The Riddle
What may increase when something is lost?
By Jean Lightner
The Polled Dorset breed of sheep did not evolve—its hornlessness is the result
of a mutation.
To answer this question let’s take a look at some sheep. The Dorset breed
of sheep was developed in southern England several hundred years ago. Dorsets had
many likable traits and were imported to the United States in the late 1800s.1
They were a medium-sized white breed. The ewes were good mothers and could give
birth more than once a year. And Dorsets always had horns. Well, until around 1948
anyway.2 At that time, in a purebred flock in the United States, a lamb
was born that never grew horns. This condition is called polled (hornless).
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Photo by Marlene Bell, <www.ewephoric.com>
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Now horns can look very attractive on sheep. However, farmers often consider them
a nuisance. Horns get caught on things, injure people or animals, and damage equipment.
In fact, since horns in sheep usually curve back toward the head, sometimes they
can actually grow into the animal’s head!3 Animals with horns
require more space, especially at the feed or water trough. To avoid these problems,
farmers can dehorn (remove the horn buds from) their lambs soon after they are born.
That way the horns don’t grow and the problems associated with them don’t
develop.
When the polled lamb was born, farmers were very interested. Imagine having all
the good qualities of the Dorset breed without the annoying horns. Just think, hornless
sheep without all the work associated with dehorning. So, when the lamb grew up,
it was used for breeding; soon there were more Dorsets with the polled trait.
Since farmers liked the polled sheep, they started selecting for them. In other
words, they would keep the polled sheep for breeding and get rid of the horned ones.
Through this artificial selection, soon a new breed had developed, the Polled Dorset.4 This breed has become so popular that it is now the second most popular
breed in the United States. Horned Dorsets are now rare.
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Photo by Marlene Bell, <www.ewephoric.com>
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The answer is in Genesis, the first book in the Bible.
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So back to our riddle. What may increase when something is lost? First let’s
ask what was lost in the polled lamb? Its horns. And what increased? Variety.5
Initially, Dorsets had always had horns; now some had horns and some did not. Variety
can be gained when some animals lose a trait that previously all animals in the
group had. Can variety also be lost? Certainly. This was done through selection.
When the Dorsets were selected for the polled trait, the horned trait was then lost
from the group. This decreased variety because none of this new breed, Polled Dorsets,
had horns.
Why was the lamb polled? This was a result of a mutation that destroyed information
in a gene necessary for horn growth. Mutations are really errors in the information
stored in genes. They are commonly known by the disease they cause6 (e.g.
sickle cell anemia in people,7 spider lamb syndrome in sheep8).
Some mutations are not obviously harmful and may go unnoticed. It is very unusual
for a mutation to be beneficial,9 although farmers may be convinced that
this one in Dorsets was. What has virtually never been observed is a mutation that
adds information, like one for growing horns on dogs or cats.
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Photo by Jenny Simpson <www.dorsetsheep.freeserve.co.uk>
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If mutations don’t add information, how did the information get there to begin
with? The answer is in Genesis, the first book in the Bible. God put it there when
he created life at the beginning. He said that he created animals (and plants) to
reproduce after their own kind.10 Dogs give birth to nothing but dogs.
Much of the variety5 we see in people, animals and plants was a part
of the information God originally placed there.11 Since the Fall of man,12
mutations have increased variety somewhat, but they have never added information
or created a new kind of animal.13
There are people today who are concerned about the loss of variety5 in
animals caused by selection. Some breeds that are no longer popular are in danger
of dying out. Yet these breeds often have important traits such as resistance to
certain diseases or parasites, or the ability to do well in extreme climates (very
wet or very hot and dry). In the United States, the American Livestock Breeds Conservancy
works to protect less popular breeds of animals. They recognize that if these breeds
are lost, any unique traits they have will be lost forever. This type of loss can
never be regained.
This all testifies to the creation of the genetic information in the beginning.
Such information can be lost, sometimes even with good effects for farmers. However,
gaining the information necessary to put horns on animals that lack the information
for horns just does not happen by natural processes.
References and notes
- Dorsets were first imported to the West Coast of the USA (Oregon) in 1860. Later,
in 1885 and afterward, they were imported from England to the East Coast. Dorset,
www.ansi.okstate.edu/breeds/sheep/dorset, 20 August 2004.
- Some sources claim a slightly different year. Polled Dorsets became a recognized
breed in 1956.
- Cobb, R., Horns on domestic farm animals, classes.aces.uiuc.edu/AnSci103/horns.html, 20 August 2004.
- There is also a Poll Dorset breed that was developed in Australia between 1937 and
1954. However, this was done by introducing the polled trait from several other
polled breeds (Corriedale and Ryeland rams) and then breeding the polled offspring
back to Dorsets, www.polldorset.org.au and www.nzsheep.co.nz/polldorset, 20 August 2004.
- The type of variety we are discussing here is known as genetic variation or genetic
diversity.
- Most genetic diseases/defects are caused by mutations. Sometimes several different
mutations can cause the same disease. There are over 4,500 genetic diseases known
in man. Mutations: evolution or degeneration? www.christiananswers.net/q-eden/genetic-mutations.html,
20 August 2004. Inheritance of single-gene defects, www.merck.com/mrkshared/mmanual/section21/chapter286/286b.jsp,
20 August 2004. Similarly, there are many genetic defects in animals. Sweiter, K.,
Gacsala, E., Esquivel, H., Genetic defects in sheep, ag.ansc.purdue.edu/sheep/ansc442/Semprojs/defects/genetic_defects.htm,
20 August 2004. Chart of genetic defects, kinne.net/ob4.htm, 20 August 2004. Canine Inherited Disorders Database, http://www.upei.ca/cidd/intro.htm, 20 August 2004.
- This mutation causes an abnormal hemoglobin to be produced. When oxygen levels are
low in the blood, the red blood cells take on an abnormal sickle shape and tend
to plug up small capillaries. See www.creation.com/sickle.
- Also known as ovine hereditary chondrodysplasia. Although lambs appear normal at
birth, within 4–6 weeks they have obvious skeletal deformities. Taraska, T.,
Spider Lamb Syndrome, College of Veterinary Medicine and Biomedical Sciences, Colorado
State University, http://www.dlab.colostate.edu/webdocs/ext_vet/cleon13.html,
20 August 2004.
- See also Wieland, C., Beetle bloopers, Creation19(3):30,
1997; www.creation.com/beetle;
Lightner, J., Special tools of life,
http://www.creation.com/article/3127.
- Genesis 1:11, 12, 21, 24, 25.
- 11. People and animals were told to multiply and fill the earth (Genesis 1:22, 28;
8:17; 9:1, 7). With this command, God gave them the ability to obey it. Everything
we know from modern genetics confirms the fact that God gave these creatures the
ability to adapt to a wide range of environments.
- Recorded in Genesis 3 (see
http://www.creation.com/article/3004). This brought death, disease
and suffering into the world. In spite of the curse that resulted from mankind’s
rebellion, God still sustains and cares for his creation (Matthew 6:25–34;
Colossians 1:16, 17). If He didn’t, it wouldn’t exist.
- Although they may form a new species. For an explanation, see: Catchpoole, D. and
Wieland, C., Speedy species surprise, Creation23(2):13–15,
2001; < http://www.creation.com/speedy,
Bell, P., Genetic engineers unwind species barrier, Creation25(4):52–53,
2003; http://www.creation.com/article/189,
Wieland, C., Brisk biters, Creation21(2):41, 1999;
http://www.creation.com/brisk.
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