Darwinian evolution is the process by which natural selection promotes genetic changes in traits that favor survival and reproduction of individuals. How fast evolution happens depends crucially on the abundance of its "fuel": how much genetic difference there is in the ability to survive and reproduce.
New research by an international research team with participation of the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) has now discovered that the raw material for evolution is much more abundant in wild animals than previously believed. The findings were published in Science.
Darwin thought of the process of evolution as something slow, visible only over geological ages. However, researchers have since discovered many examples of evolution occurring in just a few years.
One such example is that of British populations of the peppered moth, where the abundance of two color morphs changed dramatically in only a few decades, as the result of evolution by natural selection favoring different morphs depending on the level of air pollution. It was unclear however how fast animals with longer lifespans such as birds and mammals can evolve and adapt to environmental change.
Led by Dr. Timothée Bonnet from the Australian National University, a team of 40 researchers from 27 institutions addressed this question and measured how much of the "fuel of evolution" exists overall in wild populations of birds and mammals.
The answer: many populations of birds and mammals can evolve surprisingly fast—their amount of genetic difference in the ability to survive and reproduce being two to four times higher than previously thought. READ MORE...
Fossil apes can inform us about essential aspects of ape and human evolution, including the nature of our last common ancestor.
In the 150 years since Charles Darwin speculated that humans originated in Africa, the number of species in the human family tree has exploded, but so has the level of dispute concerning early human evolution. Fossil apes are often at the center of the debate, with some scientists dismissing their importance to the origins of the human lineage (the “hominins”), and others conferring them starring evolutionary roles. A new review out on May 7 in the journal Science looks at the major discoveries in hominin origins since Darwin’s works and argues that fossil apes can inform us about essential aspects of ape and human evolution, including the nature of our last common ancestor.
Humans diverged from apes — specifically, the chimpanzee lineage — at some point between about 9.3 million and 6.5 million years ago, towards the end of the Miocene epoch. To understand hominin origins, paleoanthropologists aim to reconstruct the physical characteristics, behavior, and environment of the last common ancestor of humans and chimps.
“When you look at the narrative for hominin origins, it’s just a big mess — there’s no consensus whatsoever,” said Sergio Almécija, a senior research scientist in the American Museum of Natural History’s Division of Anthropology and the lead author of the review. “People are working under completely different paradigms, and that’s something that I don’t see happening in other fields of science.”
There are two major approaches to resolving the human origins problem: “Top-down,” which relies on analysis of living apes, especially chimpanzees; and “bottom-up,” which puts importance on the larger tree of mostly extinct apes. For example, some scientists assume that hominins originated from a chimp-like knuckle-walking ancestor. Others argue that the human lineage originated from an ancestor more closely resembling, in some features, some of the strange Miocene apes. TO READ MORE, CLICK HERE...
