Human phenotypic question

Question

Identify a change in one or more aspects of a human phenotypic traits that you perceive as changing over time.

How are the changes in the phenotypes being transmitted?

Do you think the changes you see involve natural selection or epigentic process? Or both? Why?

Do you think humans are currently evolving? Why? How?

Answer 1

An example of a human phenotype that has changed over time is height.

On average humans have been getting taller and taller. This is both due to natural selection, and environmental factors which cause epigenetic change.

There has been an advantage to humans being taller, so taller humans were more likely to breed and pass their genes on to their offspring through sexual reproduction. This is how natural selection affects height.

Environmental factors such as stress levels and nutrient intake can also affect height. This happens through epigenetics, by adding methyl groups or acyl groups to wound DNA segments to either make certain genes more likely to be expressed or less likely to be expressed. Epigenetic changes can also be passed from parent to offspring through sexual reproduction.

All organisms are constantly evolving, just very slowly. This is because all organisms are trying to be the most fit for their environment in order to ensure the survival of the species.