Examples of selective pressures include competition, predation, land clearance, pollutants, diseases and illnesses, climate change and parasitism. A famous example of selective pressure is the long neck and legs of giraffes.

There are four principles at work in evolution—variation, inheritance, selection and time. These are considered the components of the evolutionary mechanism of natural selection. Selection Some individuals have inherited character (genes) that allows them to better survive or produce more offspring.

Types of selection pressures include:

• Resource availability – Presence of sufficient food, habitat (shelter / territory) and mates.
• Environmental conditions – Temperature, weather conditions or geographical access.
• Biological factors – Predators and pathogens (diseases)

Selection pressure means factors that contribute to selection which variations will provide the individual with an increase chance of surviving over others. Because of selective pressures, organisms with certain phenotypes have an advantage when it comes to survival and reproduction.

They pass on the versions of genes that produce their adaptations and the frequency of these alleles will increase within the population. Predation, competition and disease are examples of selection pressures.

So, evolution can happen by different mechanisms like natural selection and genetic drift. As our environment is always changing, natural selection is always happening. Humans are still evolving, and that is unlikely to change in the future.

Evolution is an ongoing process, although many don’t realize people are still evolving. It’s true that Homo sapiens look very different than Australopithecus afarensis, an early hominin that lived around 2.9 million years ago.