Compare And Contrast Directional Selection And Disruptive Selection

Amazingly, only 6-7% of the total land surface on Earth is covered by rainforest. On average, there are between 20 to 80 different species of trees per acre. There is also a wide variety of animal life found in the rainforest.  Many of the animals have special adaptations that allow them to live in the tropical conditions, but they would not survive outside of this ecosystem. Animal Adaptation The animals have to compete for food so many animals must adapt by learning to eat a particular food eaten by few animals or no other animal.

Animals today are facing many environmental stresses like the declince of prey and the loss habitat. Animals deal with these stresses by adapting using the mechanisms of evolution: founder effect, bottleneck, nonrandom mating, mutation, and natural selection. The animal we’ll be focusing on is the Acinonyx Jubatus, also known as the cheetah. According to the phylogenetic tree, the cheetah came from a common, but distant ancestor as the trout while sharing a common and more closely related ancestor with the red fox. The evolutionary path that led to the cheetah is shown below: As

Directional selection and disruptive selection are two of the three types of natural selection. Although both of them result in a population adapting to biotic and abiotic environments, they differ in many ways. Directional selection occurs when one extreme phenotype is favored over the other phenotypes, whereas disruptive selection occurs when two or more phenotypes are favored over the others. Another difference is that disruptive selection favors polymorphism and directional selection causes species to evolve over time and leads to the extinction of those lacking the phenotypes causing the distribution curve to shift.

Introduction Predation is a biological interaction between two organisms of different species in a community in which one acts as a predator and captures and feeds on the other, the prey. Predator-prey relationships keep animal populations in balance. When prey populations increase more food is available for predators, and they increase in number as well. An increase in predators triggers a decrease in prey populations. As prey populations decrease predator populations soon follow as their food supply diminishes.

Giraffes have also been known to make whistling, humming and flute like sounds however no one behaviour or reason has been attributed to these sounds. Giraffes with their large eyes have excellent eyesight; giraffes have the largest surface area retina and a longer focal length than any other land mammal. Giraffes monitor social patterns and subtle behavioural changes of other giraffes to gain information about them. Giraffes can communicate a vast knowledge of information through visual cues such as when giraffes are displeased or angry they lower their necks to almost a horizontal position. Giraffes also communicate through scent markings and smells, different from their relative the okapi; giraffes have scent glands on their hooves.

Most people are misinformed when it comes to the Florida alligator. Alligators just like any other animal or human being want a safe and secure area of living. These creatures want to be able to live out of harm’s way. One area that seems to be protective of these intelligent reptiles is known as The Florida Everglades.

• Over a longer period of time all Giraffes would have really long necks meaning that they would live longer but there is also some small Giraffes.

Thinking further and associated his observations with all these theories, which made more sense. Darwin observed that there were thirteen types of finches and the only differences between them were their beaks and that they each were suitable for the type of food they ate. Also observed, traits from parents can be passed to their offspring. The organisms had more offspring that their environment could “handle”. He noticed that resources were running out and that caused competition between groups.

Finally, they consume energy in a similar fashion to omnivores by devouring plants and animals for fuel. Outside of the basic characteristics, though, humans do have one crucial difference that sets them apart from animals. Unlike animals, humans survive in environments they are not normally physically equipped for. They do this through the use of clothing to help adapt to climate and environmental changes.

First of all, I need to clarify that there is no dominant method of comparison between countries. Every method has its own advantages and disadvantages involving the level of abstraction, the scope of covering, etc. (Landman & Carvalho, 2016).In the early days, Lijphart (1971) called comparing many countries when using quantitative analysis, the ‘statistical’ method and on the other hand, when comparing few countries with the use of qualitative analysis the ‘comparative’ method. But nowadays, comparative studies are conducted to compare similarities and differences across countries and within countries.

In general, the okapi are found among the tropical rainforests of the North-Eastern Democratic Republic of Congo. Okapis thrive in altitudes between 500 and 1,000 meters. (800 meters above sea level) As okapis are shy and elusive, they rely heavily on the foliage of the forest to hide from predators. Okapis live in areas with a slow-moving water source for their own hydration, but sometimes this is limited because of natural rainforest boundaries.

The animal I chose to examine for this discussion is the finch, a type of medium-sized bird. In order to determine which individuals in the population is best adapted to their environment, we simply need to observe the natural selection process. The individuals who are most successful at adapting reproduce and pass on the trait or traits that provided it with an advantage compared to the rest of its population to its offspring. An example of natural selection would be Darwin’s Finches, whom of which got their name from Charles Darwin and helped him to develop his theory of natural selection. Currently, the finches, which are located on the Galapagos Islands, are being targeted by a parasitic fly.

It was also determined that prehensile tailed platyrrhines had more pronounced and convex articular surface curvatures. Greater contour curvatures on intervertebral articular surfaces are associated with an increased range of flexibility and mobility of the caudal vertebrae, benefiting prehensile primates that use their tails in a variety of complex movements. Hence, through analyses of the morphology of caudal vertebrae, specifically their articular surface area and curvature, it was concluded prehensile and non-prehensile tails could be distinguished according to these structural features. Both of these characteristics relate to effective use of the tail during locomotion. This article is useful towards my GEM as it describes differences in bone structure of the tails of prehensile and non-prehensile primates, and explains the reasons that certain variations confer advantages to prehensile tail

These ideas are similar to Darwin 's. chapter 3: 1.Bates saw different species of moth and butterfly, also saw how they are inherited specific

Through each grade of primate we can gain a better understanding of primate evolution. Changes in body structure are especially significant in primates for purposes of