Evolutionary Hypothesis Controversy: A Genetic Analysis

The second scenario is an example of evolution because, over time, the brown beetles became the more common trait. They had a better advantage due to natural selection.

All animals with limbs have a common design. If a batwing were to be formed from a person’s hand, make the fingers extremely long; a horse elongates the middle fingers and reduce and lose the outer ones; frogs elongate the bones of the leg and fuse several of them together. All in all, despite radical changes in what limbs do and what they look like, this underlying blueprint is always present.

The emperor moth, or Saturnia pavonia, is a species of moth most notable for its beautiful collection of four eyespots on its wings; two on its front wings and two on its back wings. Because the eyespots are so visible and prominent on the wings of the moth, it can be proposed that this trait was adapted by the moth to increase its chances of viability by intimidating or confusing predators, compared to the common heath moth Ematurga atomaria which is a simple brown or grey colour (i.e. no eyespots). Eyespots on an organism is an example of mimicry – when an organism evolves a specific trait that is similar to a different organism (usually a predator), which in turn can help to improve its chances of survival. The theory behind mimicry proposes that the certain traits that a species adapts (in this case, eyespots), appear as confusing to predators, therefore hindering the predator’s ability to accurately perceive the identity of the species which allows said species even the slightest chance to escape from harm’s way (Howse 2013). There is also proof that large eyespots, such as those on the Saturnia pavonia, are beneficial to the organism because they are visibly similar to the eyes of predators such as owls (Howse 2013). The results from one experiment conducted by Blest (1957) studied the number of averted attacks by birds on a butterfly with eyespots compared to the number of averted attacks on a butterfly with the eyespots concealed from rubbing the wings (Stevens).

10. Study Figure 1.22, which shows an evolutionary “tree.” What is indicated by twig? What do the branch points represent? Where did the “common ancestor” of the Galápagos finches originate?

The most extensive metamorphic changes of insects internal organs occur with development of the thoracic musculature required for flight, the arrangement of nervous system and the development of gonads [2].

BBC - GCSE Bitesize: Evidence for natural selection. (2017). Bbc.co.uk. Retrieved 29 September 2017, from http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/environment/4_survival_of_fittest5.shtml

A popular focus for evolutionary research has been the evolution of the human brain. Such research has sought to answer the questions of why our brains evolved to be as large as they are and how this increase in brain size came to be, given the massive energy requirements of neural tissue. Encephalization quotients refer to the size of the brain compared to the size of the body; as brain size increases and body size decreases, the encephalization quotient becomes larger. As would be expected, homo sapiens possess the largest encephalization quotient of all known species on Earth, being 6 times larger than the average mammal (Martin). The evolution of larger brains, which are more metabolically expensive, was made possible by a reduction in

A variation among individuals must be present that is inherited and allows some of these individuals to be more successful at survival than others. The theory of its action was first fully expounded by Charles Darwin and if one trait has consistently experienced greater success, then that trait will become more prevalent over time in that population. Jacobs (1961) found that the frequency of ebony (e/e) flies dropped rapidly in the light compared to dark environments. Tan (+/+) males showed a direct advantage in light as compared with dark, thereby allowing relatively greater numbers of the heterozygote (+/e) males and homozygote ebony males to mate in dark conditions. The stabilization of the ebony gene is due to the ebony allele in the heterozygous fly, which increases sexual activity of males. The ebony (e/e) homozygotes have decreased sexual activity as compared with the wild type (+/e). While genetic drift typically behaves differently in each population, the results of natural selection are consistent from population to population.

In conclusion, it is hard to make a conclusion. Darwin’s Theory of evolution is easily able to be applied to other species, but it’s harder to apply to human kind. Mans advances in technology have put us in a spot where we are able to decide our future, for we are no longer at the mercy of true natural selection in Darwin’s Theory. Ethical complications lie in the background of every question of modern human evolution. The future of man is not able of being definitely decided, despite our knowledge of our evolutionary past. The path that societies take within the future years of scientific development and moral arguments will play a large role in the direction of man’s

As a result of sexual selection, many male animals have evolved extraordinary structures, usually used as ornaments for attracting females, or weapons, for fighting mating rivals (Douhard et al., 2017; O’Biren et al., 2017; McCullough et al., 2016; McCullough and Emlen, 2013; Emlen, 2008). The diversity of these structures is usually extremely high (both intra- and interspecifically) and have existed in many animal groups, including extinct trilobites and dinosaurs, to beetles, birds and hoofed mammals (ungulates) found today (O’Biren et al., 2017; McCullough et al., 2016; Emlen, 2008; Emlen et al., 2005; Emlen, 2001). Although both ornaments and weapons will increase mating opportunities for males, the mechanisms shaping the evolution of

The purpose of this experiment was to test if evolution was occurring, and if so what type. Evolution is when either the genotype frequency or the allele frequency changes overtime within a population. In other words, it is when the genotypes of a population change. The change can be due to a number of things, but the two this experiment tested were genetic drift and natural selection. If natural selection were to occur, the allele frequency would be changing consistently, but one allele would constantly be greater than the other. If genetic drift was to occur, we would end up with many more of one type than the other, and the change would not be consistent.

Natural selection is the process where an environmental factor acts upon a population and results in some organisms having more offspring then others. This is widely accepted as the cause of evolution, and the reason that populations develop and change into better individuals over time allowing their species to maximise their chances of survival and develop into a more dynamic population. One of the many types of genetic variation is camouflage. The natural colouring or form of an organism which enables it to blend in with it’s surroundings.

The class Insecta is comprised of six legged organisms which are divided into three sections, the head, thorax and abdomen. The head of most insects contains a set of antennas used for sensing and a mandible used for crushing or cutting food. The second section of the insect or the thorax of the insect contains all of the six legs and can contain the wings of some insects, it is a key part of the insect’s movements. Insects are the only the only known arthropods which can possibly have wings. The back segment, the abdomen is used by insects to contain reproductive organs and can also hold means of defense that are utilized when the insect is threated such as stingers.

Past studies showed the strength of the form and function relationship in the avian furcula, while this study examined the form and function in more modern Mesozoic birds. This study revealed that eigenshape analysis of Arvin birds furcular allows for more derived flight modes. This study confirmed that soaring birds have a more U-shaped furcula than continuously-flapping birds. It also observed that the interclavicular angle is an even more important aspect of flight mode than the curvature, and is positively correlated with body size. This study demonstrates that the Mesozoic taxa have evolved unique flight modes through different musculoskeletal

The characteristics of the phylum, Arthropoda, includes jointed legs and an exoskeleton (Freeman, 2014). The insect the team and I chose to work on were the hissing cockroaches, Gromphadorhina​ portentosa. Hissing cockroaches are small ectothermic animals and are known to have a tracheal system (Burnaford) that allows them to transfer oxygen into their body. Introduction