[kamilakaya]

Write an account of the following aspects of evaluation

• Outline the process of natural selection

• What is speciation?

• Explain how mutations lead to evolutionary change

[Curlyben]

Thank you for taking the time to copy your homework to AMHD.
Please refer to this announcement: Ask Me Help Desk - Announcements in Forum : Homework Help

[Unknown008]

Well, don't you have the notes in your book?

Natural selection is a process where some better adapted organisms live better and those not well adapted end up disappearing, specially in a new environment.

I don't know the second one.

Mutations cause changes in the way that organisms respond to their environment. Some may be good, others bad. The good mutated ones will obviously survive and not the others.

That's only a very brief description of what you have to say. For exam questions, you'll have to elaborate more. Since you do the subject, you need to know it to some extent so that you know what you're doing.

[kcroach]

I know we aren't suppose to do someone's homework for them but I think there are more accurate answers to these questions and a bit of time has past so if you were a procrastinator this will be to late.

1. Natural Selection acts on variations within and between populations or species. Individuals in a population or different groups, or species vary in genotype (the genes they carry) and phenotype (outward appearance and ability) and may have greater or lesser fitness based on the environment they interact with. Fitness for the purposes of natural selection means the number of offspring that you produce that themselves reach reproductive age. Those with higher fitness produce more offspring and therefor pass on their genes to the next generation at a higher rate, increasing those genes frequency in the population. It is important to remember the distinction between producing many offspring and producing many offspring that reach reproductive age themselves. Many organism produce hundreds or thousands of progeny per individual but only a handful will survive to maturity whereas others, such as humans, produce only a few but almost all reach adulthood.

2. Not really going to answer that one. There are at least two types of speciation. There are a number of theories about how it happens. It also depends on your definition of species as species is difficult to define when talking about clonally reproducing populations.

3. Mutations provide the substrate for natural selection to act on. If there is no variation in the population selection can not act. Mutation provides a mechanism for changes in genotype and phenotype that can be acted on by selection, allowing a population to evolve to increase its fitness in an environment.