We tend to assume that all characteristics of plants and animals are adaptations that have arisen through natural selection. Many are neither adaptations nor the result of selection at all. Why do so many of us plonk ourselves down in front of the telly with a microwave meal after a tiring day? Because it’s convenient?…
Kategori: Evolution in English
Evolution myths: Natural selection cannot explain homosexuality
There are numerous evolutionary mechanisms that might explain homosexual behaviour, which is common in many species of animals. “Simple reasoning shows that evolution cannot explain homosexuality – how would a homosexuality gene get selected for?” “Why have the genetic traits predisposing to homosexuality not been eliminated long ago?” Such arguments are surprisingly common – and…
Eggs and Their Evolution
Females of all vertebrates produce eggs, but the reptiles “invented” the eggshell — a device that could keep the egg from drying out and allow reproduction away from water (or, at least, from extremely moist environments). With the exception of the platypus and echidna, mammals provide the developing embryo with a suitable environment within the…
Chimpanzees ‘hunt using spears’
Chimpanzees in Senegal have been observed making and using wooden spears to hunt other primates, according to a study in the journal Current Biology. Researchers documented 22 cases of chimps fashioning tools to jab at smaller primates sheltering in cavities of hollow branches or tree trunks. The report’s authors, Jill Pruetz and Paco Bertolani, said…
Evolutionary Transition From Fish To Land Animals
New research has provided the first detailed look at the internal head skeleton of Tiktaalik roseae, the 375-million-year-old fossil animal that represents an important intermediate step in the evolutionary transition from fish to animals that walked on land. A new study of Tiktaalik roseae (middle), a 375-million-year-old transitional fossil, highlights an intermediate step between the…
The Evolution of Whales
The Evolution of Whales Based on November 2001 National Geographic Magazine, “The Evolution of Whales“. Covering the Evolutionary Origins of Modern Whales and Dolphins. Reviewed, with some edits by Northeastern Ohio Universities College of Medicine, Dr. J.G.M. Thewissen, with additional comments by Edward T. Babinski, and revised text and art by Sharon Mooney. All images reconstructed from…
Evolution: Out of Africa and the Eve Hypothesis / by Chris Stringer
Introduction Most palaeoanthropologists recognize the existence of two human species during the last million years – Homo erectus, now extinct, and Homo sapiens, the species which includes recent or “modern” humans. In general, they believe that Homo erectus was the ancestor of Homo sapiens. How did the transition occur ? The Multiregional Model There are…
Humans Began in Africa / By Lee Siegel
University of Utah researchers today published the strongest genetic evidence yet that modern humans originated in Africa and spread around the world rather than arising in several regions. By analyzing DNA from Asians, Europeans and Africans, “we found greater [genetic] diversity in African populations,” said Lynn Jorde, the U.’s associate chairman of human genetics. “That’s…
The Human Family Tree: 10 Adams and 18 Eves / By Nicholas Wade
The book of Genesis mentions three of Adam and Eve’s children: Cain, Abel and Seth. But geneticists, by tracing the DNA patterns found in people throughout the world, have now identified lineages descended from 10 sons of a genetic Adam and 18 daughters of Eve. The human genome is turning out to be a rich…
Observing Evolution – How Evolution Has Been Observed
Natural Selection, Macroevolution, and Ring Species The most basic direct evidence of evolution is our direct observation of evolution occurring. This is also the most basic lie which creationists tell about evolution because they constantly claim that evolution has never been observed when, in fact, it’s been observed both in the lab and the field…
Origins of Modern Humans: Multiregional or Out of Africa?
One of the most hotly debated issues in paleoanthropology (the study of human origins) focuses on the origins of modern humans, Homo sapiens.9,10,3,6,13,15,14Roughly 100,000 years ago, the Old World was occupied by a morphologically diverse group of hominids. In Africa and the Middle East there was Homo sapiens; in Asia, Homo erectus; and in Europe, Homo neanderthalensis. However, by…
The origin of diversity in modern humans
Abstract The interpretation of genetic evidence regarding modern human origins depends, among other things, on assessments of the structure and the variation of ancient populations. Because we lack genetic data from the time when the first anatomically modern humans appeared, between 200,000 and 60,000 years ago, instead we exploit the phenotype of neurocranial geometry to…
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