores</u>, like zebras, <u>are usually found in large groups because it lowers the possibilities of being individually targeted by apex predators, such as lions.</u>
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Recently, researchers have also discovered that <u>migrating species</u><u> often rely on each other to improve their migrating capabilities by producing or generating social cues that allow them to improve their orientation or in cases when environmental conditions get tough</u> (Source).
In conclusion, these lines of evidence show that social organisms who travel in groups rely on all members to carry out important behaviors that, without them, would provoke an important decline in their populations because they wouldn't be able to reproduce or feed individually as successfully as they would with the 'help' of the members of the group.
- Couzin, I.D. (2018) Collective animal migration, <em>Current Biology </em>28(17), R976-980.
