While these mechanisms served our ancestors well, though, our evolved sense of right and wrong is out of step with the modern world. Social media can turn outrage into an addiction, gender equality is still hampered by caveman thinking, and implicit bias turns to explicit oppression. How do we separate what’s natural from what’s right? How can we reshape our thinking to thrive in the modern world?
Here one of Australia’s brightest philosophers charts the evolution of morality from the first humans to today, and shows us how we can turn towards a better future.
‘In the battle of our genes, our minds, our souls, which wins? Hate and love, good and evil, right and wrong. Let Tim Dean unlock the mystery of being human. There are some thinkers just made for our times: Dean is one of them.’ – Stan Grant
Published by the Wellcome Trust, the ‘Big Picture’ explores issues around biology and medicine. Why does Darwinian evolution raise controversy when, say, quantum mechanics scarcely registers on the public consciousness?
This issue of ‘Big Picture’ looks at the theory of evolution, the evidence that supports it, unanswered questions and the history of public reaction.
There is also an associated activity in which students explore evolution through different styles of writing.
Students read, analyse and evaluate articles on evolution written in a variety of styles, including a scientific journal, a newspaper article, a web article and an exam question essay. They then write their own piece in one of the styles.
When first published (in 2007) the piece could be entered into a competition. The competition is now closed.
This colourful leaflet from the Natural Environment Research Council (NERC) looks at how environmental factors have affected human evolution. It includes a timeline and map showing how and where humans have developed and changed over millions of years.
Humans are a truly global species. We have colonised every continent. We have adapted and thrived in the harshest of environments. How did this happen? And what part did the environment, including climate change, play in human evolution and development?
Between 2002 and 2006 the Natural Environment Research Council funded an ambitious programme, Environmental Factors in the Chronology of Human Evolution & Dispersal (EFCHED), to investigate humanity’s rapid expansion out of Africa and across the globe.
The programme sought answers to several questions. When did humans move out of Africa? Did humans leave alone or did their dispersal coincide with widespread mammal migrations? Was there just one major movement of people or were there many?
After the superarchaic humans came the archaic ones: Neanderthals, Denisovans and other human groups that no longer exist.
Archaeologists have known about Neanderthals, or Homo neanderthalensis, since the 19th century, but only discovered Denisovans in 2008 (the group is so new it doesn’t have a scientific name yet).
Since then, researchers have discovered Neanderthals and Denisovans not only mated with each other, they also mated with modern humans.
“When the Max Plank Institute [for Evolutionary Anthropology] began getting nuclear DNA sequenced data from Neanderthals, then it became very clear very quickly that modern humans carried some Neanderthal DNA,” says Alan R. Rogers, a professor of anthropology and biology at the University of Utah and lead author of the Science Advances paper.
“That was a real turning point… It became widely accepted very quickly after that.”
As a more recently-discovered group, we have far less information on Denisovans than Neanderthals. But archaeologists have found evidence that they lived and mated with Neanderthals in Siberia for around 100,000 years.
The most direct evidence of this is the recent discovery of a 13-year-old girl who lived in a cave about 90,000 years ago. DNA analysis revealed that her mother was a Neanderthal and her father was a Denisovan.
Scientists are still figuring out when all this inter-group mating took place. Modern humans may have mated with Neanderthals after migrating out of Africa and into Europe and Asia around 70,000 years ago
. Apparently, this was no one-night stand—research suggests there were multiple encounters between Neanderthals and modern humans.
Less is known about the Denisovans and their movements, but research suggests modern humans mated with them in Asia and Australia between 50,000 and 15,000 years ago.
Until recently, some researchers assumed people of African descent didn’t have Neanderthal ancestry because their predecessors didn’t leave Africa to meet the Neanderthals in Europe and Asia. But in January 2020, a paper in Cell upended that narrative by reporting that modern populations across Africa also carry a significant amount of Neanderthal DNA.
Researchers suggest this could be the result of modern humans migrating back into Africa over the past 20,000 years after mating with Neanderthals in Europe and Asia.
Human groups that encountered each other probably swapped more than just genes, too.
Neanderthals living in modern-day France roughly 50,000 years ago knew how to start a fire, according to a 2018 Nature paper on which Sorensen was the lead author.
Fire-starting is a key skill that different human groups could have passed along to each other—possibly even one that Neanderthals taught to some modern humans.
“These early human groups, they really got around,” Sorensen says. “These people just move around so much that it’s very difficult to tease out these relationships.”
The hominin family tree has deep roots in Africa. The earliest fossil of our genus, Homo, yet found is a 2.8-million-year-old jaw fragment uncovered in East Africa.
Our species, Homo sapiens, didn’t appear till fairly far up the tree, branching off at least 260,000 years ago. Where exactly in Africa that happened, however, remains up for debate.
Fossils carrying a varying mix of features from both modern humans and more ancient hominins seem to be scattered across Africa,
from the 260,000-year-old Florisbad remains in South Africa and 195,000-year-old Omo remains in Ethiopia to the 315,000-year-old Jebel Irhoud remains in Morocco.
But after baking in the African heat, the DNA from these ancient fossils seems to have largely degraded.
While the hunt for ancient DNA continues, many researchers have instead turned to studying the diverse genetics of populations in Africa.
One of the deepest-rooted lines of mitochondrial DNA is commonly found in people living across southern African, and none more so than in the KhoeSan—foragers, herders, and hunters who speak languages that include a clicking sound for consonants.
Many past studies, including some of Hayes’s own work, tease apart their ancestry for clues to our species’ past.
But for this new study Hayes and her colleagues wanted to pinpoint exactly where this deep-rooted genetic line arose
. To fill in some of the gaps in the genetic record, the researchers sequenced the mitochondrial DNA of 198 individuals from Namibia and South Africa—some of whom identify as KhoeSan and others who do not—and combined them with previously collected data for a total of 1,217 individuals.
Next they grouped southern African populations by ethnicity and linguistics to lay out the geography of people carrying these deep-rooted lines of mitochondrial DNA today.
And they crafted a tree tracing their mitochondrial genetic relationships back some 200,000 years to the early days of our species.
“It’s giving you one part of the whole story of evolution at very high resolution, and that’s pretty cool,” Hawks says. “But you sort of want the rest of the story.”
Mitochondrial DNA makes up a minute fraction of our genomes: While it contains around 16,500 base pairs, nuclear DNA has more than three billion, explains Carina Schlebusch, an evolutionary geneticist at Uppsala University in Sweden.
Untangling information in our complete genomes promises a more complex tale. Researchers have made similar trees for Y-chromosome DNA, which is genetic material present in men.
While the details remain hazy, it hints at a very early branching genetic line in some modern humans living in western Africa’s Cameroon.
“On our other chromosomes,” she adds, “we have millions of these separate loci that segregate in populations that probably also have their own ancestors somewhere in the past.”
Tracing those other ancestors is another issue. The nuclear DNA signal is extremely complex. What we do know from full genomes of Africans is that the results of this study aren’t entirely out of line with past work that points to human origins in southern Africa, says Brenna Henn,
a population geneticist at the University of California, Davis, who has extensively studied African population history.
Yet scientists are still discovering new ways to study nuclear DNA. They can’t simply peek into its genetic code to read it like a book.
Intensive processing and modeling are required to understand what it all means, and the assumptions made during analysis can affect the outcome.
There are also some hints that there’s still more to learn. Several studies point to the presence of even earlier branching “ghost” populations that intermixed with our species, leaving behind small traces of their DNA in some African groups.
“We don’t know where they fit in, we don’t know who they were, but we do know some of them hung around until fairly recently,” Hawks says.
The controversy over our origins will surely continue. Unlike many fields of study, human evolution is not something you can design experiments to test, Akey adds. But then again, perhaps scientists need to rethink the debate entirely.
“Maybe the question we’re asking isn’t the right one,” he adds. “Maybe we need a more nuanced question.”
All of this work also circles the increasingly confusing definition of a species. While humans like to put everything in boxes, nature doesn’t fit into tidy categories,
Schlebusch says. There are no distinct lines between one species and the next; everything works in shades of gray.
Scientists have a general idea of how we became human, but there are still some big mysteries to solve.
Why do we walk upright?
Why don’t we have fur?
How did our brain become bigger?
There is still a lot we don’t know about how we, Homo sapiens, evolved. Scientists are piecing the puzzle together.
Modern humans, along with other great apes, evolved from a common ape-like ancestor. Early humans evolved around 7 million years ago.
Over the past 7 million years, there have been over 20 different species of early humans. They are all extinct, except us.
Our ancestors evolved in Africa and stayed there for three to four million years. Eventually our ancestors stood on two legs and developed a bigger brain. The first species to leave Africa and spread across the globe was Homo erectus.
As early humans spread out, the climate was changing. Some species adapted to the changing world. Others went extinct. Our most famous extinct relative is Homo neanderthalensis – the Nelsanderthals.
Neanderthals were a very successful species and shared the planet with us – Homo sapiens. Why did Neanderthals go extinct? Did they fight with Homo sapiens? Or did a changing climate kill them?
Neanderthals looked quite different from us and behaved differently. But what if they weren’t as different as they looked? Perhaps Homo sapiens bred with Neanderthals, leading to modern humans as we know them. Maybe you have some Neanderthal genes!
Neanderthals and all other early human species went extinct. We still don’t know why. Modern humans were the only human species to survive. We spread out across the globe, colonising almost every continent.
The beginning of humanity can be confusing, but the Bible has such an awesome explanation of how we all got here and what happened after the Garden of Eden. Curious about that story? The video below gives a great recap of what it all looked like.
Genesis is just the beginning of all God has planned for us, and we would love to tell you all about it! Click below to talk with someone about the Good News Jesus brings later in the Bible!
And the Bible is the most unreliable book.Some stories thety do make sense and some not. I think the authors re taking the wrong drugs and they come doewn with some unexplainesd bullshits
It is up to you how you read the Bible and what you ll make out of the book
The origin of human beings from far more primitive ape-like precursors is one — just one — of the definitions of “evolution” that the public and the media carry around in their heads.
Not surprisingly, the iconic transition from ape to man is the first, second, and third image produced by a Google image search for that term.
In bonus footage from the new episode of Science Uprising, “Human Evolution: The Monkey Bias,” geologist Casey Luskin explains why the iconic image is more imagination than reality.
The scientific evidence is plagued by ideology-driven interpretation, fanciful reconstructions, pathetically sparse fossil remains, “missing transitions,” and other problems.
The story of human origins is subject to constant rewriting, which is to say reimagining, making firm fact-based statements perilous.
Yet this reality is largely concealed from the public, including from students, even from non-specialists in relevant scientific fields. Why? Dr. Luskin sheds light on that question, too
Given these types of discoveries, it may be better to think about human evolution as a “braided stream,” rather than a “classical tree of evolution,” says Andrew C. Sorensen,
a postdoctoral researcher in archaeology at Leiden University in the Netherlands. Although the majority of modern humans’ DNA still comes from a group that developed in Africa
(Neanderthal and Deniosovan DNA accounts for only a small percentage of our genes), new discoveries about inter-group mating have complicated our view of human evolution.
“It seems like the more DNA evidence that we get—every question that gets answered, five more pop up,” he says. “So it’s a bit of an evolutionary wack-a-mole.”
A powdery white layer blankets the desiccated landscape of Botswana’s Makgadikgadi pans, one of the world’s largest salt flats. But some 200,000 years ago, this blank canvas would have been painted in the blues and greens of a flourishing wetland.
Set in the middle of a harsh desert in southern Africa, the lush landscape would have been an appealing place for early humans to call home.
Now, a controversial new study in Nature argues that this oasis, known as the Makgadikgadi–Okavango wetland, was not just any home, but the ancestral “homeland” for all modern humans today.
The researchers studied mitochondrial DNA—genetic material stored in the powerhouse of our cells that is passed from mother to child—of current residents across southern Africa.
Then they layered the genetic data with an analysis of past climate and modern linguistics, as well as cultural and geographic distributions of local populations.
The study’s results suggest that shifts in climate allowed branches of the ancient population to spread from the wetland to newly formed zones of green.
Thousands of years later, a small population of these wanderers’ kin eventually would leave Africa and ultimately inhabit every corner of the world.
“We all came from the same homeland in southern Africa,” says Vanessa Hayes of the Garvan Institute of Medical Research in Australia, who led the new research.
The study revives a long-simmering debate about exactly where in Africa modern humans emerged, and it has drawn sharp criticism from several scientists.
They point out that although all humans alive today have mitochondrial DNA passed on from a common ancestor—a so-called Mitochondrial Eve—this is just a tiny fraction of our total genetic material.
So even if the proposed founder population described in the new study is the source of our mitochondrial DNA, many others likely contributed to today’s genetic pool.
“The inferences from the mtDNA data are fundamentally flawed,” Mark Thomas, an evolutionary geneticist at the University College London, says via email, adding that in his view, the study amounted to “storytelling.”
Yet Rebecca Cann, a geneticist at the University of Hawaii at Manoa who was a reviewer of the study and has conducted pioneering work on mitochondrial DNA, argues that the new research is innovative, crossing multiple disciplines in search of answers.
“This is going to start a lot of conversations, and it’s going to stimulate a lot of new studies,” she says.
While the study is not perfect, she adds, “It’s going to get us further down the road.”
The analysis revealed that for some 70,000 years the early human populations remained steady.
Climate analysis revealed that the massive wetlands that sprawled across Botswana could have provided a stable home for the early humans.
But then about 130,000 to 110,000 years ago, something changed: “They go crazy,” says Hayes. “All these new human lineages just start popping up.”
The study suggests that green corridors likely opened during that period, first in the northeast and then to the southwest, which may have encouraged groups to spread to where some still live today.]
Hayes, who has long worked with people across southern Africa, discussed the results with study participants soon after the analysis.
“They were the first to hear about it, long before you guys did,” she says. “And they love these stories, they really do. It’s their story.
The new study, importantly, focuses on analyzing today’s African populations, a gaping oversight in many past genetic studies.
“Everyone recognizes we’ve been studying Europeans for way too long,” says Joshua Akey, a geneticist at Princeton University.
“As studies go out and sample more human genomic diversity, we’ll eventually have a more deep and clear understanding of human history.”
In broad strokes, the results of the new study paint a similar picture to some past work: Today’s southern African populations harbor a deep mitochondrial genetic line.
But the details of what the latest analysis revealed remain unclear, says John Hawks, a paleoanthropologist at the University of Wisconsin-Madison.
It’s difficult to know whether the populations living in those regions today are the same as those hundreds of thousands of years ago, he says.
As a result, it’s possible that the researchers are tracing mass migrations around southern Africa.
But it’s also possible that there was instead something beneficial in the mitochondrial genetics, giving it a selective advantage that allowed the DNA to spread without massive population shifts.
The complexity of our evolutionary picture has led many researchers to recently move away from the idea that we emerged from a single locale that branched outward into a global family tree. Instead, they suggest our species evolved from many points across Africa,
like a network or braided stream with many inputs, divergences, and some rejoining rivulets that leads to the mighty mix flowing through our veins.
“I don’t see any reason, really, to be wedded to any particular place,” says Thomas, a co-author of a recent paper that challenged a single origin for our species.
The new study’s authors acknowledge that our species could have arisen from multiple origins.
But there’s not yet enough data to definitively show that’s the case, says study co-author Eva Chan, a statistical geneticist at the Garvan Institute of Medical Research.
And the latest work was a cross-disciplinary attempt to fill some blanks in the picture of our evolutionary history.
“That’s not to say we have the picture r
ight now,” she says. “With more data, the picture will continue to change.