Reference no: EM131157966

Please answer the following questions in a 200-word response minimum. Try your best to reference the text I will message you privately for how to access the text book.

1. From observations made by Charles Darwin proposed the concept of natural selection. Explain the four premises of evolution as conceived by Darwin.

2. Describe Darwin's observations about the idea of speciation

3. Write a valid statement as to the support of this article, and its proposed information regarding whether humans are still evolving. Link: https://www.the-scientist.com/?articles.view/articleNo/32047/title/Are-Humans-Still-Evolving-/

4. Class, do you think humans are free from natural selection due to the current technological environment?

5. Another concept used by biologists is the ecological species concept. Describe the ecological species concept? Discuss how this approach used to define a species? What are its limitations?

Please participate (respond) to the classmate's answers with POSITIVE notable and educational input. (200 word minimum Reponses)

1. Jeff: I believe that no animal including humans are exempt for natural selection. It is true that technology has changed the ways humans can react to things like disease, natural disasters, etc. However, I still believe that natural selection is running its course among humans.

200 years ago, it may have been very common for people to have a life expectancy of 40-50 years. Today, this would seem like a life cut short. Due to advances in medical technology, humans have slowed the natural selection process, but it is still present. 200 years ago, it would be rare that a person living the United States would mate with someone from say China, or India. Today however, with access to global transportation, genetic variation on a massive scale is possible. Genetic variation can lead to certain immunities to diseases, thus the human race is evolving. I believe humans evolve differently than some animals when it comes to brain power and capacity, however many things will remain the same. Both Humans and animals will be adapting to a world that has increasing temperature, increasing pollution and other things that will change how humans look over the next 200 years. Lungs may adapt to deal with pollutants and humans may begin to deal with heat in different ways. Technology of course will slow down this process as people have access to air conditioning, and other shelters from the rising heat.

2. Jeff: Niche shift is when a species shifts it main niche when competition causes it to restrict a certain type of food or habitat that is vital to its survival. If competition for other species is not a problem, some species may exhibit competitive release, expanding its niche (Smith & Smith, 2012, p. 266). Character displacement refers to a shift in the distribution of phenotypes among competing populations. If this shift changes or involves a species morphology, behavior or physiology it is characterized as character displacement (Smith & Smith, 2012, p. 270). In the case of the Galapagos finches including Geospizafortis, and Giospizafuliginosa, character displacement in beak size in two different populations of finches. These two species have a wide variety of beak sizes within each type of species.

This relationship shows that if these species were competing on the same island for food sources, a certain type of beak size would be favorable for the type of food source present. From the data it appears to be a niche shift due to the fact that there is such variation in beak size. This means the species will experience a niche shift in feeding niches.

Smith, T.M., & Smith, R.L. (2012). Elements of Ecology (8th ed.). Retrieved from The University of Phoenix eBook Collections.

3. Tyler: What Darwin found with the premises of evolution was very noted that, each species produces more offspring than will survive to maturity, next that individuals in a population exhibit inheritable variations in their traits. Each organism compete with one another for the resources needed to survive and then those individuals with the most favorable combination of traits are most likely to survive and reproduce, which passing their genetic characters on to the next generation. There is variations in any one generation, overproduction of natural populations will increase geometrically, there is competition so there is struggle for existence, and survival to reproduce will be the better suited to the environment they are in. (Reece, Taylor, Simon, &Dickey, 2012).

Reece, J.B., Taylor, M.R., Simon, E.J., & Dickey, J.L. (2012). Campbell biology: concepts and connections (7th ed.).
Retrieved from The University of Phoenix eBook Collections.