Today, only the posts survive and even these are mostly stumps.
Plants and animals both owe their origins to are more similar to those of bacteria than to the ribosomes found in the eukaryote cell's cytoplasm; and like chloroplasts they are enclosed by a double membrane as would be expected if they derived from bacterial cells engulfed by another cell. And that is where they remained for at least 600 million years.
This is because, in the absence of a protective ozone layer, the land was bathed in lethal levels of UV radiation.
And even once the antiquity of the remains was established, many scientists refused to accept that Neandertals could be closely related to modern humans, depicting them instead as brutish and apelike.
This interpretation reflected the prevailing prejudices about human ancestry, and was supported by misinterpretation of the remains of the "Old Man of La Chapelle", whose skeleton was warped by arthritis.
Thirty years ago, it was generally accepted that humans and the great apes last shared a common ancestor perhaps 16-20 million years ago, and that the separate human branch was occupied by only a few species, each evolving from the one before.
Now we know, through a combination of new fossil finds and molecular biology, that humans and chimpanzees diverged as little as 7 million years ago, and that our own lineage is "bushy", with many different species in existence at the same time.
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Our knowledge of human evolution is changing rapidly, as new fossils are discovered and described every year.
Radiocarbon dating is the technique upon which chronologies of the late Pleistocene and Holocene have been built.