Humanity’s birthplace: Why everyone alive today can call northern Botswana home
WHERE was the evolutionary birthplace of modern humans? The East African Great Rift Valley has long been the favoured contender — until today. Our new research has used DNA to trace humanity’s earliest footsteps to a prehistoric wetland called Makgadikgadi-Okavango, south of the Great Zambezi River.
Our analysis, published in Nature, shows that the earliest population of modern humans (Homo sapiens sapiens) arose 200 000 years ago in an area that covers parts of modern-day Botswana, Namibia and Zimbabwe.
Today it is a dry and dusty land with scattered salt pans, and it is hard to believe that modern humans lived and thrived in wetlands here for 70 000 years before our ancestors began to explore the rest of Africa, and ultimately the world.
We pinpointed this region by studying mitochondrial DNA, known as the “mitogenome”.
Unlike nuclear DNA, which is passed on by both mother and father, mitochondrial DNA is passed on only by the mother, which means it is not jumbled up in each generation.
If we think of all modern humans as occupying a particular place on a huge family tree, logically we should find the most diverse mitogenomes at the very base of the tree, because it is the ultimate source of all the various branches.
We already know that genetic data points to southern Africa as the cradle of humanity (unlike fossil evidence, most of which has been found in East Africa). But we wanted to refine our search still further, to pinpoint the exact location where humans first evolved.
To do this, we turned our attention to a group of people known as the KhoeSan. KhoeSan have the most diverse mitogenomes of anyone on Earth, which suggests their DNA most closely resembles that of our shared common ancestors.
If we all sit on branches of the human family tree, then KhoeSan are the tree’s trunk.
Linguistically, KhoeSan people are click speakers, while culturally KhoeSan are foragers, with groups of San people still practising the old ways of life — hunting and gathering for subsistence.
Members of our research team have spent a decade working with KhoeSan communities, as well as people from other ethnicities and language groups, in Namibia and South Africa.
By generating mitogenome data for around 200 rare or newly discovered sub-branches of KhoeSan lineages, and merging them with all available data, we were able to zoom in on the very base of our evolutionary tree.
It is now clear our ancestors must have dispersed from a region south of the Zambezi River.
This is consistent with geographical, archaeological and climate data, including the fact that this area would have been a fertile wetland at the time the first modern humans emerged. Lush landscapes
Geological evidence suggests that at this time, the prehistoric Makgadikgadi lake that had dominated the region for millions of years had begun to break up through the shifting of the land. This would have created a vast wetland region, ideal to sustain life.
But if it was so ideal, why did our ancestors begin to explore other places between 130 000 and 110 000 years ago, first heading northeast and later southwest from the ancestral home?
Climate data suggests that at around that time the region experienced a huge drought.
Notably, about 130 000 years ago humidity increased to the northeast of the homeland, and 110 000 years ago the same happened to the southwest.
We speculate that this created passages of lush vegetation for our ancestors to leave the homeland, most likely following the game animals that were also forging into new regions.
What’s more, our genetic data suggests the southerly migrants went on to inhabit the entire southern coast of Africa, with multiple sub-populations and huge population growth.
Archaeological findings from the Blombos caves in South Africa have shown this region to be rich in evidence for cognitive human behaviour as early as 100 000 years ago.
Again, we were amazed at how well we could match timeline data, crossing different yet complimentary disciplines that have historically not worked together.
◆ Full article on www.herald.co.zw
ACCESS to justice for everyone in all communities is an important right and requirement for building fair and peaceful societies — yet this objective has been achieved in few if any nations, and the consequences are damaging for social, economic and political progress and stability.
Studies indicate that of the 1,4 billion people who for whatever reason in the past two years felt the need for recourse to law, less than half have had their justice needs met.
Barriers such as cost, complexity and corruption cause people either not to seek redress, or to be defeated by the process.
The 53 countries of the Commonwealth are committed to taking action to right this wrong.
Each member country is committed through our Commonwealth Charter to: “an independent, effective and competent legal system” which “is integral to upholding the rule of law, engendering public confidence and dispensing justice”.
That is the basis on which discussions on innovative and united action towards access to justice and related priorities will take place over coming days at the Commonwealth Law Ministers Meeting which convenes in Sri Lanka, November 5-7, 2019.
While many are fortunate to have a system that can be relied upon to give a fair hearing and resolution, for millions of people around the world, this is sadly not the case.
Problems with access to justice can seriously affect people’s lives through physical and stress-related ill health, loss of income and damage to relationships.
Vulnerable groups in many jurisdictions tend to be those that justice systems ought to do most to protect.
Our priority has to be to answer the needs of all people, and particularly those such as the poor and unemployed, victims of domestic violence, refugees and disabled or first nation people, whose experience far too often is to feel marginalised or ill-served by judicial processes.
Poverty affects access to justice in many ways, and discriminatory laws perpetuate and exacerbate disadvantage.
Income, gender, sexuality and location can all be factors in people being denied equitable access to justice.
Sometimes several of these factors combine severely to the detriment of victims or offenders from already vulnerable groups.
Indigenous women, for example, particularly those who have faced addiction, poverty or domestic violence, are often already marginalised, and then suffer the further blow of being unsupported in their search for justice, diminishing yet further the prospects for themselves, their families, and the communities in which they live.
Even where equal and progressive laws exist, swingeing cuts to legal aid, or lack of legal aid altogether, can impair access to justice, particularly for the most vulnerable.
Lack of access to justice then leads to further injustice — with people denied their rights or a voice, unable to fight discrimination and prevented from holding public bodies to account.
The result is that progress towards sustainable development at national, community or personal levels is limited, and opportunities for inclusive growth and prosperity are lost.
At worst, injustice can be the root of conflict and violence — even though people are generally not seeking revenge and retribution, but recompense and restoration. Systems should ensure these avenues to resolution are available because, without them, anger and resentment can fester.
Innovation and technology open up new horizons and possibilities. Digital resources such as e-courts, video advocacy and interactive information services are helping to improve inclusivity.
Yet even with such innovative approaches and mechanisms, those same vulnerable groups may continue to experience obstacles to affordable and equitable access.
So we need to be aware that the promising solutions technology offers can also prolong existing problems or present new ones.
This means that just as lawbreakers find ever more sophisticated ways of using technology for crime, lawmakers must leverage what technology can do to keep ahead or abreast of such threats.
Our related systems of governance and administration, and the widespread use in our jurisdictions of the Common Law, make the Commonwealth ideally placed as a community to think, plan and act together towards fairer and more inclusive access to justice with improved outcomes.
Working together in mutual support, and by learning and gaining encouragement from one another, our member countries are able to accelerate progress towards creating and delivering fair and effective national laws.
They are helped in this by Commonwealth tool-kits that guide on matters such as policy-making and legislative drafting.
The beneficial impact of this cooperation is enhanced through the expert technical assistance provided to member countries by the Commonwealth Secretariat.
Examples of this include the legal issues associated with tackling violence against women and girls, gender discrimination, corruption and climate change.
By combining to work towards all our people having proper access to genuine justice, and by sharing good practice to strengthen the foundations on which the rule of law are built, the Commonwealth shines as a beacon for multilateral cooperation, and opens up pathways towards more peaceful and prosperous societies, and a fairer and more secure future for all.
◆ Patricia Scotland is the Common
wealth Secretary-General.