Climate change is the architect of new human species

Recently, a theory has mentioned that many climatic changes have occurred over millions of years as a result of which human ancestors got separated from a branch comprising of chimpanzees and gorillas.

• This has resulted in emergence of a new branch known as hominin.

What is Evolution?

• Evolution is a process that results inheritable changes in a population spread over many generations.
• The formation of complex organisms through ‘gradual change’ from simple ancestral types over the course of geological time is termed Evolution or Organic Evolution.

Relations between Climate change and Human evolution:

• The theory named “State of the Environment 2023” published by the Centre for Science and Environmenthas highlighted the role of climate change in changing the appearance of Humans.
• We have evolved from unicellular organisms, as a result of adaptations to climatic conditions for survival.
• If conditions had not changed, perhaps there would have only been microbes in the ocean.
• There are two kinds of changes: genetic and phenotypic (observable, physical changes).
• Even now, genetic changes keep happening automatically. But they do not necessarily translate to changes in the human body or physical appearance.
• Physical changes occur only if there is a change in our diet or locomotion.
  • For example, if a species ingests tough food, it will develop a heavy jaw.
  • If it evolves to consume softer food, a heavy jaw is useless, and it recedes.
• When climatic conditions change, Species induce changes in vegetation, and that has shaped human evolution.
• Physical changes typically take 500,000 years to appear. Modern humans evolved somewhere around 300,000-500,000 years ago. 

Changes can be seen in present times:

• Genetic changes in Europeans must be seen if hot and dry conditions become recurrent.
• Around 13-14 million years ago, Europe was warm and humid.
• Roughly 16-18 varieties of apes lived there.
• And then the climate changed, transforming Europe into a cooler place. All apes disappeared from the continent.
• Every species evolves in its niche.And if that niche becomes inhabitable due to climate change, the species would perish or migrate.

What is Niche?

• Niche helps to describe an organism’s interaction with its environment, including biotic and abiotic agents.
• Habitat and Niche are closely related terms having a thin line of difference.
• Niche is the specific role any particular species plays in an ecosystem.
• Niche mainly describes how a species contribute to the energy flow of the system, how it gains energy and supplies it further in the system, e.g. if the species is a producer or consumer etc.
• In contrast, Habitat is the physical place where any particular species lives and adapts to environmental conditions, e.g. mountains or grassland.

Other factors responsible for Human evolution:

• Five different forces have influenced human evolution:
  • natural selection,
  • random genetic drift,
  • mutation,
  • population mating structure, and
  • Culture

Darwin’s Theory of Evolution:

• The Theory of Evolution by natural selection was first formulated in Charles Darwin's book "On the Origin of Species published in 1859.
• Darwin proposed that species can change over time, that new species come from pre-existing species, and that all species share a common ancestor.
• According to the theory, individuals with traits that enable them to adapt to their environments will help them survive and have more offspring, which will inherit those traits. Individuals with less adaptive traits will less frequently survive to pass them on.
• Darwin chose the term "natural selection" to be in contrast with "artificial selection," in which animal breeders select for particular traits that they deem desirable.
• In natural selection, it's the natural environment, rather than a human being, that does the selecting.