Racism, Evolution and the Unity of the Human Race

In his 6/15/17 Briefing, Dr. Mohler discussed, on the one hand, this week’s SBC condemnation of racism and white supremacy, and on the other, recent fossil discoveries by scientists that suggest that our species may have evolved, not in a single region in East Africa 200,000 years ago, as previously thought, but as a network of groups spread across the whole African continent stretching back 300,000 years.

Dr. Mohler emphasized that rejection of racism relies on belief in the unity of humanity, and that Christians "ground the unity of the entire human race in the fact that we all have ultimately one human father and one human mother known in the Scripture as Adam and Eve.” So, in Dr. Mohler’s view, this revision of the evolutionary narrative of human origins poses an even more serious problem for the unity of humanity, and so for equal respect, than evolutionary theory already did:

“... the unity of the human race is made not only implausible, it’s impossible in terms of this telling of the story.... One of the biggest questions we should have ... [for] evolutionary scientists is how exactly they would argue for the unity of the human race. Taken at face value, these media reports concerning the scientific research would seem to undermine utterly any claims for the unity of humanity and that puts us in a very bad position [morally].”

Although not an evolutionary scientist, I will answer Dr. Mohler’s question. What Dr. Mohler’s discussion lacks is the concept of a ‘gene pool’, defined as “the stock of different genes in an interbreeding population.”

If different groups of proto-humans had evolved separately in different places, and stayed put, and never mixed in any way until the present day, the chances are they would not even be a single species today. But that is very far from what is being claimed. The idea is that there were many different groups spread across Africa, but that there was (perhaps only occasionally) interbreeding between them, so that successful genes spread through the various groups over time. Since those early times there has been a great deal of mixing, so that we all share many ancestors from many different places.

This fact – that we all belong to the same gene pool – is the basis for the unity of humanity. We are all different but we also all share an overwhelming amount. The fact is that, biologically, there are no races. Genetic diversity is far more multifarious and overlapping than division into a few racial groups is capable of describing. (See the works of Cavalli-Sforza.) You see this in the recent TV ads for “23 and me”, where people are discovering, from a test of their DNA, their many different ancestral origins.

Even if we all don't share a single pair of human parents, we still – according to the scientific/secular worldview – belong to the same extended human family.

Reply to Dr. Mohler on Global Warming

I commend Dr. Mohler for emphasizing our responsibility of stewardship over the planet in his 6-2-17 Briefing. However, there is another responsibility he neglected to mention – the responsibility to help those we have harmed. Dr. Mohler also made many errors in his accounts of the Paris accord and of global warming.

Dr. Mohler says of the Paris Agreement,

“.. it involved a rather significant transfer of billions of American dollars to nations around the world, especially in the so-called developing world, in order to encourage them towards a lack of dependence upon carbon-based fuels. But those nations already had a good deal of incentive to move in those directions.”

Mohler is speaking here of the Green Climate Fund, which Trump announced he would terminate contributions to. According to Matthew Kotchen, a Yale professor of economics and a former U.S. representative on the governing board of the fund, writing in the Washington Post,

“The aim of the fund is twofold. The first is to help developing countries reduce emissions that cause climate change. The second is to help these same countries adapt to the unavoidable changes already set in motion by historic emissions.”

The United States is the largest contributor to those historic emissions. If the historic and continuing burning of fossil fuels by industrialized nations is responsible for the bulk of the measured increase of greenhouse gases in the atmosphere, and this increase is warming the planet, and this warming is causing changes in climate and sea level and ocean acidity which threaten to harm nations which have contributed very little or not at all to these changes, isn’t it the responsibility of the polluters to help mitigate the harm their actions cause? Isn’t it their moral responsibility? Dr. Mohler has yet to address this question.

As for helping other nations reduce emissions, here’s one way to look at it: there is only so much CO2 the earth’s atmosphere can hold before it causes harmful warming effects, like flooding coastal cities. This is called the carbon budget. Just as the air belongs to everybody, so does this capacity of it to absorb a certain amount of greenhouse gases without causing serious harm. But the industrialized nations have already used most of that capacity, so by the time developing nations come along, it is no longer safe for them to develop by profligately burning fossil fuels the way we have done. It is in the whole planet’s interest for them to leapfrog to clean energy. Once again, it can be argued that the industrialized nations have a responsibility to help them, since we have used most of a common birthright, leaving them less than their fair share.

Of course, neither of these moral responsibilities exists if human carbon emissions are not warming the planet. The only evidence for this Dr. Mohler mentions is what he calls “the retroactive recreation of climate conditions.” Presumably Dr. Mohler is skeptical of such efforts since he is a young earth creationist, so he doesn’t trust research on climate that stretches hundreds of thousands or millions of years into the past. However, there are many sources of evidence that do not rely on reconstructions of ancient climates.

The fact that carbon dioxide emissions would warm the planet was predicted before it was observed and before we knew much about past climates, simply on the basis of known physical principles. Carbon dioxide absorbs infrared radiation (the kind produced by a heat lamp), just as glass does. In a greenhouse, the sun’s light passes through the glass, heats the interior, but the resulting heat rays from warmed surfaces can’t escape back through the glass, so the greenhouse heats up. The same happens with our atmosphere. The amount of CO2 in the atmosphere is an important factor in determining the earth’s temperature, and increasing the amount must warm the planet, according to this well-understood greenhouse effect. (By how much is a much more complicated matter.) If we emit more CO2 into the atmosphere than can be absorbed by the ocean and terrestrial biosphere, the amount in the atmosphere must go up.

Since the 1950s, on a mountaintop observatory in Hawaii, a precise record of CO2 concentration in the atmosphere has been kept. That record is called the Keeling Curve, and it has gone up steadily from 315 parts per million in 1958 to 410 ppm today. That’s an increase of 30% in this important temperature-regulating gas in a very short amount of time. Another measure of CO2, its C13/C12 isotope ratio, can distinguish CO2 resulting from the burning of plant material (including fossil fuels) from that from other sources. The concentration of plant-sourced CO2 in the atmosphere, also measured at Mauna Loa, has also been rising. Historical records of this ratio gleaned from sediments and tree rings show a dramatic departure from natural variation starting at about 1850 and increasing until today, indicating growing human contribution to atmospheric CO2. (The Human Fingerprint in Global Warming, How do we know that recent CO2 increases are due to human activities?, Anthropogenic CO2)

Dr. Mohler says,

“... people on the left politically and in the scientific community increasingly refer to the current historical epoch as Anthropocene, that is the age of man. And you need to note they see this largely as a problem. It was as if the cosmos was perfect until human beings arrived on the scene with our needs and our wants and our building of cities and the building of houses and the building of communities and, yes, eventually the use of fossil fuels.”

This is a misinterpretation of the significance of the term ‘Anthropocene’. From the ‘-cene’ you can tell this is a name given to a geological age, like the Paleocene or the Miocene. Such names denote not only time periods, but rock strata. To call this the Anthropocene is to say that humans have become such a determining influence on the state of the planet – on its oceans, its atmosphere, and on all life living on it – that the very rocks will, in future ages, announce this age as the one when human beings came to dominate the planet. In Christian terms, the term Anthropocene is about dominion – that we have achieved it, and now the question is whether we will take responsibility for it.

Dr. Mohler says,

“... science itself is predicated upon a worldview, and that worldview in so many ways is very clear in seeing human beings as the problem and denying any kind of divine purpose to the creation, not to mention to the role of human beings within.”

It’s true that science does not affirm any divine purpose to the world or to human beings, but that is not the same as denying such a purpose, though it can be very difficult to reconcile divine purpose with the worldview science produces, but that is not science’s task. It is even less true that the scientific worldview sees human beings as a problem. A problem for what or for whom? Science describes what is, not what should be. People bring their own values to the table, and some environmentalists may value non-human life or perhaps what they perceive as nature so highly that they perceive humans as a problem. But such a position is not determined by the scientific worldview. On the contrary, science from the beginning has been seen as a tool to benefit humanity. The call by scientists to heed the threat of global warming is in that tradition.

It’s a bit ironic that Dr. Mohler says of people in developing countries around the world “what they are looking for is just basic, dry, safe housing... what Americans now take for granted” and “There is indeed a moral dimension to telling people around the world that they can’t have those things while we do,” as if anyone was advocating that. If warming proceeds and the oceans continue to rise, potentially millions of people could be looking for dry, safe housing, including many in this country.

Dr. Mohler’s final point was this:

“... in the modern age, no society has ever willingly forfeited a technology it has developed and embraced.”

This is defeatist and is simply not true. CFCs (chlorofluorocarbons) were very handy chemicals, widely used in aerosol cans and refrigerators and air conditioners. (Freon was DuPont’s brand name for one.) They don’t occur naturally. When it was discovered that CFCs were harming the protective ozone layer of the atmosphere, even leading to a dramatic hole in the ozone layer over Antarctica, by international agreement (the Montreal Protocol) CFCs were phased out, and their manufacture ceased. Substitutes were found. Another example: leaded gasoline. It was useful, but harmful to humans, so the federal government eventually banned lead additives to automobile gasoline. Crisco and margarine and food additives made from partially hydrogenated vegetable oil – trans fats – were very popular for decades, until it was discovered that they led to increased LDL cholesterol, a risk factor for heart disease. Trans fat content was first ordered to be labeled and is now being phased out by order of the FDA.

We are capable of willingly forfeiting a technology we have embraced once we discover it is seriously harmful. Giving up something so central to our economy and way of life as fossil fuels is a very great challenge. But it is possible. Alternatives are available. But time is also a factor. How urgent is the threat, and is the free market capable of responding in the right direction and in time without government action to provide incentives? Assessing the objective risks to human well-being should be a matter for science, not for politics. Whether human-caused global warming is real and whether it poses a serious problem should not be a partisan issue. But policy decisions on how to respond to the risks are properly political – and moral – questions.