To understand the origin of whales, it's necessary to have a basic understanding of how natural selection works.
Natural selection can change a species in small ways, causing a population to change color or size over the course of several generations.
Natural selection is part of Darwin's theory of evolution saying that those individuals within a species that don't adapt well to their environment will eventually die off, while those that do adapt will continue on with future generations.
in evolution, the process by which certain individuals of a species, having characters that help them adapt to their specific environment, tend to leave more progeny and transmit their characters, while other individuals of the same species, less able to adapt, tend to leave fewer progeny or to die out: over the course of generations, the gene pool of the species comes to reflect this adaptation The process in nature by which, according to Darwin's theory of evolution, organisms that are better adapted to their environment tend to survive longer and transmit more of their genetic characteristics to succeeding generations than do those that are less well adapted.
The last shore-dwelling ancestor of modern whales was Sinonyx, top left, a hyena-like animal.
Over 60 million years, several transitional forms evolved: from top to bottom, Indohyus, Ambulocetus, Rodhocetus, Basilosaurus, Dorudon, and finally, the modern humpback whale.
Here, "fitness" refers not to an organism's strength or athletic ability, but rather the ability to survive and reproduce.
For example, a study on human evolution on 1,900 students, published online in the journal Personality and Individual Differences in October 2017, found that many people may have trouble finding a mate because of rapidly changing social technological advances that are evolving faster than humans.
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. The theory is sometimes described as "survival of the fittest," but that can be misleading, Pobiner said.Darwin was so embarrassed by the ridicule he received that the swimming-bear passage was removed from later editions of the book.Scientists now know that Darwin had the right idea but the wrong animal.THE AMERICAN HERITAGE® DICTIONARY OF THE ENGLISH LANGUAGE, FIFTH EDITION by the Editors of the American Heritage Dictionaries.Copyright © 2016, 2011 by Houghton Mifflin Harcourt Publishing Company.