Tag Archives: genetics

How can we understand genetics from dogs?

 Imagine two dogs: one with short hair and one with long hair.  Now imagine these two dogs leaving Noah’s Ark, reproducing, and spreading out across the world.  Some of the dogs travel North and enter into colder regions.  The short hair dogs suffer from the elements and are not able to survive.  They die out, but the long haired dogs survive because they have the necessary protection from the cold.  They are able to reproduce and pass on their genes, creating more long haired dogs who can withstand the harsh cold environment.  However, these dogs will only be able to produce more long-haired dogs because the short-hair DNA information is now lost.  On the reversal, if the long haired dogs stayed near the equator, it would be too hot for them to survive.  They would die out while the short haired dogs would thrive and reproduce.  This illustration shows why we see high densities of long haired and short haired dogs in cold and warm climates, respectively.

 

The long haired dogs survived in the colder climates whille the short haired dogs survived in the hotter climates. (Source: Answers in Genesis)

The medium length hair dogs below have the DNA for long hair and short hair, so they can produce a variety of hair lengths.  If two long haired dogs reproduce, they will isolate the genes and only produce long haired dogs.  This explains why we would see a certain trait carried on in animals or people in specific areas.  This can change when alternate DNA is introduced, such as a long haired dog breeding with a short haired dog. 

 

Animals lose DNA information when isolated. The long haired dogs will only be able to produce more long haired dogs until they mix up the DNA with short haired dogs again. (Source: Answers in Genesis)

 

Apply this concept to other traits we see.  People with darker skin live in sunnier regions where their skin is not affected as much by the heat and they have lower risks of skin cancer.  Light skinned people would not do well in these hotter regions because they are at risk of skin cancer.  On the other hand, people with dark skin who live in colder, less sunnier climates would not receive as much Vitamin D in their skin, thus they would be at risk for rickets and other vitamin D deficiency disorders.

When a specific trait like light-colored skin is lost and only dark-skinned people remain, the light-colored trait will not return until a dark-skinned person has a child with a light-skinned person. The child’s skin shade would be determined on the dominant and recessive genes.  If that child had the light-colored skin, he/she would be able to pass on that trait to another generation.  However, if the environment was not favorable to them (if they got cancer, for example), then their chances of survival or successful reproduction would be lower.  Neither the dark-skinned nor light-skinned people “evolved” to their surroundings, but rather, their already existing favorable traits allowed them to survive and thrive in that particular environment.

 

How can a Punnett Square be used to explain basic genetics?

 

A Punnett Square (Source: Answers in Genesis)

 

When studying genetics, the Punnett Square is used to simplify the DNA possibilities.  Let’s use the picture to understand skin tones.  The capital letters “A,B” represent a person with more melanin (dark skin), and the lower-case letters “a,b” represent having very little melanin (light skin).  If a dark-skinned mother (A,B) has a child with a dark-skinned father (A,B), their child will have dark skin (A,A,B,B) because that is the only option in the DNA.  If a light-skinned mother (a,b) has a child with a light-skinned father (a,b), then that child will have light skin (a,a,b,b).  If you mix it up with a (A,B) mother and a (a,b) father, you have multiple possibilities.  In fact, some sets of twins have been born where one is light-skinned and the other is dark-skinned. 

 

Both parents had a “white” mother and a “black” father. Together, they had twins with different skin tones. (Source: Answers in Genesis)

 

You can see from the chart that there are many possibilities when you mix up mothers and fathers with different skin colors.  The chart shows that the most frequent combination would be a medium-brown skin color (remember that we are all shades of brown).  The majority of the world’s population is also medium-brown.

Here is another example of mixing DNA.  The following example is very basic–the required information needed for specific traits is far more complex, but hopefully this illustration will show the potentials within the DNA combinations.

 

A basic illustration of the possible combinations in DNA to show variations of the kind (Source: Answers in Genesis)

 

 

What “color” of skin did Adam and Eve have?

Source: Answers in Genesis

Children’s books often portray Adam and Eve with light colored skin.  However, using basic genetics, if Adam and Eve were both light colored, then all of their children, including people today, would be light colored.  If Adam and Eve were both dark colored, then all people today would be dark colored.  Neither of these scenarios is possible because there are people with dark, medium, and light colored skin throughout the world. However, if Adam was dark colored and Eve was light colored, then they would be able to produce a wide variety of children.  Or, if they both had medium-colored skin and had the genetics for light and dark skin, that would also allow for the diversity of colors we see today.

 

Source: Answers in Genesis

 

Where did all of the different people groups come from?

 

Source: Answers in Genesis

At the time of the dispersal at Babel, there were all types of skin tones, eye, mouth, nose, and ear shapes and sizes.  These genetic traits were specific to the families present.  After the dispersal, the families separated, carrying the same genetic traits and passing them on within their family.  In Asia, many of the people have the trait of black hair and an extra layer of fat in their eyelids.  Most likely, one family went to the Asian continent and spread out to form different countries (China, Japan, Korea, Vietnam, etc.) where all of these traits are still seen today.  Latin Americans and American Indians have similar skin tones, implying that they may all be direct descendants.  We see dark skinned people primarily living in hot regions, and light skinned people living in colder regions. 

As families trekked across the globe, the dark skinned people suffered in the colder areas because they did not get enough sun light, thus causing a vitamin D deficiency.  On the reversal, families that were light skinned suffered in hot areas because they got sun burns and skin cancers.  This is where survival of the fittest comes into play.  The fit ones—the dark in the sunny areas and the light in the not so sunny areas—were able to survive and continue reproducing, causing a great population density of their particular genetic traits.  To help better understand genetic isolation, see the following article: How can we understand genetics from dogs?

What is the Genesis kind?

When classifying a living thing, it is done through a specific process by placing it into categories that begin with a broad title and end with a specific name.  You may remember from school the following order of classification: Kingdom (broad), Phylum, Class, Order, Family, Genus, and Species (specific).  When we study Creation in the Bible, we do not see the aforementioned classification order but instead are introduced to the word “kind.”  You will find the word “kind” used in the following verses, just to name a few: Gen. 1:12; Gen. 1:21; Gen. 1:24; and Gen. 1:25.  God created the plants, birds, fish, and land animals, and commanded them to reproduce “after their kind.”  The “kind” is considered by the majority of creationists to equal that of the Family in the classification order.  There is current research being done to help better define “kind.”  As mentioned, “Family” is often referred to as the kind, but some have suggested it may also be the Order or the Genus.  There is more information on that below.
The “kind” is better understood as the canine (dog) kind, the feline (cat) kind, the equidae (horse) kind, etc.  “After their kind” means that dogs would reproduce within the dog kind, cats would reproduce within the cat kind, and horses would reproduce within the horse kind.  This is what we observe today.  See the “Creation Orchard” below, which is much different than the Evolution Tree of Life

 

Instead of all life forms coming from a common ancestor, Creation teaches that the different life forms came from an original representative kind, like the canine kind and the feline kind. Natural selection and mutations resulted in the vast array of variations we see today, yet, all changes only occur within the kind.

The DNA holds an awesome amount of information, and when the proteins formed by the DNA are switched around, the results are different variations of the animal kind.  This is what creationists refer to as micro-evolution, or some may refer to it as “adaptive variation.” The DNA is made so that it can only be altered to produce more animals after its specific kind.  That is why we don’t find hideous dog/cat hybrids—the DNA would not allow for it to ever happen (an Darwinian evolution doesn’t necessarily teach that).  There are times when after so much variation has occurred, the DNA has altered to the extent that certain species within the kind can no longer reproduce with each other.  This is referred to as a ring species.  This is not evolution, but instead a loss of information (reverse evolution).  To help understand why we see different species in certain parts of the world but not in others, see the article about genetics

Let’s use the canine family as an example to better understand this “kind” concept.  There are hundreds of variations of the canine kind such as the German Shepherd, Boxer, Shih-Tzu, and Labrador.  There are also variations of these variations, such as the Black Labrador, Yellow Labrador, White Labrador, and Chocolate Labrador.  These are all dogs and will always be dogs.  They will never change into another family (kind) of animal.  The canine kind is not limited to dogs as we know them—it also includes foxes, dingos, wolves, and coyotes–and many within the canine kind can reproduce with one another to create new hybrids. 

There was a male and female canine representative on Noah’s Ark, and after the global flood, these two dogs reproduced, and due to natural selection and mutations, we have a variety of dogs today.

There is a field of Creation Science called “Baraminology” which comes from the Hebrew words bara and min.  Translated, those words mean “created kind.”  This is a study of the taxonomy of God’s creation.  More information about this interesting field of research can be found at www.creationbiology.org  The most recent research shows that of the Mammal kind, there were about 350 kinds identified.  Of the Aviary kind, there were about 196 kinds.  The research continues.