Galapagos or Darwin’s Finch (Geospizinae), Santa Cruz Island, Galapagos, Ecuador
Darwin’s finches are an excellent example of the way in which species’ gene pools have adapted in order for long term survival via their offspring. Darwin’s Finches diagram below illustrates the way the finch has adapted to take advantage of feeding in different ecological niches.
Their beaks have evolved over time to be best suited to their function. For example, the finches who eat grubs have a thin extended beak to poke into holes in the ground and extract the grubs. Finches who eat buds and fruit would be less successful at doing this, while their claw-like beaks can grind down their food and thus give them a selective advantage in circumstances where buds are the only real food source for finches.
Polymorphism pertains to the existence of two distinctly different groups of species that still belong to the same species. Alleles for these organisms over time are governed by the theory of natural selection, and over this time the genetic differences between groups in different environments soon become apparent, as in the case of industrial melanism.
Industrial melanism occurs in a species called the peppered moth, where the occurrence has become of more frequent occurrence since the beginning of the industrial age. The following argument elaborates on the basis of principles involved in natural selection as far as industrial melanism is concerned.
Consider this argument of natural selection in the case of sickle cell trait, a genetic defect common in Africa.
This is how science has understood natural selection since the first studies involving Darwin. In the 21st century, humans selectively breed species to create hybrid species possessing the best genes of both parents via a process known as selective breeding. This is investigated in the next tutorial.
Apart from vitamins, the human body also requires high energy sources such as carbohydrates and fats. If you want an ove..
Lymphocytes are a type of white blood cell capable of producing a specific immune response to unique antigens. In thi..
Muscle cells are specialized to generate force and movement. Learn about the different types of muscle tissues in this t..
According to Charles Darwin's theory of natural selection, preferable genes are favored by nature in the gene pool, and ..
There are more species of insects than any other species combined. This surely illustrates that insects have the selecti..