Evolution means that species of organisms and population change with time. Environmental pressure could be a drought that favors plants and animals who can survive with less water or who are able to move to places that have more water.
More simply put, the theory can be described as "descent with modification," said Briana Pobiner, an anthropologist and educator at the Smithsonian Institution National Museum of Natural History in Washington, D. Similarly, natural selection eliminates inferior species gradually over time.
Image credit: NOAA Natural selection To understand the origin of whales, it's necessary to have a basic understanding of how natural selection works. An English parson named Thomas Malthus published a book in called Essay on the Principle of Population in which he warned his fellow Englishmen that most policies designed to help the poor were doomed because of the relentless pressure of population growth.
Typically, they claimed that evolution was guided by some long-term trend. On the other hand, "improvement in fitness" is not dependent on the differential survival and reproduction of individuals due to differences in phenotype, it is dependent on the absolute survival of the particular variant.
This is called "microevolution. A wealth of evidence Even though scientists could predict what early whales should look like, they lacked the fossil evidence to back up their claim. Yet the choice of terminology isn't random: Ben Stein wants you to stop thinking of evolution as an actual science supported by verifiable facts and logical arguments and to start thinking of it as a dogmatic, atheistic ideology akin to Marxism.
The process of natural selection starts with individuals who have genes that produce characteristics that give them a survival advantage. Darwin's general theory presumes the development of life from non-life and stresses a purely naturalistic undirected "descent with modification".
To read the theory in its original form, see Darwin's book, " On the Origin of Species.