Human Species

Most of us do not realize that there have been around 21 human species that have lived on this planet Earth. I came across this article that gives an introduction to the past history of humans.
Homo sapiens. But we weren't always the only humans. The Smithsonian Institute estimates that some 21 different human species have roamed the Earth (though the number varies due to conflicting definitions of what is “human&rdquoWinking. Many of those species are in the genus Homo, which has only one surviving species today (that’s us). The list of hominids also includes other species considered by most scientists to be early humans, such as the Australopithecus afarensis, a member of the genus Australopithecus.
Homo sapiens were Homo habilis, Homo rudolfensis, and Homo erectus, and evidence suggests they coexisted in East Africa some 1.9 million years ago. This kind of cohabitation was a familiar fixture of human evolution. When Homo sapiens first appeared around 300,000 years ago, our ancestors lived among many other now-extinct human cousins. Modern humans famously fraternized with Neanderthals, Denisovans, and other populations. Homo sapiens also shared the planet with lesser-known species such as Homo floresiensis, Homo naledi, Homo luzonensis, and the straggling survivors of Homo erectus. But because some of these groups lived in remote communities, it’s possible that modern humans never even laid eyes on them. Scientists theorize that our ancestors wiped out many of these human species (Neanderthals were the last to fall, beginning to go extinct around 40,000 years ago) by demonstrating superior strategizing and cooperation skills. Our ancestors’ social intelligence helped them rise to the top of the food chain, and the population grew exponentially. Today, modern humans stand alone in the genus Homo, but we only have ourselves to blame. "
"Each one of the billions of people living on Earth today belongs to the same species:

The first humans in the same genus as


No Tails For Us

It appears that scientists may have found a reason why humans and apes do not have tails yet monkeys do through evolutionary history. It is all in the DNA…
Here is
the story:

<NYU Grossman School of Medicine suggests that a genetic change in our ancient ancestors could partially explain why humans don’t have tails, unlike monkeys.
Recently published in the journal Nature, the work compared the DNA of tail-less apes and humans to that of tailed monkeys and found an insertion of DNA shared by apes and humans, but missing in monkeys. When the research team engineered a series of mice to examine whether the insertion, in a gene called TBXT, affected their tails, they found a variety of tail effects, including some mice born without tails.>>

Our First Genome

DNA has been found on the recovered remains of a 4500-year-old human skeleton in Ethiopia. This is the first time DNA has been able to be extracted. They wonder if they will be able to go back further at some time in even older humans, possibly a million years back in time. Read more here.

"A team of scientists reported on Thursday that it had recovered the genome from a 4,500-year-old human skeleton in Ethiopia — the first time a complete assemblage of DNA has been retrieved from an ancient human in Africa.

The DNA of the Ethiopian fossil is strikingly different from that of living Africans. Writing in the journal Science, the researchers conclude that people from the Near East spread into Africa 3,000 years ago. In later generations, their DNA ended up scattered across the continent."

Early Human Footprints

Scientists have found the earliest evidence of human footprints outside of Africa. The prints were found on the Norfolk Coast in the eastern part of England. The footprints are considered more than 800,000 years old and were found on the shores of Happisburgh. They believe that there may have been a land bridge in that area to the western shore of France.
A more detailed description can be found here.

Neanderthals and Humans

I read an interesting science article discussing where Neanderthals and Humans were close in sharing genetic material and more detail on where the divergence most likely happened. They believe that the level of shared genes is at about 2%, more found in non-African people and essentially very little relationship with African people to Neanderthals. Some of the alleles that control addiction to smoking, Type II Diabetes, and some other diseases appear to have some coverage between the groups. They believe any interbreeding between Humans and Neanderthals occurred near the end of our divergence. One can find more details in the article found here.
RapidWeaver Icon

Made in RapidWeaver