'The criteria that people use for race are based entirely on external
features that we are programmed to recognize...'
Douglas C. Wallace, (professor of molecular genetics at Emory
University School of Medicine in Atlanta), Do races differ? Not
Really, DNA shows, New York Times web, Aug. 22, 2000.
did different skin colors come about?
As was discussed in Where did the human races
come from?, we learned that all humans on earth today are descended from
Noah and his wife, his three sons and their wives, and before that from Adam
and Eve (Genesis 1-11). But today we have many different groups, often called
"races," with what seem to be greatly differing features. The most obvious
of these is skin color. Many see this as a reason to doubt the Bible's record
of history. They believe that the various groups could have arisen only by
evolving separately over tens of thousands of years. However, as we shall
see, this does not follow from the biological evidence.
know that skin color is governed by more than one pair of genes. For simplicity,
let's assume there are only two, 1 located at
positions A and B on the chromosomes. One form of the gene, "M," "says" to
make lots of melanin; another form of the gene, "m," says to only make a little
melanin. At position A we could have a pair such as MAMA,
MAmA, or mAmA 3
which would instruct the skin cells to make a lot, some, or little melanin.
Similarly, at position B we could have the gene pairs MBMB,
MBmB, or mBmB instructing cells
to make a lot, some or little melanin. Thus very dark people could have MAMAMBMB,
for example (see figure 1).
the sperm and eggs of such people could only be MAMB,
(remember, only one of each A or B pair goes to each sperm or egg) they could
only produce children with exactly the same combination of genes as themselves.
So the children will all be very dark. Likewise, very light people, with mAmAmBmB,
could produce children only like themselves (see figure 2, below).
look at what combinations would result from parents who are the type of brown-skinned
person called a mulatto, or MAmAMBmB
(the offspring of an MAMAMBMB
and mAmAmBmB union, for example;
see figure 3, below).
can do this with a diagram called a "Punnett square" (see figure 4 below).
side (of the above table) shows the four different gene combinations possible
in the sperm from the father and the top gives the combinations possible in
the eggs from the mother (remember that a parent can only pass on one of each
pair of genes to each sperm or egg). We locate a particular sperm gene combination
and follow the row across to the column below a particular egg gene combination
(like finding a location on a street map). The intersection gives the generic
makeup of the offspring from that particular sperm and egg union.
an MAmB sperm and an mAMB egg
would produce a child with MAmAMBmB,
just the same as the parents. The other possibilities mean that five levels
of melanin (shades of color) can result in the different offspring of such
a mulatto marriage, as roughly indicated by the level of shading in the diagram.
If three gene pairs were involved, seven levels of melanin would be possible.
a range of 'colors,' from very light to very dark, can result in a single
generation, beginning with this particular type of mid-brown parents.
people with MAMAMBMB , who are
"pure" black (in the sense of having no genes for lightness at all), were
to intermarry and migrate to a place where their offspring could not marry
other people of lighter color, all their descendants would be black -- a pure
"black line" would result.
If "white" people (mAmAmBmB)
were to marry only other whites and migrate to a place where their offspring
could not marry darker people, a pure (in the same sense) "white line" would
result -- they would have lost the genes needed to produce a large amount
of melanin and be black.
It is thus easily possible,
beginning with two middle-brown parents, to get not only all the "colors,"
but also people groups with stable shades of skin color.
But what about people
groups that are permanently middle-brown, such as we have today? Again, this
is easily explained. If those with genes MAMAmBmB
or mAmAMBMB no longer intermarry
with others, they will be able to produce only mid-brown offspring
as in figure 3. (You may want to work this out with your own Punnett square.)
If either of these lines were to interbreed again with the other, the process
would be reversed. In a short time, their descendants would show a whole range
of colors, often in the same family. Figure 5 shows what were called Britain's
most amazing twins. One is obviously quite light in complexion, while the
other is clearly darker skinned.
Of course, this is not
amazing at all when you do the exercise on paper, based on what we have discussed.
(A clue if you want to do it yourself: mother cannot be MAMAMBMB.
Also, the twins are obviously not identical twins, which are derived from
the same egg -- that is, monozygous).
If all the people on
earth were to intermarry freely, and then break into random groups that kept
to themselves, a whole new set of gene combinations could emerge. It may be
possible to have almond eyes with black skin, blue eyes with black, tightly
curled hair, etc. We need to remember, of course, that the way in which genes
express themselves is much more complex than this simplified picture. For
example, sometimes certain genes are linked together. However, the basic point
Even today, within a
particular people group you will often see a feature normally associated with
another people group. For instance, you will occasionally see a European with
a broad flat nose, or a Chinese person with very pale skin or Caucasian eyes.
Most scientists now agree that, for modern humans, "race" has little or no
biological meaning. This also argues strongly against the idea that the people
groups have been evolving separately for long periods.
can now reconstruct the true history of the people groups, using:
information given by the Creator himself in the Book of Genesis.
background information given above.
consideration of the effect on the environment.
created man, Adam, from whom all other humans are descended, was created with
the best possible combination of genes -- for skin color, for example. A long
time after creation, a worldwide flood destroyed all humans except a man called
Noah, his wife, his three sons, and their wives. This flood greatly changed
the environment. Afterwards, God commanded the survivors to multiply and cover
the earth (Genesis 9:1). A few hundred years later, people chose to disobey
God and to remain united in building a great city, with the Tower of Babel
as the focal point of rebellious worship.
From Genesis 11, we understand
that up to this time there was only one language. God judged the people's
disobedience by imposing different languages, so that they could not work
together against God. The confusion forced the people to scatter over the
earth as God intended.
So all the people groups
-- black Africans, Indo-Europeans, Mongolians, and others -- have come into
existence since Babel.
and his family were probably mid-brown, with genes for both dark and light
skin, because a medium skin color would seem to be the most generally suitable
(dark enough to protect against skin cancer, yet light enough to allow vitamin
D production). As all the factors for skin color were present in Adam and
Eve, they would most likely have been mid-brown as well, with brown eyes and
brown (or black) hair. In fact, most of the world's population today is still
After the flood, for
the few centuries until Babel, there was only one language and one culture
group. Thus, there were no barriers to marriage within this group. This would
tend to keep the skin color of the population away from the extremes. Very
dark and very light skin would appear, of course, but people tending in either
direction would be free to marry someone lighter or darker than themselves,
ensuring that the average color stayed roughly the same.
The same would be true
of characteristics other than skin color. Under these sorts of circumstances,
distinct differences in appearance will never emerge. To obtain such separate
lines, you would need to break a large breeding group into smaller groups
and keep them separate, that is, prevent interbreeding between groups. This
would be true for animal as well as human populations, as every biologist
Effects of Babel
is exactly what happened at Babel. Once separate languages were imposed, there
were instantaneous barriers. Not only would people tend not to marry someone
they couldn't understand, but entire groups which spoke the same language
would have difficulty relating to and trusting those which did not. Thus,
they would move away or be forced away from each other, into different environments.
This, of course, is what God intended.
It is unlikely that each
small group would carry the same broad range of skin colors as the original,
larger group. One group might have more dark genes, on average, while another
might have more light genes. The same thing would occur with other characteristics:
nose shape, eye shape, etc. And since they would intermarry only within their
own language group, these differences would no longer be averaged out as before.
As these groups migrated
away from Babel, they encountered new and different climate zones. This would
also have affected the balance of inherited factors in the population. However,
the effects of the environment are nowhere near as important as the initial
genetic mix of each group.
COLOR AND SUNLIGHT
As an example, consider a group
of people who moved to a cold region with little sunlight. Here, the dark-skinned
members would not be able to produce enough vitamin D, and thus would be less
healthy and have fewer children. So, in time, the light-skinned members would
predominate. If several different groups went to such an area, and if one
group happened to be carrying few genes for lightness, this particular group
could, in time, die out. Thus, natural selection acts on the characteristics
already present, and does not create new ones.
It is interesting to note that
Neanderthals of Europe,
recognized as fully human, show evidence of vitamin D deficiency in that many
of their bones were bent. In fact, this, plus a large dose of evolutionary
prejudice, caused them to be classified as "ape-men" for a long time. It is
thus quite plausible that they were a dark-skinned people who were unfit for
the environment into which they moved because of the skin color genes they
began with. Notice (again) that this natural selection, as it is called,
does not produce skin colors, but only acts on the created capacity
for making skin pigment that is already there.
fair-skinned people in very sunny regions could easily be affected by skin
cancer. Thus, in these regions dark-skinned people would more readily survive
and come to predominate.
So we see that the pressure of
the environment can (a) affect the balance of genes within this group, and
(b) even eliminate entire groups. This is why we see, to a large extent, that
the physical characteristics of people tend to match the environment where
they live (e.g., Nordic people with pale skin, equatorial people with dark
But this is not always so. The
Inuit (Eskimo) have brown skin, yet live where there is not much sun. Presumably
they all have a genetic makeup such as MAMAmBmB
which would not be able to produce lighter skin. On the other hand, native
South Americans living on the equator do not have black skin. These examples
confirm that natural selection does not create new information -- if the genetic
makeup of a group of people does not allow variation in color toward the desirable,
natural selection cannot create such variation.
Pygmies live in a hot area, but
rarely experience strong sunshine in their dense jungle environment; yet they
have dark skin. Pygmies may be a good example of another factor that has affected
the racial history of man: discrimination.
People different from the "norm"
(e.g., a very light person in a dark people group), have historically been
regarded as abnormal and rejected by the group. Thus, such a person would
find it hard to get a marriage partner. This would further tend to eliminate
light genes from a dark people, and vise versa. In this way, groups have tended
to "purify" themselves.
Also, in some instances, interbreeding
within a small group can accentuate a commonly occurring unusual feature that
would otherwise be swamped by marriage outside the group. There is a tribe
in Africa whose members all have grossly deformed feet as a result of this
Let us return to the Pygmies.
If people possessing genes for short stature were discriminated against,
small group of them might seek refuge in the deepest forest. By marrying
only each other they would ensure a Pygmy "race" from then on. The fact
that Pygmy tribes do not have their own languages, but instead speak dialects
non-Pygmy tribal languages, is good evidence to support this.
Effects of Choice
genetic characteristics may have influenced people groups to make deliberate
(or semi-deliberate) choices concerning the environments to which they migrated.
For instance, people with genes for a thicker, more insulating layer of fat
under their skin would tend to leave areas that were uncomfortably hot.
The evidence for the Bible's account of human origins is more than just biological
and genetic. Since all peoples have descended from Noah's family, and a relatively
short time ago, we would expect to find some memory of the catastrophic flood
in the stories distorted by time retelling. In fact, an overwhelming number
of cultures do have accounts that recall a world-destroying flood. Often these
have startling parallels to the true, original account (such as: eight people
saved in a boat, the sending of birds, a rainbow, and more).
we conclude that the dispersion at Babel broke up a large interbreeding group
into small, interbreeding groups. This ensured that the resultant groups would
have different mixes of genes for various physical features. By itself, this
dispersion would ensure, in a short time, that there would be certain fixed
differences in some of these groups, commonly called "races." In addition,
the selection pressure of the environment would modify the existing combinations
of genes so that the physical characteristics of each group would tend to
suit their environment.
There has been no simple-to-complex
evolution of any genes, for the genes were present already. The dominant features
of the various people groups result from different combinations of previously
existing created genes, plus some minor degenerative changes, resulting from
mutation (accidental changes which can be inherited). The originally created
(genetic) information has been either reshuffled or has degenerated, but has
not been added to.
more about these and related issues...
simplification is not done to help our case -- the more genes there are,
the easier it is to have a huge range of "different" colors. The principle
involved can be understood by using two as an example.
forms of a gene are called "alleles," but that is not important here.
the technically minded, this type of genetic expression, where allele
dosage affects the trait, is called partial dominance.