Evolution Part Two

What does it mean to Evolve? Can I Evolve? Individual organisms don't evolve. Populations evolve. Because individuals in a population vary, some in the population are better able to survive and reproduce given a particular set of environmental conditions. These individuals generally survive and produce more offspring, thus passing their advantageous traits on to the next generation. Over time, the population changes. But why are there so many different types of organisms on one planet? Biodiversity arises from the huge variety of environments you see. In addition these environments change over time. Traits for survival must change as well to avoid the extinction of a species.

Which Bear species is which? One species does not "turn into" another. In order for one population to diverge enough from another to become a new species, there needs to be something to keep the populations from mixing. Often a physical boundary divides the species into two (or more) populations and keeps them from interbreeding. If separated for long enough and presented with different environmental conditions, each population takes its own distinct evolutionary path. Which Bear species is which? Grizzly Black Sloth Polar Sun Panda Spectacled Brown

TAG TEAM! Wegener and Darwin 19th Century Science Monsters How might the movement of continents (i.e. Breaking up of Pangaea / Plate Tectonics) effect a species and promote biodiversity on the planet? OK.... – I know why different characteristics in organisms develop, but how can these appear? I’d love to have “wings” but can’t grow them no matter how hard I try... Mutations, or alterations in genetic material occur frequently. Because genes are passes on through reproduction, undesirable mutations (ones that don’t provide some particular advantage for a species in its environment to more efficiently reproduce) do not become more common. Alternatively, the few mutations that give a survival advantage are in fact more likely to be passed on and accumulated through reproduction. NATURAL SELECTION!

SEX! I n A d d i t i o n Consider the following..... Sexual reproduction allows an organism to combine half of its genes with half of another individual's genes, which means new combinations of genes are produced every generation. In addition, when eggs and sperm are produced, genetic material is shuffled and recombined in ways that produce new combinations of genes. Sexual reproduction thus increases genetic variation, which increases the raw material on which natural selection operates. Genetic variation within a species -- also known as genetic diversity -- increases a species' opportunity for change over successive generations. The fact that plants photosynthesize and animals use oxygen is no doubt a product of helpful mutations piling up over billions of years.

Popular Questions: READ: Humans did not evolve from monkeys. Humans share a common ancestor with modern African apes, like gorillas and chimpanzees. Scientists show this common ancestor existed 5 to 8 million years ago. Species diverged into two separate lineages. One of these lineages ultimately evolved into gorillas and chimps, and the other evolved into early human ancestors called hominids. Since the earliest hominid species diverged from the ancestor we share with modern African apes, 5 to 8 million years ago, there have been at least a dozen different species of these humanlike creatures. Some of the extinct hominids known today, are almost certainly direct ancestors of Homo sapiens (us). The picture becomes clearer as new fossils are found. Humans certainly evolved through the same biological processes that govern the evolution of all life on Earth!

Other animals too, have noticeable skeletal clues to their ancestry: Some Clues Feel the area in the lowest part of your back – in the center just below your belt. What is called your tailbone is actually a series of 3-5 vertebrae fused together at the base of your spine. The proper term is a coccyx. This is in fact what remains of a once useful tail in the history of our evolution. Other animals too, have noticeable skeletal clues to their ancestry: Why do you get goose bumps?

Is there evidence for evolution Is there evidence for evolution? How do we know what happened millions of years age if no one was there? In the 150 years since Darwin proposed the theory of evolution by natural selection, a mountain of evidence has accumulated to support the theory. A greatly expanded fossil record since Darwin's time, the discovery of DNA and the process of genetic replication, an understanding of radioactive decay, observations of natural selection in the wild and in laboratories, and evidence in the genomes of many different organisms, including humans, have all bolstered the validity of the fact of evolution.